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Needed: More studies of CSF molecular biomarkers in psychiatric disorders
Psychiatry and neurology are the brain’s twin medical disciplines. Unlike neurologic brain disorders, where localizing the “lesion” is a primary objective, psychiatric brain disorders are much more subtle, with no “gross” lesions but numerous cellular and molecular pathologies within neural circuits.
Measuring the molecular components of the cerebrospinal fluid (CSF), the glorious “sewage system” of the brain, may help reveal granular clues to the neurobiology of psychiatric disorders.
Mental illnesses involve the disruption of brain structures and functions in a diffuse manner across the cortex. Abnormal neuroplasticity has been implicated in several major psychiatric disorders. Examples include hypoplasia of the hippocampus in major depressive disorder and cortical thinning/dysplasia in schizophrenia. Reductions of neurotropic factors such as nerve growth factor or brain-derived neurotropic factor have been reported in mood and psychotic disorders, and appear to correlate with neuroplasticity changes.
Recent advances in psychiatric neuroscience have provided many clues to the pathophysiology of psychopathological conditions, including neuroinflammation, oxidative stress, apoptosis, impaired energy metabolism, abnormal metabolomics and lipidomics, and hypo- and hyperfunction of various neurotransmitters systems (especially glutamate N-methyl-
Thus, psychiatric research should focus on exploring and detecting molecular signatures (ie, biomarkers) of psychiatric disorders, including biomarkers of axonal and synaptic damage, glial activation, and oxidative stress. This is especially critical given the extensive heterogeneity of schizophrenia and mood and anxiety disorders. The CSF is a vastly unexploited substrate for discovering molecular biomarkers that will pave the way to precision psychiatry, and possibly open the door for completely new therapeutic strategies to tackle the most challenging neuropsychiatric disorders.
A role for CSF analysis
It’s quite puzzling why acute psychiatric episodes of schizophrenia, bipolar disorder, major depressive disorder, or panic attacks are not routinely assessed with a spinal tap, in conjunction with other brain measures such as neuroimaging (morphology, spectroscopy, cerebral blood flow, and diffusion tensor imaging) as well as a comprehensive neurocognitive examination and neurophysiological tests such as pre-pulse inhibition, mismatch negativity, and P-50, N-10, and P-300 evoked potentials. Combining CSF analysis with all those measures may help us stratify the spectra of psychosis, depression, and anxiety, as well as posttraumatic stress disorder and obsessive-compulsive disorder, into unique biotypes with overlapping clinical phenotypes and specific treatment approaches.
There are relatively few published CSF studies in psychiatric patients (mostly schizophrenia and bipolar and depressive disorders). The Table1-9 shows some of those findings. More than 365 biomarkers have been reported in schizophrenia, most of them in serum and tissue.10 However, none of them can be used for diagnostic purposes because schizophrenia is a syndrome comprised of several hundred different diseases (biotypes) that have similar clinical symptoms. Many of the serum and tissue biomarkers have not been studied in CSF, and they must if advances in the neurobiology and treatment of the psychotic and mood spectra are to be achieved. And adapting the CSF biomarkers described in neurologic disorders such as multiple sclerosis11 to schizophrenia and bipolar disorder (which also have well-established myelin pathologies) may yield a trove of neurobiologic findings.
If CSF studies eventually prove to be very useful for identifying subtypes for diagnosis and treatment, psychiatrists do not have to do the lumbar puncture themselves, but may refer patients to a “spinal tap” laboratory, just as they refer patients to a phlebotomy laboratory for routine blood tests. The adoption of CSF assessment in psychiatry will solidify its status as a clinical neuroscience, like its sister, neurology.
1. Vasic N, Connemann BJ, Wolf RC, et al. Cerebrospinal fluid biomarker candidates of schizophrenia: where do we stand? Eur Arch Psychiatry Clin Neurosci. 2012;262(5):375-391.
2. Pollak TA, Drndarski S, Stone JM, et al. The blood-brain barrier in psychosis. Lancet Psychiatry. 2018;5(1):79-92.
3. Katisko K, Cajanus A, Jääskeläinen O, et al. Serum neurofilament light chain is a discriminative biomarker between frontotemporal lobar degeneration and primary psychiatric disorders. J Neurol. 2020;267(1):162-167.
4. Bechter K, Reiber H, Herzog S, et al. Cerebrospinal fluid analysis in affective and schizophrenic spectrum disorders: identification of subgroups with immune responses and blood-CSF barrier dysfunction. J Psychiatr Res. 2010;44(5):321-330.
5. Hidese S, Hattori K, Sasayama D, et al. Cerebrospinal fluid neural cell adhesion molecule levels and their correlation with clinical variables in patients with schizophrenia, bipolar disorder, and major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2017;76:12-18.
6. Tunca Z, Kıvırcık Akdede B, Özerdem A, et al. Diverse glial cell line-derived neurotrophic factor (GDNF) support between mania and schizophrenia: a comparative study in four major psychiatric disorders. Eur Psychiatry. 2015;30(2):198-204.
7. Al Shweiki MR, Oeckl P, Steinacker P, et al. Major depressive disorder: insight into candidate cerebrospinal fluid protein biomarkers from proteomics studies. Expert Rev Proteomics. 2017;14(6):499-514.
8. Kroksmark H, Vinberg M. Does S100B have a potential role in affective disorders? A literature review. Nord J Psychiatry. 2018;72(7):462-470.
9. Orlovska-Waast S, Köhler-Forsberg O, Brix SW, et al. Cerebrospinal fluid markers of inflammation and infections in schizophrenia and affective disorders: a systematic review and meta-analysis. Mol Psychiatry. 2019;24(6):869-887.
10. Nasrallah HA. Lab tests for psychiatric disorders: few clinicians are aware of them. Current Psychiatry. 2013;12(2):5-7.
11. Porter L, Shoushtarizadeh A, Jelinek GA, et al. Metabolomic biomarkers of multiple sclerosis: a systematic review. Front Mol Biosci. 2020;7:574133. doi: 10.3389/fmolb.2020.574133
Psychiatry and neurology are the brain’s twin medical disciplines. Unlike neurologic brain disorders, where localizing the “lesion” is a primary objective, psychiatric brain disorders are much more subtle, with no “gross” lesions but numerous cellular and molecular pathologies within neural circuits.
Measuring the molecular components of the cerebrospinal fluid (CSF), the glorious “sewage system” of the brain, may help reveal granular clues to the neurobiology of psychiatric disorders.
Mental illnesses involve the disruption of brain structures and functions in a diffuse manner across the cortex. Abnormal neuroplasticity has been implicated in several major psychiatric disorders. Examples include hypoplasia of the hippocampus in major depressive disorder and cortical thinning/dysplasia in schizophrenia. Reductions of neurotropic factors such as nerve growth factor or brain-derived neurotropic factor have been reported in mood and psychotic disorders, and appear to correlate with neuroplasticity changes.
Recent advances in psychiatric neuroscience have provided many clues to the pathophysiology of psychopathological conditions, including neuroinflammation, oxidative stress, apoptosis, impaired energy metabolism, abnormal metabolomics and lipidomics, and hypo- and hyperfunction of various neurotransmitters systems (especially glutamate N-methyl-
Thus, psychiatric research should focus on exploring and detecting molecular signatures (ie, biomarkers) of psychiatric disorders, including biomarkers of axonal and synaptic damage, glial activation, and oxidative stress. This is especially critical given the extensive heterogeneity of schizophrenia and mood and anxiety disorders. The CSF is a vastly unexploited substrate for discovering molecular biomarkers that will pave the way to precision psychiatry, and possibly open the door for completely new therapeutic strategies to tackle the most challenging neuropsychiatric disorders.
A role for CSF analysis
It’s quite puzzling why acute psychiatric episodes of schizophrenia, bipolar disorder, major depressive disorder, or panic attacks are not routinely assessed with a spinal tap, in conjunction with other brain measures such as neuroimaging (morphology, spectroscopy, cerebral blood flow, and diffusion tensor imaging) as well as a comprehensive neurocognitive examination and neurophysiological tests such as pre-pulse inhibition, mismatch negativity, and P-50, N-10, and P-300 evoked potentials. Combining CSF analysis with all those measures may help us stratify the spectra of psychosis, depression, and anxiety, as well as posttraumatic stress disorder and obsessive-compulsive disorder, into unique biotypes with overlapping clinical phenotypes and specific treatment approaches.
There are relatively few published CSF studies in psychiatric patients (mostly schizophrenia and bipolar and depressive disorders). The Table1-9 shows some of those findings. More than 365 biomarkers have been reported in schizophrenia, most of them in serum and tissue.10 However, none of them can be used for diagnostic purposes because schizophrenia is a syndrome comprised of several hundred different diseases (biotypes) that have similar clinical symptoms. Many of the serum and tissue biomarkers have not been studied in CSF, and they must if advances in the neurobiology and treatment of the psychotic and mood spectra are to be achieved. And adapting the CSF biomarkers described in neurologic disorders such as multiple sclerosis11 to schizophrenia and bipolar disorder (which also have well-established myelin pathologies) may yield a trove of neurobiologic findings.
If CSF studies eventually prove to be very useful for identifying subtypes for diagnosis and treatment, psychiatrists do not have to do the lumbar puncture themselves, but may refer patients to a “spinal tap” laboratory, just as they refer patients to a phlebotomy laboratory for routine blood tests. The adoption of CSF assessment in psychiatry will solidify its status as a clinical neuroscience, like its sister, neurology.
Psychiatry and neurology are the brain’s twin medical disciplines. Unlike neurologic brain disorders, where localizing the “lesion” is a primary objective, psychiatric brain disorders are much more subtle, with no “gross” lesions but numerous cellular and molecular pathologies within neural circuits.
Measuring the molecular components of the cerebrospinal fluid (CSF), the glorious “sewage system” of the brain, may help reveal granular clues to the neurobiology of psychiatric disorders.
Mental illnesses involve the disruption of brain structures and functions in a diffuse manner across the cortex. Abnormal neuroplasticity has been implicated in several major psychiatric disorders. Examples include hypoplasia of the hippocampus in major depressive disorder and cortical thinning/dysplasia in schizophrenia. Reductions of neurotropic factors such as nerve growth factor or brain-derived neurotropic factor have been reported in mood and psychotic disorders, and appear to correlate with neuroplasticity changes.
Recent advances in psychiatric neuroscience have provided many clues to the pathophysiology of psychopathological conditions, including neuroinflammation, oxidative stress, apoptosis, impaired energy metabolism, abnormal metabolomics and lipidomics, and hypo- and hyperfunction of various neurotransmitters systems (especially glutamate N-methyl-
Thus, psychiatric research should focus on exploring and detecting molecular signatures (ie, biomarkers) of psychiatric disorders, including biomarkers of axonal and synaptic damage, glial activation, and oxidative stress. This is especially critical given the extensive heterogeneity of schizophrenia and mood and anxiety disorders. The CSF is a vastly unexploited substrate for discovering molecular biomarkers that will pave the way to precision psychiatry, and possibly open the door for completely new therapeutic strategies to tackle the most challenging neuropsychiatric disorders.
A role for CSF analysis
It’s quite puzzling why acute psychiatric episodes of schizophrenia, bipolar disorder, major depressive disorder, or panic attacks are not routinely assessed with a spinal tap, in conjunction with other brain measures such as neuroimaging (morphology, spectroscopy, cerebral blood flow, and diffusion tensor imaging) as well as a comprehensive neurocognitive examination and neurophysiological tests such as pre-pulse inhibition, mismatch negativity, and P-50, N-10, and P-300 evoked potentials. Combining CSF analysis with all those measures may help us stratify the spectra of psychosis, depression, and anxiety, as well as posttraumatic stress disorder and obsessive-compulsive disorder, into unique biotypes with overlapping clinical phenotypes and specific treatment approaches.
There are relatively few published CSF studies in psychiatric patients (mostly schizophrenia and bipolar and depressive disorders). The Table1-9 shows some of those findings. More than 365 biomarkers have been reported in schizophrenia, most of them in serum and tissue.10 However, none of them can be used for diagnostic purposes because schizophrenia is a syndrome comprised of several hundred different diseases (biotypes) that have similar clinical symptoms. Many of the serum and tissue biomarkers have not been studied in CSF, and they must if advances in the neurobiology and treatment of the psychotic and mood spectra are to be achieved. And adapting the CSF biomarkers described in neurologic disorders such as multiple sclerosis11 to schizophrenia and bipolar disorder (which also have well-established myelin pathologies) may yield a trove of neurobiologic findings.
If CSF studies eventually prove to be very useful for identifying subtypes for diagnosis and treatment, psychiatrists do not have to do the lumbar puncture themselves, but may refer patients to a “spinal tap” laboratory, just as they refer patients to a phlebotomy laboratory for routine blood tests. The adoption of CSF assessment in psychiatry will solidify its status as a clinical neuroscience, like its sister, neurology.
1. Vasic N, Connemann BJ, Wolf RC, et al. Cerebrospinal fluid biomarker candidates of schizophrenia: where do we stand? Eur Arch Psychiatry Clin Neurosci. 2012;262(5):375-391.
2. Pollak TA, Drndarski S, Stone JM, et al. The blood-brain barrier in psychosis. Lancet Psychiatry. 2018;5(1):79-92.
3. Katisko K, Cajanus A, Jääskeläinen O, et al. Serum neurofilament light chain is a discriminative biomarker between frontotemporal lobar degeneration and primary psychiatric disorders. J Neurol. 2020;267(1):162-167.
4. Bechter K, Reiber H, Herzog S, et al. Cerebrospinal fluid analysis in affective and schizophrenic spectrum disorders: identification of subgroups with immune responses and blood-CSF barrier dysfunction. J Psychiatr Res. 2010;44(5):321-330.
5. Hidese S, Hattori K, Sasayama D, et al. Cerebrospinal fluid neural cell adhesion molecule levels and their correlation with clinical variables in patients with schizophrenia, bipolar disorder, and major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2017;76:12-18.
6. Tunca Z, Kıvırcık Akdede B, Özerdem A, et al. Diverse glial cell line-derived neurotrophic factor (GDNF) support between mania and schizophrenia: a comparative study in four major psychiatric disorders. Eur Psychiatry. 2015;30(2):198-204.
7. Al Shweiki MR, Oeckl P, Steinacker P, et al. Major depressive disorder: insight into candidate cerebrospinal fluid protein biomarkers from proteomics studies. Expert Rev Proteomics. 2017;14(6):499-514.
8. Kroksmark H, Vinberg M. Does S100B have a potential role in affective disorders? A literature review. Nord J Psychiatry. 2018;72(7):462-470.
9. Orlovska-Waast S, Köhler-Forsberg O, Brix SW, et al. Cerebrospinal fluid markers of inflammation and infections in schizophrenia and affective disorders: a systematic review and meta-analysis. Mol Psychiatry. 2019;24(6):869-887.
10. Nasrallah HA. Lab tests for psychiatric disorders: few clinicians are aware of them. Current Psychiatry. 2013;12(2):5-7.
11. Porter L, Shoushtarizadeh A, Jelinek GA, et al. Metabolomic biomarkers of multiple sclerosis: a systematic review. Front Mol Biosci. 2020;7:574133. doi: 10.3389/fmolb.2020.574133
1. Vasic N, Connemann BJ, Wolf RC, et al. Cerebrospinal fluid biomarker candidates of schizophrenia: where do we stand? Eur Arch Psychiatry Clin Neurosci. 2012;262(5):375-391.
2. Pollak TA, Drndarski S, Stone JM, et al. The blood-brain barrier in psychosis. Lancet Psychiatry. 2018;5(1):79-92.
3. Katisko K, Cajanus A, Jääskeläinen O, et al. Serum neurofilament light chain is a discriminative biomarker between frontotemporal lobar degeneration and primary psychiatric disorders. J Neurol. 2020;267(1):162-167.
4. Bechter K, Reiber H, Herzog S, et al. Cerebrospinal fluid analysis in affective and schizophrenic spectrum disorders: identification of subgroups with immune responses and blood-CSF barrier dysfunction. J Psychiatr Res. 2010;44(5):321-330.
5. Hidese S, Hattori K, Sasayama D, et al. Cerebrospinal fluid neural cell adhesion molecule levels and their correlation with clinical variables in patients with schizophrenia, bipolar disorder, and major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2017;76:12-18.
6. Tunca Z, Kıvırcık Akdede B, Özerdem A, et al. Diverse glial cell line-derived neurotrophic factor (GDNF) support between mania and schizophrenia: a comparative study in four major psychiatric disorders. Eur Psychiatry. 2015;30(2):198-204.
7. Al Shweiki MR, Oeckl P, Steinacker P, et al. Major depressive disorder: insight into candidate cerebrospinal fluid protein biomarkers from proteomics studies. Expert Rev Proteomics. 2017;14(6):499-514.
8. Kroksmark H, Vinberg M. Does S100B have a potential role in affective disorders? A literature review. Nord J Psychiatry. 2018;72(7):462-470.
9. Orlovska-Waast S, Köhler-Forsberg O, Brix SW, et al. Cerebrospinal fluid markers of inflammation and infections in schizophrenia and affective disorders: a systematic review and meta-analysis. Mol Psychiatry. 2019;24(6):869-887.
10. Nasrallah HA. Lab tests for psychiatric disorders: few clinicians are aware of them. Current Psychiatry. 2013;12(2):5-7.
11. Porter L, Shoushtarizadeh A, Jelinek GA, et al. Metabolomic biomarkers of multiple sclerosis: a systematic review. Front Mol Biosci. 2020;7:574133. doi: 10.3389/fmolb.2020.574133
Short sleep is linked to future dementia
, according to a new analysis of data from the Whitehall II cohort study.
Previous work had identified links between short sleep duration and dementia risk, but few studies examined sleep habits long before onset of dementia. Those that did produced inconsistent results, according to Séverine Sabia, PhD, who is a research associate at Inserm (France) and the University College London.
“One potential reason for these inconstancies is the large range of ages of the study populations, and the small number of participants within each sleep duration group. The novelty of our study is to examine this association among almost 8,000 participants with a follow-up of 30 years, using repeated measures of sleep duration starting in midlife to consider sleep duration at specific ages,” Dr. Sabia said in an interview. She presented the research at the 2021 Alzheimer’s Association International Conference.
Those previous studies found a U-shaped association between sleep duration and dementia risk, with lowest risk associated with 7-8 hours of sleep, but greater risk for shorter and longer durations. However, because the studies had follow-up periods shorter than 10 years, they are at greater risk of reverse causation bias. Longer follow-up studies tended to have small sample sizes or to focus on older adults.
The longer follow-up in the current study makes for a more compelling case, said Claire Sexton, DPhil, director of Scientific Programs & Outreach for the Alzheimer’s Association. Observations of short or long sleep closer to the onset of symptoms could just be a warning sign of dementia. “But looking at age 50, age 60 ... if you’re seeing those relationships, then it’s less likely that it is just purely prodromal,” said Dr. Sexton. But it still doesn’t necessarily confirm causation. “It could also be a risk factor,” Dr. Sexton added.
Multifactorial risk
Dr. Sabia also noted that the magnitude of risk was similar to that seen with smoking or obesity, and many factors play a role in dementia risk. “Even if the risk of dementia was 30% higher in those with persistent short sleep duration, in absolute terms, the percentage of those with persistent short duration who developed dementia was 8%, and 6% in those with persistent sleep duration of 7 hours. Dementia is a multifactorial disease, which means that several factors are likely to influence its onset. Sleep duration is one of them, but if a person has poor sleep and does not manage to increase it, there are other important prevention measures. It is important to keep a healthy lifestyle and cardiometabolic measures in the normal range. All together it is likely to be beneficial for brain health in later life,” she said.
Dr. Sexton agreed. “With sleep we’re still trying to tease apart what aspect of sleep is important. Is it the sleep duration? Is it the quality of sleep? Is it certain sleep stages?” she said.
Regardless of sleep’s potential influence on dementia risk, both Dr. Sexton and Dr. Sabia noted the importance of sleep for general health. “These types of problems are very prevalent, so it’s good for people to be aware of them. And then if they notice any problems with their sleep, or any changes, to go and see their health care provider, and to be discussing them, and then to be investigating the cause, and to see whether changes in sleep hygiene and treatments for insomnia could address these sleep problems,” said Dr. Sexton.
Decades of data
During the Whitehall II study, researchers assessed average sleep duration (“How many hours of sleep do you have on an average weeknight?”) six times over 30 years of follow-up. Dr. Sabia’s group extracted self-reported sleep duration data at ages 50, 60, and 70. Short sleep duration was defined as fewer than 5 hours, or 6 hours. Normal sleep duration was defined as 7 hours. Long duration was defined as 8 hours or more.
A questioner during the Q&A period noted that this grouping is a little unusual. Many studies define 7-8 hours as normal. Dr. Sabia answered that they were unable to examine periods of 9 hours or more due to the nature of the data, and the lowest associated risk was found at 7 hours.
The researchers analyzed data from 7,959 participants (33.0% women). At age 50, compared with 7 hours of sleep, 6 or few hours of sleep was associated with a higher risk of dementia over the ensuing 25 years of follow-up (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.01-1.48). The same was true at age 60 (15 years of follow-up HR, 1.37; 95% CI, 1.10-1.72). There was a trend at age 70 (8 years follow-up; HR, 1.24; 95% CI, 0.98-1.57). For 8 or more hours of sleep, there were trends toward increased risk at age 50 (HR, 1.25; 95% CI, 0.98-1.60). Long sleep at age 60 and 70 was associated with heightened risk, but the confidence intervals were well outside statistical significance.
Twenty percent of participants had persistent short sleep over the course of follow-up, 37% had persistent normal sleep, and 7% had persistent long sleep. Seven percent of participants experienced a change from normal sleep to short sleep, 16% had a change from short sleep to normal sleep, and 13% had a change from normal sleep to long sleep.
Persistent short sleep between age 50 and 70 was associated with a 30% increased risk of dementia (HR, 1.30; 95% CI, 1.00-1.69). There were no statistically significant associations between dementia risk and any of the changing sleep pattern groups.
Dr. Sabia and Dr. Sexton have no relevant financial disclosures.
, according to a new analysis of data from the Whitehall II cohort study.
Previous work had identified links between short sleep duration and dementia risk, but few studies examined sleep habits long before onset of dementia. Those that did produced inconsistent results, according to Séverine Sabia, PhD, who is a research associate at Inserm (France) and the University College London.
“One potential reason for these inconstancies is the large range of ages of the study populations, and the small number of participants within each sleep duration group. The novelty of our study is to examine this association among almost 8,000 participants with a follow-up of 30 years, using repeated measures of sleep duration starting in midlife to consider sleep duration at specific ages,” Dr. Sabia said in an interview. She presented the research at the 2021 Alzheimer’s Association International Conference.
Those previous studies found a U-shaped association between sleep duration and dementia risk, with lowest risk associated with 7-8 hours of sleep, but greater risk for shorter and longer durations. However, because the studies had follow-up periods shorter than 10 years, they are at greater risk of reverse causation bias. Longer follow-up studies tended to have small sample sizes or to focus on older adults.
The longer follow-up in the current study makes for a more compelling case, said Claire Sexton, DPhil, director of Scientific Programs & Outreach for the Alzheimer’s Association. Observations of short or long sleep closer to the onset of symptoms could just be a warning sign of dementia. “But looking at age 50, age 60 ... if you’re seeing those relationships, then it’s less likely that it is just purely prodromal,” said Dr. Sexton. But it still doesn’t necessarily confirm causation. “It could also be a risk factor,” Dr. Sexton added.
Multifactorial risk
Dr. Sabia also noted that the magnitude of risk was similar to that seen with smoking or obesity, and many factors play a role in dementia risk. “Even if the risk of dementia was 30% higher in those with persistent short sleep duration, in absolute terms, the percentage of those with persistent short duration who developed dementia was 8%, and 6% in those with persistent sleep duration of 7 hours. Dementia is a multifactorial disease, which means that several factors are likely to influence its onset. Sleep duration is one of them, but if a person has poor sleep and does not manage to increase it, there are other important prevention measures. It is important to keep a healthy lifestyle and cardiometabolic measures in the normal range. All together it is likely to be beneficial for brain health in later life,” she said.
Dr. Sexton agreed. “With sleep we’re still trying to tease apart what aspect of sleep is important. Is it the sleep duration? Is it the quality of sleep? Is it certain sleep stages?” she said.
Regardless of sleep’s potential influence on dementia risk, both Dr. Sexton and Dr. Sabia noted the importance of sleep for general health. “These types of problems are very prevalent, so it’s good for people to be aware of them. And then if they notice any problems with their sleep, or any changes, to go and see their health care provider, and to be discussing them, and then to be investigating the cause, and to see whether changes in sleep hygiene and treatments for insomnia could address these sleep problems,” said Dr. Sexton.
Decades of data
During the Whitehall II study, researchers assessed average sleep duration (“How many hours of sleep do you have on an average weeknight?”) six times over 30 years of follow-up. Dr. Sabia’s group extracted self-reported sleep duration data at ages 50, 60, and 70. Short sleep duration was defined as fewer than 5 hours, or 6 hours. Normal sleep duration was defined as 7 hours. Long duration was defined as 8 hours or more.
A questioner during the Q&A period noted that this grouping is a little unusual. Many studies define 7-8 hours as normal. Dr. Sabia answered that they were unable to examine periods of 9 hours or more due to the nature of the data, and the lowest associated risk was found at 7 hours.
The researchers analyzed data from 7,959 participants (33.0% women). At age 50, compared with 7 hours of sleep, 6 or few hours of sleep was associated with a higher risk of dementia over the ensuing 25 years of follow-up (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.01-1.48). The same was true at age 60 (15 years of follow-up HR, 1.37; 95% CI, 1.10-1.72). There was a trend at age 70 (8 years follow-up; HR, 1.24; 95% CI, 0.98-1.57). For 8 or more hours of sleep, there were trends toward increased risk at age 50 (HR, 1.25; 95% CI, 0.98-1.60). Long sleep at age 60 and 70 was associated with heightened risk, but the confidence intervals were well outside statistical significance.
Twenty percent of participants had persistent short sleep over the course of follow-up, 37% had persistent normal sleep, and 7% had persistent long sleep. Seven percent of participants experienced a change from normal sleep to short sleep, 16% had a change from short sleep to normal sleep, and 13% had a change from normal sleep to long sleep.
Persistent short sleep between age 50 and 70 was associated with a 30% increased risk of dementia (HR, 1.30; 95% CI, 1.00-1.69). There were no statistically significant associations between dementia risk and any of the changing sleep pattern groups.
Dr. Sabia and Dr. Sexton have no relevant financial disclosures.
, according to a new analysis of data from the Whitehall II cohort study.
Previous work had identified links between short sleep duration and dementia risk, but few studies examined sleep habits long before onset of dementia. Those that did produced inconsistent results, according to Séverine Sabia, PhD, who is a research associate at Inserm (France) and the University College London.
“One potential reason for these inconstancies is the large range of ages of the study populations, and the small number of participants within each sleep duration group. The novelty of our study is to examine this association among almost 8,000 participants with a follow-up of 30 years, using repeated measures of sleep duration starting in midlife to consider sleep duration at specific ages,” Dr. Sabia said in an interview. She presented the research at the 2021 Alzheimer’s Association International Conference.
Those previous studies found a U-shaped association between sleep duration and dementia risk, with lowest risk associated with 7-8 hours of sleep, but greater risk for shorter and longer durations. However, because the studies had follow-up periods shorter than 10 years, they are at greater risk of reverse causation bias. Longer follow-up studies tended to have small sample sizes or to focus on older adults.
The longer follow-up in the current study makes for a more compelling case, said Claire Sexton, DPhil, director of Scientific Programs & Outreach for the Alzheimer’s Association. Observations of short or long sleep closer to the onset of symptoms could just be a warning sign of dementia. “But looking at age 50, age 60 ... if you’re seeing those relationships, then it’s less likely that it is just purely prodromal,” said Dr. Sexton. But it still doesn’t necessarily confirm causation. “It could also be a risk factor,” Dr. Sexton added.
Multifactorial risk
Dr. Sabia also noted that the magnitude of risk was similar to that seen with smoking or obesity, and many factors play a role in dementia risk. “Even if the risk of dementia was 30% higher in those with persistent short sleep duration, in absolute terms, the percentage of those with persistent short duration who developed dementia was 8%, and 6% in those with persistent sleep duration of 7 hours. Dementia is a multifactorial disease, which means that several factors are likely to influence its onset. Sleep duration is one of them, but if a person has poor sleep and does not manage to increase it, there are other important prevention measures. It is important to keep a healthy lifestyle and cardiometabolic measures in the normal range. All together it is likely to be beneficial for brain health in later life,” she said.
Dr. Sexton agreed. “With sleep we’re still trying to tease apart what aspect of sleep is important. Is it the sleep duration? Is it the quality of sleep? Is it certain sleep stages?” she said.
Regardless of sleep’s potential influence on dementia risk, both Dr. Sexton and Dr. Sabia noted the importance of sleep for general health. “These types of problems are very prevalent, so it’s good for people to be aware of them. And then if they notice any problems with their sleep, or any changes, to go and see their health care provider, and to be discussing them, and then to be investigating the cause, and to see whether changes in sleep hygiene and treatments for insomnia could address these sleep problems,” said Dr. Sexton.
Decades of data
During the Whitehall II study, researchers assessed average sleep duration (“How many hours of sleep do you have on an average weeknight?”) six times over 30 years of follow-up. Dr. Sabia’s group extracted self-reported sleep duration data at ages 50, 60, and 70. Short sleep duration was defined as fewer than 5 hours, or 6 hours. Normal sleep duration was defined as 7 hours. Long duration was defined as 8 hours or more.
A questioner during the Q&A period noted that this grouping is a little unusual. Many studies define 7-8 hours as normal. Dr. Sabia answered that they were unable to examine periods of 9 hours or more due to the nature of the data, and the lowest associated risk was found at 7 hours.
The researchers analyzed data from 7,959 participants (33.0% women). At age 50, compared with 7 hours of sleep, 6 or few hours of sleep was associated with a higher risk of dementia over the ensuing 25 years of follow-up (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.01-1.48). The same was true at age 60 (15 years of follow-up HR, 1.37; 95% CI, 1.10-1.72). There was a trend at age 70 (8 years follow-up; HR, 1.24; 95% CI, 0.98-1.57). For 8 or more hours of sleep, there were trends toward increased risk at age 50 (HR, 1.25; 95% CI, 0.98-1.60). Long sleep at age 60 and 70 was associated with heightened risk, but the confidence intervals were well outside statistical significance.
Twenty percent of participants had persistent short sleep over the course of follow-up, 37% had persistent normal sleep, and 7% had persistent long sleep. Seven percent of participants experienced a change from normal sleep to short sleep, 16% had a change from short sleep to normal sleep, and 13% had a change from normal sleep to long sleep.
Persistent short sleep between age 50 and 70 was associated with a 30% increased risk of dementia (HR, 1.30; 95% CI, 1.00-1.69). There were no statistically significant associations between dementia risk and any of the changing sleep pattern groups.
Dr. Sabia and Dr. Sexton have no relevant financial disclosures.
FROM AAIC 2021
Inflammatory diet is linked to dementia
according to a new analysis of longitudinal data from the Framingham Heart Study Offspring Cohort.
The lack of an association with Alzheimer’s disease was a surprise because amyloid-beta prompts microglia and astrocytes to release markers of systemic inflammation, according to Debora Melo van Lent, PhD, who is a postdoctoral fellow at the University of Texas Health San Antonio – Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases. “We expected to see a relationship between higher DII scores and an increased risk for incident Alzheimer’s disease,” said Dr. Melo van Lent, who presented the findings at the 2021 Alzheimer’s Association International Conference.
Dr. Melo van Lent added that the most likely explanation is that the study was underpowered to produce a positive association, and the team is conducting further study in a larger population.
A modifiable risk factor
The study is the first to look at all-cause dementia and Alzheimer’s disease dementia and their association with DII, Dr. Melo van Lent said.
“As diet is a modifiable risk factor, we can actually do something about it. If we take a closer look at five components of the DII which are most anti-inflammatory, these components are present in green leafy vegetables, vegetables, fruit, soy, whole grains, and green and black tea. Most of these components are included in the Mediterranean diet. When we look at the three most proinflammatory components, they are present in high caloric products; such as butter or margarine, pastries and sweets, fried snacks, and red or processed meat. These components are present in ‘Western diets,’ which are discouraged,” said Dr. Melo van Lent.
The researchers analyzed data from 1,486 participants who were free of dementia, stroke, or other neurologic diseases at baseline. They analyzed DII scores both in a continuous range and divided into quartiles, using the first quartile as a reference.
The mean age of participants was 69 years, and 53% were women. During follow-up, 11.3% developed AD dementia, and 14.8% developed non-AD dementia.
In the continuous model, DII was associated with increased risk of all-cause dementia after adjusting for age, sex, APOE E4 status, body mass index, smoking, physical activity index score, total energy intake, lipid-lowering medications, and total cholesterol to HDL cholesterol ratio (hazard ratio, 1.18; P =.001). In the quartile analysis, after adjustments, compared with quartile 1, there was an increased risk of all-cause dementia for those in quartile 3 (HR, 1.69; P =.020) and quartile 4 (HR, 1.84; P =.013).
In the continuous analysis, after adjustments, there was an association between DII score and Alzheimer’s dementia (HR, 1.15; P =.020). In the quartile analysis, no associations were significant, though there was a trend of quartile 4 versus quartile 1 (HR, 1.65; P =.077).
The researchers found no significant interactions between higher DII scores and sex, the APOE E4 allele, or physical activity with respect to all-cause dementia or Alzheimer’s dementia.
Intertwined variables
The results were interesting, but cause and effect relationships can be difficult to tease out from such a study, according to Claire Sexton, DPhil, director of scientific programs and outreach at the Alzheimer’s Association, who was asked to comment on the study. Dr. Sexton noted that individuals who eat well are more likely to have energy to exercise, which could in turn help them to sleep better, and all of those factors could be involved in reducing dementia risk. “They’re all kind of intertwined. So in this study, they were taking into account physical activity, but they can’t take into account every single variable. It’s important for them to be followed up by randomized control trials.”
Dr. Sexton also referenced the U.S. Pointer study being conducted by the Alzheimer’s Association, which is examining various interventions related to diet, physical activity, and cognitive stimulation. “Whether intervening and improving people’s health behaviors then goes on to reduce their risk for dementia is a key question. We still need more results from studies to be reporting out before we get definitive answers,” she said.
The study was funded by the ASPEN Rhoads Research Foundation. Dr. Melo van Lent and Dr. Sexton have no relevant financial disclosures.
according to a new analysis of longitudinal data from the Framingham Heart Study Offspring Cohort.
The lack of an association with Alzheimer’s disease was a surprise because amyloid-beta prompts microglia and astrocytes to release markers of systemic inflammation, according to Debora Melo van Lent, PhD, who is a postdoctoral fellow at the University of Texas Health San Antonio – Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases. “We expected to see a relationship between higher DII scores and an increased risk for incident Alzheimer’s disease,” said Dr. Melo van Lent, who presented the findings at the 2021 Alzheimer’s Association International Conference.
Dr. Melo van Lent added that the most likely explanation is that the study was underpowered to produce a positive association, and the team is conducting further study in a larger population.
A modifiable risk factor
The study is the first to look at all-cause dementia and Alzheimer’s disease dementia and their association with DII, Dr. Melo van Lent said.
“As diet is a modifiable risk factor, we can actually do something about it. If we take a closer look at five components of the DII which are most anti-inflammatory, these components are present in green leafy vegetables, vegetables, fruit, soy, whole grains, and green and black tea. Most of these components are included in the Mediterranean diet. When we look at the three most proinflammatory components, they are present in high caloric products; such as butter or margarine, pastries and sweets, fried snacks, and red or processed meat. These components are present in ‘Western diets,’ which are discouraged,” said Dr. Melo van Lent.
The researchers analyzed data from 1,486 participants who were free of dementia, stroke, or other neurologic diseases at baseline. They analyzed DII scores both in a continuous range and divided into quartiles, using the first quartile as a reference.
The mean age of participants was 69 years, and 53% were women. During follow-up, 11.3% developed AD dementia, and 14.8% developed non-AD dementia.
In the continuous model, DII was associated with increased risk of all-cause dementia after adjusting for age, sex, APOE E4 status, body mass index, smoking, physical activity index score, total energy intake, lipid-lowering medications, and total cholesterol to HDL cholesterol ratio (hazard ratio, 1.18; P =.001). In the quartile analysis, after adjustments, compared with quartile 1, there was an increased risk of all-cause dementia for those in quartile 3 (HR, 1.69; P =.020) and quartile 4 (HR, 1.84; P =.013).
In the continuous analysis, after adjustments, there was an association between DII score and Alzheimer’s dementia (HR, 1.15; P =.020). In the quartile analysis, no associations were significant, though there was a trend of quartile 4 versus quartile 1 (HR, 1.65; P =.077).
The researchers found no significant interactions between higher DII scores and sex, the APOE E4 allele, or physical activity with respect to all-cause dementia or Alzheimer’s dementia.
Intertwined variables
The results were interesting, but cause and effect relationships can be difficult to tease out from such a study, according to Claire Sexton, DPhil, director of scientific programs and outreach at the Alzheimer’s Association, who was asked to comment on the study. Dr. Sexton noted that individuals who eat well are more likely to have energy to exercise, which could in turn help them to sleep better, and all of those factors could be involved in reducing dementia risk. “They’re all kind of intertwined. So in this study, they were taking into account physical activity, but they can’t take into account every single variable. It’s important for them to be followed up by randomized control trials.”
Dr. Sexton also referenced the U.S. Pointer study being conducted by the Alzheimer’s Association, which is examining various interventions related to diet, physical activity, and cognitive stimulation. “Whether intervening and improving people’s health behaviors then goes on to reduce their risk for dementia is a key question. We still need more results from studies to be reporting out before we get definitive answers,” she said.
The study was funded by the ASPEN Rhoads Research Foundation. Dr. Melo van Lent and Dr. Sexton have no relevant financial disclosures.
according to a new analysis of longitudinal data from the Framingham Heart Study Offspring Cohort.
The lack of an association with Alzheimer’s disease was a surprise because amyloid-beta prompts microglia and astrocytes to release markers of systemic inflammation, according to Debora Melo van Lent, PhD, who is a postdoctoral fellow at the University of Texas Health San Antonio – Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases. “We expected to see a relationship between higher DII scores and an increased risk for incident Alzheimer’s disease,” said Dr. Melo van Lent, who presented the findings at the 2021 Alzheimer’s Association International Conference.
Dr. Melo van Lent added that the most likely explanation is that the study was underpowered to produce a positive association, and the team is conducting further study in a larger population.
A modifiable risk factor
The study is the first to look at all-cause dementia and Alzheimer’s disease dementia and their association with DII, Dr. Melo van Lent said.
“As diet is a modifiable risk factor, we can actually do something about it. If we take a closer look at five components of the DII which are most anti-inflammatory, these components are present in green leafy vegetables, vegetables, fruit, soy, whole grains, and green and black tea. Most of these components are included in the Mediterranean diet. When we look at the three most proinflammatory components, they are present in high caloric products; such as butter or margarine, pastries and sweets, fried snacks, and red or processed meat. These components are present in ‘Western diets,’ which are discouraged,” said Dr. Melo van Lent.
The researchers analyzed data from 1,486 participants who were free of dementia, stroke, or other neurologic diseases at baseline. They analyzed DII scores both in a continuous range and divided into quartiles, using the first quartile as a reference.
The mean age of participants was 69 years, and 53% were women. During follow-up, 11.3% developed AD dementia, and 14.8% developed non-AD dementia.
In the continuous model, DII was associated with increased risk of all-cause dementia after adjusting for age, sex, APOE E4 status, body mass index, smoking, physical activity index score, total energy intake, lipid-lowering medications, and total cholesterol to HDL cholesterol ratio (hazard ratio, 1.18; P =.001). In the quartile analysis, after adjustments, compared with quartile 1, there was an increased risk of all-cause dementia for those in quartile 3 (HR, 1.69; P =.020) and quartile 4 (HR, 1.84; P =.013).
In the continuous analysis, after adjustments, there was an association between DII score and Alzheimer’s dementia (HR, 1.15; P =.020). In the quartile analysis, no associations were significant, though there was a trend of quartile 4 versus quartile 1 (HR, 1.65; P =.077).
The researchers found no significant interactions between higher DII scores and sex, the APOE E4 allele, or physical activity with respect to all-cause dementia or Alzheimer’s dementia.
Intertwined variables
The results were interesting, but cause and effect relationships can be difficult to tease out from such a study, according to Claire Sexton, DPhil, director of scientific programs and outreach at the Alzheimer’s Association, who was asked to comment on the study. Dr. Sexton noted that individuals who eat well are more likely to have energy to exercise, which could in turn help them to sleep better, and all of those factors could be involved in reducing dementia risk. “They’re all kind of intertwined. So in this study, they were taking into account physical activity, but they can’t take into account every single variable. It’s important for them to be followed up by randomized control trials.”
Dr. Sexton also referenced the U.S. Pointer study being conducted by the Alzheimer’s Association, which is examining various interventions related to diet, physical activity, and cognitive stimulation. “Whether intervening and improving people’s health behaviors then goes on to reduce their risk for dementia is a key question. We still need more results from studies to be reporting out before we get definitive answers,” she said.
The study was funded by the ASPEN Rhoads Research Foundation. Dr. Melo van Lent and Dr. Sexton have no relevant financial disclosures.
FROM AAIC 2021
Alzheimer’s disease plasma biomarkers may be nuanced
Such tests are likely to be widely available in the near future.
But work remains to be done to translate findings from academic studies to the more general population. A key consideration is that plasma levels of these biomarkers could be affected by other conditions, which could in turn skew test results, according to Michelle Mielke, PhD, who spoke on the topic at the 2021 Alzheimer’s Association International Conference.
“The markers, which we’ve published on as well, look really promising. But they have primarily been looked at in more specialty clinics or memory clinics, and have not been examined in the general community. The goal of this presentation was really just to take a look at this in the community, in older individuals that have multiple comorbidities, and to understand what factors might affect the levels of these markers. Because as we do go forward and develop cut points, we are going to have to consider these aspects,” said Dr. Mielke in an interview. She is a professor of epidemiology and neurology at the Mayo Clinic in Rochester, Minn.
Case in point
To illustrate the point, Dr. Mielke presented data from her group, which analyzed P-tau 181 and P-tau 217 data from 1,329 Mayo clinic patients. Of that total, 1,161 were cognitively unimpaired (CU), 153 had mild cognitive impairment (MCI), and 15 had dementia. The median age was 67, 55% were male, and 26% had the APOE e4 allele.
After adjustment for age and sex, there were statistically significantly elevated levels of both biomarkers among patients who had tested positive for amyloid and patients who had had a stroke or myocardial infarction, and in the presence of chronic kidney disease (CKD). There also was a trend towards an increase of biomarker levels with increasing body mass index. The differences remained even after the analysis was restricted to individuals who were amyloid negative.
The researchers then looked more closely at the impact of CKD, stroke, and MI on P-tau cut points and the ability to predict abnormal amyloid positron emission tomography (PET) scans. They defined an abnormal range as 1.96 standard deviation units beyond the mean among amyloid-negative individuals who are cognitively impaired. They excluded subjects with those risk factors and then established new cut points in the absence of the factors. The approach led to a significant change for the cutoff of P-tau 181 values, from 1.57 pg/mL or greater for individuals without stroke, MI, or CKD, and 1.75 pg/mL or greater for individuals with one such factor. There was little difference in the cutoff value for P-tau 217, from 0.25 pg/mL to 0.26 pg/mL.
Among people without a history of stroke, MI, or CKD, a P-tau 181 cutoff of 1.57 pg/mL or greater had an area under the receiving operating characteristic (AUROC) value of 0.717 (95% confidence interval, 0.691-0.744), compared with an AUROC of 0.687 (95% CI, 0.662-0.712) at a cutoff of 1.75 pg/mL or greater among people with those conditions. For P-tau 217, the values were 0.737 pg/mL (95% CI, 0.712-0.762) and 0.724 pg/mL (95% CI, 0.699-0.748), respectively.
“The sensitivity was better when they excluded those individuals with these conditions. Specificity was slightly, but not significantly, lower,” said Dr. Mielke during her talk.
Other considerations
Dr. Mielke added that it will be important to account for these and other factors when applying biomarkers in community settings, but they should also be considered in the context of health care disparities. Stroke, MI, and CKD are more common in African Americans, for example, suggesting that there could be racial differences in biomarker levels, though she said the difference in biomarker levels would be more likely attributable to the underlying comorbidities than race per se. “As shown, these factors can affect the consideration of an accuracy of cut points for clinical use. So I think future discussions will be needed as to how best to determine the cut points, and how to base them off of (different) populations,” said Dr. Mielke.
These sorts of refinements are important, according to Christopher Weber, PhD, who was asked for comment. “We have learned the importance of an early and accurate diagnosis. The blood test is a biomarker that does detect the hallmarks of Alzheimer’s disease sometimes up to decades before symptoms even appear,” said Dr. Weber, who is director of Global Science Initiatives at the Alzheimer’s Association.
But “there’s a lot more that we need to learn regarding when exactly to use them, who they’re appropriate for. And I think validation is the key to these blood biomarkers,” Dr. Weber added.
Dr. Mielke has been a consultant with the Brain Protection Company and Biogen. Dr. Weber has no relevant financial disclosures.
Such tests are likely to be widely available in the near future.
But work remains to be done to translate findings from academic studies to the more general population. A key consideration is that plasma levels of these biomarkers could be affected by other conditions, which could in turn skew test results, according to Michelle Mielke, PhD, who spoke on the topic at the 2021 Alzheimer’s Association International Conference.
“The markers, which we’ve published on as well, look really promising. But they have primarily been looked at in more specialty clinics or memory clinics, and have not been examined in the general community. The goal of this presentation was really just to take a look at this in the community, in older individuals that have multiple comorbidities, and to understand what factors might affect the levels of these markers. Because as we do go forward and develop cut points, we are going to have to consider these aspects,” said Dr. Mielke in an interview. She is a professor of epidemiology and neurology at the Mayo Clinic in Rochester, Minn.
Case in point
To illustrate the point, Dr. Mielke presented data from her group, which analyzed P-tau 181 and P-tau 217 data from 1,329 Mayo clinic patients. Of that total, 1,161 were cognitively unimpaired (CU), 153 had mild cognitive impairment (MCI), and 15 had dementia. The median age was 67, 55% were male, and 26% had the APOE e4 allele.
After adjustment for age and sex, there were statistically significantly elevated levels of both biomarkers among patients who had tested positive for amyloid and patients who had had a stroke or myocardial infarction, and in the presence of chronic kidney disease (CKD). There also was a trend towards an increase of biomarker levels with increasing body mass index. The differences remained even after the analysis was restricted to individuals who were amyloid negative.
The researchers then looked more closely at the impact of CKD, stroke, and MI on P-tau cut points and the ability to predict abnormal amyloid positron emission tomography (PET) scans. They defined an abnormal range as 1.96 standard deviation units beyond the mean among amyloid-negative individuals who are cognitively impaired. They excluded subjects with those risk factors and then established new cut points in the absence of the factors. The approach led to a significant change for the cutoff of P-tau 181 values, from 1.57 pg/mL or greater for individuals without stroke, MI, or CKD, and 1.75 pg/mL or greater for individuals with one such factor. There was little difference in the cutoff value for P-tau 217, from 0.25 pg/mL to 0.26 pg/mL.
Among people without a history of stroke, MI, or CKD, a P-tau 181 cutoff of 1.57 pg/mL or greater had an area under the receiving operating characteristic (AUROC) value of 0.717 (95% confidence interval, 0.691-0.744), compared with an AUROC of 0.687 (95% CI, 0.662-0.712) at a cutoff of 1.75 pg/mL or greater among people with those conditions. For P-tau 217, the values were 0.737 pg/mL (95% CI, 0.712-0.762) and 0.724 pg/mL (95% CI, 0.699-0.748), respectively.
“The sensitivity was better when they excluded those individuals with these conditions. Specificity was slightly, but not significantly, lower,” said Dr. Mielke during her talk.
Other considerations
Dr. Mielke added that it will be important to account for these and other factors when applying biomarkers in community settings, but they should also be considered in the context of health care disparities. Stroke, MI, and CKD are more common in African Americans, for example, suggesting that there could be racial differences in biomarker levels, though she said the difference in biomarker levels would be more likely attributable to the underlying comorbidities than race per se. “As shown, these factors can affect the consideration of an accuracy of cut points for clinical use. So I think future discussions will be needed as to how best to determine the cut points, and how to base them off of (different) populations,” said Dr. Mielke.
These sorts of refinements are important, according to Christopher Weber, PhD, who was asked for comment. “We have learned the importance of an early and accurate diagnosis. The blood test is a biomarker that does detect the hallmarks of Alzheimer’s disease sometimes up to decades before symptoms even appear,” said Dr. Weber, who is director of Global Science Initiatives at the Alzheimer’s Association.
But “there’s a lot more that we need to learn regarding when exactly to use them, who they’re appropriate for. And I think validation is the key to these blood biomarkers,” Dr. Weber added.
Dr. Mielke has been a consultant with the Brain Protection Company and Biogen. Dr. Weber has no relevant financial disclosures.
Such tests are likely to be widely available in the near future.
But work remains to be done to translate findings from academic studies to the more general population. A key consideration is that plasma levels of these biomarkers could be affected by other conditions, which could in turn skew test results, according to Michelle Mielke, PhD, who spoke on the topic at the 2021 Alzheimer’s Association International Conference.
“The markers, which we’ve published on as well, look really promising. But they have primarily been looked at in more specialty clinics or memory clinics, and have not been examined in the general community. The goal of this presentation was really just to take a look at this in the community, in older individuals that have multiple comorbidities, and to understand what factors might affect the levels of these markers. Because as we do go forward and develop cut points, we are going to have to consider these aspects,” said Dr. Mielke in an interview. She is a professor of epidemiology and neurology at the Mayo Clinic in Rochester, Minn.
Case in point
To illustrate the point, Dr. Mielke presented data from her group, which analyzed P-tau 181 and P-tau 217 data from 1,329 Mayo clinic patients. Of that total, 1,161 were cognitively unimpaired (CU), 153 had mild cognitive impairment (MCI), and 15 had dementia. The median age was 67, 55% were male, and 26% had the APOE e4 allele.
After adjustment for age and sex, there were statistically significantly elevated levels of both biomarkers among patients who had tested positive for amyloid and patients who had had a stroke or myocardial infarction, and in the presence of chronic kidney disease (CKD). There also was a trend towards an increase of biomarker levels with increasing body mass index. The differences remained even after the analysis was restricted to individuals who were amyloid negative.
The researchers then looked more closely at the impact of CKD, stroke, and MI on P-tau cut points and the ability to predict abnormal amyloid positron emission tomography (PET) scans. They defined an abnormal range as 1.96 standard deviation units beyond the mean among amyloid-negative individuals who are cognitively impaired. They excluded subjects with those risk factors and then established new cut points in the absence of the factors. The approach led to a significant change for the cutoff of P-tau 181 values, from 1.57 pg/mL or greater for individuals without stroke, MI, or CKD, and 1.75 pg/mL or greater for individuals with one such factor. There was little difference in the cutoff value for P-tau 217, from 0.25 pg/mL to 0.26 pg/mL.
Among people without a history of stroke, MI, or CKD, a P-tau 181 cutoff of 1.57 pg/mL or greater had an area under the receiving operating characteristic (AUROC) value of 0.717 (95% confidence interval, 0.691-0.744), compared with an AUROC of 0.687 (95% CI, 0.662-0.712) at a cutoff of 1.75 pg/mL or greater among people with those conditions. For P-tau 217, the values were 0.737 pg/mL (95% CI, 0.712-0.762) and 0.724 pg/mL (95% CI, 0.699-0.748), respectively.
“The sensitivity was better when they excluded those individuals with these conditions. Specificity was slightly, but not significantly, lower,” said Dr. Mielke during her talk.
Other considerations
Dr. Mielke added that it will be important to account for these and other factors when applying biomarkers in community settings, but they should also be considered in the context of health care disparities. Stroke, MI, and CKD are more common in African Americans, for example, suggesting that there could be racial differences in biomarker levels, though she said the difference in biomarker levels would be more likely attributable to the underlying comorbidities than race per se. “As shown, these factors can affect the consideration of an accuracy of cut points for clinical use. So I think future discussions will be needed as to how best to determine the cut points, and how to base them off of (different) populations,” said Dr. Mielke.
These sorts of refinements are important, according to Christopher Weber, PhD, who was asked for comment. “We have learned the importance of an early and accurate diagnosis. The blood test is a biomarker that does detect the hallmarks of Alzheimer’s disease sometimes up to decades before symptoms even appear,” said Dr. Weber, who is director of Global Science Initiatives at the Alzheimer’s Association.
But “there’s a lot more that we need to learn regarding when exactly to use them, who they’re appropriate for. And I think validation is the key to these blood biomarkers,” Dr. Weber added.
Dr. Mielke has been a consultant with the Brain Protection Company and Biogen. Dr. Weber has no relevant financial disclosures.
FROM AAIC 2021
Can a supplement that mimics the keto diet reduce seizures?
early research suggests. However, at least one expert has concerns.
In an open-label feasibility study, researchers assessed a liquid supplement known as K.Vita (Vitaflo International), which contains both decanoic acid and octanoic acid.
Although the study was small, the findings are promising, said coinvestigator Matthew Walker, MD, PhD, University College London Institute of Neurology, department of clinical and experimental epilepsy.
“The dietary supplement was reasonably well tolerated and while we weren’t specifically looking for efficacy here, we did see some patients had quite dramatic results in terms of reduced seizures,” Dr. Walker said.
Unlike the ketogenic diet, this dietary supplement is “very easy” to follow, involves only minor dietary modifications, and doesn’t require the intervention of a dietitian, he added.
The findings were published online July 23, 2021, in Brain Communications.
Key ingredients
In the ketogenic diet, the body uses body fat as its primary fuel source. The switch from carbohydrates to fat for body fuel results in built-up ketones.
Previous research shows the ketogenic diet is effective in reducing seizures in some patients with epilepsy. However, many patients find it difficult to tolerate, especially for extended periods. Dr. Walker also noted that ketones may have other long-term side effects, including osteoporosis.
He added that his team was keen to learn what elements of the ketogenic diet affect seizures. “Interestingly, we found that one of the fats used in the ketogenic diet, decanoic acid, has quite marked antiseizure effects,” Dr. Walker said.
Previous research has shown that decanoic acid, a medium-chain triglyceride–derived fatty acid, can cross the blood-brain barrier and decrease excitatory neurotransmission and network excitability in vitro.
Dr. Walker noted that ketones are necessary in order to reduce seizures.
“Rather than have a very high-fat, low-carbohydrate diet that causes ketones, we thought ‘why don’t we use a diet in which we just use mainly this fat, this decanoic acid, and avoid ketosis,’ ” he said.
The researchers then went to work developing the K.Vita dietary supplement, which mainly contains decanoic acid but also another fat, octanoic acid.
Assessing feasibility
The feasibility study included 61 patients (59% female) who began taking the supplement. Of these, 35 were children (aged 3-18 years) and 26 were adults. The children had Dravet syndrome or another genetically driven form of epilepsy, while most of the adults had a focal epilepsy.
All participants had failed multiple antiseizure medications – a median of 3 for children and 10 for adults who completed the trial. Of the 61 original participants, 20 (19 children and 1 adult) had tried the ketogenic diet but had stopped it for various reasons, including noncompliance and lack of efficacy.
The liquid supplement was introduced gradually. The amount administered was based on weight in the children and was a standard amount in adults, with the target being 240 mL.
Participants consumed the supplement in equal servings taken at regular intervals as part of a meal or snack. They could take it alone or mix it with yogurt or another food.
Patients with feeding tubes took the supplement immediately before or after or mixed into an enteral feed, with a water flush afterward.
Researchers provided patients and caregivers with guidance on excluding highly refined sugary foods and beverages. Starchy foods such as bread, pasta, rice, and potatoes were not restricted.
The study consisted of three visits: baseline, 5 weeks, and 12 weeks, in addition to regular phone and email contact. Participants were also asked to keep a seizure diary.
Highly acceptable to patients
Overall, the study withdrawal rate was 33%. After a protocol change involving a slower introduction of the supplement, there were fewer withdrawals, Dr. Walker reported. He noted that the proportion of participants who completed the study (41 of 61) is “much better than with most studies of adults following the ketogenic diet.”
The most frequently reported gastrointestinal symptoms with the supplement were bloating and constipation, but these were predominantly mild and tended to decrease over time. This, said Dr. Walker, contrasts to the ketogenic diet where side effects tend to persist.
There was no significant change in body weight or body mass index. “We did not see weight gain as a problem at all,” Dr. Walker said.
Of 15 caregivers and 19 adults who returned an acceptability questionnaire, 84% agreed or strongly agreed the supplement had a good flavor (strawberry); 88% liked the appearance and color; 77% liked the texture and consistency; and 88% agreed or strongly agreed it was easy to take.
About one-third of adults and two-thirds of caregivers said they believed the supplement reduced seizures.
50% seizure reduction
Only three children and one adult became ketotic. This is typically classified as a beta-hydroxybutyrate (BHB) greater than 1 mmol/L (10.4 mg/dL). The BHB levels detected were markedly lower than those observed in individuals following a ketogenic diet, the investigators note.
Of the 41 participants, 19 completed the diaries. There were also data from physician recordings, so researchers were able to retrieve seizure frequencies for 32 of the 41 (78%). Of these 32 patients, 14 (44%) had a 50% or greater reduction in seizures. Overall, children and adults “responded similarly,” Dr. Walker said.
He acknowledged the study numbers are small and emphasized that larger studies are needed to determine efficacy. He also hopes for a future randomized controlled trial comparing K.Vita with another supplement that contains different types of fats.
Interestingly, the product has already “passed” the regulatory approval process in the United Kingdom, so it can be labeled as a medicinal food and should be available for use at the beginning of 2022, Dr. Walker said.
Study concerns
Asked to comment on the findings, Daniel Goldenholz, MD, PhD, instructor in the department of neurology, Beth Israel Deaconess Medical Center, Boston, said the supplement may be helpful, but he has concerns about the study.
Many patients with epilepsy are “desperate” for therapies that will help treat their seizures, said Dr. Goldenholz, who was not involved with the research. “If there’s a dietary therapy that has the potential for being helpful, I’m loving that. I need that. My patients are begging for something that works.” It is “really exciting” that researchers are working on that goal, Dr. Goldenholz added.
However, he noted that it is too soon to start talking to patients about this new product. He also pointed out that a significant fraction of the study participants dropped out, many because they couldn’t tolerate the supplement. In addition, others didn’t produce a seizure diary.
Dr. Goldenholz and colleagues have published several studies showing that patients with no intervention at all can sometimes show a reduction in seizures compared with their baseline results.
“We found sizable 50% reductions attributable entirely to the natural fluctuations in seizure rates, rather than any therapy at all, he said.
Dr. Goldenholz added that he hopes to see future studies on this topic, and on similar therapies “with sufficient data and more reliable metrics for efficacy.”
The study was funded by Vitaflo International. Dr. Walker reports having received grants from Vitaflo International and personal fees from UCB Pharma, Eisai, and Sage. In addition, along with colleagues, he has a patent (Nutritional product) pending.
A version of this article first appeared on Medscape.com.
early research suggests. However, at least one expert has concerns.
In an open-label feasibility study, researchers assessed a liquid supplement known as K.Vita (Vitaflo International), which contains both decanoic acid and octanoic acid.
Although the study was small, the findings are promising, said coinvestigator Matthew Walker, MD, PhD, University College London Institute of Neurology, department of clinical and experimental epilepsy.
“The dietary supplement was reasonably well tolerated and while we weren’t specifically looking for efficacy here, we did see some patients had quite dramatic results in terms of reduced seizures,” Dr. Walker said.
Unlike the ketogenic diet, this dietary supplement is “very easy” to follow, involves only minor dietary modifications, and doesn’t require the intervention of a dietitian, he added.
The findings were published online July 23, 2021, in Brain Communications.
Key ingredients
In the ketogenic diet, the body uses body fat as its primary fuel source. The switch from carbohydrates to fat for body fuel results in built-up ketones.
Previous research shows the ketogenic diet is effective in reducing seizures in some patients with epilepsy. However, many patients find it difficult to tolerate, especially for extended periods. Dr. Walker also noted that ketones may have other long-term side effects, including osteoporosis.
He added that his team was keen to learn what elements of the ketogenic diet affect seizures. “Interestingly, we found that one of the fats used in the ketogenic diet, decanoic acid, has quite marked antiseizure effects,” Dr. Walker said.
Previous research has shown that decanoic acid, a medium-chain triglyceride–derived fatty acid, can cross the blood-brain barrier and decrease excitatory neurotransmission and network excitability in vitro.
Dr. Walker noted that ketones are necessary in order to reduce seizures.
“Rather than have a very high-fat, low-carbohydrate diet that causes ketones, we thought ‘why don’t we use a diet in which we just use mainly this fat, this decanoic acid, and avoid ketosis,’ ” he said.
The researchers then went to work developing the K.Vita dietary supplement, which mainly contains decanoic acid but also another fat, octanoic acid.
Assessing feasibility
The feasibility study included 61 patients (59% female) who began taking the supplement. Of these, 35 were children (aged 3-18 years) and 26 were adults. The children had Dravet syndrome or another genetically driven form of epilepsy, while most of the adults had a focal epilepsy.
All participants had failed multiple antiseizure medications – a median of 3 for children and 10 for adults who completed the trial. Of the 61 original participants, 20 (19 children and 1 adult) had tried the ketogenic diet but had stopped it for various reasons, including noncompliance and lack of efficacy.
The liquid supplement was introduced gradually. The amount administered was based on weight in the children and was a standard amount in adults, with the target being 240 mL.
Participants consumed the supplement in equal servings taken at regular intervals as part of a meal or snack. They could take it alone or mix it with yogurt or another food.
Patients with feeding tubes took the supplement immediately before or after or mixed into an enteral feed, with a water flush afterward.
Researchers provided patients and caregivers with guidance on excluding highly refined sugary foods and beverages. Starchy foods such as bread, pasta, rice, and potatoes were not restricted.
The study consisted of three visits: baseline, 5 weeks, and 12 weeks, in addition to regular phone and email contact. Participants were also asked to keep a seizure diary.
Highly acceptable to patients
Overall, the study withdrawal rate was 33%. After a protocol change involving a slower introduction of the supplement, there were fewer withdrawals, Dr. Walker reported. He noted that the proportion of participants who completed the study (41 of 61) is “much better than with most studies of adults following the ketogenic diet.”
The most frequently reported gastrointestinal symptoms with the supplement were bloating and constipation, but these were predominantly mild and tended to decrease over time. This, said Dr. Walker, contrasts to the ketogenic diet where side effects tend to persist.
There was no significant change in body weight or body mass index. “We did not see weight gain as a problem at all,” Dr. Walker said.
Of 15 caregivers and 19 adults who returned an acceptability questionnaire, 84% agreed or strongly agreed the supplement had a good flavor (strawberry); 88% liked the appearance and color; 77% liked the texture and consistency; and 88% agreed or strongly agreed it was easy to take.
About one-third of adults and two-thirds of caregivers said they believed the supplement reduced seizures.
50% seizure reduction
Only three children and one adult became ketotic. This is typically classified as a beta-hydroxybutyrate (BHB) greater than 1 mmol/L (10.4 mg/dL). The BHB levels detected were markedly lower than those observed in individuals following a ketogenic diet, the investigators note.
Of the 41 participants, 19 completed the diaries. There were also data from physician recordings, so researchers were able to retrieve seizure frequencies for 32 of the 41 (78%). Of these 32 patients, 14 (44%) had a 50% or greater reduction in seizures. Overall, children and adults “responded similarly,” Dr. Walker said.
He acknowledged the study numbers are small and emphasized that larger studies are needed to determine efficacy. He also hopes for a future randomized controlled trial comparing K.Vita with another supplement that contains different types of fats.
Interestingly, the product has already “passed” the regulatory approval process in the United Kingdom, so it can be labeled as a medicinal food and should be available for use at the beginning of 2022, Dr. Walker said.
Study concerns
Asked to comment on the findings, Daniel Goldenholz, MD, PhD, instructor in the department of neurology, Beth Israel Deaconess Medical Center, Boston, said the supplement may be helpful, but he has concerns about the study.
Many patients with epilepsy are “desperate” for therapies that will help treat their seizures, said Dr. Goldenholz, who was not involved with the research. “If there’s a dietary therapy that has the potential for being helpful, I’m loving that. I need that. My patients are begging for something that works.” It is “really exciting” that researchers are working on that goal, Dr. Goldenholz added.
However, he noted that it is too soon to start talking to patients about this new product. He also pointed out that a significant fraction of the study participants dropped out, many because they couldn’t tolerate the supplement. In addition, others didn’t produce a seizure diary.
Dr. Goldenholz and colleagues have published several studies showing that patients with no intervention at all can sometimes show a reduction in seizures compared with their baseline results.
“We found sizable 50% reductions attributable entirely to the natural fluctuations in seizure rates, rather than any therapy at all, he said.
Dr. Goldenholz added that he hopes to see future studies on this topic, and on similar therapies “with sufficient data and more reliable metrics for efficacy.”
The study was funded by Vitaflo International. Dr. Walker reports having received grants from Vitaflo International and personal fees from UCB Pharma, Eisai, and Sage. In addition, along with colleagues, he has a patent (Nutritional product) pending.
A version of this article first appeared on Medscape.com.
early research suggests. However, at least one expert has concerns.
In an open-label feasibility study, researchers assessed a liquid supplement known as K.Vita (Vitaflo International), which contains both decanoic acid and octanoic acid.
Although the study was small, the findings are promising, said coinvestigator Matthew Walker, MD, PhD, University College London Institute of Neurology, department of clinical and experimental epilepsy.
“The dietary supplement was reasonably well tolerated and while we weren’t specifically looking for efficacy here, we did see some patients had quite dramatic results in terms of reduced seizures,” Dr. Walker said.
Unlike the ketogenic diet, this dietary supplement is “very easy” to follow, involves only minor dietary modifications, and doesn’t require the intervention of a dietitian, he added.
The findings were published online July 23, 2021, in Brain Communications.
Key ingredients
In the ketogenic diet, the body uses body fat as its primary fuel source. The switch from carbohydrates to fat for body fuel results in built-up ketones.
Previous research shows the ketogenic diet is effective in reducing seizures in some patients with epilepsy. However, many patients find it difficult to tolerate, especially for extended periods. Dr. Walker also noted that ketones may have other long-term side effects, including osteoporosis.
He added that his team was keen to learn what elements of the ketogenic diet affect seizures. “Interestingly, we found that one of the fats used in the ketogenic diet, decanoic acid, has quite marked antiseizure effects,” Dr. Walker said.
Previous research has shown that decanoic acid, a medium-chain triglyceride–derived fatty acid, can cross the blood-brain barrier and decrease excitatory neurotransmission and network excitability in vitro.
Dr. Walker noted that ketones are necessary in order to reduce seizures.
“Rather than have a very high-fat, low-carbohydrate diet that causes ketones, we thought ‘why don’t we use a diet in which we just use mainly this fat, this decanoic acid, and avoid ketosis,’ ” he said.
The researchers then went to work developing the K.Vita dietary supplement, which mainly contains decanoic acid but also another fat, octanoic acid.
Assessing feasibility
The feasibility study included 61 patients (59% female) who began taking the supplement. Of these, 35 were children (aged 3-18 years) and 26 were adults. The children had Dravet syndrome or another genetically driven form of epilepsy, while most of the adults had a focal epilepsy.
All participants had failed multiple antiseizure medications – a median of 3 for children and 10 for adults who completed the trial. Of the 61 original participants, 20 (19 children and 1 adult) had tried the ketogenic diet but had stopped it for various reasons, including noncompliance and lack of efficacy.
The liquid supplement was introduced gradually. The amount administered was based on weight in the children and was a standard amount in adults, with the target being 240 mL.
Participants consumed the supplement in equal servings taken at regular intervals as part of a meal or snack. They could take it alone or mix it with yogurt or another food.
Patients with feeding tubes took the supplement immediately before or after or mixed into an enteral feed, with a water flush afterward.
Researchers provided patients and caregivers with guidance on excluding highly refined sugary foods and beverages. Starchy foods such as bread, pasta, rice, and potatoes were not restricted.
The study consisted of three visits: baseline, 5 weeks, and 12 weeks, in addition to regular phone and email contact. Participants were also asked to keep a seizure diary.
Highly acceptable to patients
Overall, the study withdrawal rate was 33%. After a protocol change involving a slower introduction of the supplement, there were fewer withdrawals, Dr. Walker reported. He noted that the proportion of participants who completed the study (41 of 61) is “much better than with most studies of adults following the ketogenic diet.”
The most frequently reported gastrointestinal symptoms with the supplement were bloating and constipation, but these were predominantly mild and tended to decrease over time. This, said Dr. Walker, contrasts to the ketogenic diet where side effects tend to persist.
There was no significant change in body weight or body mass index. “We did not see weight gain as a problem at all,” Dr. Walker said.
Of 15 caregivers and 19 adults who returned an acceptability questionnaire, 84% agreed or strongly agreed the supplement had a good flavor (strawberry); 88% liked the appearance and color; 77% liked the texture and consistency; and 88% agreed or strongly agreed it was easy to take.
About one-third of adults and two-thirds of caregivers said they believed the supplement reduced seizures.
50% seizure reduction
Only three children and one adult became ketotic. This is typically classified as a beta-hydroxybutyrate (BHB) greater than 1 mmol/L (10.4 mg/dL). The BHB levels detected were markedly lower than those observed in individuals following a ketogenic diet, the investigators note.
Of the 41 participants, 19 completed the diaries. There were also data from physician recordings, so researchers were able to retrieve seizure frequencies for 32 of the 41 (78%). Of these 32 patients, 14 (44%) had a 50% or greater reduction in seizures. Overall, children and adults “responded similarly,” Dr. Walker said.
He acknowledged the study numbers are small and emphasized that larger studies are needed to determine efficacy. He also hopes for a future randomized controlled trial comparing K.Vita with another supplement that contains different types of fats.
Interestingly, the product has already “passed” the regulatory approval process in the United Kingdom, so it can be labeled as a medicinal food and should be available for use at the beginning of 2022, Dr. Walker said.
Study concerns
Asked to comment on the findings, Daniel Goldenholz, MD, PhD, instructor in the department of neurology, Beth Israel Deaconess Medical Center, Boston, said the supplement may be helpful, but he has concerns about the study.
Many patients with epilepsy are “desperate” for therapies that will help treat their seizures, said Dr. Goldenholz, who was not involved with the research. “If there’s a dietary therapy that has the potential for being helpful, I’m loving that. I need that. My patients are begging for something that works.” It is “really exciting” that researchers are working on that goal, Dr. Goldenholz added.
However, he noted that it is too soon to start talking to patients about this new product. He also pointed out that a significant fraction of the study participants dropped out, many because they couldn’t tolerate the supplement. In addition, others didn’t produce a seizure diary.
Dr. Goldenholz and colleagues have published several studies showing that patients with no intervention at all can sometimes show a reduction in seizures compared with their baseline results.
“We found sizable 50% reductions attributable entirely to the natural fluctuations in seizure rates, rather than any therapy at all, he said.
Dr. Goldenholz added that he hopes to see future studies on this topic, and on similar therapies “with sufficient data and more reliable metrics for efficacy.”
The study was funded by Vitaflo International. Dr. Walker reports having received grants from Vitaflo International and personal fees from UCB Pharma, Eisai, and Sage. In addition, along with colleagues, he has a patent (Nutritional product) pending.
A version of this article first appeared on Medscape.com.
FROM BRAIN COMMUNICATION
Changes in metabolism tied to risk of subsequent dementia
in new findings that may provide a prevention target.
Investigators found one of the clusters includes small high-density lipoprotein (HDL) metabolites associated with vascular dementia, while another cluster involves ketone bodies and citrate that are primarily associated with Alzheimer’s disease.
Ketone bodies, or ketones, are three related compounds – acetone, acetoacetic acid, and beta-hydroxybutyric acid (BHB) – produced by the liver during fat metabolism. Citrate is a salt or ester of citric acid.
These metabolite clusters are not only linked to the future development of dementia but also correlate with early pathology in those under age 60 years, said study investigator Cornelia M. van Duijn, PhD, professor of epidemiology at Nuffield Department of Population Health, Oxford (England) University.
“These metabolites flag early and late pathology and may be relevant as targets for prevention of dementia,” she noted.
The findings were presented at the 2021 Alzheimer’s Association International Conference.
Weight loss before dementia explained?
For the study, investigators included 125,000 patients from the UK Biobank, which includes 51,031 who were over age 60 at baseline. Of these, 1,188 developed dementia during a follow-up of about 10 years; 553 were diagnosed with Alzheimer’s disease and 298 with vascular dementia.
Researchers used a platform that covers 249 metabolic measures, including small molecules, fatty acids, and lipoprotein lipids.
They estimated risk associated with these metabolites, adjusting for age, sex, body mass index, technical variables, ethnicity, smoking, alcohol, education, metabolic and neuropsychiatric medication, and APOE4 genotypes.
Of the 249 metabolites, 47 (19%) were associated with dementia risk in those over age 60, after adjustment.
The investigators examined effect estimates for associations of metabolites with both Alzheimer’s disease and vascular dementia over age 60 versus hippocampal volume under age 60. They found a “very strong, very significant” association for Alzheimer’s disease, and a “marginally significant” association for vascular dementia, said Dr. van Duijn.
This would be expected, as there is a much stronger correlation between hippocampal and Alzheimer’s disease versus vascular dementia, she added.
“We not only see that the metabolites predict dementia, but also early pathology. This makes these findings rather interesting for targeting prevention,” she said. An analysis of total brain volume showed “very strong, very similar, very significant associations” for both Alzheimer’s disease and vascular dementia,” added Dr. van Duijn.
The researchers found a major shift in various metabolites involved in energy metabolism in the 10-year period before the diagnosis of Alzheimer’s disease. These changes include low levels of branched-chain amino acids and omega-3 fatty acids and high levels of glucose, citrate, acetone, beta-hydroxybutyrate, and acetate. “This finding is in line with that in APOE models that show reduced energy metabolism over age in the brain,” said Dr. van Duijn.
She added that high levels of some of these metabolites are associated with low body weight before dementia onset, which may explain the weight loss seen in patients before developing the disease. “Our hypothesis is that the liver is burning the fat reserves of the patients in order to provide the brain with fuel,” she explained.
Diet a prevention target?
The results also showed ketone bodies increase with age, which may represent the aging brain’s “compensation mechanism” to deal with an energy shortage, said Dr. van Duijn. “Supplementation of ketone bodies, branched-chain amino and omega-3 fatty acids may help support brain function.”
The fact that ketone bodies were positively associated with the risk of dementia is “a very important finding,” she said.
Following this and other presentations, session cochair Rima Kaddurah-Daouk, PhD, professor in psychiatry and behavioral sciences, Institute for Brain Sciences, Duke University, Durham, N.C., noted the research is “an important part of trying to decipher some of the mysteries in Alzheimer’s disease.”
The research contributes to the understanding of how nutrition and diet could influence metabolism and then the brain and is “opening the horizon” for thinking about “strategies for therapeutic interventions,” she said.
The study received funding support from the National Institute on Aging. The investigators have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in new findings that may provide a prevention target.
Investigators found one of the clusters includes small high-density lipoprotein (HDL) metabolites associated with vascular dementia, while another cluster involves ketone bodies and citrate that are primarily associated with Alzheimer’s disease.
Ketone bodies, or ketones, are three related compounds – acetone, acetoacetic acid, and beta-hydroxybutyric acid (BHB) – produced by the liver during fat metabolism. Citrate is a salt or ester of citric acid.
These metabolite clusters are not only linked to the future development of dementia but also correlate with early pathology in those under age 60 years, said study investigator Cornelia M. van Duijn, PhD, professor of epidemiology at Nuffield Department of Population Health, Oxford (England) University.
“These metabolites flag early and late pathology and may be relevant as targets for prevention of dementia,” she noted.
The findings were presented at the 2021 Alzheimer’s Association International Conference.
Weight loss before dementia explained?
For the study, investigators included 125,000 patients from the UK Biobank, which includes 51,031 who were over age 60 at baseline. Of these, 1,188 developed dementia during a follow-up of about 10 years; 553 were diagnosed with Alzheimer’s disease and 298 with vascular dementia.
Researchers used a platform that covers 249 metabolic measures, including small molecules, fatty acids, and lipoprotein lipids.
They estimated risk associated with these metabolites, adjusting for age, sex, body mass index, technical variables, ethnicity, smoking, alcohol, education, metabolic and neuropsychiatric medication, and APOE4 genotypes.
Of the 249 metabolites, 47 (19%) were associated with dementia risk in those over age 60, after adjustment.
The investigators examined effect estimates for associations of metabolites with both Alzheimer’s disease and vascular dementia over age 60 versus hippocampal volume under age 60. They found a “very strong, very significant” association for Alzheimer’s disease, and a “marginally significant” association for vascular dementia, said Dr. van Duijn.
This would be expected, as there is a much stronger correlation between hippocampal and Alzheimer’s disease versus vascular dementia, she added.
“We not only see that the metabolites predict dementia, but also early pathology. This makes these findings rather interesting for targeting prevention,” she said. An analysis of total brain volume showed “very strong, very similar, very significant associations” for both Alzheimer’s disease and vascular dementia,” added Dr. van Duijn.
The researchers found a major shift in various metabolites involved in energy metabolism in the 10-year period before the diagnosis of Alzheimer’s disease. These changes include low levels of branched-chain amino acids and omega-3 fatty acids and high levels of glucose, citrate, acetone, beta-hydroxybutyrate, and acetate. “This finding is in line with that in APOE models that show reduced energy metabolism over age in the brain,” said Dr. van Duijn.
She added that high levels of some of these metabolites are associated with low body weight before dementia onset, which may explain the weight loss seen in patients before developing the disease. “Our hypothesis is that the liver is burning the fat reserves of the patients in order to provide the brain with fuel,” she explained.
Diet a prevention target?
The results also showed ketone bodies increase with age, which may represent the aging brain’s “compensation mechanism” to deal with an energy shortage, said Dr. van Duijn. “Supplementation of ketone bodies, branched-chain amino and omega-3 fatty acids may help support brain function.”
The fact that ketone bodies were positively associated with the risk of dementia is “a very important finding,” she said.
Following this and other presentations, session cochair Rima Kaddurah-Daouk, PhD, professor in psychiatry and behavioral sciences, Institute for Brain Sciences, Duke University, Durham, N.C., noted the research is “an important part of trying to decipher some of the mysteries in Alzheimer’s disease.”
The research contributes to the understanding of how nutrition and diet could influence metabolism and then the brain and is “opening the horizon” for thinking about “strategies for therapeutic interventions,” she said.
The study received funding support from the National Institute on Aging. The investigators have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in new findings that may provide a prevention target.
Investigators found one of the clusters includes small high-density lipoprotein (HDL) metabolites associated with vascular dementia, while another cluster involves ketone bodies and citrate that are primarily associated with Alzheimer’s disease.
Ketone bodies, or ketones, are three related compounds – acetone, acetoacetic acid, and beta-hydroxybutyric acid (BHB) – produced by the liver during fat metabolism. Citrate is a salt or ester of citric acid.
These metabolite clusters are not only linked to the future development of dementia but also correlate with early pathology in those under age 60 years, said study investigator Cornelia M. van Duijn, PhD, professor of epidemiology at Nuffield Department of Population Health, Oxford (England) University.
“These metabolites flag early and late pathology and may be relevant as targets for prevention of dementia,” she noted.
The findings were presented at the 2021 Alzheimer’s Association International Conference.
Weight loss before dementia explained?
For the study, investigators included 125,000 patients from the UK Biobank, which includes 51,031 who were over age 60 at baseline. Of these, 1,188 developed dementia during a follow-up of about 10 years; 553 were diagnosed with Alzheimer’s disease and 298 with vascular dementia.
Researchers used a platform that covers 249 metabolic measures, including small molecules, fatty acids, and lipoprotein lipids.
They estimated risk associated with these metabolites, adjusting for age, sex, body mass index, technical variables, ethnicity, smoking, alcohol, education, metabolic and neuropsychiatric medication, and APOE4 genotypes.
Of the 249 metabolites, 47 (19%) were associated with dementia risk in those over age 60, after adjustment.
The investigators examined effect estimates for associations of metabolites with both Alzheimer’s disease and vascular dementia over age 60 versus hippocampal volume under age 60. They found a “very strong, very significant” association for Alzheimer’s disease, and a “marginally significant” association for vascular dementia, said Dr. van Duijn.
This would be expected, as there is a much stronger correlation between hippocampal and Alzheimer’s disease versus vascular dementia, she added.
“We not only see that the metabolites predict dementia, but also early pathology. This makes these findings rather interesting for targeting prevention,” she said. An analysis of total brain volume showed “very strong, very similar, very significant associations” for both Alzheimer’s disease and vascular dementia,” added Dr. van Duijn.
The researchers found a major shift in various metabolites involved in energy metabolism in the 10-year period before the diagnosis of Alzheimer’s disease. These changes include low levels of branched-chain amino acids and omega-3 fatty acids and high levels of glucose, citrate, acetone, beta-hydroxybutyrate, and acetate. “This finding is in line with that in APOE models that show reduced energy metabolism over age in the brain,” said Dr. van Duijn.
She added that high levels of some of these metabolites are associated with low body weight before dementia onset, which may explain the weight loss seen in patients before developing the disease. “Our hypothesis is that the liver is burning the fat reserves of the patients in order to provide the brain with fuel,” she explained.
Diet a prevention target?
The results also showed ketone bodies increase with age, which may represent the aging brain’s “compensation mechanism” to deal with an energy shortage, said Dr. van Duijn. “Supplementation of ketone bodies, branched-chain amino and omega-3 fatty acids may help support brain function.”
The fact that ketone bodies were positively associated with the risk of dementia is “a very important finding,” she said.
Following this and other presentations, session cochair Rima Kaddurah-Daouk, PhD, professor in psychiatry and behavioral sciences, Institute for Brain Sciences, Duke University, Durham, N.C., noted the research is “an important part of trying to decipher some of the mysteries in Alzheimer’s disease.”
The research contributes to the understanding of how nutrition and diet could influence metabolism and then the brain and is “opening the horizon” for thinking about “strategies for therapeutic interventions,” she said.
The study received funding support from the National Institute on Aging. The investigators have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
FROM AAIC 2021
‘Staggering’ increase in global dementia cases predicted by 2050
, new global prevalence data show. “These extreme increases are due largely to demographic trends, including population growth and aging,” said study investigator Emma Nichols, MPH, a researcher at the Institute for Health Metrics and Evaluation at the University of Washington in Seattle.
“Our estimates of expected increases can and should inform policy and planning efforts that will be needed to address the needs of the growing number of individuals with dementia in the future,” Ms. Nichols said.
The latest global prevalence data were reported at the 2021 Alzheimer’s Association International Conference.
“The numbers are staggering: Nearly 153 million cases of dementia are predicted worldwide by the year 2050. To put that in context, that number is equal to approximately half of the U.S. population in 2020,” Heather M. Snyder, PhD, vice president of medical and scientific relations for the Alzheimer’s Association, said in a statement.
Prevalence by country
To more accurately forecast global dementia prevalence and produce country-level estimates, the investigators leveraged data from 1999 to 2019 from the Global Burden of Disease study, a comprehensive set of estimates of worldwide health trends.
These data suggest global dementia cases will increase from 57.4 million (50.4 to 65.1) in 2019 to 152.8 million (130.8 to 175.9) in 2050.
Regions that will experience the worst of the increase are eastern Sub-Saharan Africa, North Africa, and the Middle East.
The researchers also factored into the forecasts expected trends in obesity, diabetes, smoking, and educational attainment.
Increases in better education around the world are projected to decrease dementia prevalence by 6.2 million cases worldwide by 2050. However, anticipated trends in smoking, high body mass index, and diabetes will offset this gain, increasing global dementia cases by 6.8 million cases.
“A reversal of these expected trends in cardiovascular risks would be necessary to alter the anticipated trends,” Ms. Nichols said. “Interventions targeted at modifiable risk factors for dementia represent a viable strategy to help address the anticipated trends in dementia burden,” she added.
Need for effective prevention, treatment
Commenting on the research, Rebecca M. Edelmayer, PhD, senior director of scientific engagement at the Alzheimer’s Association, said the global increase in dementia cases is something the association has been following for many years. “We know that if we do not find effective treatments that are going to stop, slow, or prevent Alzheimer’s disease, this number will continue to grow and it will continue to impact people globally,” Dr. Edelmayer said.
She noted that although there are some positive trends, including the fact that increased education may drive down dementia risk, other factors, such as smoking, high body mass index, and high blood sugar level, are predicted to increase in prevalence.
“Some of these factors are actually counterbalancing each other, and in the end, if we don’t continue to develop culturally tailored interventions or even risk reduction strategies for individuals across the globe, we will continue to see those numbers rise overall,” Dr. Edelmayer said.
A version of this article first appeared on Medscape.com.
, new global prevalence data show. “These extreme increases are due largely to demographic trends, including population growth and aging,” said study investigator Emma Nichols, MPH, a researcher at the Institute for Health Metrics and Evaluation at the University of Washington in Seattle.
“Our estimates of expected increases can and should inform policy and planning efforts that will be needed to address the needs of the growing number of individuals with dementia in the future,” Ms. Nichols said.
The latest global prevalence data were reported at the 2021 Alzheimer’s Association International Conference.
“The numbers are staggering: Nearly 153 million cases of dementia are predicted worldwide by the year 2050. To put that in context, that number is equal to approximately half of the U.S. population in 2020,” Heather M. Snyder, PhD, vice president of medical and scientific relations for the Alzheimer’s Association, said in a statement.
Prevalence by country
To more accurately forecast global dementia prevalence and produce country-level estimates, the investigators leveraged data from 1999 to 2019 from the Global Burden of Disease study, a comprehensive set of estimates of worldwide health trends.
These data suggest global dementia cases will increase from 57.4 million (50.4 to 65.1) in 2019 to 152.8 million (130.8 to 175.9) in 2050.
Regions that will experience the worst of the increase are eastern Sub-Saharan Africa, North Africa, and the Middle East.
The researchers also factored into the forecasts expected trends in obesity, diabetes, smoking, and educational attainment.
Increases in better education around the world are projected to decrease dementia prevalence by 6.2 million cases worldwide by 2050. However, anticipated trends in smoking, high body mass index, and diabetes will offset this gain, increasing global dementia cases by 6.8 million cases.
“A reversal of these expected trends in cardiovascular risks would be necessary to alter the anticipated trends,” Ms. Nichols said. “Interventions targeted at modifiable risk factors for dementia represent a viable strategy to help address the anticipated trends in dementia burden,” she added.
Need for effective prevention, treatment
Commenting on the research, Rebecca M. Edelmayer, PhD, senior director of scientific engagement at the Alzheimer’s Association, said the global increase in dementia cases is something the association has been following for many years. “We know that if we do not find effective treatments that are going to stop, slow, or prevent Alzheimer’s disease, this number will continue to grow and it will continue to impact people globally,” Dr. Edelmayer said.
She noted that although there are some positive trends, including the fact that increased education may drive down dementia risk, other factors, such as smoking, high body mass index, and high blood sugar level, are predicted to increase in prevalence.
“Some of these factors are actually counterbalancing each other, and in the end, if we don’t continue to develop culturally tailored interventions or even risk reduction strategies for individuals across the globe, we will continue to see those numbers rise overall,” Dr. Edelmayer said.
A version of this article first appeared on Medscape.com.
, new global prevalence data show. “These extreme increases are due largely to demographic trends, including population growth and aging,” said study investigator Emma Nichols, MPH, a researcher at the Institute for Health Metrics and Evaluation at the University of Washington in Seattle.
“Our estimates of expected increases can and should inform policy and planning efforts that will be needed to address the needs of the growing number of individuals with dementia in the future,” Ms. Nichols said.
The latest global prevalence data were reported at the 2021 Alzheimer’s Association International Conference.
“The numbers are staggering: Nearly 153 million cases of dementia are predicted worldwide by the year 2050. To put that in context, that number is equal to approximately half of the U.S. population in 2020,” Heather M. Snyder, PhD, vice president of medical and scientific relations for the Alzheimer’s Association, said in a statement.
Prevalence by country
To more accurately forecast global dementia prevalence and produce country-level estimates, the investigators leveraged data from 1999 to 2019 from the Global Burden of Disease study, a comprehensive set of estimates of worldwide health trends.
These data suggest global dementia cases will increase from 57.4 million (50.4 to 65.1) in 2019 to 152.8 million (130.8 to 175.9) in 2050.
Regions that will experience the worst of the increase are eastern Sub-Saharan Africa, North Africa, and the Middle East.
The researchers also factored into the forecasts expected trends in obesity, diabetes, smoking, and educational attainment.
Increases in better education around the world are projected to decrease dementia prevalence by 6.2 million cases worldwide by 2050. However, anticipated trends in smoking, high body mass index, and diabetes will offset this gain, increasing global dementia cases by 6.8 million cases.
“A reversal of these expected trends in cardiovascular risks would be necessary to alter the anticipated trends,” Ms. Nichols said. “Interventions targeted at modifiable risk factors for dementia represent a viable strategy to help address the anticipated trends in dementia burden,” she added.
Need for effective prevention, treatment
Commenting on the research, Rebecca M. Edelmayer, PhD, senior director of scientific engagement at the Alzheimer’s Association, said the global increase in dementia cases is something the association has been following for many years. “We know that if we do not find effective treatments that are going to stop, slow, or prevent Alzheimer’s disease, this number will continue to grow and it will continue to impact people globally,” Dr. Edelmayer said.
She noted that although there are some positive trends, including the fact that increased education may drive down dementia risk, other factors, such as smoking, high body mass index, and high blood sugar level, are predicted to increase in prevalence.
“Some of these factors are actually counterbalancing each other, and in the end, if we don’t continue to develop culturally tailored interventions or even risk reduction strategies for individuals across the globe, we will continue to see those numbers rise overall,” Dr. Edelmayer said.
A version of this article first appeared on Medscape.com.
From AAIC 2021
Coffee and the brain: ‘Concerning’ new data
according to the results of a large study.
“With coffee intake, moderation is the key, and especially high levels of consumption may have adverse long-term effects on the brain,” said study investigator Elina Hypponen, PhD, professor of nutritional and genetic epidemiology and director of the Australian Center for Precision Health at the University of South Australia.
“These new data are concerning, and there is a need to conduct further carefully controlled studies to clarify the effects of coffee on the brain.”
The study was published online June 24 in Nutritional Neuroscience.
Potent stimulant
Coffee is a potent nervous system stimulant and is among the most popular nonalcoholic beverages. Some previous research suggests it benefits the brain, but the investigators noted that other research shows a negative or U-shaped relationship.
To investigate, the researchers examined data from the U.K. Biobank, a long-term prospective epidemiologic study of more than 500,000 participants aged 37-73 years who were recruited in 22 assessment centers in the United Kingdom between March 2006 and October 2010.
During the baseline assessment, information was gathered using touchscreen questionnaires, verbal interviews, and physical examinations that involved collection of blood, urine, and saliva samples. An imaging substudy was incorporated in 2014, the goal of which was to conduct brain, heart, and body MRI imaging for 100,000 participants.
The investigators conducted analyses on disease outcomes for 398,646 participants for whom information on habitual coffee consumption was available. Brain volume analyses were conducted in 17,702 participants for whom valid brain imaging data were available.
Participants reported coffee intake in cups per day. Researchers grouped coffee consumption into seven categories: nondrinkers, decaffeinated coffee drinkers, and caffeinated coffee drinkers who consumed less than 1 cup/d, 1-2 cups/d, 3-4 cups/d, 5-6 cups/d, and more than 6 cups/d.
The reference category was those who consumed 1-2 cups/d, rather than those who abstained from coffee, because persons who abstain are more likely to be at suboptimal health.
“Comparing the health of coffee drinkers to the health of those choosing to abstain from coffee will typically lead to an impression of a health benefit, even if there would not be one,” said Dr. Hypponen.
The researchers obtained total and regional brain volumes from the MRI imaging substudy starting 4-6 years after baseline assessment. They accessed information on incident dementia and stroke using primary care data, hospital admission electronic health records, national death registers, and self-reported medical conditions.
Covariates included socioeconomic, health, and other factors, such as smoking, alcohol and tea consumption, physical activity, stressful life events, and body mass index.
The investigators found that there was a linear inverse association between coffee consumption and total brain volume (fully adjusted beta per cup, –1.42; 95% confidence interval, –1.89 to –0.94), with consistent patterns for gray matter, white matter, and hippocampal volumes.
There was no evidence to support an association with white matter hyperintensity (WMH) volume (beta –0.01; 95% CI, –0.07 to 0.05).
Higher consumption, higher risk
The analysis also revealed a nonlinear association between coffee consumption and the odds of dementia (P nonlinearity = .0001), with slightly higher odds seen with non–coffee drinkers and decaffeinated-coffee drinkers and more notable increases for participants in the highest categories of coffee consumption compared with light coffee drinkers.
After adjustment for all covariates, the odds ratio of dementia among persons in the category of coffee intake was 1.53 (95% CI, 1.28-1.83). After full adjustments, the association with heavy coffee consumption and stroke was not significant, although “we can’t exclude a weak effect,” said Dr. Hypponen.
“For the highest coffee consumption group, the data support an association which may be anywhere from 0% to 37% higher odds of stroke after full adjustment,” she added.
People at risk for hypertension may develop “unpleasant sensations” and stop drinking coffee before a serious adverse event occurs, said Dr. Hypponen. In a previous study, she and her colleagues showed that those who have genetically higher blood pressure tend to drink less coffee than their counterparts without the condition.
“This type of effect might be expected to naturally limit the adverse effects of coffee on the risk of stroke,” said Dr. Hypponen.
The odds remained elevated for participants drinking more than 6 cups/d after the researchers accounted for sleep quality. There were no differences in risk between men and women or by age.
An examination of the consumption of tea, which often contains caffeine, did not show an association with brain volume or the odds of dementia or stroke.
“We don’t know whether the difference between associations seen for coffee and tea intake reflects the difference in related caffeine intake or some other explanation, such as dehydration or effects operating through blood cholesterol,” said Dr. Hypponen.
Although reverse causation is possible, there’s no reason to believe that it is relevant to the study results. Genetic evidence suggests a causal role of higher coffee intake on risk for Alzheimer’s disease. In addition, results of a clinical trial support the association between higher caffeine intake and smaller gray matter volume, said Dr. Hypponen.
The mechanisms linking coffee consumption to brain volumes and dementia are not well established. However, Dr. Hypponen noted that caffeine has been used to induce apoptosis in cancer studies using glial cells.
“Furthermore, adenosine receptors, which mediate many of the effects of caffeine in the brain, have been suggested to influence the release of growth factors, which in turn can have an influence on astrocyte proliferation and angiogenesis in the brain,” she said.
Some types of coffee contain cafestol, which increases blood cholesterol and can have adverse effects though related mechanisms, said Dr. Hypponen.
The mechanism may also involve dehydration, which may have a harmful effect on the brain. The study suggested a correlation between dehydration and high coffee intake. “Of course, if this is the case, it is good news, as then we can do something about it simply by drinking some water every time we have a cup of coffee,” she said.
Misleading conclusions
Coffee contains antioxidants, and although previous studies have suggested it might be beneficial, this hypothesis is “too simplistic,” said Dr. Hypponen. “While coffee is not going to be all ‘bad’ either, there are a lot of controversies and suggestions about beneficial effects of coffee which may not be true, or at least do not reflect the full story.”
If the drinking of coffee is at least partly determined by an individual’s health status, then that would often lead to misleading conclusions in observational studies, said Dr. Hypponen.
“When one uses as a comparison people who already have poor health and who do not drink coffee because of that, coffee intake will by default appear beneficial simply because there are more people with disease among those choosing abstinence,” she said.
Before now, there was “very little evidence about the association between coffee intake and brain morphology,” and the studies that were conducted were relatively small, said Dr. Hypponen.
One of these smaller studies included a group of women aged 13-30 years. It found that coffee consumption was not associated with total brain volumes, but the findings suggested a U-shaped association with hippocampal volume; higher values were seen both for nondrinkers and the groups with higher consumption.
A small study of elderly patients with diabetes showed no evidence of an association with white matter volume, but there was a possible age-dependent association with gray matter volume.
The largest of the earlier studies had results that were very similar to those of the current study, suggesting that increasing coffee intake is associated with smaller hippocampal volumes, said Dr. Hypponen.
One of the study’s limitations included the fact that full dietary information was available only for a subsample and that factors such as dehydration were measured at baseline rather than at the time of brain MRI.
Another possible study limitation was the use of self-reported data and the fact that lifestyle changes may have occurred between baseline and MRI or covariate measurement.
In addition, the study is subject to a healthy-volunteer bias, and its implications are restricted to White British persons. The association needs to be studied in other ethnic populations, the authors noted.
A reason to cut back?
Commenting on the findings, Walter Willett, MD, DrPH, professor of epidemiology and nutrition, Harvard T. H. Chan School of Public Health, Boston, said the study is large and quite well done.
“It does raise questions about an increase in risk of dementia with six or more cups of coffee per day,” said Dr. Willett. “At the same time, it provides reassurance about lack of adverse effects of coffee for those consuming three or four cups per day, and little increase in risk, if any, with five cups per day.”
It’s not entirely clear whether the increase in risk with six or more cups of coffee per day represents a “true effect” of coffee, inasmuch as the study did not seem to adjust fully for dietary factors, high consumption of alcohol, or past smoking, said Dr. Willett.
The findings don’t suggest that coffee lovers should give up their Java. “But six or more cups per day is a lot, and those who drink that much might consider cutting back a bit while research continues,” said Dr. Willett.
The study was supported by the National Health and Medical Research Council.
A version of this article first appeared on Medscape.com.
according to the results of a large study.
“With coffee intake, moderation is the key, and especially high levels of consumption may have adverse long-term effects on the brain,” said study investigator Elina Hypponen, PhD, professor of nutritional and genetic epidemiology and director of the Australian Center for Precision Health at the University of South Australia.
“These new data are concerning, and there is a need to conduct further carefully controlled studies to clarify the effects of coffee on the brain.”
The study was published online June 24 in Nutritional Neuroscience.
Potent stimulant
Coffee is a potent nervous system stimulant and is among the most popular nonalcoholic beverages. Some previous research suggests it benefits the brain, but the investigators noted that other research shows a negative or U-shaped relationship.
To investigate, the researchers examined data from the U.K. Biobank, a long-term prospective epidemiologic study of more than 500,000 participants aged 37-73 years who were recruited in 22 assessment centers in the United Kingdom between March 2006 and October 2010.
During the baseline assessment, information was gathered using touchscreen questionnaires, verbal interviews, and physical examinations that involved collection of blood, urine, and saliva samples. An imaging substudy was incorporated in 2014, the goal of which was to conduct brain, heart, and body MRI imaging for 100,000 participants.
The investigators conducted analyses on disease outcomes for 398,646 participants for whom information on habitual coffee consumption was available. Brain volume analyses were conducted in 17,702 participants for whom valid brain imaging data were available.
Participants reported coffee intake in cups per day. Researchers grouped coffee consumption into seven categories: nondrinkers, decaffeinated coffee drinkers, and caffeinated coffee drinkers who consumed less than 1 cup/d, 1-2 cups/d, 3-4 cups/d, 5-6 cups/d, and more than 6 cups/d.
The reference category was those who consumed 1-2 cups/d, rather than those who abstained from coffee, because persons who abstain are more likely to be at suboptimal health.
“Comparing the health of coffee drinkers to the health of those choosing to abstain from coffee will typically lead to an impression of a health benefit, even if there would not be one,” said Dr. Hypponen.
The researchers obtained total and regional brain volumes from the MRI imaging substudy starting 4-6 years after baseline assessment. They accessed information on incident dementia and stroke using primary care data, hospital admission electronic health records, national death registers, and self-reported medical conditions.
Covariates included socioeconomic, health, and other factors, such as smoking, alcohol and tea consumption, physical activity, stressful life events, and body mass index.
The investigators found that there was a linear inverse association between coffee consumption and total brain volume (fully adjusted beta per cup, –1.42; 95% confidence interval, –1.89 to –0.94), with consistent patterns for gray matter, white matter, and hippocampal volumes.
There was no evidence to support an association with white matter hyperintensity (WMH) volume (beta –0.01; 95% CI, –0.07 to 0.05).
Higher consumption, higher risk
The analysis also revealed a nonlinear association between coffee consumption and the odds of dementia (P nonlinearity = .0001), with slightly higher odds seen with non–coffee drinkers and decaffeinated-coffee drinkers and more notable increases for participants in the highest categories of coffee consumption compared with light coffee drinkers.
After adjustment for all covariates, the odds ratio of dementia among persons in the category of coffee intake was 1.53 (95% CI, 1.28-1.83). After full adjustments, the association with heavy coffee consumption and stroke was not significant, although “we can’t exclude a weak effect,” said Dr. Hypponen.
“For the highest coffee consumption group, the data support an association which may be anywhere from 0% to 37% higher odds of stroke after full adjustment,” she added.
People at risk for hypertension may develop “unpleasant sensations” and stop drinking coffee before a serious adverse event occurs, said Dr. Hypponen. In a previous study, she and her colleagues showed that those who have genetically higher blood pressure tend to drink less coffee than their counterparts without the condition.
“This type of effect might be expected to naturally limit the adverse effects of coffee on the risk of stroke,” said Dr. Hypponen.
The odds remained elevated for participants drinking more than 6 cups/d after the researchers accounted for sleep quality. There were no differences in risk between men and women or by age.
An examination of the consumption of tea, which often contains caffeine, did not show an association with brain volume or the odds of dementia or stroke.
“We don’t know whether the difference between associations seen for coffee and tea intake reflects the difference in related caffeine intake or some other explanation, such as dehydration or effects operating through blood cholesterol,” said Dr. Hypponen.
Although reverse causation is possible, there’s no reason to believe that it is relevant to the study results. Genetic evidence suggests a causal role of higher coffee intake on risk for Alzheimer’s disease. In addition, results of a clinical trial support the association between higher caffeine intake and smaller gray matter volume, said Dr. Hypponen.
The mechanisms linking coffee consumption to brain volumes and dementia are not well established. However, Dr. Hypponen noted that caffeine has been used to induce apoptosis in cancer studies using glial cells.
“Furthermore, adenosine receptors, which mediate many of the effects of caffeine in the brain, have been suggested to influence the release of growth factors, which in turn can have an influence on astrocyte proliferation and angiogenesis in the brain,” she said.
Some types of coffee contain cafestol, which increases blood cholesterol and can have adverse effects though related mechanisms, said Dr. Hypponen.
The mechanism may also involve dehydration, which may have a harmful effect on the brain. The study suggested a correlation between dehydration and high coffee intake. “Of course, if this is the case, it is good news, as then we can do something about it simply by drinking some water every time we have a cup of coffee,” she said.
Misleading conclusions
Coffee contains antioxidants, and although previous studies have suggested it might be beneficial, this hypothesis is “too simplistic,” said Dr. Hypponen. “While coffee is not going to be all ‘bad’ either, there are a lot of controversies and suggestions about beneficial effects of coffee which may not be true, or at least do not reflect the full story.”
If the drinking of coffee is at least partly determined by an individual’s health status, then that would often lead to misleading conclusions in observational studies, said Dr. Hypponen.
“When one uses as a comparison people who already have poor health and who do not drink coffee because of that, coffee intake will by default appear beneficial simply because there are more people with disease among those choosing abstinence,” she said.
Before now, there was “very little evidence about the association between coffee intake and brain morphology,” and the studies that were conducted were relatively small, said Dr. Hypponen.
One of these smaller studies included a group of women aged 13-30 years. It found that coffee consumption was not associated with total brain volumes, but the findings suggested a U-shaped association with hippocampal volume; higher values were seen both for nondrinkers and the groups with higher consumption.
A small study of elderly patients with diabetes showed no evidence of an association with white matter volume, but there was a possible age-dependent association with gray matter volume.
The largest of the earlier studies had results that were very similar to those of the current study, suggesting that increasing coffee intake is associated with smaller hippocampal volumes, said Dr. Hypponen.
One of the study’s limitations included the fact that full dietary information was available only for a subsample and that factors such as dehydration were measured at baseline rather than at the time of brain MRI.
Another possible study limitation was the use of self-reported data and the fact that lifestyle changes may have occurred between baseline and MRI or covariate measurement.
In addition, the study is subject to a healthy-volunteer bias, and its implications are restricted to White British persons. The association needs to be studied in other ethnic populations, the authors noted.
A reason to cut back?
Commenting on the findings, Walter Willett, MD, DrPH, professor of epidemiology and nutrition, Harvard T. H. Chan School of Public Health, Boston, said the study is large and quite well done.
“It does raise questions about an increase in risk of dementia with six or more cups of coffee per day,” said Dr. Willett. “At the same time, it provides reassurance about lack of adverse effects of coffee for those consuming three or four cups per day, and little increase in risk, if any, with five cups per day.”
It’s not entirely clear whether the increase in risk with six or more cups of coffee per day represents a “true effect” of coffee, inasmuch as the study did not seem to adjust fully for dietary factors, high consumption of alcohol, or past smoking, said Dr. Willett.
The findings don’t suggest that coffee lovers should give up their Java. “But six or more cups per day is a lot, and those who drink that much might consider cutting back a bit while research continues,” said Dr. Willett.
The study was supported by the National Health and Medical Research Council.
A version of this article first appeared on Medscape.com.
according to the results of a large study.
“With coffee intake, moderation is the key, and especially high levels of consumption may have adverse long-term effects on the brain,” said study investigator Elina Hypponen, PhD, professor of nutritional and genetic epidemiology and director of the Australian Center for Precision Health at the University of South Australia.
“These new data are concerning, and there is a need to conduct further carefully controlled studies to clarify the effects of coffee on the brain.”
The study was published online June 24 in Nutritional Neuroscience.
Potent stimulant
Coffee is a potent nervous system stimulant and is among the most popular nonalcoholic beverages. Some previous research suggests it benefits the brain, but the investigators noted that other research shows a negative or U-shaped relationship.
To investigate, the researchers examined data from the U.K. Biobank, a long-term prospective epidemiologic study of more than 500,000 participants aged 37-73 years who were recruited in 22 assessment centers in the United Kingdom between March 2006 and October 2010.
During the baseline assessment, information was gathered using touchscreen questionnaires, verbal interviews, and physical examinations that involved collection of blood, urine, and saliva samples. An imaging substudy was incorporated in 2014, the goal of which was to conduct brain, heart, and body MRI imaging for 100,000 participants.
The investigators conducted analyses on disease outcomes for 398,646 participants for whom information on habitual coffee consumption was available. Brain volume analyses were conducted in 17,702 participants for whom valid brain imaging data were available.
Participants reported coffee intake in cups per day. Researchers grouped coffee consumption into seven categories: nondrinkers, decaffeinated coffee drinkers, and caffeinated coffee drinkers who consumed less than 1 cup/d, 1-2 cups/d, 3-4 cups/d, 5-6 cups/d, and more than 6 cups/d.
The reference category was those who consumed 1-2 cups/d, rather than those who abstained from coffee, because persons who abstain are more likely to be at suboptimal health.
“Comparing the health of coffee drinkers to the health of those choosing to abstain from coffee will typically lead to an impression of a health benefit, even if there would not be one,” said Dr. Hypponen.
The researchers obtained total and regional brain volumes from the MRI imaging substudy starting 4-6 years after baseline assessment. They accessed information on incident dementia and stroke using primary care data, hospital admission electronic health records, national death registers, and self-reported medical conditions.
Covariates included socioeconomic, health, and other factors, such as smoking, alcohol and tea consumption, physical activity, stressful life events, and body mass index.
The investigators found that there was a linear inverse association between coffee consumption and total brain volume (fully adjusted beta per cup, –1.42; 95% confidence interval, –1.89 to –0.94), with consistent patterns for gray matter, white matter, and hippocampal volumes.
There was no evidence to support an association with white matter hyperintensity (WMH) volume (beta –0.01; 95% CI, –0.07 to 0.05).
Higher consumption, higher risk
The analysis also revealed a nonlinear association between coffee consumption and the odds of dementia (P nonlinearity = .0001), with slightly higher odds seen with non–coffee drinkers and decaffeinated-coffee drinkers and more notable increases for participants in the highest categories of coffee consumption compared with light coffee drinkers.
After adjustment for all covariates, the odds ratio of dementia among persons in the category of coffee intake was 1.53 (95% CI, 1.28-1.83). After full adjustments, the association with heavy coffee consumption and stroke was not significant, although “we can’t exclude a weak effect,” said Dr. Hypponen.
“For the highest coffee consumption group, the data support an association which may be anywhere from 0% to 37% higher odds of stroke after full adjustment,” she added.
People at risk for hypertension may develop “unpleasant sensations” and stop drinking coffee before a serious adverse event occurs, said Dr. Hypponen. In a previous study, she and her colleagues showed that those who have genetically higher blood pressure tend to drink less coffee than their counterparts without the condition.
“This type of effect might be expected to naturally limit the adverse effects of coffee on the risk of stroke,” said Dr. Hypponen.
The odds remained elevated for participants drinking more than 6 cups/d after the researchers accounted for sleep quality. There were no differences in risk between men and women or by age.
An examination of the consumption of tea, which often contains caffeine, did not show an association with brain volume or the odds of dementia or stroke.
“We don’t know whether the difference between associations seen for coffee and tea intake reflects the difference in related caffeine intake or some other explanation, such as dehydration or effects operating through blood cholesterol,” said Dr. Hypponen.
Although reverse causation is possible, there’s no reason to believe that it is relevant to the study results. Genetic evidence suggests a causal role of higher coffee intake on risk for Alzheimer’s disease. In addition, results of a clinical trial support the association between higher caffeine intake and smaller gray matter volume, said Dr. Hypponen.
The mechanisms linking coffee consumption to brain volumes and dementia are not well established. However, Dr. Hypponen noted that caffeine has been used to induce apoptosis in cancer studies using glial cells.
“Furthermore, adenosine receptors, which mediate many of the effects of caffeine in the brain, have been suggested to influence the release of growth factors, which in turn can have an influence on astrocyte proliferation and angiogenesis in the brain,” she said.
Some types of coffee contain cafestol, which increases blood cholesterol and can have adverse effects though related mechanisms, said Dr. Hypponen.
The mechanism may also involve dehydration, which may have a harmful effect on the brain. The study suggested a correlation between dehydration and high coffee intake. “Of course, if this is the case, it is good news, as then we can do something about it simply by drinking some water every time we have a cup of coffee,” she said.
Misleading conclusions
Coffee contains antioxidants, and although previous studies have suggested it might be beneficial, this hypothesis is “too simplistic,” said Dr. Hypponen. “While coffee is not going to be all ‘bad’ either, there are a lot of controversies and suggestions about beneficial effects of coffee which may not be true, or at least do not reflect the full story.”
If the drinking of coffee is at least partly determined by an individual’s health status, then that would often lead to misleading conclusions in observational studies, said Dr. Hypponen.
“When one uses as a comparison people who already have poor health and who do not drink coffee because of that, coffee intake will by default appear beneficial simply because there are more people with disease among those choosing abstinence,” she said.
Before now, there was “very little evidence about the association between coffee intake and brain morphology,” and the studies that were conducted were relatively small, said Dr. Hypponen.
One of these smaller studies included a group of women aged 13-30 years. It found that coffee consumption was not associated with total brain volumes, but the findings suggested a U-shaped association with hippocampal volume; higher values were seen both for nondrinkers and the groups with higher consumption.
A small study of elderly patients with diabetes showed no evidence of an association with white matter volume, but there was a possible age-dependent association with gray matter volume.
The largest of the earlier studies had results that were very similar to those of the current study, suggesting that increasing coffee intake is associated with smaller hippocampal volumes, said Dr. Hypponen.
One of the study’s limitations included the fact that full dietary information was available only for a subsample and that factors such as dehydration were measured at baseline rather than at the time of brain MRI.
Another possible study limitation was the use of self-reported data and the fact that lifestyle changes may have occurred between baseline and MRI or covariate measurement.
In addition, the study is subject to a healthy-volunteer bias, and its implications are restricted to White British persons. The association needs to be studied in other ethnic populations, the authors noted.
A reason to cut back?
Commenting on the findings, Walter Willett, MD, DrPH, professor of epidemiology and nutrition, Harvard T. H. Chan School of Public Health, Boston, said the study is large and quite well done.
“It does raise questions about an increase in risk of dementia with six or more cups of coffee per day,” said Dr. Willett. “At the same time, it provides reassurance about lack of adverse effects of coffee for those consuming three or four cups per day, and little increase in risk, if any, with five cups per day.”
It’s not entirely clear whether the increase in risk with six or more cups of coffee per day represents a “true effect” of coffee, inasmuch as the study did not seem to adjust fully for dietary factors, high consumption of alcohol, or past smoking, said Dr. Willett.
The findings don’t suggest that coffee lovers should give up their Java. “But six or more cups per day is a lot, and those who drink that much might consider cutting back a bit while research continues,” said Dr. Willett.
The study was supported by the National Health and Medical Research Council.
A version of this article first appeared on Medscape.com.
FROM NUTRITIONAL NEUROSCIENCE
Remote cognitive assessments get positive mark
That is the message behind numerous publications in recent years, and the COVID-19 pandemic has accelerated that trend.
“The publications have just skyrocketed since 2018, but I think there are still some additional tests that we need to validate using this medium of assessment. Also, I think we need to kind of put on our thinking caps as a field and think outside the box. What novel tests can we develop that will capitalize upon the telehealth environment – interactive tests that are monitoring [the individuals’] performance in real time and giving the examiner feedback, things like that,” said Munro Cullum, PhD, in an interview. Dr. Cullum spoke on the topic at the 2021 Alzheimer’s Association International Conference.
Still, challenges remain, especially factors in the home environment that can adversely affect testing. “Some of our tests are a question-answer, pencil-paper sort of tests that can be well suited to a telemedicine environment, [but] other tests don’t translate as well. So we still have a ways to go to kind of get our test to the next generation when being administered during this type of assessment. But a lot of the verbal tests work extremely well,” said Dr. Cullum, who is a professor of psychiatry at the University of Texas Southwestern Medical Center, Dallas.
Preliminary evidence of equivalence
Some years ago, Dr. Cullum was interested in getting a better understanding of what existing tests could best be performed remotely, and what populations could most benefit from remote assessments. Existing studies were generally supportive of remote testing, but varied significantly in their methodology and design. He went on to publish a study in 2014 showing equivalency of existing tests in the in-person and remote environment, and that helped pave the way for a wave of more recent studies that seem to confirm equivalence of in-person methods.
“If you look at the literature overall, there is a nice, growing body of evidence suggesting support for a host of neuropsychological test instruments. For the most part, almost all have shown good reliability across test conditions,” Dr. Cullum said during the talk.
He said that he is often asked if different test norms will be required for remote tests, but that doesn’t seem to be a concern. “It looks like the regular old neuropsych test norms should serve as well in this remote assessment environment. Although as within hospital testing of patients, conservative use of norms is always an order. They are interpretive guidelines,” he added.
One concern is potential threats to validity within the home environment. He posted an image of a woman at home, taking a remote cognitive test. The desk she sat at overlooked a wooded scene, and had a sewing machine on it. A small dog lay in her lap. “So assessing the home environment, ensuring that it is as close to a clinical standard setting as possible, is certainly advised,” said Dr. Cullum.
Although much progress has been made in studying existing tests in a telemedicine environment, many commonly used tests still haven’t been studied. The risk of intrusions and distractions, and even connectivity issues, can be limiting factors. Some tests may be ineligible for remote use due to copyright issues that might prevent required materials from being displayed online. For those reasons and others, not all individuals are suited for a remote test.
Finally, remote tests should be viewed with healthy skepticism. “In doing clinical evaluations this way, we have to be extra careful to not mis- or overinterpret the findings in case there were any distractions or glitches in the examination that came up during the test,” said Dr. Cullum.
Looking toward the future
Moving forward, Dr. Cullum called for more research to design new tests to exploit the telehealth format. “I think this is a really important opportunity for new test development in neuropsychology with increasing incorporation of computerized measures and integration with more cognitive neuroscience and clinical neuropsychology principles.”
He also suggested that remote testing could be combined with neuroimaging, neuromodulation, and even portable magnetoencephalography. “These opportunities for research can enhance compliance, enhance large-scale studies to allow for the inclusion of brief cognitive outcome metrics that might not have other otherwise been [possible],” said Dr. Cullum.
During the question-and-answer session, someone asked if the momentum towards telehealth will continue once the COVID-19 pandemic recedes. “We believe telehealth is here to stay, or at least I do,” said session moderator Allison Lindauer, PhD, who was asked to comment. Dr. Lindauer is an associate professor at the Layton Aging and Alzheimer’s Disease Center in Portland, Ore.
Dr. Lindauer has also conducted studies on telehealth-delivered assessments and also found encouraging results. “Work like this says, we have confidence in our work, we can believe that what we’re assessing and what we’re doing – if we did it face to face, we would get similar results,” Dr. Lindauer said in an interview.
Plenty of challenges remain, and the most important is widely available broadband internet, said Dr. Lindauer. “We need a huge push to get broadband everywhere. Granted, you’re going to have people that don’t want to use the computer, or they’re nervous about doing it online. But in my experience, most people with enough coaching can do it and are fine with it.”
Dr. Cullum and Dr. Lindauer have no relevant financial disclosures.
That is the message behind numerous publications in recent years, and the COVID-19 pandemic has accelerated that trend.
“The publications have just skyrocketed since 2018, but I think there are still some additional tests that we need to validate using this medium of assessment. Also, I think we need to kind of put on our thinking caps as a field and think outside the box. What novel tests can we develop that will capitalize upon the telehealth environment – interactive tests that are monitoring [the individuals’] performance in real time and giving the examiner feedback, things like that,” said Munro Cullum, PhD, in an interview. Dr. Cullum spoke on the topic at the 2021 Alzheimer’s Association International Conference.
Still, challenges remain, especially factors in the home environment that can adversely affect testing. “Some of our tests are a question-answer, pencil-paper sort of tests that can be well suited to a telemedicine environment, [but] other tests don’t translate as well. So we still have a ways to go to kind of get our test to the next generation when being administered during this type of assessment. But a lot of the verbal tests work extremely well,” said Dr. Cullum, who is a professor of psychiatry at the University of Texas Southwestern Medical Center, Dallas.
Preliminary evidence of equivalence
Some years ago, Dr. Cullum was interested in getting a better understanding of what existing tests could best be performed remotely, and what populations could most benefit from remote assessments. Existing studies were generally supportive of remote testing, but varied significantly in their methodology and design. He went on to publish a study in 2014 showing equivalency of existing tests in the in-person and remote environment, and that helped pave the way for a wave of more recent studies that seem to confirm equivalence of in-person methods.
“If you look at the literature overall, there is a nice, growing body of evidence suggesting support for a host of neuropsychological test instruments. For the most part, almost all have shown good reliability across test conditions,” Dr. Cullum said during the talk.
He said that he is often asked if different test norms will be required for remote tests, but that doesn’t seem to be a concern. “It looks like the regular old neuropsych test norms should serve as well in this remote assessment environment. Although as within hospital testing of patients, conservative use of norms is always an order. They are interpretive guidelines,” he added.
One concern is potential threats to validity within the home environment. He posted an image of a woman at home, taking a remote cognitive test. The desk she sat at overlooked a wooded scene, and had a sewing machine on it. A small dog lay in her lap. “So assessing the home environment, ensuring that it is as close to a clinical standard setting as possible, is certainly advised,” said Dr. Cullum.
Although much progress has been made in studying existing tests in a telemedicine environment, many commonly used tests still haven’t been studied. The risk of intrusions and distractions, and even connectivity issues, can be limiting factors. Some tests may be ineligible for remote use due to copyright issues that might prevent required materials from being displayed online. For those reasons and others, not all individuals are suited for a remote test.
Finally, remote tests should be viewed with healthy skepticism. “In doing clinical evaluations this way, we have to be extra careful to not mis- or overinterpret the findings in case there were any distractions or glitches in the examination that came up during the test,” said Dr. Cullum.
Looking toward the future
Moving forward, Dr. Cullum called for more research to design new tests to exploit the telehealth format. “I think this is a really important opportunity for new test development in neuropsychology with increasing incorporation of computerized measures and integration with more cognitive neuroscience and clinical neuropsychology principles.”
He also suggested that remote testing could be combined with neuroimaging, neuromodulation, and even portable magnetoencephalography. “These opportunities for research can enhance compliance, enhance large-scale studies to allow for the inclusion of brief cognitive outcome metrics that might not have other otherwise been [possible],” said Dr. Cullum.
During the question-and-answer session, someone asked if the momentum towards telehealth will continue once the COVID-19 pandemic recedes. “We believe telehealth is here to stay, or at least I do,” said session moderator Allison Lindauer, PhD, who was asked to comment. Dr. Lindauer is an associate professor at the Layton Aging and Alzheimer’s Disease Center in Portland, Ore.
Dr. Lindauer has also conducted studies on telehealth-delivered assessments and also found encouraging results. “Work like this says, we have confidence in our work, we can believe that what we’re assessing and what we’re doing – if we did it face to face, we would get similar results,” Dr. Lindauer said in an interview.
Plenty of challenges remain, and the most important is widely available broadband internet, said Dr. Lindauer. “We need a huge push to get broadband everywhere. Granted, you’re going to have people that don’t want to use the computer, or they’re nervous about doing it online. But in my experience, most people with enough coaching can do it and are fine with it.”
Dr. Cullum and Dr. Lindauer have no relevant financial disclosures.
That is the message behind numerous publications in recent years, and the COVID-19 pandemic has accelerated that trend.
“The publications have just skyrocketed since 2018, but I think there are still some additional tests that we need to validate using this medium of assessment. Also, I think we need to kind of put on our thinking caps as a field and think outside the box. What novel tests can we develop that will capitalize upon the telehealth environment – interactive tests that are monitoring [the individuals’] performance in real time and giving the examiner feedback, things like that,” said Munro Cullum, PhD, in an interview. Dr. Cullum spoke on the topic at the 2021 Alzheimer’s Association International Conference.
Still, challenges remain, especially factors in the home environment that can adversely affect testing. “Some of our tests are a question-answer, pencil-paper sort of tests that can be well suited to a telemedicine environment, [but] other tests don’t translate as well. So we still have a ways to go to kind of get our test to the next generation when being administered during this type of assessment. But a lot of the verbal tests work extremely well,” said Dr. Cullum, who is a professor of psychiatry at the University of Texas Southwestern Medical Center, Dallas.
Preliminary evidence of equivalence
Some years ago, Dr. Cullum was interested in getting a better understanding of what existing tests could best be performed remotely, and what populations could most benefit from remote assessments. Existing studies were generally supportive of remote testing, but varied significantly in their methodology and design. He went on to publish a study in 2014 showing equivalency of existing tests in the in-person and remote environment, and that helped pave the way for a wave of more recent studies that seem to confirm equivalence of in-person methods.
“If you look at the literature overall, there is a nice, growing body of evidence suggesting support for a host of neuropsychological test instruments. For the most part, almost all have shown good reliability across test conditions,” Dr. Cullum said during the talk.
He said that he is often asked if different test norms will be required for remote tests, but that doesn’t seem to be a concern. “It looks like the regular old neuropsych test norms should serve as well in this remote assessment environment. Although as within hospital testing of patients, conservative use of norms is always an order. They are interpretive guidelines,” he added.
One concern is potential threats to validity within the home environment. He posted an image of a woman at home, taking a remote cognitive test. The desk she sat at overlooked a wooded scene, and had a sewing machine on it. A small dog lay in her lap. “So assessing the home environment, ensuring that it is as close to a clinical standard setting as possible, is certainly advised,” said Dr. Cullum.
Although much progress has been made in studying existing tests in a telemedicine environment, many commonly used tests still haven’t been studied. The risk of intrusions and distractions, and even connectivity issues, can be limiting factors. Some tests may be ineligible for remote use due to copyright issues that might prevent required materials from being displayed online. For those reasons and others, not all individuals are suited for a remote test.
Finally, remote tests should be viewed with healthy skepticism. “In doing clinical evaluations this way, we have to be extra careful to not mis- or overinterpret the findings in case there were any distractions or glitches in the examination that came up during the test,” said Dr. Cullum.
Looking toward the future
Moving forward, Dr. Cullum called for more research to design new tests to exploit the telehealth format. “I think this is a really important opportunity for new test development in neuropsychology with increasing incorporation of computerized measures and integration with more cognitive neuroscience and clinical neuropsychology principles.”
He also suggested that remote testing could be combined with neuroimaging, neuromodulation, and even portable magnetoencephalography. “These opportunities for research can enhance compliance, enhance large-scale studies to allow for the inclusion of brief cognitive outcome metrics that might not have other otherwise been [possible],” said Dr. Cullum.
During the question-and-answer session, someone asked if the momentum towards telehealth will continue once the COVID-19 pandemic recedes. “We believe telehealth is here to stay, or at least I do,” said session moderator Allison Lindauer, PhD, who was asked to comment. Dr. Lindauer is an associate professor at the Layton Aging and Alzheimer’s Disease Center in Portland, Ore.
Dr. Lindauer has also conducted studies on telehealth-delivered assessments and also found encouraging results. “Work like this says, we have confidence in our work, we can believe that what we’re assessing and what we’re doing – if we did it face to face, we would get similar results,” Dr. Lindauer said in an interview.
Plenty of challenges remain, and the most important is widely available broadband internet, said Dr. Lindauer. “We need a huge push to get broadband everywhere. Granted, you’re going to have people that don’t want to use the computer, or they’re nervous about doing it online. But in my experience, most people with enough coaching can do it and are fine with it.”
Dr. Cullum and Dr. Lindauer have no relevant financial disclosures.
FROM AAIC 2021
Reducing air pollution is linked to slowed brain aging and lower dementia risk
, new research reveals. The findings have implications for individual behaviors, such as avoiding areas with poor air quality, but they also have implications for public policy, said study investigator, Xinhui Wang, PhD, assistant professor of research neurology, department of neurology, University of Southern California, Los Angeles.
“Controlling air quality has great benefits not only for the short-term, for example for pulmonary function or very broadly mortality, but can impact brain function and slow memory function decline and in the long run may reduce dementia cases.”
The findings were presented at the 2021 Alzheimer’s Association International Conference.
New approach
Previous research examining the impact of reducing air pollution, which has primarily examined respiratory illnesses and mortality, showed it is beneficial. However, no previous studies have examined the impact of improved air quality on cognitive function.
The current study used a subset of participants from the Women’s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO), which evaluated whether postmenopausal women derive cognitive benefit from hormone therapy.
The analysis included 2,232 community-dwelling older women aged 74-92 (mean age, 81.5 years) who did not have dementia at study enrollment.
Researchers obtained measures of participants’ annual cognitive function from 2008 to 2018. These measures included general cognitive status assessed using the Telephone Interview for Cognitive Status-modified (TICSm) and episodic memory assessed by the telephone-based California Verbal Learning Test (CVLT).
The investigators used complex geographical covariates to estimate exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2), in areas where individual participants lived from 1996 to 2012. The investigators averaged measures over 3-year periods immediately preceding (recent exposure) and 10 years prior to (remote exposure) enrollment, then calculated individual-level improvements in air quality as the reduction from remote to recent exposures.
The researchers examined pollution exposure and cognitive outcomes at different times to determine causation.
“Maybe the relationship isn’t causal and is just an association, so we tried to separate the timeframe for exposure and outcome and make sure the exposure was before we measured the outcome,” said Dr. Wang.
The investigators adjusted for multiple sociodemographic, lifestyle, and clinical characteristics.
Reduced dementia risk
The analysis showed air quality improved significantly for both PM2.5 and NO2 before study enrollment. “For almost 95% of the subjects in our study, air quality improved over the 10 years,” said Dr. Wang.
During a median follow-up of 6.2 years, there was a significant decline in cognitive status and episodic memory in study participants, which makes sense, said Dr. Wang, because cognitive function naturally declines with age.
However, a 10% improvement in air quality PM2.5 and NO2 resulted in a respective 14% and 26% decreased risk for dementia. This translates into a level of risk seen in women 2 to 3 years younger.
Greater air quality improvement was associated with slower decline in both general cognitive status and episodic memory.
“Participants all declined in cognitive function, but living in areas with the greatest air quality improvement slowed this decline,” said Dr. Wang.
“Whether you look at global cognitive function or memory-specific function, and whether you look at PM2.5 or NO2, slower decline was in the range of someone who is 1-2 years younger.”
The associations did not significantly differ by age, region, education, APOE ε4 genotypes, or cardiovascular risk factors.
Patients concerned about cognitive decline can take steps to avoid exposure to pollution by wearing a mask; avoiding heavy traffic, fires, and smoke; or moving to an area with better air quality, said Dr. Wang.
“But our study mainly tried to provide some evidence for policymakers and regulators,” she added.
Another study carried out by the same investigators suggests pollution may affect various cognitive functions differently. This analysis used the same cohort, timeframe, and air quality improvement indicators as the first study but examined the association with specific cognitive domains, including episodic memory, working memory, attention/executive function, and language.
The investigators found women living in locations with greater PM2.5 improvement performed better on tests of episodic memory (P = .002), working memory (P = .01) and attention/executive function (P = .01), but not language. Findings were similar for improved NO2.
When looking at air quality improvement and trajectory slopes of decline across cognitive functions, only the association between improved NO2 and slower episodic memory decline was statistically significant (P < 0.001). “The other domains were marginal or not significant,” said Dr. Wang.
“This suggests that brain regions are impacted differently,” she said, adding that various brain areas oversee different cognitive functions.
Important policy implications
Commenting on the research, Rebecca Edelmayer, PhD, senior director of scientific engagement, Alzheimer’s Association, said she welcomes new research on environmental factors that affect Alzheimer’s disease.
Whereas previous studies have linked longterm air pollution exposure to accumulation of Alzheimer’s disease-related brain plaques and increased risk of dementia, “these newer studies provide some of the first evidence to suggest that actually reducing pollution is associated with lower risk of all-cause dementia,” said Dr. Edelmayer.
Individuals can control some factors that contribute to dementia risk, such as exercise, diet, and physical activity, but it’s more difficult for them to control exposure to smog and pollution, she said.
“This is probably going to require changes to policy from federal and local governments and businesses, to start addressing the need to improve air quality to help reduce risk for dementia.”
A version of this article first appeared on Medscape.com.
, new research reveals. The findings have implications for individual behaviors, such as avoiding areas with poor air quality, but they also have implications for public policy, said study investigator, Xinhui Wang, PhD, assistant professor of research neurology, department of neurology, University of Southern California, Los Angeles.
“Controlling air quality has great benefits not only for the short-term, for example for pulmonary function or very broadly mortality, but can impact brain function and slow memory function decline and in the long run may reduce dementia cases.”
The findings were presented at the 2021 Alzheimer’s Association International Conference.
New approach
Previous research examining the impact of reducing air pollution, which has primarily examined respiratory illnesses and mortality, showed it is beneficial. However, no previous studies have examined the impact of improved air quality on cognitive function.
The current study used a subset of participants from the Women’s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO), which evaluated whether postmenopausal women derive cognitive benefit from hormone therapy.
The analysis included 2,232 community-dwelling older women aged 74-92 (mean age, 81.5 years) who did not have dementia at study enrollment.
Researchers obtained measures of participants’ annual cognitive function from 2008 to 2018. These measures included general cognitive status assessed using the Telephone Interview for Cognitive Status-modified (TICSm) and episodic memory assessed by the telephone-based California Verbal Learning Test (CVLT).
The investigators used complex geographical covariates to estimate exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2), in areas where individual participants lived from 1996 to 2012. The investigators averaged measures over 3-year periods immediately preceding (recent exposure) and 10 years prior to (remote exposure) enrollment, then calculated individual-level improvements in air quality as the reduction from remote to recent exposures.
The researchers examined pollution exposure and cognitive outcomes at different times to determine causation.
“Maybe the relationship isn’t causal and is just an association, so we tried to separate the timeframe for exposure and outcome and make sure the exposure was before we measured the outcome,” said Dr. Wang.
The investigators adjusted for multiple sociodemographic, lifestyle, and clinical characteristics.
Reduced dementia risk
The analysis showed air quality improved significantly for both PM2.5 and NO2 before study enrollment. “For almost 95% of the subjects in our study, air quality improved over the 10 years,” said Dr. Wang.
During a median follow-up of 6.2 years, there was a significant decline in cognitive status and episodic memory in study participants, which makes sense, said Dr. Wang, because cognitive function naturally declines with age.
However, a 10% improvement in air quality PM2.5 and NO2 resulted in a respective 14% and 26% decreased risk for dementia. This translates into a level of risk seen in women 2 to 3 years younger.
Greater air quality improvement was associated with slower decline in both general cognitive status and episodic memory.
“Participants all declined in cognitive function, but living in areas with the greatest air quality improvement slowed this decline,” said Dr. Wang.
“Whether you look at global cognitive function or memory-specific function, and whether you look at PM2.5 or NO2, slower decline was in the range of someone who is 1-2 years younger.”
The associations did not significantly differ by age, region, education, APOE ε4 genotypes, or cardiovascular risk factors.
Patients concerned about cognitive decline can take steps to avoid exposure to pollution by wearing a mask; avoiding heavy traffic, fires, and smoke; or moving to an area with better air quality, said Dr. Wang.
“But our study mainly tried to provide some evidence for policymakers and regulators,” she added.
Another study carried out by the same investigators suggests pollution may affect various cognitive functions differently. This analysis used the same cohort, timeframe, and air quality improvement indicators as the first study but examined the association with specific cognitive domains, including episodic memory, working memory, attention/executive function, and language.
The investigators found women living in locations with greater PM2.5 improvement performed better on tests of episodic memory (P = .002), working memory (P = .01) and attention/executive function (P = .01), but not language. Findings were similar for improved NO2.
When looking at air quality improvement and trajectory slopes of decline across cognitive functions, only the association between improved NO2 and slower episodic memory decline was statistically significant (P < 0.001). “The other domains were marginal or not significant,” said Dr. Wang.
“This suggests that brain regions are impacted differently,” she said, adding that various brain areas oversee different cognitive functions.
Important policy implications
Commenting on the research, Rebecca Edelmayer, PhD, senior director of scientific engagement, Alzheimer’s Association, said she welcomes new research on environmental factors that affect Alzheimer’s disease.
Whereas previous studies have linked longterm air pollution exposure to accumulation of Alzheimer’s disease-related brain plaques and increased risk of dementia, “these newer studies provide some of the first evidence to suggest that actually reducing pollution is associated with lower risk of all-cause dementia,” said Dr. Edelmayer.
Individuals can control some factors that contribute to dementia risk, such as exercise, diet, and physical activity, but it’s more difficult for them to control exposure to smog and pollution, she said.
“This is probably going to require changes to policy from federal and local governments and businesses, to start addressing the need to improve air quality to help reduce risk for dementia.”
A version of this article first appeared on Medscape.com.
, new research reveals. The findings have implications for individual behaviors, such as avoiding areas with poor air quality, but they also have implications for public policy, said study investigator, Xinhui Wang, PhD, assistant professor of research neurology, department of neurology, University of Southern California, Los Angeles.
“Controlling air quality has great benefits not only for the short-term, for example for pulmonary function or very broadly mortality, but can impact brain function and slow memory function decline and in the long run may reduce dementia cases.”
The findings were presented at the 2021 Alzheimer’s Association International Conference.
New approach
Previous research examining the impact of reducing air pollution, which has primarily examined respiratory illnesses and mortality, showed it is beneficial. However, no previous studies have examined the impact of improved air quality on cognitive function.
The current study used a subset of participants from the Women’s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO), which evaluated whether postmenopausal women derive cognitive benefit from hormone therapy.
The analysis included 2,232 community-dwelling older women aged 74-92 (mean age, 81.5 years) who did not have dementia at study enrollment.
Researchers obtained measures of participants’ annual cognitive function from 2008 to 2018. These measures included general cognitive status assessed using the Telephone Interview for Cognitive Status-modified (TICSm) and episodic memory assessed by the telephone-based California Verbal Learning Test (CVLT).
The investigators used complex geographical covariates to estimate exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2), in areas where individual participants lived from 1996 to 2012. The investigators averaged measures over 3-year periods immediately preceding (recent exposure) and 10 years prior to (remote exposure) enrollment, then calculated individual-level improvements in air quality as the reduction from remote to recent exposures.
The researchers examined pollution exposure and cognitive outcomes at different times to determine causation.
“Maybe the relationship isn’t causal and is just an association, so we tried to separate the timeframe for exposure and outcome and make sure the exposure was before we measured the outcome,” said Dr. Wang.
The investigators adjusted for multiple sociodemographic, lifestyle, and clinical characteristics.
Reduced dementia risk
The analysis showed air quality improved significantly for both PM2.5 and NO2 before study enrollment. “For almost 95% of the subjects in our study, air quality improved over the 10 years,” said Dr. Wang.
During a median follow-up of 6.2 years, there was a significant decline in cognitive status and episodic memory in study participants, which makes sense, said Dr. Wang, because cognitive function naturally declines with age.
However, a 10% improvement in air quality PM2.5 and NO2 resulted in a respective 14% and 26% decreased risk for dementia. This translates into a level of risk seen in women 2 to 3 years younger.
Greater air quality improvement was associated with slower decline in both general cognitive status and episodic memory.
“Participants all declined in cognitive function, but living in areas with the greatest air quality improvement slowed this decline,” said Dr. Wang.
“Whether you look at global cognitive function or memory-specific function, and whether you look at PM2.5 or NO2, slower decline was in the range of someone who is 1-2 years younger.”
The associations did not significantly differ by age, region, education, APOE ε4 genotypes, or cardiovascular risk factors.
Patients concerned about cognitive decline can take steps to avoid exposure to pollution by wearing a mask; avoiding heavy traffic, fires, and smoke; or moving to an area with better air quality, said Dr. Wang.
“But our study mainly tried to provide some evidence for policymakers and regulators,” she added.
Another study carried out by the same investigators suggests pollution may affect various cognitive functions differently. This analysis used the same cohort, timeframe, and air quality improvement indicators as the first study but examined the association with specific cognitive domains, including episodic memory, working memory, attention/executive function, and language.
The investigators found women living in locations with greater PM2.5 improvement performed better on tests of episodic memory (P = .002), working memory (P = .01) and attention/executive function (P = .01), but not language. Findings were similar for improved NO2.
When looking at air quality improvement and trajectory slopes of decline across cognitive functions, only the association between improved NO2 and slower episodic memory decline was statistically significant (P < 0.001). “The other domains were marginal or not significant,” said Dr. Wang.
“This suggests that brain regions are impacted differently,” she said, adding that various brain areas oversee different cognitive functions.
Important policy implications
Commenting on the research, Rebecca Edelmayer, PhD, senior director of scientific engagement, Alzheimer’s Association, said she welcomes new research on environmental factors that affect Alzheimer’s disease.
Whereas previous studies have linked longterm air pollution exposure to accumulation of Alzheimer’s disease-related brain plaques and increased risk of dementia, “these newer studies provide some of the first evidence to suggest that actually reducing pollution is associated with lower risk of all-cause dementia,” said Dr. Edelmayer.
Individuals can control some factors that contribute to dementia risk, such as exercise, diet, and physical activity, but it’s more difficult for them to control exposure to smog and pollution, she said.
“This is probably going to require changes to policy from federal and local governments and businesses, to start addressing the need to improve air quality to help reduce risk for dementia.”
A version of this article first appeared on Medscape.com.
From AAIC 2021