Nephrology

Progression of chronic kidney disease (CKD) and cardiovascular disease risk in hypertensive adults was significantly slower among those who consumed more fruits and vegetables or oral sodium bicarbonate, compared with controls who received usual care.

A primary focus on pharmacologic strategies has failed to reduced hypertension-related CKD and cardiovascular disease mortality, Nimrit Goraya, MD, of Texas A&M Health Sciences Center College of Medicine, Temple, and colleagues wrote. High-acid diets (those with greater amounts of animal-sourced foods) have been associated with increased incidence and progression of CKD and with increased risk of cardiovascular disease.

Diets high in fruits and vegetables are associated with reduced CKD and cardiovascular disease but are not routinely used as part of hypertension treatment. The researchers hypothesized that dietary acid reduction could slow kidney disease progression and reduce cardiovascular disease risk.

In a study published in The American Journal of Medicine, the researchers randomized 153 adults aged 18-70 years with hypertension and CKD to fruits and vegetables, oral sodium bicarbonate (NaHCO₃), or usual care; 51 to each group. The fruit and vegetable group received 2-4 cups daily of base-producing food items including apples, apricots, oranges, peaches, pears, raisins, strawberries, carrots, cauliflower, eggplant, lettuce, potatoes, spinach, tomatoes, and zucchini. Participants were not instructed how to incorporate these foods into their diets. The sodium bicarbonate group received an average of four to five NaHCO₃ tablets daily (650 mg), divided into two doses.

The mean age of the participants was 48.8 years, 51% were female, and 47% were African American. The primary outcome was CKD progression and cardiovascular disease risk over 5 years. All participants met criteria at baseline for macroalbuminuria (a urine albumin to creatinine ratio of at least 200 mg/g) and were considered at increased risk for CKD progression.

Over the 5-year follow-up, CKD progression was significantly slower in the groups receiving fruits and vegetables and oral sodium bicarbonate, compared with usual care, based on trajectories showing a lower decline of estimated glomerular filtration rates (mean declines of 1.08 and 1.17 for fruits/vegetables and NaHCO₃, respectively, vs 19.4 for usual care, P < .001 for both).

However, systolic blood pressure and subsequent cardiovascular disease risk indicators were lower only in the fruit and vegetable group, compared with both the NaHCO₃ or usual-care groups over the long term. “Specifically, with fruits and vegetables, systolic blood pressure, plasma LDL and Lp(a) cholesterol, and body mass index decreased from baseline, consistent with better cardiovascular disease protection,” the researchers wrote. The protection against cardiovascular disease in the fruits and vegetables group occurred with lower doses of antihypertensive and statin medications and was not affected by baseline differences in medication doses.

The findings were limited by several factors, including the lack of data on compliance with the NaHCO₃ supplements, although urine net acid excretion in this group suggested increased alkali intake similar to that provided by fruits and vegetables, the researchers noted. Other limitations included the focus only on individuals with very high albuminuria.

More basic science studies are needed to explore how the potential vascular injury suggested by albuminuria affects CKD progression and cardiovascular disease, and clinical studies are needed to assess the impact of dietary acid reduction on patients with lower levels of albuminuria that the current study, the researchers said.

However, the results suggest that consuming fruits and vegetables, rather than NaHCO₃, is the preferred strategy for dietary acid reduction for patients with primary hypertension and CKD, they concluded. The findings also support routine measurement of urine albumin-to-creatinine ratios in hypertensive patients to identify CKD and assess risk for progression and subsequent cardiovascular disease.

The study was supported by the Larry and Jane Woirhaye Memorial Endowment in Renal Research at the Texas Tech University Health Sciences Center, the University Medical Center (both in Lubbock, Texas), the Endowment, Academic Operations Division of Baylor Scott & White Health, and the Episcopal Health Foundation. The researchers had no financial conflicts to disclose.

Progression of chronic kidney disease (CKD) and cardiovascular disease risk in hypertensive adults was significantly slower among those who consumed more fruits and vegetables or oral sodium bicarbonate, compared with controls who received usual care.

A primary focus on pharmacologic strategies has failed to reduced hypertension-related CKD and cardiovascular disease mortality, Nimrit Goraya, MD, of Texas A&M Health Sciences Center College of Medicine, Temple, and colleagues wrote. High-acid diets (those with greater amounts of animal-sourced foods) have been associated with increased incidence and progression of CKD and with increased risk of cardiovascular disease.

Diets high in fruits and vegetables are associated with reduced CKD and cardiovascular disease but are not routinely used as part of hypertension treatment. The researchers hypothesized that dietary acid reduction could slow kidney disease progression and reduce cardiovascular disease risk.

In a study published in The American Journal of Medicine, the researchers randomized 153 adults aged 18-70 years with hypertension and CKD to fruits and vegetables, oral sodium bicarbonate (NaHCO₃), or usual care; 51 to each group. The fruit and vegetable group received 2-4 cups daily of base-producing food items including apples, apricots, oranges, peaches, pears, raisins, strawberries, carrots, cauliflower, eggplant, lettuce, potatoes, spinach, tomatoes, and zucchini. Participants were not instructed how to incorporate these foods into their diets. The sodium bicarbonate group received an average of four to five NaHCO₃ tablets daily (650 mg), divided into two doses.

The mean age of the participants was 48.8 years, 51% were female, and 47% were African American. The primary outcome was CKD progression and cardiovascular disease risk over 5 years. All participants met criteria at baseline for macroalbuminuria (a urine albumin to creatinine ratio of at least 200 mg/g) and were considered at increased risk for CKD progression.

Over the 5-year follow-up, CKD progression was significantly slower in the groups receiving fruits and vegetables and oral sodium bicarbonate, compared with usual care, based on trajectories showing a lower decline of estimated glomerular filtration rates (mean declines of 1.08 and 1.17 for fruits/vegetables and NaHCO₃, respectively, vs 19.4 for usual care, P < .001 for both).

However, systolic blood pressure and subsequent cardiovascular disease risk indicators were lower only in the fruit and vegetable group, compared with both the NaHCO₃ or usual-care groups over the long term. “Specifically, with fruits and vegetables, systolic blood pressure, plasma LDL and Lp(a) cholesterol, and body mass index decreased from baseline, consistent with better cardiovascular disease protection,” the researchers wrote. The protection against cardiovascular disease in the fruits and vegetables group occurred with lower doses of antihypertensive and statin medications and was not affected by baseline differences in medication doses.

The findings were limited by several factors, including the lack of data on compliance with the NaHCO₃ supplements, although urine net acid excretion in this group suggested increased alkali intake similar to that provided by fruits and vegetables, the researchers noted. Other limitations included the focus only on individuals with very high albuminuria.

More basic science studies are needed to explore how the potential vascular injury suggested by albuminuria affects CKD progression and cardiovascular disease, and clinical studies are needed to assess the impact of dietary acid reduction on patients with lower levels of albuminuria that the current study, the researchers said.

However, the results suggest that consuming fruits and vegetables, rather than NaHCO₃, is the preferred strategy for dietary acid reduction for patients with primary hypertension and CKD, they concluded. The findings also support routine measurement of urine albumin-to-creatinine ratios in hypertensive patients to identify CKD and assess risk for progression and subsequent cardiovascular disease.

The study was supported by the Larry and Jane Woirhaye Memorial Endowment in Renal Research at the Texas Tech University Health Sciences Center, the University Medical Center (both in Lubbock, Texas), the Endowment, Academic Operations Division of Baylor Scott & White Health, and the Episcopal Health Foundation. The researchers had no financial conflicts to disclose.

Progression of chronic kidney disease (CKD) and cardiovascular disease risk in hypertensive adults was significantly slower among those who consumed more fruits and vegetables or oral sodium bicarbonate, compared with controls who received usual care.

A primary focus on pharmacologic strategies has failed to reduced hypertension-related CKD and cardiovascular disease mortality, Nimrit Goraya, MD, of Texas A&M Health Sciences Center College of Medicine, Temple, and colleagues wrote. High-acid diets (those with greater amounts of animal-sourced foods) have been associated with increased incidence and progression of CKD and with increased risk of cardiovascular disease.

Diets high in fruits and vegetables are associated with reduced CKD and cardiovascular disease but are not routinely used as part of hypertension treatment. The researchers hypothesized that dietary acid reduction could slow kidney disease progression and reduce cardiovascular disease risk.

In a study published in The American Journal of Medicine, the researchers randomized 153 adults aged 18-70 years with hypertension and CKD to fruits and vegetables, oral sodium bicarbonate (NaHCO₃), or usual care; 51 to each group. The fruit and vegetable group received 2-4 cups daily of base-producing food items including apples, apricots, oranges, peaches, pears, raisins, strawberries, carrots, cauliflower, eggplant, lettuce, potatoes, spinach, tomatoes, and zucchini. Participants were not instructed how to incorporate these foods into their diets. The sodium bicarbonate group received an average of four to five NaHCO₃ tablets daily (650 mg), divided into two doses.

The mean age of the participants was 48.8 years, 51% were female, and 47% were African American. The primary outcome was CKD progression and cardiovascular disease risk over 5 years. All participants met criteria at baseline for macroalbuminuria (a urine albumin to creatinine ratio of at least 200 mg/g) and were considered at increased risk for CKD progression.

Over the 5-year follow-up, CKD progression was significantly slower in the groups receiving fruits and vegetables and oral sodium bicarbonate, compared with usual care, based on trajectories showing a lower decline of estimated glomerular filtration rates (mean declines of 1.08 and 1.17 for fruits/vegetables and NaHCO₃, respectively, vs 19.4 for usual care, P < .001 for both).

However, systolic blood pressure and subsequent cardiovascular disease risk indicators were lower only in the fruit and vegetable group, compared with both the NaHCO₃ or usual-care groups over the long term. “Specifically, with fruits and vegetables, systolic blood pressure, plasma LDL and Lp(a) cholesterol, and body mass index decreased from baseline, consistent with better cardiovascular disease protection,” the researchers wrote. The protection against cardiovascular disease in the fruits and vegetables group occurred with lower doses of antihypertensive and statin medications and was not affected by baseline differences in medication doses.

The findings were limited by several factors, including the lack of data on compliance with the NaHCO₃ supplements, although urine net acid excretion in this group suggested increased alkali intake similar to that provided by fruits and vegetables, the researchers noted. Other limitations included the focus only on individuals with very high albuminuria.

More basic science studies are needed to explore how the potential vascular injury suggested by albuminuria affects CKD progression and cardiovascular disease, and clinical studies are needed to assess the impact of dietary acid reduction on patients with lower levels of albuminuria that the current study, the researchers said.

However, the results suggest that consuming fruits and vegetables, rather than NaHCO₃, is the preferred strategy for dietary acid reduction for patients with primary hypertension and CKD, they concluded. The findings also support routine measurement of urine albumin-to-creatinine ratios in hypertensive patients to identify CKD and assess risk for progression and subsequent cardiovascular disease.

The study was supported by the Larry and Jane Woirhaye Memorial Endowment in Renal Research at the Texas Tech University Health Sciences Center, the University Medical Center (both in Lubbock, Texas), the Endowment, Academic Operations Division of Baylor Scott & White Health, and the Episcopal Health Foundation. The researchers had no financial conflicts to disclose.

TOPLINE:

Very high and very low levels of high-density lipoprotein cholesterol (HDL-C) are linked to a higher risk for kidney disease in women with type 2 diabetes (T2D), but not in men.

METHODOLOGY:

• Studies have reported a strong association between low HDL-C levels and the risk for diabetic kidney disease, but whether higher HDL-C levels can influence the risk for diabetic kidney disease remains unclear.
• Researchers conducted a cross-sectional observational study of 936 patients with T2D (mean age, about 60 years; 41% women; 33% with diabetic kidney disease) from the Endocrinology Department at the Jinhua Hospital between September 2020 and July 2021.
• To examine the relationship between HDL-C levels and the risk for diabetic kidney disease, researchers used logistic regression to assess the continuous and categorical associations and a restricted cubic spline curve to assess the nonlinear association.
• HDL-C levels were categorized into four groups, with 0.40-0.96 mmol/L corresponding to the lowest quartile and 1.32-6.27 mmol/L corresponding to the highest quartile.
• The researchers observed a U-shaped association between HDL-C levels and the risk for diabetic kidney disease (P_nonlinear = .010) and selected two threshold values of 0.95 and 1.54 mmol/L.

TAKEAWAY:

• The risk for diabetic kidney disease was higher when the HDL-C levels were < 0.95 mmol/L or > 1.54 mmol/L.
• Compared with patients with HDL-C levels in the range of 0.95-1.54 mmol/L, those with very high and very low HDL-C levels had a 128% and 77% increased risk for diabetic kidney disease, respectively.
• The association was significant in women (P = .006) and not in men (P = .054), after adjusting for confounding factors.
• HDL-C level as a continuous variable was not associated with the risk for kidney disease (P = .902).

IN PRACTICE:

“Although HDL-C is generally considered a cardiovascular protective factor, at very high levels, this protective effect does not seem to hold true and may be associated with an increased DKD [diabetic kidney disease] risk,” the authors wrote.

SOURCE:

This study was led by Huabin Wang, from the Department of Clinical Laboratory, Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, China, and was published online in Scientific Reports.

LIMITATIONS:

The cross-sectional nature of the study limited the ability to establish a causal relationship between high HDL-C levels and the risk for diabetic kidney disease. The sample size of the study was relatively small at the higher end of the HDL-C concentration spectrum. Moreover, the study did not consider other potential confounding factors such as diet, sedentary lifestyle, obesity, genetic diseases, drug effects on HDL-C levels, and fluctuating estrogen levels, which could affect the overall findings.

DISCLOSURES:

The study was funded by the Department of Science and Technology of Zhejiang Province, China, and The Science and Technology Bureau of Jinhua City. The authors declared no competing interests.

A version of this article first appeared on Medscape.com.

TOPLINE:

Very high and very low levels of high-density lipoprotein cholesterol (HDL-C) are linked to a higher risk for kidney disease in women with type 2 diabetes (T2D), but not in men.

METHODOLOGY:

• Studies have reported a strong association between low HDL-C levels and the risk for diabetic kidney disease, but whether higher HDL-C levels can influence the risk for diabetic kidney disease remains unclear.
• Researchers conducted a cross-sectional observational study of 936 patients with T2D (mean age, about 60 years; 41% women; 33% with diabetic kidney disease) from the Endocrinology Department at the Jinhua Hospital between September 2020 and July 2021.
• To examine the relationship between HDL-C levels and the risk for diabetic kidney disease, researchers used logistic regression to assess the continuous and categorical associations and a restricted cubic spline curve to assess the nonlinear association.
• HDL-C levels were categorized into four groups, with 0.40-0.96 mmol/L corresponding to the lowest quartile and 1.32-6.27 mmol/L corresponding to the highest quartile.
• The researchers observed a U-shaped association between HDL-C levels and the risk for diabetic kidney disease (P_nonlinear = .010) and selected two threshold values of 0.95 and 1.54 mmol/L.

TAKEAWAY:

• The risk for diabetic kidney disease was higher when the HDL-C levels were < 0.95 mmol/L or > 1.54 mmol/L.
• Compared with patients with HDL-C levels in the range of 0.95-1.54 mmol/L, those with very high and very low HDL-C levels had a 128% and 77% increased risk for diabetic kidney disease, respectively.
• The association was significant in women (P = .006) and not in men (P = .054), after adjusting for confounding factors.
• HDL-C level as a continuous variable was not associated with the risk for kidney disease (P = .902).

IN PRACTICE:

“Although HDL-C is generally considered a cardiovascular protective factor, at very high levels, this protective effect does not seem to hold true and may be associated with an increased DKD [diabetic kidney disease] risk,” the authors wrote.

SOURCE:

This study was led by Huabin Wang, from the Department of Clinical Laboratory, Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, China, and was published online in Scientific Reports.

LIMITATIONS:

The cross-sectional nature of the study limited the ability to establish a causal relationship between high HDL-C levels and the risk for diabetic kidney disease. The sample size of the study was relatively small at the higher end of the HDL-C concentration spectrum. Moreover, the study did not consider other potential confounding factors such as diet, sedentary lifestyle, obesity, genetic diseases, drug effects on HDL-C levels, and fluctuating estrogen levels, which could affect the overall findings.

DISCLOSURES:

The study was funded by the Department of Science and Technology of Zhejiang Province, China, and The Science and Technology Bureau of Jinhua City. The authors declared no competing interests.

A version of this article first appeared on Medscape.com.

TOPLINE:

Very high and very low levels of high-density lipoprotein cholesterol (HDL-C) are linked to a higher risk for kidney disease in women with type 2 diabetes (T2D), but not in men.

METHODOLOGY:

• Studies have reported a strong association between low HDL-C levels and the risk for diabetic kidney disease, but whether higher HDL-C levels can influence the risk for diabetic kidney disease remains unclear.
• Researchers conducted a cross-sectional observational study of 936 patients with T2D (mean age, about 60 years; 41% women; 33% with diabetic kidney disease) from the Endocrinology Department at the Jinhua Hospital between September 2020 and July 2021.
• To examine the relationship between HDL-C levels and the risk for diabetic kidney disease, researchers used logistic regression to assess the continuous and categorical associations and a restricted cubic spline curve to assess the nonlinear association.
• HDL-C levels were categorized into four groups, with 0.40-0.96 mmol/L corresponding to the lowest quartile and 1.32-6.27 mmol/L corresponding to the highest quartile.
• The researchers observed a U-shaped association between HDL-C levels and the risk for diabetic kidney disease (P_nonlinear = .010) and selected two threshold values of 0.95 and 1.54 mmol/L.

TAKEAWAY:

• The risk for diabetic kidney disease was higher when the HDL-C levels were < 0.95 mmol/L or > 1.54 mmol/L.
• Compared with patients with HDL-C levels in the range of 0.95-1.54 mmol/L, those with very high and very low HDL-C levels had a 128% and 77% increased risk for diabetic kidney disease, respectively.
• The association was significant in women (P = .006) and not in men (P = .054), after adjusting for confounding factors.
• HDL-C level as a continuous variable was not associated with the risk for kidney disease (P = .902).

IN PRACTICE:

“Although HDL-C is generally considered a cardiovascular protective factor, at very high levels, this protective effect does not seem to hold true and may be associated with an increased DKD [diabetic kidney disease] risk,” the authors wrote.

SOURCE:

This study was led by Huabin Wang, from the Department of Clinical Laboratory, Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, China, and was published online in Scientific Reports.

LIMITATIONS:

The cross-sectional nature of the study limited the ability to establish a causal relationship between high HDL-C levels and the risk for diabetic kidney disease. The sample size of the study was relatively small at the higher end of the HDL-C concentration spectrum. Moreover, the study did not consider other potential confounding factors such as diet, sedentary lifestyle, obesity, genetic diseases, drug effects on HDL-C levels, and fluctuating estrogen levels, which could affect the overall findings.

DISCLOSURES:

The study was funded by the Department of Science and Technology of Zhejiang Province, China, and The Science and Technology Bureau of Jinhua City. The authors declared no competing interests.

A version of this article first appeared on Medscape.com.

TOPLINE:

Older adults show an increase in creatinine and cystatin C levels after exposure to extreme heat in a dry setting despite staying hydrated; however, changes in these kidney function biomarkers are much more modest in a humid setting and in young adults.

METHODOLOGY:

• Older adults are vulnerable to heat-related morbidity and mortality, with kidney complications accounting for many excess hospital admissions during heat waves.
• Researchers investigated plasma-based markers of kidney function following extreme heat exposure for 3 hours in 20 young (21-39 years) and 18 older (65-76 years) adults recruited from the Dallas-Fort Worth area.
• All participants underwent heat exposure in a chamber at 47 °C (116 °F) and 15% relative humidity (dry setting) and 41 °C (105 °F) and 40% relative humidity (humid setting) on separate days. They performed light physical activity mimicking their daily tasks and drank 3 mL/kg body mass of water every hour while exposed to heat.
• Blood samples were collected at baseline, immediately before the end of heat exposure (end-heating), and 2 hours after heat exposure.
• Plasma creatinine was the primary outcome, with a change ≥ 0.3 mg/dL considered as clinically meaningful. Cystatin C was the secondary outcome.

TAKEAWAY:

• The plasma creatinine level showed a modest increase from baseline to end-heating (difference, 0.10 mg/dL; P = .004) and at 2 hours post exposure (difference, 0.17 mg/dL; P < .001) in older adults facing heat exposure in the dry setting.
• The mean cystatin C levels also increased from baseline to end-heating by 0.29 mg/L (P = .01) and at 2 hours post heat exposure by 0.28 mg/L (P = .004) in older adults in the dry setting.
• The mean creatinine levels increased by only 0.06 mg/dL (P = .01) from baseline to 2 hours post exposure in older adults facing heat exposure in the humid setting.
• Young adults didn’t show any significant change in the plasma cystatin C levels during or after heat exposure; however, there was a modest increase in the plasma creatinine levels after 2 hours of heat exposure (difference, 0.06; P = .004).

IN PRACTICE:

“These findings provide limited evidence that the heightened thermal strain in older adults during extreme heat may contribute to reduced kidney function,” the authors wrote. 

SOURCE:

The study was led by Zachary J. McKenna, PhD, from the Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, and was published online in JAMA.

LIMITATIONS:

The use of plasma-based markers of kidney function, a short laboratory-based exposure, and a small number of generally healthy participants were the main limitations that could affect the generalizability of this study’s findings to broader populations and real-world settings. 

DISCLOSURES:

The National Institutes of Health and American Heart Association funded this study. Two authors declared receiving grants and nonfinancial support from several sources. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

TOPLINE:

Older adults show an increase in creatinine and cystatin C levels after exposure to extreme heat in a dry setting despite staying hydrated; however, changes in these kidney function biomarkers are much more modest in a humid setting and in young adults.

METHODOLOGY:

• Older adults are vulnerable to heat-related morbidity and mortality, with kidney complications accounting for many excess hospital admissions during heat waves.
• Researchers investigated plasma-based markers of kidney function following extreme heat exposure for 3 hours in 20 young (21-39 years) and 18 older (65-76 years) adults recruited from the Dallas-Fort Worth area.
• All participants underwent heat exposure in a chamber at 47 °C (116 °F) and 15% relative humidity (dry setting) and 41 °C (105 °F) and 40% relative humidity (humid setting) on separate days. They performed light physical activity mimicking their daily tasks and drank 3 mL/kg body mass of water every hour while exposed to heat.
• Blood samples were collected at baseline, immediately before the end of heat exposure (end-heating), and 2 hours after heat exposure.
• Plasma creatinine was the primary outcome, with a change ≥ 0.3 mg/dL considered as clinically meaningful. Cystatin C was the secondary outcome.

TAKEAWAY:

• The plasma creatinine level showed a modest increase from baseline to end-heating (difference, 0.10 mg/dL; P = .004) and at 2 hours post exposure (difference, 0.17 mg/dL; P < .001) in older adults facing heat exposure in the dry setting.
• The mean cystatin C levels also increased from baseline to end-heating by 0.29 mg/L (P = .01) and at 2 hours post heat exposure by 0.28 mg/L (P = .004) in older adults in the dry setting.
• The mean creatinine levels increased by only 0.06 mg/dL (P = .01) from baseline to 2 hours post exposure in older adults facing heat exposure in the humid setting.
• Young adults didn’t show any significant change in the plasma cystatin C levels during or after heat exposure; however, there was a modest increase in the plasma creatinine levels after 2 hours of heat exposure (difference, 0.06; P = .004).

IN PRACTICE:

“These findings provide limited evidence that the heightened thermal strain in older adults during extreme heat may contribute to reduced kidney function,” the authors wrote. 

SOURCE:

The study was led by Zachary J. McKenna, PhD, from the Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, and was published online in JAMA.

LIMITATIONS:

The use of plasma-based markers of kidney function, a short laboratory-based exposure, and a small number of generally healthy participants were the main limitations that could affect the generalizability of this study’s findings to broader populations and real-world settings. 

DISCLOSURES:

The National Institutes of Health and American Heart Association funded this study. Two authors declared receiving grants and nonfinancial support from several sources. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

TOPLINE:

Older adults show an increase in creatinine and cystatin C levels after exposure to extreme heat in a dry setting despite staying hydrated; however, changes in these kidney function biomarkers are much more modest in a humid setting and in young adults.

METHODOLOGY:

• Older adults are vulnerable to heat-related morbidity and mortality, with kidney complications accounting for many excess hospital admissions during heat waves.
• Researchers investigated plasma-based markers of kidney function following extreme heat exposure for 3 hours in 20 young (21-39 years) and 18 older (65-76 years) adults recruited from the Dallas-Fort Worth area.
• All participants underwent heat exposure in a chamber at 47 °C (116 °F) and 15% relative humidity (dry setting) and 41 °C (105 °F) and 40% relative humidity (humid setting) on separate days. They performed light physical activity mimicking their daily tasks and drank 3 mL/kg body mass of water every hour while exposed to heat.
• Blood samples were collected at baseline, immediately before the end of heat exposure (end-heating), and 2 hours after heat exposure.
• Plasma creatinine was the primary outcome, with a change ≥ 0.3 mg/dL considered as clinically meaningful. Cystatin C was the secondary outcome.

TAKEAWAY:

• The plasma creatinine level showed a modest increase from baseline to end-heating (difference, 0.10 mg/dL; P = .004) and at 2 hours post exposure (difference, 0.17 mg/dL; P < .001) in older adults facing heat exposure in the dry setting.
• The mean cystatin C levels also increased from baseline to end-heating by 0.29 mg/L (P = .01) and at 2 hours post heat exposure by 0.28 mg/L (P = .004) in older adults in the dry setting.
• The mean creatinine levels increased by only 0.06 mg/dL (P = .01) from baseline to 2 hours post exposure in older adults facing heat exposure in the humid setting.
• Young adults didn’t show any significant change in the plasma cystatin C levels during or after heat exposure; however, there was a modest increase in the plasma creatinine levels after 2 hours of heat exposure (difference, 0.06; P = .004).

IN PRACTICE:

“These findings provide limited evidence that the heightened thermal strain in older adults during extreme heat may contribute to reduced kidney function,” the authors wrote. 

SOURCE:

The study was led by Zachary J. McKenna, PhD, from the Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, and was published online in JAMA.

LIMITATIONS:

The use of plasma-based markers of kidney function, a short laboratory-based exposure, and a small number of generally healthy participants were the main limitations that could affect the generalizability of this study’s findings to broader populations and real-world settings. 

DISCLOSURES:

The National Institutes of Health and American Heart Association funded this study. Two authors declared receiving grants and nonfinancial support from several sources. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.

Hyperkalemia tends to cause panic in healthcare professionals, and rightfully so. On a good day, it causes weakness in the legs; on a bad day, it causes cardiac arrest.

It makes sense that a high potassium level causes clinicians to feel a bit jumpy. This anxiety tends to result in treating the issue by overly restricting potassium in the diet. The problem with this method is that it should be temporary but often isn’t. There are only a few concerns that justify long-term potassium restriction.

As a dietitian, I have seen numerous patients with varying disease states who are terrified of potassium because they were never properly educated on the situation that required restriction or were never notified that their potassium was corrected. 

I’ve seen patients whose potassium level hasn’t been elevated in years refuse banana bread because they were told that they could never eat a banana again. I’ve worked with patients who continued to needlessly restrict, which eventually led to hypokalemia.

Not only does this indicate ineffective education — banana bread is actually a low-potassium food at about 80 mg per slice — but also poor follow-up. 

Potassium has been designated by the United States Department of Agriculture as a nutrient of public health concern due to its underconsumption in the general population. Although there is concern in the public health community that the current guidelines for potassium intake (3500-4700 mg/d) are unattainable, with some professionals arguing for lowering the standard, there remains significant deficiency in the general population. This deficiency has also been connected to increasing rates of hypertension and cardiovascular disease. 
 

Nondietary Causes of Hyperkalemia 

There are many causes of hyperkalemia, of which excessive potassium intake is only one, and an uncommon one at that. A high potassium level should resolve during the course of treatment for metabolic acidosis, hyperglycemia, and dehydration. We may also see resolution with medication changes. But the question remains: Are we relaying this information to patients?

Renal insufficiency is a common cause of hyperkalemia, but it is also a common cause of chronic constipation that can cause hyperkalemia as well. Are we addressing bowel movements with these patients? I often work with patients who aren’t having their bowel movements addressed until the patient themselves voices discomfort. 

Depending upon the urgency of treatment, potassium restriction may be the most effective and efficient way to address an acutely elevated value. However, long-term potassium restriction may not be an appropriate intervention for all patients, even those with kidney conditions.

As a dietitian, I have seen many patients who overly restrict dietary potassium because they had one elevated value. These patients tend to view potassium as the enemy because they were never educated on the actual cause of their hyperkalemia. They were simply given a list of high-potassium foods and told to avoid them. A lack of follow-up education may cause them to avoid those foods forever. 
 

Benefits of Potassium

The problem with this perpetual avoidance of high potassium foods is that a potassium-rich diet has been shown to be exceptionally beneficial. 

Potassium exists in many forms in the Western diet: as a preservative and additive, a salt substitute, and naturally occurring in both animal and plant products. My concern regarding blanket potassium restriction is that potassium-rich plant and animal products can actually be beneficial, even to those with kidney and heart conditions who are most often advised to restrict its intake. 

Adequate potassium intake can: 

• Decrease blood pressure by increasing urinary excretion of sodium
• Improve nephrolithiasis by decreasing urinary excretion of calcium
• Decrease incidence of metabolic acidosis by providing precursors to bicarbonate that facilitate excretion of potassium
• Increase bone density in postmenopausal women
• Decrease risk for stroke and cardiovascular disease in the general population

One study found that metabolic acidosis can be corrected in patients with stage 4 chronic kidney disease, without hyperkalemia, by increasing fruit and vegetable intake when compared with those treated with bicarbonate alone, thus preserving kidney function.

Do I suggest encouraging a patient with acute hyperkalemia to eat a banana? Of course not. But I would suggest finding ways to work with patients who have chronic hyperkalemia to increase intake of potassium-rich plant foods to maintain homeostasis while liberalizing diet and preventing progression of chronic kidney disease. 
 

When to Refer to a Dietitian

In patients for whom a potassium-restricted diet is a necessary long-term treatment of hyperkalemia, education with a registered dietitian can be beneficial. A registered dietitian has the time and expertise to address the areas in the diet where excessive potassium exists without forfeiting other nutritional benefits that come from whole foods like fruits, vegetables, lean protein, legumes, nuts, and seeds in a way that is both realistic and helpful. A dietitian can work with patients to reduce intake of potassium-containing salt substitutes, preservatives, and other additives while still encouraging a whole-food diet rich in antioxidants, fiber, and healthy fats.

Dietitians also provide education on serving size and methods to reduce potassium content of food.

For example, tomatoes are a high-potassium food at 300+ mg per medium-sized tomato. But how often does a patient eat a whole tomato? A slice of tomato on a sandwich or a handful of cherry tomatoes in a salad are actually low in potassium per serving and can provide additional nutrients like vitamin C, beta-carotene, and antioxidants like lycopene, which is linked to a decreased incidence of prostate cancer.

By incorporating the assistance of a registered dietitian into the treatment of chronic hyperkalemia, we can develop individualized restrictions that are realistic for the patient and tailored to their nutritional needs to promote optimal health and thus encourage continued compliance. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She disclosed no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

Hyperkalemia tends to cause panic in healthcare professionals, and rightfully so. On a good day, it causes weakness in the legs; on a bad day, it causes cardiac arrest.

It makes sense that a high potassium level causes clinicians to feel a bit jumpy. This anxiety tends to result in treating the issue by overly restricting potassium in the diet. The problem with this method is that it should be temporary but often isn’t. There are only a few concerns that justify long-term potassium restriction.

As a dietitian, I have seen numerous patients with varying disease states who are terrified of potassium because they were never properly educated on the situation that required restriction or were never notified that their potassium was corrected. 

I’ve seen patients whose potassium level hasn’t been elevated in years refuse banana bread because they were told that they could never eat a banana again. I’ve worked with patients who continued to needlessly restrict, which eventually led to hypokalemia.

Not only does this indicate ineffective education — banana bread is actually a low-potassium food at about 80 mg per slice — but also poor follow-up. 

Potassium has been designated by the United States Department of Agriculture as a nutrient of public health concern due to its underconsumption in the general population. Although there is concern in the public health community that the current guidelines for potassium intake (3500-4700 mg/d) are unattainable, with some professionals arguing for lowering the standard, there remains significant deficiency in the general population. This deficiency has also been connected to increasing rates of hypertension and cardiovascular disease. 
 

Nondietary Causes of Hyperkalemia 

There are many causes of hyperkalemia, of which excessive potassium intake is only one, and an uncommon one at that. A high potassium level should resolve during the course of treatment for metabolic acidosis, hyperglycemia, and dehydration. We may also see resolution with medication changes. But the question remains: Are we relaying this information to patients?

Renal insufficiency is a common cause of hyperkalemia, but it is also a common cause of chronic constipation that can cause hyperkalemia as well. Are we addressing bowel movements with these patients? I often work with patients who aren’t having their bowel movements addressed until the patient themselves voices discomfort. 

Depending upon the urgency of treatment, potassium restriction may be the most effective and efficient way to address an acutely elevated value. However, long-term potassium restriction may not be an appropriate intervention for all patients, even those with kidney conditions.

As a dietitian, I have seen many patients who overly restrict dietary potassium because they had one elevated value. These patients tend to view potassium as the enemy because they were never educated on the actual cause of their hyperkalemia. They were simply given a list of high-potassium foods and told to avoid them. A lack of follow-up education may cause them to avoid those foods forever. 
 

Benefits of Potassium

The problem with this perpetual avoidance of high potassium foods is that a potassium-rich diet has been shown to be exceptionally beneficial. 

Potassium exists in many forms in the Western diet: as a preservative and additive, a salt substitute, and naturally occurring in both animal and plant products. My concern regarding blanket potassium restriction is that potassium-rich plant and animal products can actually be beneficial, even to those with kidney and heart conditions who are most often advised to restrict its intake. 

Adequate potassium intake can: 

• Decrease blood pressure by increasing urinary excretion of sodium
• Improve nephrolithiasis by decreasing urinary excretion of calcium
• Decrease incidence of metabolic acidosis by providing precursors to bicarbonate that facilitate excretion of potassium
• Increase bone density in postmenopausal women
• Decrease risk for stroke and cardiovascular disease in the general population

One study found that metabolic acidosis can be corrected in patients with stage 4 chronic kidney disease, without hyperkalemia, by increasing fruit and vegetable intake when compared with those treated with bicarbonate alone, thus preserving kidney function.

Do I suggest encouraging a patient with acute hyperkalemia to eat a banana? Of course not. But I would suggest finding ways to work with patients who have chronic hyperkalemia to increase intake of potassium-rich plant foods to maintain homeostasis while liberalizing diet and preventing progression of chronic kidney disease. 
 

When to Refer to a Dietitian

In patients for whom a potassium-restricted diet is a necessary long-term treatment of hyperkalemia, education with a registered dietitian can be beneficial. A registered dietitian has the time and expertise to address the areas in the diet where excessive potassium exists without forfeiting other nutritional benefits that come from whole foods like fruits, vegetables, lean protein, legumes, nuts, and seeds in a way that is both realistic and helpful. A dietitian can work with patients to reduce intake of potassium-containing salt substitutes, preservatives, and other additives while still encouraging a whole-food diet rich in antioxidants, fiber, and healthy fats.

Dietitians also provide education on serving size and methods to reduce potassium content of food.

For example, tomatoes are a high-potassium food at 300+ mg per medium-sized tomato. But how often does a patient eat a whole tomato? A slice of tomato on a sandwich or a handful of cherry tomatoes in a salad are actually low in potassium per serving and can provide additional nutrients like vitamin C, beta-carotene, and antioxidants like lycopene, which is linked to a decreased incidence of prostate cancer.

By incorporating the assistance of a registered dietitian into the treatment of chronic hyperkalemia, we can develop individualized restrictions that are realistic for the patient and tailored to their nutritional needs to promote optimal health and thus encourage continued compliance. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She disclosed no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

Hyperkalemia tends to cause panic in healthcare professionals, and rightfully so. On a good day, it causes weakness in the legs; on a bad day, it causes cardiac arrest.

It makes sense that a high potassium level causes clinicians to feel a bit jumpy. This anxiety tends to result in treating the issue by overly restricting potassium in the diet. The problem with this method is that it should be temporary but often isn’t. There are only a few concerns that justify long-term potassium restriction.

As a dietitian, I have seen numerous patients with varying disease states who are terrified of potassium because they were never properly educated on the situation that required restriction or were never notified that their potassium was corrected. 

I’ve seen patients whose potassium level hasn’t been elevated in years refuse banana bread because they were told that they could never eat a banana again. I’ve worked with patients who continued to needlessly restrict, which eventually led to hypokalemia.

Not only does this indicate ineffective education — banana bread is actually a low-potassium food at about 80 mg per slice — but also poor follow-up. 

Potassium has been designated by the United States Department of Agriculture as a nutrient of public health concern due to its underconsumption in the general population. Although there is concern in the public health community that the current guidelines for potassium intake (3500-4700 mg/d) are unattainable, with some professionals arguing for lowering the standard, there remains significant deficiency in the general population. This deficiency has also been connected to increasing rates of hypertension and cardiovascular disease. 
 

Nondietary Causes of Hyperkalemia 

There are many causes of hyperkalemia, of which excessive potassium intake is only one, and an uncommon one at that. A high potassium level should resolve during the course of treatment for metabolic acidosis, hyperglycemia, and dehydration. We may also see resolution with medication changes. But the question remains: Are we relaying this information to patients?

Renal insufficiency is a common cause of hyperkalemia, but it is also a common cause of chronic constipation that can cause hyperkalemia as well. Are we addressing bowel movements with these patients? I often work with patients who aren’t having their bowel movements addressed until the patient themselves voices discomfort. 

Depending upon the urgency of treatment, potassium restriction may be the most effective and efficient way to address an acutely elevated value. However, long-term potassium restriction may not be an appropriate intervention for all patients, even those with kidney conditions.

As a dietitian, I have seen many patients who overly restrict dietary potassium because they had one elevated value. These patients tend to view potassium as the enemy because they were never educated on the actual cause of their hyperkalemia. They were simply given a list of high-potassium foods and told to avoid them. A lack of follow-up education may cause them to avoid those foods forever. 
 

Benefits of Potassium

The problem with this perpetual avoidance of high potassium foods is that a potassium-rich diet has been shown to be exceptionally beneficial. 

Potassium exists in many forms in the Western diet: as a preservative and additive, a salt substitute, and naturally occurring in both animal and plant products. My concern regarding blanket potassium restriction is that potassium-rich plant and animal products can actually be beneficial, even to those with kidney and heart conditions who are most often advised to restrict its intake. 

Adequate potassium intake can: 

• Decrease blood pressure by increasing urinary excretion of sodium
• Improve nephrolithiasis by decreasing urinary excretion of calcium
• Decrease incidence of metabolic acidosis by providing precursors to bicarbonate that facilitate excretion of potassium
• Increase bone density in postmenopausal women
• Decrease risk for stroke and cardiovascular disease in the general population

One study found that metabolic acidosis can be corrected in patients with stage 4 chronic kidney disease, without hyperkalemia, by increasing fruit and vegetable intake when compared with those treated with bicarbonate alone, thus preserving kidney function.

Do I suggest encouraging a patient with acute hyperkalemia to eat a banana? Of course not. But I would suggest finding ways to work with patients who have chronic hyperkalemia to increase intake of potassium-rich plant foods to maintain homeostasis while liberalizing diet and preventing progression of chronic kidney disease. 
 

When to Refer to a Dietitian

In patients for whom a potassium-restricted diet is a necessary long-term treatment of hyperkalemia, education with a registered dietitian can be beneficial. A registered dietitian has the time and expertise to address the areas in the diet where excessive potassium exists without forfeiting other nutritional benefits that come from whole foods like fruits, vegetables, lean protein, legumes, nuts, and seeds in a way that is both realistic and helpful. A dietitian can work with patients to reduce intake of potassium-containing salt substitutes, preservatives, and other additives while still encouraging a whole-food diet rich in antioxidants, fiber, and healthy fats.

Dietitians also provide education on serving size and methods to reduce potassium content of food.

For example, tomatoes are a high-potassium food at 300+ mg per medium-sized tomato. But how often does a patient eat a whole tomato? A slice of tomato on a sandwich or a handful of cherry tomatoes in a salad are actually low in potassium per serving and can provide additional nutrients like vitamin C, beta-carotene, and antioxidants like lycopene, which is linked to a decreased incidence of prostate cancer.

By incorporating the assistance of a registered dietitian into the treatment of chronic hyperkalemia, we can develop individualized restrictions that are realistic for the patient and tailored to their nutritional needs to promote optimal health and thus encourage continued compliance. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She disclosed no relevant conflicts of interest.

A version of this article first appeared on Medscape.com.

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.