CV Impairments Seen in Diabetic Teens During Exercise

Major Finding: During exercise, cardiac output/fat-free mass was significantly lower in adolescents with type 2 diabetes than in adolescents who were obese or in healthy controls.

Data Source: A nonrandomized, prospective study of cardiovascular function in 13 adolescents with type 2 diabetes, 27 nondiabetic, overweight or obese subjects, and 19 nondiabetic, nonobese controls.

Disclosures: Dr. Pinto said she had nothing to disclose. The study was funded by an unrestricted grant from Novo Nordisk.

BOSTON – Independent of weight, type 2 diabetes negatively impacts both central and peripheral vascular function during exercise in adolescents, according a small, prospective study.

These early changes are similar to those documented in adults with type 2 diabetes, said Dr. Teresa Pinto, who presented the findings at the meeting

The study compared cardiovascular function in 13 adolescents (aged 12-20 years) with type 2 diabetes vs. 27 overweight or obese nondiabetic subjects and 19 nondiabetic, nonobese controls. Cardiac and femoral flow MRI images were taken at rest and during or immediately after submaximal exercise using a cycle ergometer specially designed for exercise within the MRI. Body composition was assessed using dual-energy x-ray absorptiometry (DXA), said Dr. Pinto, a pediatric endocrinologist now associated with Dalhousie University in Halifax, N.S. Dr. Pinto conducted the study at the University of Auckland (N.Z.).

At rest, no difference was found in cardiac output indexed for fat-free mass. During exercise, however, cardiac output/fat-free mass was significantly lower in the type 2 diabetes group, compared with both the obese and control groups.

Because cardiac output reflects both stroke volume and heart rate, Dr. Pinto then looked more carefully at stroke volume and its components, end-diastolic and end-systolic volume. She found that during exercise, those with diabetes were not able to increase their stroke volume as well as those in the other groups: Stroke volume increased by 11.1% in the control group and 5.98% in the obese group, but by only 0.76% in the diabetes group.

Looking at left end-diastolic volume, Dr. Pinto found evidence of diastolic dysfunction: The volume indexed for fat-free mass was significantly lower in the diabetes group, both at rest and during exercise. During exercise, end-diastolic volume decreased by 2.1% in the control group, by 0.9% in the obese group, and by 6.1% in the diabetes group. Likewise, end-systolic volume was significantly lower in the diabetes group, compared with the controls, both at rest and during exercise, which suggested that the heart is trying to compensate for reduced end-diastolic volume by increasing contractility.

Dr. Pinto also studied femoral artery flow as a marker of peripheral vascular function. After exercise, significant deficits in those with type 2 diabetes were also found for average femoral artery flow per minute and net forward volume, both indexed for fat-free mass, compared with controls.

“This study suggests that some of the cardiac changes we see existing in adults with type 2 diabetes may already be present at a young age in adolescents. There is evidence in adults that gradual exercise training showed some reversibility of those early changes,” said Dr. Pinto.

The effects of exercise on cardiovascular function were assessed on MRI with use of a cycle ergometer.

Source Courtesy Silmara Gusso, Liggins Institute, University of Auckland

Major Finding: During exercise, cardiac output/fat-free mass was significantly lower in adolescents with type 2 diabetes than in adolescents who were obese or in healthy controls.

Data Source: A nonrandomized, prospective study of cardiovascular function in 13 adolescents with type 2 diabetes, 27 nondiabetic, overweight or obese subjects, and 19 nondiabetic, nonobese controls.

Disclosures: Dr. Pinto said she had nothing to disclose. The study was funded by an unrestricted grant from Novo Nordisk.

BOSTON – Independent of weight, type 2 diabetes negatively impacts both central and peripheral vascular function during exercise in adolescents, according a small, prospective study.

These early changes are similar to those documented in adults with type 2 diabetes, said Dr. Teresa Pinto, who presented the findings at the meeting

The study compared cardiovascular function in 13 adolescents (aged 12-20 years) with type 2 diabetes vs. 27 overweight or obese nondiabetic subjects and 19 nondiabetic, nonobese controls. Cardiac and femoral flow MRI images were taken at rest and during or immediately after submaximal exercise using a cycle ergometer specially designed for exercise within the MRI. Body composition was assessed using dual-energy x-ray absorptiometry (DXA), said Dr. Pinto, a pediatric endocrinologist now associated with Dalhousie University in Halifax, N.S. Dr. Pinto conducted the study at the University of Auckland (N.Z.).

At rest, no difference was found in cardiac output indexed for fat-free mass. During exercise, however, cardiac output/fat-free mass was significantly lower in the type 2 diabetes group, compared with both the obese and control groups.

Because cardiac output reflects both stroke volume and heart rate, Dr. Pinto then looked more carefully at stroke volume and its components, end-diastolic and end-systolic volume. She found that during exercise, those with diabetes were not able to increase their stroke volume as well as those in the other groups: Stroke volume increased by 11.1% in the control group and 5.98% in the obese group, but by only 0.76% in the diabetes group.

Looking at left end-diastolic volume, Dr. Pinto found evidence of diastolic dysfunction: The volume indexed for fat-free mass was significantly lower in the diabetes group, both at rest and during exercise. During exercise, end-diastolic volume decreased by 2.1% in the control group, by 0.9% in the obese group, and by 6.1% in the diabetes group. Likewise, end-systolic volume was significantly lower in the diabetes group, compared with the controls, both at rest and during exercise, which suggested that the heart is trying to compensate for reduced end-diastolic volume by increasing contractility.

Dr. Pinto also studied femoral artery flow as a marker of peripheral vascular function. After exercise, significant deficits in those with type 2 diabetes were also found for average femoral artery flow per minute and net forward volume, both indexed for fat-free mass, compared with controls.

“This study suggests that some of the cardiac changes we see existing in adults with type 2 diabetes may already be present at a young age in adolescents. There is evidence in adults that gradual exercise training showed some reversibility of those early changes,” said Dr. Pinto.

The effects of exercise on cardiovascular function were assessed on MRI with use of a cycle ergometer.

Source Courtesy Silmara Gusso, Liggins Institute, University of Auckland

Major Finding: During exercise, cardiac output/fat-free mass was significantly lower in adolescents with type 2 diabetes than in adolescents who were obese or in healthy controls.

Data Source: A nonrandomized, prospective study of cardiovascular function in 13 adolescents with type 2 diabetes, 27 nondiabetic, overweight or obese subjects, and 19 nondiabetic, nonobese controls.

Disclosures: Dr. Pinto said she had nothing to disclose. The study was funded by an unrestricted grant from Novo Nordisk.

BOSTON – Independent of weight, type 2 diabetes negatively impacts both central and peripheral vascular function during exercise in adolescents, according a small, prospective study.

These early changes are similar to those documented in adults with type 2 diabetes, said Dr. Teresa Pinto, who presented the findings at the meeting

The study compared cardiovascular function in 13 adolescents (aged 12-20 years) with type 2 diabetes vs. 27 overweight or obese nondiabetic subjects and 19 nondiabetic, nonobese controls. Cardiac and femoral flow MRI images were taken at rest and during or immediately after submaximal exercise using a cycle ergometer specially designed for exercise within the MRI. Body composition was assessed using dual-energy x-ray absorptiometry (DXA), said Dr. Pinto, a pediatric endocrinologist now associated with Dalhousie University in Halifax, N.S. Dr. Pinto conducted the study at the University of Auckland (N.Z.).

At rest, no difference was found in cardiac output indexed for fat-free mass. During exercise, however, cardiac output/fat-free mass was significantly lower in the type 2 diabetes group, compared with both the obese and control groups.

Because cardiac output reflects both stroke volume and heart rate, Dr. Pinto then looked more carefully at stroke volume and its components, end-diastolic and end-systolic volume. She found that during exercise, those with diabetes were not able to increase their stroke volume as well as those in the other groups: Stroke volume increased by 11.1% in the control group and 5.98% in the obese group, but by only 0.76% in the diabetes group.

Looking at left end-diastolic volume, Dr. Pinto found evidence of diastolic dysfunction: The volume indexed for fat-free mass was significantly lower in the diabetes group, both at rest and during exercise. During exercise, end-diastolic volume decreased by 2.1% in the control group, by 0.9% in the obese group, and by 6.1% in the diabetes group. Likewise, end-systolic volume was significantly lower in the diabetes group, compared with the controls, both at rest and during exercise, which suggested that the heart is trying to compensate for reduced end-diastolic volume by increasing contractility.

Dr. Pinto also studied femoral artery flow as a marker of peripheral vascular function. After exercise, significant deficits in those with type 2 diabetes were also found for average femoral artery flow per minute and net forward volume, both indexed for fat-free mass, compared with controls.

“This study suggests that some of the cardiac changes we see existing in adults with type 2 diabetes may already be present at a young age in adolescents. There is evidence in adults that gradual exercise training showed some reversibility of those early changes,” said Dr. Pinto.

The effects of exercise on cardiovascular function were assessed on MRI with use of a cycle ergometer.

Source Courtesy Silmara Gusso, Liggins Institute, University of Auckland