The association among autonomic nervous system function, incident diabetes, and intervention arm in the Diabetes Prevention Program.
OBJECTIVE
Autonomic nervous system dysfunction, a correlate of obesity and poor cardiorespiratory fitness, is associated with the development of diabetes. We tested whether estimates of autonomic nervous system function improved in the intensive lifestyle versus metformin or placebo arms of the Diabetes Prevention Program (DPP) and whether baseline or a change in autonomic nervous system function was associated with the development of diabetes over 3.2 years.


METHODS
In 2,980 DPP participants, 12-lead electrocardiograms were measured at baseline and annually. Heart rate, heart rate variability (HRV), and QT duration were used to estimate fitness and autonomic nervous system function.


RESULTS
In the lifestyle arm, heart rate and QT indexes decreased, and HRV increased over time. The magnitude of decline in heart rate and QT duration was substantially smaller in the other arms, whereas HRV did not increase. Baseline heart rate was the only index significantly (P < 0.05) associated with incident diabetes after adjustment for demographics and weight change (hazard ratio for lifestyle and metformin arms = 1.19 and 1.17 per 10.6 beats/min, respectively). Decreases in heart rate and QT indexes and increases in HRV over time were associated with a lower risk of developing diabetes. The protective association between decreased heart rate and incident diabetes in the lifestyle arm remained significant after accounting for change in weight and physical activity.


CONCLUSIONS
Indexes that reflect autonomic function and fitness improved (i.e., heart rate decreased and HRV increased) in the lifestyle modification arm of the DPP. Improvements in these indexes are inversely associated with the development of diabetes independent of weight change.
Department of Preventive Medicine, Northwestern University, Chicago, Illinois, USA. dppmail@biostat.bsc.gwu.edu
Mercedes R
MR
Carnethon
Ronald J
RJ
Prineas
Marinella
M
Temprosa
Zhu-Ming
ZM
Zhang
Gabriel
G
Uwaifo
Mark E
ME
Molitch
D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology*; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000628:therapy*; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D012307:Risk Factors
D007004:Hypoglycemic Agents; D008687:Metformin