Association of vagal tone with serum insulin, glucose, and diabetes mellitus--The ARIC Study.

Reduced vagal activity assessed by heart rate variability (HRV) has been observed in studies of diabetics, but this association has not been reported at the population level. To investigate the association of HRV with diabetes mellitus, as well as fasting serum insulin, and glucose, we examined a stratified random sample of 1933 individuals (154 diabetics and 1779 non-diabetics), aged 45-65 years from the Atherosclerosis Risk in Communities (ARIC) study cohort. Two-minute, resting, supine beat-to-beat heart rate records were collected. Power spectral density estimation was used to derive HRV high frequency power (HF, 0.15-0.35 Hz) as the conventional marker of vagal function. Age, race, and gender-adjusted geometric means of HF were 0.78 and 1.27 (beat/min)(2) for diabetics and non-diabetics respectively (P for mean difference