We used nondenaturing polyacrylamide gradient gel electrophoresis to examine the associations of high-density lipoprotein (HDL) subclasses with adiposity, physical activity, resting heart rate (an indicator of sympathetic drive), and plasma insulin and glucose levels in 97 men with angiographically documented coronary artery disease. These men neither smoked nor used medications known to affect lipoproteins. The absorbency of protein stain was used as an index of mass concentrations at intervals of 0.01 nm within five HDL subclasses: HDL3c (7.2 to 7.8 nm), HDL3b (7.8 to 8.2 nm), HDL3a (8.2 to 8.8 nm), HDL2a (8.8 to 9.7 nm), and HDL2b (9.7 to 12 nm). HDL peak diameter was determined from the predominant peak of the HDL particle distribution when plotted against particle diameter. Four men who were non-insulin-dependent diabetics as defined by a fasting glucose exceeding 140 mg/dL had significantly higher plasma HDL3b levels and significantly smaller HDL peak diameters than nondiabetic men, and were therefore excluded from further analyses. In the remaining 93 nondiabetic men, plasma HDL3b levels correlated positively with indices of truncal obesity (waist to hip ratio and subscapular skinfold), whereas plasma HDL2b levels correlated negatively with indices of total adiposity (body mass index [BMI]) and truncal obesity (subscapular and abdominal skinfold). Fasting plasma insulin levels correlated negatively with HDL3a, HDL2a, and HDL2b. Obesity significantly affected the relationships of resting heart rate with insulin and HDL subclasses.(ABSTRACT TRUNCATED AT 250 WORDS)