INCREASES IN HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL WITH ENDURANCE EXERCISE TRAINING ARE BLUNTED IN OBESE COMPARED WITH LEAN MEN

The effectiveness of endurance exercise training (without concomitant weight loss) for improving lipoprotein lipid levels in obese individua ls remains controversial. The purpose of this study was to determine w hether lipoprotein lipid responses to endurance exercise training are affected by obesity. Healthy middle-aged and older (57+/-2 years) lean (n=16; body mass index [BMS], 22 to 26 kg/m(2)), moderately obese (n= 15; BMI, 27 to 30 kg/m(2)), and obese (n=15; BMI, 31 to 37 kg/m(2)) me n underwent a 9-month endurance exercise training program. The groups differed in the initial degree of obesity, waist circumference, and wa ist to hip ratio (WHR), but not in age or maximal aerobic capacity (<( V)over dot (2)) max). The obese group had lower baseline levels of hig h-density lipoprotein cholesterol (HDL-C) and HDL2-C, and higher trigl yceride (TG) levels than the lean group. Exercise training increased < (V)over dot (2)> max to a comparable degree in lean, moderately obese, and obese groups (18%, 24%, and 18%, respectively P <.01). Exercise t raining significantly decreased TG levels in all groups, whereas total cholesterol and low-density lipoprotein cholesterol (LDL-C) decreased only in the obese group. Exercise training increased HDL-C and HDL2-C levels in lean (14% and 81%, respectively, P <.05) and moderately obe se (7% and 59%, respectively, P <.05) men, whereas neither HDL-C nor H DL2-C changed in obese men. The change in HDL-C correlated negatively with initial BMI (r=-.42, P <.01) and waist circumference (r=-.43, P < .01). These results show that the effects of exercise training on HDL- C are blunted in obese middle-aged and older men, whereas improvements in TG occur independently of the degree of obesity. Copyright (C) 199 7 by W.B. Saunders Company.