EFFECTS OF WEIGHT-LOSS VS AEROBIC EXERCISE TRAINING ON RISK-FACTORS FOR CORONARY-DISEASE IN HEALTHY, OBESE, MIDDLE-AGED AND OLDER MEN - A RANDOMIZED CONTROLLED TRIAL

Objective.-To compare the effects of weight loss vs aerobic exercise t raining on coronary artery disease risk factors in healthy sedentary, obese, middle-aged and older men. Design.-Randomized controlled trial. Subjects.-A total of 170 obese (body mass index, 30+/-1 kg/m(2) [mean +/-SEM]), middle-aged and older (61+/-1 years) men. Interventions.-A g -month diet-induced weight loss intervention, 9-month aerobic exercise training program, and a weight-maintenance control group. Main Outcom e Measures.-Change in body composition, maximal aerobic capacity (VO(2 )max), blood pressure, lipoprotein concentrations, and glucose toleran ce. Results.-Forty-four of 73 men randomized to weight loss completed the intervention and had a 10% mean reduction in weight (-9.5+/-0,.7 k g; P<.001), with no change in VO(2)max, Forty-nine of 71 men randomize d to aerobic exercise completed the intervention, increased their VO(2 )max by a mean of 17% (P<.001), and did not change their weight, where as the 18 men who completed in the control group had no significant ch anges in body composition or VO(2)max. Weight loss decreased fasting g lucose concentrations by 2%, insulin by 18%, and glucose and insulin a reas during the oral glucose tolerance test (OGTT) by 8% and 26%, resp ectively (P<.01). By contrast, aerobic exercise did not improve fastin g glucose or insulin concentrations or glucose responses during the OG TT but decreased insulin areas by 17% (P<.001). In analysis of varianc e, the decrement in fasting glucose and insulin levels and glucose are as with intervention differed between weight loss and aerobic exercise when compared with the control group (P<.05). Similarly, weight loss but not aerobic exercise increased high-density lipoprotein cholestero l levels (+13%) and decreased blood pressure compared with the control group. In multiple regression analyses, the improvement in lipoprotei ns and glucose metabolism was related primarily to the reduction in ob esity. Conclusions.-These results suggest that weight loss is the pref erred treatment to improve coronary artery disease risk factors in ove rweight, middle-aged and older men.