Influence of body fatness on the coronary risk profile of physically active postmenopausal women

We have shown previously that endurance-trained postmenopausal runners demonstrate more favorable coronary heart disease (CHD) risk factors compared with age-matched sedentary women. However, the runners exhibited higher levels of physical activity and lower levels of body fatness, both of which can influence CHD risk factors. To gain insight into the influence of body fatness per se, we studied 38 postmenopausal healthy women: 10 swimmers, 10 runners, and nine obese and nine leaner sedentary subjects matched for age, hormone replacement use, and years postmenopause. Swimmers and runners were further matched for exercise training volume (4.5+/-0.2 v 4.6+/-0.6 h/wk) and relative competitive performance (79%+/-5% v 77+/-3% of age-adjusted world record). Maximal oxygen consumption (VO2max) on the treadmill was lower (P < .01) in swimmers versus runners. Body mass (65.0+/-2.0 v 59.0+/-1.3 kg), percent body fat (29%+/-2% v 23%+/-2%), and waist circumference (79+/-3 v 71+/-1 cm) were greater (P < .01) in swimmers than in runners. There were no significant differences in total caloric intake or dietary composition between swimmers and runners. Insulin sensitivity (via Bergman's minimal model) and fasting plasma concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), glucose, and plasminogen activator inhibitor-1 (PAI-1) activity were not different between the groups. However, plasma high-density lipoprotein cholesterol (HDL-C), HDL2-C, HDL-C/TC, insulin, fibrinogen, fibrin D-dimer, PAI antigen, tissue plasminogen activator (t-PA) activity, and t-PA antigen levels all were less favorable (P < .05) in swimmers versus runners. Daytime, nighttime, and 24-hour systolic blood pressure (SBP) was 6 to 10 mm Hg higher in swimmers compared with runners, but resting blood pressure, 24-hour blood pressure load, and blood pressure variability were not significantly different. Stepwise regression showed that measures of body fatness were the primary independent determinants of most of the metabolic CHD risk factors. When analysis of covariance (ANCOVA) was performed with body fatness as a covariate, differences in CHD risk factors between swimmers and runners were abolished (P=.18 to .90). We conclude that among endurance-trained postmenopausal women matched for training volume and competitive eliteness, higher total and abdominal body fatness is, in general, associated with a less favorable metabolic CHD risk profile. Thus, high levels of habitual aerobic exercise do not appear to negate the deleterious effects of adiposity on the coronary risk profile of healthy middle-aged and older women.