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 exhibi ted higher levels of physical activity and lower levels of body fatnes s, both of which can influence CHD risk factors. To gain insight into the influence of body fatness per se, we studied 38 postmenopausal hea lthy women: 10 swimmers, 10 runners, and nine obese and nine leaner se dentary subjects matched for age, hormone replacement use, and years p ostmenopause. Swimmers and runners were further matched for exercise t raining volume (4.5 +/- 0.2 v 4.6 +/- 0.6 h/wk) and relative competiti ve performance (79% +/- 5% v 77 +/- 3% of age-adjusted world record). Maximal oxygen consumption ((V)over dot O(2)max) 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 wais t circumference (79 +/- 3 v 71 +/- 1 cm) were greater (P < .01) in swi mmers than in runners, There were no significant differences in total caloric intake or dietary composition between swimmers and runners. In sulin sensitivity (via Bergman's minimal model) and fasting plasma con centrations of total cholesterol (TC), low-density lipoprotein cholest erol (LDL-C), triglyceride (TG), glucose, and plasminogen activator in hibitor-1 (PAI-1) activity were not different between the groups. Howe ver, plasma high-density lipoprotein cholesterol (HDL-C), HDL2-C, HDL- C/TC, insulin, fibrinogen, fibrin D-dimer, PAI antigen, tissue plasmin ogen activator (t-PA) activity, and t-PA antigen levels all were less favorable (P < .05) in swimmers versus runners. Daytime, nighttime, an d 24-hour systolic blood pressure (SBP) was 6 to 10 mm Hg higher in sw immers compared with runners, but resting blood pressure, 24-hour bloo d pressure load, and blood pressure variability were not significantly different. Stepwise regression showed that measures of body fatness w ere 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 s wimmers and runners were abolished (P = .18 to .90). We conclude that among endurance-trained postmenopausal women matched for training volu me and competitive eliteness, higher total and abdominal body fatness is, in general, associated with a less favorable metabolic CHD risk pr ofile. Thus, high levels of habitual aerobic exercise do not appear to negate the deleterious effects of adiposity on the coronary risk prof ile of healthy middle-aged and older women. Copyright (C) 1998 by W.B. Saunders Company.