EFFECTS OF EXERCISE AND STRESS ON BODY-FAT DISTRIBUTION IN MALE CYNOMOLGUS MONKEYS

The effects of exercise and stress on regional and whole body adiposit y were examined in an established animal model of diet-induced coronar y artery atherosclerosis, the cynomolgus monkey (Macaca fascicularis). A total of 79 adult male monkeys were assigned to four experimental g roups after baseline stabilization and training: (i) exercise, stress, (n = 20); (ii) exercise, no stress (n = 20); (iii) sedentary, stress (n = 20); and (iv) sedentary, no stress (n = 19). The monkeys consumed an ad libitum diet containing 188 mg cholesterol per day with 43% of calories as saturated fat. Anthropometric measurements of regional and whole body adiposity were collected throughout the study. A subset (n = 40) of animals representing all four groups underwent computerized tomography (CT) scans at the end of the study to determine amounts of total abdominal, intra-abdominal and subcutaneous abdominal adipose ti ssue. Results indicate that, in general, stress interacted with exerci se to affect anthropometric measurements of regional adiposity. In con trast, stress had independent and significant effects on the amount an d distribution of abdominal fat as measured using CT. Stressed monkeys in both the exercise and sedentary groups had more intra-abdominal fa t (and thus greater intra-abdominal: subcutaneous abdominal fat ratios ) than their non-stressed counterparts. There were no significant inte ractions between exercise and stress or exercise effects on abdominal fat distribution as measured by CT. These results support the belief t hat an arousal syndrome caused by chronic stress, and resulting in inc reased activity along the hypothalamo-adrenal axis, may play a role in the preferential deposition of fat in the abdomen. Finally, anthropom etric measurements did not predict the proportion of intra-abdominal v ersus subcutaneous fat in abdominal depots, suggesting that anthropome tric measurements and CT assess different characteristics of fat distr ibution.