Body composition, not body weight, is related to cardiovascular disease risk factors and sex hormone levels in men

To clarify the independent relationships of obesity and over-weight to cardiovascular disease risk factors and sex steroid levels, three age-matched groups of men were studied: (i) 8 normal weight men, < 15 % body fat, by hydrostatic weighing; (il) 16 overweight, obese men,> 25 % body fat and 135-160% of ideal body weight (IBW); and (ill) 8 overweight, lean men, 135-160 % IBW, but < 15 % fat. Diastolic blood pressure was significantly greater for the obese (mean±SEM, 82±2 mmHg) than the normal (71±2) and overweight lean (72±2) groups, as were low density lipoprotein levels (131±9 vs. 98+11 and 98+14 mg/dl), the ratio of high density lipoprotein to total cholesterol (0.207±0.01 vs. 0.308±0.03 and 0.302±0.03), fasting plasma insulin (22±3 vs. 12±1 and 13±2;U/ml), and the estradiol/testosterone ratio (0.076±0.01 vs. 0.042+0.02 and 0.052±0.02); P < 0.05. Estradiol was 25 % greater for the overweight lean group (40±5 pg/ml) than the obese (30±3 pg/ml) and normal groups (29±2 pg/ml), P = 0.08, whereas total testosterone was significantly lower in the obese (499±33 ng/dl) compared with the normal and overweight, lean groups (759±98 and 797±82 ng/dl). Estradiol was uncorrelated with risk factors and the estradiol/testosterone ratio appeared to be a function of the reduced testosterone levels in obesity, not independently correlated with lipid levels after adjustment for body fat content. Furthermore, no risk factors were signifi-cantly different between the normal and overweight lean groups. We conclude that (a) body composition, rather than body weight per se, is associated with increased cardiovascular disease risk factors; and (b) sex steroid alterations are related to body composition and are not an independent cardiovascular disease risk factor