Gender as a risk factor in young, not in old, women undergoing coronary artery bypass grafting.

BMI or waist girth (1,2), these measures of body fat are relatively imprecise, and residual confounding is possible. In the current study, the more precise DEXA scanning method was used to measure body fat and trunk fat. These DEXA measures correlated more strongly than BMI with both CRP levels and physical fitness. A limitation of the current study was variability in serum CRP levels. This variability reduced the statistical power of the study and, therefore, a small effect of improved physical fitness on CRP levels, independent of changes in body fat, cannot be excluded. Few previous studies have reported the effects of exercise training on CRP levels. Mattusch et al. (7) found a significant reduction in CRP levels after nine months of marathon training in 12 athletes. Smith et al. (8) reported a trend toward lower CRP levels in 43 volunteers after six months of exercise training. These studies did not include a control group and did not measure body fat. In conclusion, our findings suggest that the association between greater physical fitness and lower serum CRP levels is explained, at least in part, by long-term regular exercise reducing body fat.