Associations of body fat distribution, circulating sex hormones, and bone density in postmenopausal women.

The associations of body fat distribution, sex hormone levels, and bone mineral density (BMD) were examined in 52 postmenopausal Caucasian women. Body fat distribution was assessed by waist to hip ratio (WHR) and abdominal fat weight (between the iliac crest and L1), as determined by dual energy x-ray absorptiometry. Bone mineral densities were determined by dual energy x-ray absorptiometry, and total estradiol, total testosterone, and sex hormone-binding globulin (SHBG) levels were determined by RIA. Subjects taking hormone replacement had significantly greater total estradiol and SHBG concentrations and a lower free androgen index. BMDs tended to be higher in subjects taking estrogen replacement after adjustment for body weight. There was no difference between subjects taking hormone replacement or not taking hormone replacement in WHR or abdominal fat weight. Subjects with a gynoid (lower body) distribution of body fat had higher SHBG concentrations than subjects with a more android (upper body) distribution of body fat. Subjects with an android distribution of body fat had greater BMDs than subjects with a gynoid distribution of body fat. Abdominal fat weight and WHR were significant predictors in regression models for all BMD parameters. The results of this study suggest that there is an association between body fat distribution and BMD, with the android distribution having higher BMDs.