The aim of this study was to investigate the role of body fat distribution on steroid hormone serum concentrations in obese adolescent girls before and after weight reduction. Ninety-two girls (age, 15.1 +/- 0.7 yr) with a mean body mass index of 31.2 +/- 4.6 kg/m2 participated in this 6-week intervention study. Initially, girls with abdominal obesity (waist to hip ratio, > 0.86; n = 30) had higher levels of total and free testosterone and lower levels of sex hormone-binding globulin as well as lower morning levels of total and free cortisol than girls with gluteal-femoral obesity (waist to hip ratio, < 0.80; n = 31) independent of their body mass index. After a mean weight loss of 8.3 +/- 2.6 kg by a standardized weight loss program, significant reductions were observed in estradiol, total and free testosterone, dehydroepiandrosterone sulfate, and the ratio of LH to FSH, whereas sex hormone-binding globulin and free cortisol levels increased significantly. Decreases in total and free testosterone and increases in total and free cortisol were significantly greater in the girls with abdominal obesity than in the girls with gluteal-femoral obesity. Our results suggest that obese girls with an abdominal pattern of fat distribution exhibit more pronounced steroid hormone aberrations, in particular a high androgenic activity, than girls with a gluteal-femoral pattern of fat distribution. The reduction of excess body weight by a conventional treatment regimen is associated with a remarkable improvement of steroid hormone abnormalities in this particular subtype of obese adolescent girls.