Serum leptin levels and body composition in postmenopausal women: effects of hormone therapy

Objective: To confirm the effect of postmenopausal hypoestrogenism and hormone therapy (HT) on body composition and serum leptin levels. Design: Prospective, longitudinal study evaluating body composition (body mass index, and total and percent fat mass and lean mass measured at the arms, legs and trunk) with dual-energy x-ray absorptiometry and serum leptin levels by radioimmunoassay in 44 healthy postmenopausal women randomized to receive either no treatment (n = 22) or transdermal 17beta-estradiol (50 mug/day) in continuous regimen and nomegestrol (5 mg/day for 12 days/month) in a sequential regimen (n = 22). Results: One year after the beginning of the study, in untreated women, total and trunk fat mass and percent fat were significantly increased, whereas trunk lean mass was significantly decreased. On the contrary, women treated with HT did not show any significant difference in body composition parameters. In untreated women, serum leptin levels were significantly increased at the end of the study in comparison with baseline values. Serum leptin levels at the other times evaluated were not significantly different from baseline values. In women treated with HT, serum leptin levels did not show significant changes throughout the study. Conclusions: Untreated postmenopausal women show an increase in total and percent fat mass and a centralization of fat distribution. Serum leptin levels parallel this increase, resulting in significantly higher levels I year after the study. Women treated with HT are protected against these changes. This may represent a protective mechanism against cardiovascular diseases.