Serum leptin levels and body composition in postmenopausal women treated with tibolone and raloxifene

Abstract

To compare body composition and serum leptin levels in untreated postmenopausal women and postmenopausal women treated with tibolone or raloxifene. This was a prospective, randomized, controlled study. Sixty-eight postmenopausal women were randomized to receive either no treatment (group A, n = 21) or tibolone 2.5 mg/day (group B; n = 23) or raloxifene 60 mg/day (group C; n = 24). All women underwent height, weight, body mass index evaluation and dual energy x-ray absorptiometry determination of body composition at the beginning of the study and after 12 months. Serum leptin levels were determined at the beginning of the study and after 1, 3, 6, and 12 months in all groups. Women in group A showed no significant changes in both fat and lean mass of arms and legs, whereas a significant increase in trunk fat mass, total fat mass, total percentage of body fat, and trunk percentage of fat was detected 1 year after the beginning of the study. After 12 months, the total percentage of fat mass was significantly higher in group A compared with group B, and the trunk percentage of fat mass was significantly higher in group A compared with groups. In subjects in groups B and C, after 1 year, fat mass, both total and at all areas evaluated, did not show any significant change compared with baseline values. In subjects in group B, total lean and lean mass of the trunk and legs increased significantly at the end of the study, whereas no significant changes were observed in lean mass, total and at all areas evaluated in subjects in group C. After 12 months, total lean mass and lean mass of the legs were significantly higher in group B compared with the other groups. In group A, serum leptin levels were significantly increased at the end of the study compared with baseline values. Leptin concentrations were significantly higher in group A compared with groups B and C after 6 and 12 months. No significant change in serum leptin levels in subjects in groups B and C was detected throughout the study. Serum leptin levels showed a positive, significant correlation with all body composition parameters and body mass index in all groups at the beginning and at the end of the study. The present study confirms that postmenopausal hypoestrogenism leads to increased fat content and serum leptin levels. Raloxifene and tibolone seem to prevent postmenopausal body composition changes without significant modifications of serum leptin levels.