Cyclic progestin administration increases energy expenditure and decreases body fat mass in perimenopausal women.

OBJECTIVE:The menopause transition is characterized by luteal phase defect anovulatory cycles, and changes in body weight and body composition. Resting metabolic rate (RMR) is increased in the luteal phase of the menstrual cycle. We evaluated whether progestin administration increases RMR and influences body composition of perimenopausal women. DESIGN:Thirty-six perimenopausal women were randomly allocated to receive either calcium (1 g/day) continuously plus the progestin nomegestrol acetate (NOMAc; 5 mg/day for 10 days x month for 12 months) or calcium alone. Body composition, RMR, energy intake, and climacteric and psychological symptoms were evaluated at baseline and after 12 months. In the NOMAc group, body composition and RMR analyses were performed twice during the first month of treatment. One evaluation was performed after almost 8 days of NOMAc adjunct, and an another before or almost 15 days after NOMAc administration. RESULTS:Resting metabolic rate was increased by NOMAc administration of 54.5 +/- 73.8 kcal/24 h (P < 0.01). In women treated with NOMAc, fat mass decreased by 1.2 +/- 0.6 kg (P < 0.001). In comparison with controls, body weight (P < 0.05) and body mass index (P < 0.05) were also reduced after 12 months of therapy with NOMAc. CONCLUSIONS:In perimenopausal women the use of NOMAc increases RMR. During the menopause transition, cyclic NOMAc administration may contribute to reduce negative modification of body composition.