Body composition and resting metabolic rate of perimenopausal women using continuous progestogen contraception.

Objective: The effect on body composition and in particular on fat mass (FM) of 12 months' use of a desogestrel (DSG)-only contraceptive pill or the levonorgestrel-releasing intrauterine system (LNG-IUS) was evaluated in women in the perimenopause.

Methods: An observational study comprised 102 perimenopausal women: 42 received a 75 μg DSG pill, 34 received the 52 mg LNG-IUS, and 26 received no treatment. Body composition, body weight and resting metabolic rate (RMR) were evaluated at baseline and again after 12 months.

Results: FM did not change in the control group (- 0.5 ± 1.6%) but significantly increased in the LNG-IUS group (+ 1.1 ± 2.9%; p = 0.02 vs. controls) and in the DSG group (+ 2.8 ± 3.5%; p = 0.0001 vs. controls; p = 0.02 vs. LNG-IUS). Women treated with DSG or the LNG-IUS showed a non-significant increase in body weight, body mass index and waist circumference. RMR did not significantly vary in the control group (- 3.8 ± 292.9 kJ/ 24 h) and tended to decrease but not significantly in the LNG-IUS (115.5 ± 531.8 kJ/ 24 h) and DSG groups (305.9 ± 556.9 kJ/24 h).

Conclusions: The results of this preliminary study seem to indicate that in perimenopausal women continuous use of the DSG-only pill and to a lesser extent the LNG-IUS may favour FM accumulation.