ObjectivesThe aim of the present study was to evaluate differences between two regimens of estrogen/progestogen replacement therapy on nocturnal sleep in postmenopausal women.MethodsTwenty-one (21) postmenopausal women were studied. They were randomized into two treatment groups: (1) estrogen (Premarin 0.625 mg) and medroxyprogesterone acetate (Provera 5 mg) (n= 11) or (2) estrogen (Premarin 0.625 mg) and oral micronized progesterone (Prometrium 200 mg) (n= 10). Postmenopausal women were recorded for two consecutive nights in the sleep laboratory at baseline and again after 6 months of treatment in a randomized trial. The women also had to fill out evening and morning sleep and vigilance questionnaires for 7 days before baseline recordings and for 23 days before month 6 recordings.ResultsSleep efficiency was found to be significantly improved in the micronized progesterone group. It increased by 8% (p= 0.014) with no such increase observed in the medroxyprogesterone acetate group. Time spent awake after sleep onset was also significantly improved in the micronized progesterone group but not in the medroxyprogesterone acetate group. On the other hand, menopausal symptoms and subjective measures of sleep (questionnaires) improved in both groups after treatment.ConclusionThis study suggests that medroxyprogesterone acetate and micronized progesterone are both effective for treating menopausal symptoms but that the latter might better improve the quality of sleep in postmenopausal women taking estrogen.