Hormone replacement therapy may alleviate sleep apnea in menopausal women: a pilot study.

OBJECTIVE: The incidence of sleep apnea syndrome (SAS) in women increases after menopause. Progestins alone do not alleviate SAS in menopausal women. However, progestins may require concomitant estrogen administration and estrogen alone may stimulate breathing during sleep. To test these hypotheses, we studied the effects of estrogen alone and estrogen combined with progestin on SAS in menopausal women, using a prospective, cross-over, inception cohort study.

DESIGN: In this pilot study, five women who developed SAS after menopause underwent 2 nights of polysomnography to obtain a baseline, then returned for polysomnography after 3-4 weeks of taking micronized 17 beta-estradiol (E2) and after 10-12 days of taking E2 combined with medroxyprogesterone acetate (E2 + P). Sleep stages were scored according to Rechtshaffen and Kales, frequency and length of apneas were recorded for each subject each night, and the data were analyzed by Student's t test.

RESULTS: E2 and E2 + P both reduced the Respiratory Distress Index. E2 also raised the lowest oxygen desaturation associated with apneic episodes. Total minutes of rapid eye movement sleep increased, and the number of waking episodes decreased when the women were taking E2 and E2 + P, as previously reported.

CONCLUSIONS: Within 1 month after initiating E2 or E2 + P, SAS was reduced in all patients. The Respiratory Distress Index decreased by 25%, and the addition of progestin brought the SAS reduction to 50% in this pilot study. A randomized study in a large group of patients is justified by the findings of this study. Because SAS increases the risk of cardiovascular disease and fatal accidents, the amelioration of SAS by sex steroid hormones could have significant implications for the health of menopausal women.