Type of Menopause, Age at Menopause, and Risk of Developing Obstructive Sleep Apnea in Postmenopausal Women

Abstract

Despite established sex differences and longstanding hypotheses of sex hormones in obstructive sleep apnea (OSA) etiology, no studies have evaluated type of menopause and age at menopause, which affect postmenopausal hormonal milieu, in relation to OSA risk in women. We followed 50,473 postmenopausal women from the Nurses' Health Study (NHS) between 2002-2012 and 53,827 postmenopausal women from the NHSII between 1995-2013, with 1,712 and 2,560 incident OSA diagnoses, respectively. Compared with natural menopause, the pooled HR for OSA was 1.27 (95% CI: 1.17, 1.38) for surgical menopause by hysterectomy/oophorectomy. The association remained the same after further accounting for age at menopause (HR=1.26; 95% CI: 1.15, 1.38). The risk associated with surgical menopause was higher in non-obese women as well as women who never used hormone therapy (P-interaction<0.05). Earlier menopause was associated with higher OSA risk prior to adjustment for type of menopause (HR comparing <40 years versus 50-54 years=1.21; 95% CI: 1.08, 1.35; p=0.008 for trend), although no association was observed after the adjustment. Surgical as compared with natural menopause was independently associated with higher OSA risk in postmenopausal women. Our results provide additional evidence for a role of sex hormones, particularly abrupt hormonal changes, in modulating OSA risk.