Asthma and the menopause: A systematic review and meta-analysis

Objective To review the available literature to determine whether the menopausal transition is associated with asthma incidence. Methods We performed a systematic review and meta-analysis of cohort and cross-sectional studies providing a definition/assessment of menopausal status, incidence or prevalence of a defined diagnosis of asthma, and providing a measure of the association or of menopausal state and asthma or enough data for a calculation of this association. Where possible these meta-analytic estimates were also stratified by intake of menopausal hormone therapy (MHT). Results Of 76 potentially relevant articles, 8 studies met the inclusion criteria and were included in the review, and 6 in the meta-analysis. There was heterogeneity across studies: four studies reported slightly increased prevalence rates of asthma in post-menopause, one large cohort yielded a lower asthma incidence and one cross-sectional study a lower prevalence in post-menopause. Overall, the meta-analysis showed no significant association between menopause and asthma rates. When stratifying by use of MHT, the association between menopause and asthma rates was increased in women reporting use of MHT (RR 1.32, 95%CI 1.01–1.74), but not in women not using MHT. Conclusion We found no significant association of menopause with asthma prevalence or incidence except for women reporting use of MHT. However, these findings result from a small number of studies, including only 1 large cohort with incidence rates for pre- as well as post-menopause. Further studies are needed addressing more closely subgroup analyses and a possible modification of the association of menopause and asthma by MHT.