The association between age at natural menopause and risk of asthma among postmenopausal women from the Canadian Longitudinal Study on Aging.

Objective: This study aimed to investigate the association between age at natural menopause and incidence of asthma among postmenopausal Canadian women.

Methods: Women between the ages of 45-85 yr were followed for a 10-yr period. Analysis was restricted to naturally postmenopausal women who are nonsmokers and did not have asthma prior to menopause. Age at natural menopause was examined using the following categories: 40-44, 45-49, 50-54 (reference), and ≥55. Survival analysis was utilized to determine time to onset of asthma. Multivariable Cox regression analysis was performed to assess the relationship between age at natural menopause and asthma after adjusting for covariates.

Results: The multivariable Cox regression analysis showed a 30% decreased risk of asthma in women with age at natural menopause of 40-44 yr compared with age at natural menopause of 50-54 yr with a hazard ratio of 0.7 (95% confidence interval: 0.49-0.95).

Conclusions: Women with later ages at natural menopause may be at increased risk for asthma.