Age at menarche and natural menopause and number of reproductive years in association with mortality: Results from a median follow-up of 11.2 years among 31,955 naturally menopausal Chinese women

Background: Studies conducted in Western countries suggest that early age at menarche and early age at menopause are both associated with increased total mortality, but limited data are available for Asian populations. We examined associations of age at menarche and natural menopause and duration of the reproductive span with mortality in a population-based cohort study of Chinese women. Methods: We evaluated the effects of age at menarche, age at natural menopause, and number of reproductive years on total and cause-specific mortality among 31,955 naturally menopausal Chinese women who participated in the Shanghai Women's Health Study, a population-based, prospective cohort study. Results: A total of 3,158 deaths occurred during a median follow-up of 11.2 years. Results from Cox proportional hazards models showed that younger age at menopause (<46.64 years) was associated with higher risk of total mortality (P_trend = 0.02). Younger age at menarche (<14 years) was associated with higher risk of mortality from stroke (P_trend = 0.03) and diabetes (P_trend = 0.02) but lower risk of mortality from respiratory system cancer (P_trend = 0.01). Women with a shorter reproductive span had lower risk of mortality from gynecological cancers (P _trend = 0.03). Conclusions: Our study found that menstrual characteristics are important predictors of mortality, suggesting an important role of sex hormones in biological aging.