Menopausal status, age at menopause and risk of all-cause mortality among Chinese women: findings from a 10-year prospective study.

Introduction: Menopause characteristics (menopausal status and age at menopause) have been implicated in future health consequences. However, evidence of the impact on menopause on total mortality has been inconsistent. The present study aimed to investigate the associations of menopausal status and age at menopause with the risk of all-cause mortality in Chinese women. Methods: We used prospective data from the China Kadoorie Biobank cohort study that recruited over 300 000 women aged 30-79 years from 10 regions across China between 2004 and 2008. All participants were prospectively followed up, with a median follow-up of 10.20 years. Cox proportional hazard regression was used to examine HRs with 95% CIs for all-cause mortality associated with menopausal status and age at menopause. Results: Compared with premenopausal women, postmenopausal women were at higher risk of all-cause mortality with adjusted HR of 1.11 (95% CI 1.03 to 1.20). Among postmenopausal women, the HRs of total mortality were 1.25 (95% CI 1.14 to 1.36), 1.09 (95% CI 1.03 to 1.15), 0.98 (95% CI 0.94 to 1.02) and 0.97 (95% CI 0.91 to 1.04) for menopause at ages less than 40, 40-44, 50-53 and 54 years or older, respectively, relative to 45-49 years. In addition, for each 1-year increase in age at menopause was associated with a 1% decreased risk of death from all causes (95% CI 0.98 to 0.99). Conclusions: Women with postmenopausal status had a higher risk of all-cause mortality than premenopausal women, particularly for ages at menopause younger than 45 years.