Age at menopause, cause-specific mortality and total life expectancy

Background: A later menopause has been associated with a decreased cardiovascular risk but with an increased risk for breast and endometrial cancer. The net effect on mortality is unclear. We determined the association of age at menopause with longevity and with the balance between cardiovascular and cancer mortality. Methods: We analyzed data from a breast cancer screening cohort comprising 12,134 postmenopausal women followed for an average of 17 years. We used Cox proportional hazards models and life tables to calculate the life expectancy of an average Dutch woman at age 50. Results: During 204,024 person-years, there were 2607 deaths, of which 963 were due to cardiovascular diseases and 812 due to cancer. Ischemic heart disease risk decreased with a later menopause (hazard ratio [HR] = 0.98 per year; 95% confidence interval = 0.96-0.99), but the risk of fatal uterine or ovarian cancer increased (1.07 per year; 1.01-1.12). A later menopause was associated with longer overall survival; HR for total mortality was 0.98 per year (0.97-0.99). Life expectancy in women with menopause after age 55 was 2.0 years longer than those with menopause before age 40. Adjustment for potential confounders did not materially change the results. Conclusions: Age-adjusted mortality is reduced 2% with each increasing year of age at menopause. In particular, ischemic heart disease mortality is 2% lower. Although the risk of death from uterine or ovarian cancer is increased by 5%, the net effect of a later menopause is an increased lifespan.