Sex differences in all-cause mortality and life span between women with premature menopause and men: propensity score matching analysis

Objective: This study investigated sex differences in all-cause mortality and life span between women undergoing premature menopause and men using propensity score matching analysis. Methods: Data were from the National Health and Nutrition Examination Survey (1999-2018) and the National Health and Nutrition Examination Survey III (1988-1994). We included 3,214 women experiencing premature menopause and 23,067 men. The participants were all older than 40 years. Propensity score matching analysis created matched cohorts of women and men using a 1:1 ratio. We employed Cox proportional hazard models to estimate unadjusted and adjusted hazard ratios (HR) (95% confidence interval [CI]) for the association between sex and both all-cause mortality and survival up to the 75th percentile of life span. A subgroup analysis examined the effects of hormone therapy on mortality and life span. Results: Compared with men in the matched cohorts, the adjusted HR values (95% CI) for all-cause mortality in women with age at menopause at <35, 35 to 39, and <40 years were 0.65 (0.54-0.78), 0.72 (0.59-0.87), and 0.67 (0.60-0.76), respectively. However, the adjusted HR values (95% CI) for women and men to survive to the 75th percentile of life span were not statistically significant. Besides, there was no significant difference in the mean life span between deceased women and men in the matched cohorts. In the subgroup analysis, the mean life span did not differ significantly between deceased women taking hormone therapy and men. However, the average life span of women never using hormone therapy was significantly longer than that of men (78.3 +/- 11.6 vs 76.6 +/- 11.9 years, P = 0.0154). Conclusions: Women experiencing premature menopause had lower risks of all-cause mortality than men, but the advantage that women had in terms of life span was insignificant.