Purpose: The purpose of this study was to examine the association between age at menopause and mortality in a population-based sample of women in the United States.
Methods: This study was based on data from the National Health and Examination Survey (NHANES) Epidemiologic Follow-up Study; 3191 women aged 50-86 years were included. There were 345 deaths over a mean follow-up time of 4.0 years. We used age-stratified and Poisson regression procedures to assess mortality risk by age at natural menopause, with adjustment for age, duration of follow-up, race, education, smoking, and use of hormone replacement therapy. We conducted a separate analysis for surgical menopause with bilateral oophorectomy.
Results: Compared with women who were menstruating to age 50 or later, the adjusted mortality rate ratios (RR) were 1.50 (95% confidence interval (CI), 0.97-2.34) for women with a natural menopause at age < 40, 1.04 (95% CI, 0.72-1.51) for those with menopause at age 40-44, and 0.96 (95% CI, 0.72-1.26) for those with menopause at age 45-49. Women with a natural menopause at age 40-44 years experienced an increased risk of cancer-related mortality (adjusted RR 2.34, 95% CI, 1.20-4.58). No age-related increased mortality risk was seen among women who had surgical menopause with bilateral oophorectomy.
Conclusions: This study provides some support for the concept that age at natural menopause serves as a biological marker of health and aging, with potential implications extending beyond cardiovascular diseases.