The association between menopause and dementia risk

Abstract

AbstractBackgroundWomen have a higher prevalence of Alzheimer’s disease compared to men. Studies are conflicting as to whether an earlier age of menopause or hysterectomy prior to natural menopause, are associated with an increased risk of cognitive impairment. The goal of this study was to determine whether age of menopause and hysterectomy are associated with incident dementia in a group of older, community‐dwelling women.MethodFemale participants from three ongoing Rush cohorts, the Rush Memory and Aging Project, the Religious Orders Study, and the Minority Aging Research Study were included (total n = 3122, mean age = 77 years at baseline, SD = 7.8). Annual clinical assessments allowed for dementia status categorization, based on detailed neuropsychological testing and clinical judgment, using the NINDS‐ADRDA criteria. Age at menopause and hysterectomy status was based on self‐report at baseline. Data on ovarian preservation or removal at time of surgery was not available. Age of menopause was categorized into tertiles (<45, 45‐50, >50). Risk of dementia, with age at dementia diagnosis as the outcome, was evaluated using Cox proportional regression models adjusting for race, early‐life socioeconomic status, education, diabetes, and smoking status.ResultAt the time of these analyses, women were followed for an average of 8.3 years (SD = 5.6). Women in the earliest tertile of menopause age were less likely to be white, more likely to report having diabetes, and have longer hormone therapy use (p<0.01). In fully adjusted models, women with menopause at age 45‐50 (HR 0.80, 95% CI 0.67‐0.96) and age >50 (HR 0.74, 95% CI 0.62‐0.90) had a lower risk of dementia compared to women with menopause at age <45. Hysterectomy prior to natural menopause was not associated with an elevated risk of dementia (HR = 1.01, 95% CI 0.87‐1.19).ConclusionIn a group of older women, earlier age at menopause but not hysterectomy was associated with an elevated risk of dementia. Future research will determine whether these associations differ by race or ethnicity and the factors that may contribute to such differences.Funding: P30‐AG072975, R01‐AG17917, R01‐AG22081