Reproductive Factors and Risk of Dementia in Natural Postmenopausal Women: a Cross-sectional Study
Abstract Background: Women comprise more than half of people suffering cognitive impairment. This study aims to evaluate the association or interaction between reproductive factors and the risk of dementia in Chinese women with natural menopause.Methods: The cross-sectional study was conducted in 112 community primary health care centers in rural northern China between April 2019 and January 2020. A total of 4,275 women aged ≥ 65 years who had natural menopause were included. Reproductive factors were recorded by self-report. Reproductive period was calculated as age at menopause minus age at menarche.Results: Compared to those without dementia, women with dementia were significantly older at menarche and younger at menopause; had significantly shorter duration of reproductive period; and had more pregnancies and parities. There were 0.757, 0.698, and 0.708 times to get dementia for women who experienced reproductive periods with 31-33 years, 34-36 years, and ≥ 37 years, respectively, as compared with ≤ 30 years. Reproductive period could positively predict MMSE score (β = 0.112) and negative prediction of the number of parities (β = -0.449); the number of parities could negatively predict MMSE score (β = -0.851) as well.Conclusions: Longer duration of reproductive period, directly or through lower number of pregnancies/parities indirectly, lowers the risk of dementia in late life.