The Association between Female Reproductive Factors and Subjective and Objective Cognitive Function: a Cross-sectional Analysis from the Pingyin Cohort

Background The association between female reproductive factors and cognitive function was unclear, there still lack studies on female reproductive factors and subjective cognitive function. Objective Exploring the relationship between female reproductive factors and subjective or objective cognitive function, and providing theoretical basis for the prevention and intervention of cognitive decline and dementia. Methods The baseline survey was conducted in July 2023 in Pingyin, Jinan (in three townships). After using a multi-stage cluster random sampling method, 2 165 valid participants aged 45-70 were recruited at baseline. We collected sociodemographic data, medical histories, lifestyle factors, and female reproductive factors through a self-designed comprehensive questionnaire. The subjective and objective cognitive function of participants were evaluated by the Subjective Cognitive Decline-Questionnaire 9 (SCD-Q9) and Montreal Cognitive Assessment Scale-Basic (MoCA-B), respectively. In addition, we also collected anthropometric data (included height and weight) and blood samples (to get APOE e4 alleles). Multivariate Logistic regression and Local weighted regression (Loess) were used to analyze the influence of female reproductive factors on cognitive function and to detect potential nonlinear relationships between age at menarche, age at menopause, length of reproductive period and MoCA-B scores. Results This study was based on a baseline population and included 1 044 postmenopausal women. The prevalence of abnormal SCD-Q9 scores was 48.37% (505/1 044), while the prevalence of abnormal MoCA-B scores was 67.43% (704/1 044). Women who had 3 or more children had a lower risk of subjective cognitive decline compared with those who had 1 or fewer children (OR=0.59, 95%CI=0.36-0.98). Women with a breastfeeding duration <6 months had a higher risk of subjective cognitive decline compared with those with a breastfeeding duration of 6-12 months (OR=3.69, 95%CI=1.03-13.16). Age at menarche >18 years (OR=1.91, 95%CI=1.09-3.35), age at menopause ≤45 years (OR=1.61, 95%CI=1.00-2.62), and reproductive period ≤30 years (OR=1.56, 95%CI=1.07-2.29) or >40 years (OR=2.22, 95%CI=1.05-4.72) were all associated with poorer objective cognitive function (P<0.05). Loess analysis revealed an inverted "J-shaped" relationship between age at menarche, age at menopause, reproductive period and MoCA-B scores. Conclusion Women with more children (≥3) have a lower risk of subjective cognitive decline and women with shorter breastfeeding duration (<6 months) have a higher risk of subjective cognitive decline. Age at menarche >18 years, early menopause (≤45 years), and excessively long or short reproductive periods are all associated with poorer objective cognitive function. We should pay attention to the influence of female reproductive factors on cognitive function in order to delay the process of cognitive decline.