Male- and female-specific reproductive risk factors across the lifespan for dementia or cognitive decline: a systematic review and meta-analysis

• Published in: BMC medicine 2023-11, Vol.21 (1), p.457-457, Article 457
• Main Authors: Han, Shuang-Ling, Liu, De-Chun, Tan, Chen-Chen, Tan, Lan, Xu, Wei
• Format: Article
• Language: English
• Subjects: 17β-Estradiol; Analysis; Androgen Antagonists; Androgens; Bias; Breastfeeding & lactation; Cognition & reasoning; Cognitive ability; Cognitive appraisal; Cognitive decline; Cognitive Dysfunction - epidemiology; Cognitive Dysfunction - etiology; Cohort analysis; Cryptorchidism; Dementia; Dementia - complications; Dementia - epidemiology; Dementia disorders; Female; Females; Globulins; Humans; Life span; Longevity; Male; Males; Menarche; Menopause; Menstruation; Meta-analysis; Obstetrics; Ovariectomy; Ovaries; Parity; Pregnancy; Prevention; Prostatic Neoplasms; Quality; Risk Factors; Sex differences; Sex hormones; Systematic review; Womens health
• ISSN: 1741-7015; 1741-7015
• DOI: 10.1186/s12916-023-03159-0

Sex difference exists in the prevalence of dementia and cognitive decline. The impacts of sex-specific reproductive risk factors across the lifespan on the risk of dementia or cognitive decline are still unclear. Herein, we conducted this systemic review and meta-analysis to finely depict the longitudinal associations between sex-specific reproductive factors and dementia or cognitive decline. PubMed, EMBASE, and Cochrane Library were searched up to January 2023. Studies focused on the associations of female- and male-specific reproductive factors with dementia or cognitive decline were included. Multivariable-adjusted effects were pooled via the random effect models. Evidence credibility was scored by the GRADE system. The study protocol was pre-registered in PROSPERO and the registration number is CRD42021278732. A total of 94 studies were identified for evidence synthesis, comprising 9,839,964 females and 3,436,520 males. Among the identified studies, 63 of them were included in the meta-analysis. According to the results, seven female-specific reproductive factors including late menarche (risk increase by 15%), nulliparous (11%), grand parity (32%), bilateral oophorectomy (8%), short reproductive period (14%), early menopause (22%), increased estradiol level (46%), and two male-specific reproductive factors, androgen deprivation therapy (18%), and serum sex hormone-binding globulin (22%) were associated with an elevated risk of dementia or cognitive decline. These findings potentially reflect sex hormone-driven discrepancy in the occurrence of dementia and could help build sex-based precise strategies for preventing dementia.