Early-Life Risk Factors for Dementia and Cognitive Impairment in Later Life: A Systematic Review and Meta-Analysis

Article type: Research Article

Authors: Wang, Xue-Jie^a | Xu, Wei^b | Li, Jie-Qiong^a | Cao, Xi-Peng^c | Tan, Lan^{a; b; *} | Yu, Jin-Tai^{a; d; *}

Affiliations: [a] Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China | [b] College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, China | [c] Clinical Research Center, Qingdao Municipal Hospital, Qingdao University, Qingdao, China | [d] Department of Neurology, Huashan Hospital, Fudan University, China

Correspondence: [*] Correspondence to: Dr. Jin-Tai Yu, Department of Neurology, Huashan Hospital, Fudan University, No. 12 Wulumuqi Road, Shanghai, China; or Dr. Lan Tan, Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, No.5 Donghai Middle Road, Qingdao, China. Tel.: +86 532 8890 5659; Fax: +86 532 8890 5659; E-mails: yu-jintai@163.com (J.T. Yu); dr.tanlan@163.com (L. Tan).

Abstract: Background:Early-life environment is related to childhood brain development and cognitive function in later life. However, the associations of early-life risk factors with dementia and cognitive impairment were still controversial. Objective:Our study aims to investigate early-life risk factors for dementia and cognitive impairment. Methods:PubMed and Cochrane Library were searched to identify prospective cohort and retrospective case-control studies exploring early-life factors for dementia and cognitive impairment. Pooled effect estimates for each factor were calculated by random-effect model. Results:Thirty-seven studies with 46,727 participants were included. The pooled results indicated significant associations of dementia with food deficiency (OR = 2.05, 95% CI = 1. 22–3.44), low education level (RR = 1.80, 95% CI = 1.60–2.02), and shorter leg length (OR = 1.19, 95% CI = 1.07–1.32). Other potential risk factors identified in the systematic review include rural residence, number of siblings, history of head trauma, early parental death or re-marriage, and poor learning ability. Conclusion:Early-life factors, including education level, leg length, history of childhood head trauma, family-related factors and learning ability, were associated with the risk of dementia and cognitive impairment in later life. Further high-quality longitudinal studies are needed to verify the causality between early-life risk factors and dementia and cognitive impairment.

Keywords: Cognitive impairment, dementia, early-life, meta-analysis, risk factors, systematic review

DOI: 10.3233/JAD-180856

Journal: Journal of Alzheimer's Disease, vol. 67, no. 1, pp. 221-229, 2019