Midlife Long-Hour Working and Later-life Social Engagement Are Associated with Reduced Risks of Mild Cognitive Impairment among Community-Living Singapore Elderly

Article type: Research Article

Authors: Deng, Jing-Huan^a | Huang, Kai-Yong^b | Hu, Xiao-Xiao^c | Huang, Xiao-Wei^c | Tang, Xian-Yan^d | Wei, Xiao^b | Feng, Lei^{e; 1; *} | Lu, Guo-Dong^{a; c; 1; *}

Affiliations: [a] The Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, School of Public Health, Guangxi Medical University, Nanning, Guangxi Province, China | [b] Department of Occupational Health and Occupational Medicine, School of Public Health, Guangxi Medical University, Nanning, Guangxi Province, China | [c] Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi Province, China | [d] Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning, Guangxi Province, China | [e] Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore

Correspondence: [*] Correspondence to: Lei Feng, Department of Psychological Medicine, National University of Singapore, NUHS Tower Block Level 9, 1E Kent Ridge Road, Singapore 119228. Tel.: +65 67723489; Fax: +65 67772191; E-mail: pcmfl@nus.edu.sg and Guo-Dong Lu, Department of Toxicology, School of Public Health, Guangxi Medical University. 22 Shuangyong Road, Nanning 530021, Guangxi Province, P.R. China. Tel.: +86 771-5358114; Fax: +86 771-5358539; E-mail: golden_lu@hotmail.com.

Note: [1] These authors contributed equally to the work.

Abstract: Mild cognitive impairment (MCI), as a transitional stage between normal aging and dementia, causes cognitive decline among one-fifth of elders aged 65 years and older. Health-related lifestyles (HRL) are generally regarded as modifiable influencing factors of cognitive decline. The present study investigated how HRLs at two different life stages (one at midlife and the other at later life) affect MCI occurrence among community-dwelling elders, as part of the Diet and Healthy Aging (DaHA) study in Singapore. The frequencies of major HRL activities were compared between 119 clinical diagnosed MCI cases and 632 normal aging controls with functional cognition. The associations of HRLs with MCI were determined by multivariate logistic regression analysis and adjusted according to known factors including age, childhood education, and major chronic diseases (hypertension, stroke, diabetes, and cataracts or glaucoma). Long-hour working in midlife (adjusted OR = 0.418 with 95% CI 0.215–0.812) and social engagement in later-life (adjusted OR = 0.532 with 95% CI 0.329–0.859) were associated with reduced risks of MCI, respectively. It is important to note that those elders who had both midlife long-hour working and later-life social engagement were related to the lowest risk of MCI (adjusted OR = 0.285 with 95% CI 0.143-0.565), when compared to the least active subgroup who neither had worked long hours in midlife nor participate in social activities in later-life. Therefore, the present study demonstrated that midlife long-hour working and later-life social engagement were modifiable factors for the maintenance of cognitive functions.

Keywords: Health-related lifestyle, later-life, midlife, mild cognitive impairment, social engagement, work

DOI: 10.3233/JAD-180605

Journal: Journal of Alzheimer's Disease, vol. 67, no. 3, pp. 1067-1077, 2019