Impact of Social Frailty on Alzheimer’s Disease Onset: A 53-Month Longitudinal Cohort Study

Article type: Research Article

Authors: Tsutsumimoto, Kota^{a; b; c; *} | Doi, Takehiko^a | Nakakubo, Sho^a | Kim, Minji^a | Kurita, Satoshi^a | Ishii, Hideaki^a | Shimada, Hiroyuki^d | Kawachi, Ichiro^c

Affiliations: [a] Department of Preventive Gerontology, Section for Health Promotion, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan | [b] Japan Society for the Promotion of Science, Tokyo, Japan | [c] Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA | [d] Department of Preventive Gerontology, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan

Correspondence: [*] Correspondence to: Kota Tsutsumimoto, Department of Preventive Gerontology, Section for Health Promotion, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, 7-430, Morioka-cho, Obu City, Aichi Prefecture, 474-8511, Japan. Tel.: +81 562 44 5651; Fax: +81 562 46 8294; E-mail: k-tsutsu@ncgg.go.jp.

Abstract: We investigated the association between social frailty and Alzheimer’s disease (AD) incidence among community-dwelling older adults in Japan. A 53-month follow-up cohort study was conducted in Obu City, Japan. Participants comprised 3,720 community-dwelling older adults (mean age, 71.7 years; 48.4% men). The operational definition of social frailty comprised five items: going out infrequently, rarely visiting friends, feeling unhelpful to friends or family, living alone, and not always talking with someone each day. During follow-up, the cumulative AD incidence risk between socially robust, pre-frail, and frail groups was 4.1%, 5.5%, and 10.7%, respectively. In both crude (HR 2.72, 95% CI 1.90–3.89, p < 0.001) and adjusted Cox proportional hazards models (HR 1.53, 95% CI 1.03–2.28, p = 0.035), social frailty was associated with a significantly higher AD incidence risk. The present study revealed that social frailty is strongly associated with AD incidence among Japanese older adults. Further research should elucidate whether social frailty prevention is effective for decreasing AD risk.

Keywords: Alzheimer’s disease, older adults, social frailty

DOI: 10.3233/JAD-181178

Journal: Journal of Alzheimer's Disease, vol. 70, no. 2, pp. 587-595, 2019