Decline in Handgrip Strength From Midlife to Late-Life is Associated With Dementia in a Japanese Community: The Hisayama Study.

Yozo Hatabe,Takanori Honda,Mao Shibata,Emi Oishi,Takanari Kitazono,Tomoyuki Ohara,Shigenobu Kanba,Jun Hata,Daigo Yoshida,Toshiharu Ninomiya

doi:10.2188/jea.je20180137

Abstract

BackgroundThe association between decline in handgrip strength from midlife to late life and dementia is unclear.MethodsJapanese community-dwellers without dementia aged 60 to 79 years (ie, individuals in late life; mean age, 68 years) were followed for 24 years (1988–2012) (n = 1,055); 835 of them had participated in a health examination in 1973–1974 (mean age, 53 years), and these earlier data were used for the midlife analysis. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973–74 to 1988) from midlife to late life on the development of total dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012.ResultsDuring the follow-up, 368 subjects experienced total dementia. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [−14 to −1%] 28.4, and severely decreased [≤−15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval, 1.14–1.99, P < 0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Similar significant findings were observed for AD, but not for VaD.ConclusionsOur findings suggest that a greater decline in handgrip strength from midlife to late life is an important indicator for late-life onset of dementia.

Highlights

Accumulating epidemiological evidence suggests that maintaining higher levels of physical activity is important to prevent premature death, disability, and cognitive impairment in late life.[1,2,3,4] We previously reported the relationship between late life physical activity and the development of dementia in a Japanese elderly population.[5]
These findings raise the possibility that maintaining handgrip strength, as well as systemic muscle strength, from midlife to late life would be important for preventing late-life risk of dementia, because these muscle strengths begin to decrease with age after midlife.[18]
The age- and sex-adjusted cumulative incidence for total dementia and its subtypes according to %change of handgrip strength, the Hisayama Study, 1988–2012

Summary

Introduction

Accumulating epidemiological evidence suggests that maintaining higher levels of physical activity is important to prevent premature death, disability, and cognitive impairment in late life.[1,2,3,4] We previously reported the relationship between late life physical activity and the development of dementia in a Japanese elderly population.[5]. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973–74 to 1988) from midlife to late life on the development of total dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [−14 to −1%] 28.4, and severely decreased [≤−15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval, 1.14–1.99, P < 0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Conclusions: Our findings suggest that a greater decline in handgrip strength from midlife to late life is an important indicator for late-life onset of dementia

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