The Relationship between Handgrip Strength and Cognitive Function in Elderly Koreans over 8 Years: A Prospective Population-Based Study Using Korean Longitudinal Study of Ageing

BACKGROUND: Decreased physical performance, such as weakened handgrip strength and cognitive decline, is associated with disability and premature death in old age. We investigated the association between handgrip strength and cognitive impairment in Korean elderly adults with normal cognitive function. METHODS: This prospective study used the database from the Korean Longitudinal Study of Ageing. The participants included 2,378 adults aged 65 years or older with normal cognitive function (Korean Mini-Mental Status Evaluation [K-MMSE] score ≥21). Using a mixed-effects model, we examined the associations at baseline and over an 8-year follow-up period between handgrip strength and K-MMSE score. We investigated handgrip strength as a predictor of change in cognitive function. RESULTS: This study included 1,138 women (mean maximum handgrip strength 19.2 kg, mean K-MMSE score 25.1) and 1,240 men (mean maximum handgrip strength 30.7 kg, mean MMSE score 26.2). The baseline handgrip strength was positively associated with the baseline K-MMSE score (b=0.18, P<0.001). Using a mixed-effects model, we found that higher handgrip strength at baseline can predict MMSE scores positively over time (b=0.14, P<0.001) and the change of handgrip strength over time was a predictor of high MMSE scores over the study period (b=0.01, P<0.01). CONCLUSION: We observed significant associations between baseline handgrip strength and baseline and change of cognition, as well as the longitudinal influence of handgrip strength on the change of cognitive function in elderly Korean adults with normal cognitive function.