Longitudinal bidirectional association between hand grip strength and cognitive function in Chinese older adults: Evidence from the China Health and Retirement Longitudinal Study.

Abstract

ObjectiveThis study examined the longitudinal association between handgrip strength and cognitive function and the temporal sequence of changes in both factors in a national longitudinal cohort of Chinese older adults.MethodData were derived from 3 waves (2011 baseline, 2013 follow-up, 2015 follow-up) of the China Health and Retirement Longitudinal Study (CHARLS). Participants were those with no memory-related disorders at baseline and follow-up, and those who had complete handgrip strength and cognitive data. Handgrip strength in at least one hand was measured in all 3 waves. The highest recorded value during the handgrip test was used as the outcome of the strength measurement. Mental intactness and episodic memory were used to assess the overall cognitive function at each wave of data collection. Cross-lagged panel models were used to examine the relationship between handgrip strength and cognition over time.ResultsA total of 2550 participants were included in the data analysis. Age of participants at baseline was 60-83 years, and 43.9% were female (n = 1120). The 5.7% of participants with weak muscle strength (n = 145) had slightly lower cognitive function than those in the normal group. Cross-lagged panel analysis showed that baseline overall cognitive scores predicted subsequent handgrip strength. At the same time, handgrip strength at baseline predicted subsequent overall cognitive scores. The results remained robust after accounting for confounding factors.ConclusionThere was a longitudinal bidirectional correlation between handgrip strength and cognitive function in elderly Chinese individuals. Future studies should determine whether interventions to improve one (e.g., handgrip strength) might slow the development of the other (e.g., cognitive impairment).