Bidirectional associations of grip strength-gait speed with mild cognitive impairment and specific cognitive abilities among older adults: A longitudinal analysis.

Background: Previous studies showed that physical performance was associated with mild cognitive impairment (MCI). As the easily measured aging biomarkers, grip strength and gait speed could effectively reflect physical function. However, whether grip strength, gait speed, and the combination of the two were bidirectionally associated with MCI and specific cognitive function domains, have not been explored.

Methods: The bidirectional relationships between grip strength and MCI, gait speed and MCI, and the combination of grip strength with gait speed and MCI, were examined by generalized estimating equation (GEE). GEE was performed to further estimate the bidirectional relationships between grip strength combined with gait speed and the five domains of cognitive function, respectively.

Results: In total, 2,227 older adults (3 waves) were included. The MCI risk was higher for low grip strength group (OR = 1.78; P < 0.001) compared to normal grip strength group, as well as higher for low gait speed group (OR = 1.71; P < 0.001) compared to normal gait speed group. Low grip strength combined with low gait speed had the maximum associations with MCI (OR = 4.13; P < 0.001) and decline in orientation, immediate memory, delayed memory, attention and calculation, and language. Older adults with MCI and decline in those five domains of cognition also longitudinally related to lower grip strength and lower gait speed.

Conclusion: The main findings revealed the importance of regularly monitoring grip strength, gait speed, global cognition, and specific cognitive function domains among older people. Early interventions for grip strength, gait speed, and cognition function might achieve reciprocal benefits.