Background: Ageing is associated with declines in both cognitive and physical functions. A correlation between these declines may be hypothesized due to their shared underlying mechanisms including increased oxidative stress, chronic inflammation, and imbalanced energy metabolism. This study aimed to determine the association between cognitive functions and several physical function measures in community-dwelling older adults at risk of falls.
Methods: This is a preliminary analysis of baseline data from the Capacity of Older Individuals after Nut Supplementation (COINS) study, a randomised controlled trial investigating the effect of peanut butter on functional capacity in community-dwelling older adults. Participants were adults aged ≥ 65 years, generally healthy or with metabolic disease(s) managed through lifestyle or common medications and at risk for falls, defined by a score of ≥ 2 points on a simplified falls risk screening questionnaire. Cognitive function was assessed by the Montreal Cognitive Assessment (MoCA) (higher score indicating better cognitive functions) and the trail-making tests A and B (longer time indicating poorer cognitive functions). Physical function was assessed using 4-meter gait speed (m/s), standing balance (score), 5-times chair stands (seconds) and the number of chair stands in 30 seconds, timed-up-and-go (seconds), 4-square step tests (seconds), handgrip and knee extensor muscle strength (kg). Linear regression analyses were performed and adjusted for age and sex.
Results: Data from 80 participants who completed the baseline assessment were included in the analysis (56% females, mean±SD age 75.2±4.5 years). MoCA score was associated with higher gait speed [β=0.20 (Standard Error, 0.00), p=0.048] and a higher number of chair stands in 30 seconds [β=0.25 (0.10), p=0.019]. Longer time in trail-making test A was associated with slower gait speed [β= -0.01 (0.00), p=0.027], longer time in timed up and go [β=0.04 (0.02), p=0.014] and 4-square step tests [β=0.07 (0.02), p=0.04]. Trail-making test B time was not associated with any physical performance test.
Conclusion: The preliminary data suggests a positive association between cognitive function and physical function, particularly gait speed in community-dwelling older adults at risk of falls. These findings should be confirmed in larger longitudinal studies, potentially to understand any causal relationships. Clinical practice may benefit from future studies investigating the effectiveness of lifestyle interventions to prevent and manage both conditions simultaneously.