Cross-sectional and longitudinal associations of activity diversity with physical function in community-dwelling older adults

BACKGROUND: The role of activity diversity across physical, cognitive, and social domains in preserving physical function remains unexplored. AIMS: To investigate the associations between multidomain activity diversity and physical function in community-dwelling older adults. METHODS: We analyzed data from 763 participants (mean age: 74.8 ± 6.2 years; 63.8% female) in the 2018 Tarumizu Study. Activity diversity was assessed using 12 items (physical, cognitive, and social activities; four per domain). High engagement was defined as participation in ≥ 3 within a domain. Participants were categorized by the number of highly engaged domains (0-1, 2, and 3). Low physical function was defined as low grip strength (< 28 kg for males; <18 kg for females) and/or slow gait speed (< 1.0 m/s). Logistic regression analyses examined cross-sectional (n = 763) and 5-year longitudinal (n = 175 among those without low physical function at baseline) associations. RESULTS: Cross-sectionally, low physical function occurred in 45.3%, 29.1%, and 21.4% in the 0-1, 2, and 3 domain groups, respectively. Participants engaged in two or three domains had significantly lower odds of low physical function than those engaged in 0-1 domains. Over 5 years, incident low physical function occurred in 35.1%, 16.2%, and 11.4% of the 0-1, 2, and 3 domain groups, respectively, with significantly lower risks in the 2 and 3 domain groups, and a linear trend (p for trend = 0.023). DISCUSSION: Engagement in ≥ 2 activity domains was associated with reduced risk of low physical function in older adults. CONCLUSIONS: Maintaining diverse lifestyle activities supports physical function in later life.