Weida Lyu, Tomoki Tanaka, Katsuya Iijima
AIM: Identifying the modifiable lifestyle-related factors associated with intrinsic capacity (IC) is essential for developing population approaches. This study examined the cross-sectional associations of nutrition-related, physical, and social factors with IC among community-dwelling older adults. METHODS: Participants were 822 community-dwelling older adults. IC was assessed across five domains of locomotion, vitality, psychological capacity, cognitive function, and sensory function. Each IC domain score was log-transformed and standardized, and a gender-specific Confirmatory factor analysis (CFA)-weighted composite IC score was constructed by fitting single-factor CFA models separately for men and women. Nutrition-related, physical, and social factors were defined according to our previous study. Participants were classified according to the quantity of lifestyle-related factors met (0-3). Multivariate linear regression analyses were performed to investigate the association between IC score with three factors comprehensively and separately on the total sample stratified by gender. RESULTS: The mean age was 79.0 ± 6.6 (women, 43.3%). Compared to implementing no factors, implementing two or three factors was consistently associated with significantly higher IC scores (Unstandardized Coefficient B [95% CI], 0.49 [0.31-0.67] and 0.68 [0.47-0.89]). Implementing one factor did not reach statistical significance after full multivariable adjustment (0.17 [-0.04-0.34]). These graded associations were broadly consistent across women and men. Moreover, factor-specific analyses showed that nutrition-related, physical, and social factors were all positively associated with IC in the total sample (0.22 [0.07-0.36], 0.36 [0.20-0.52] and 0.33 [0.17-0.49]). CONCLUSION: In this cross-sectional study, a greater number of favorable lifestyle-related factors was positively associated with IC among community-dwelling older adults. These findings provide preliminary evidence to inform future longitudinal and intervention studies on healthy aging.