Association Between Self-Reported Sitting Time and the Physical Function Domain of the Kihon Checklist Among Community-Dwelling Older Adults

Objective Interventions that reduce sitting time are easier to implement than those that aim to increase physical activity in compliance with the guidelines. There is no consensus on the association between sitting time as assessed by the International Physical Activity Questionnaire (IPAQ) and physical function. We investigated the association between self-reported sitting time and physical function according to the Kihon Checklist (KCL) among community-dwelling older adults. Methods This cross-sectional study included 87 community-dwelling middle-aged and older adults who had participated in a long-term preventive care and health promotion project. The project was conducted three times between March 2023 and March 2024. Sitting time was self-reported using the IPAQ. Physical function was assessed using the KCL. A generalized linear model was used to analyze the association between sitting time and physical function. In the adjusted model, handgrip strength, walking speed, five times sit to stand test, skeletal muscle mass index, living alone, pain, sex, and age were used as covariates to adjust for confounders. Results Eight subjects met the exclusion criteria, leaving a final cohort of 79 community-dwelling older adults (mean age: 75 ± 6 years, 73% female). Our analysis revealed that sitting time was associated with physical function, even after adjusting for covariates (standardized β coefficient = 0.22, p = 0.023). Conclusions Our findings emphasize the usefulness of assessing sitting time to maintain physical function in community-dwelling older adults. Furthermore, it may be important to reduce sitting time to maintain or improve physical function.