The association between social activity and physical frailty among community-dwelling older adults in Japan

BACKGROUND: Physical frailty is associated with social activity. However, the relationship between physical frailty and levels of engagement with other people during social activities remains unclear. Thus, we aimed to clarify the relationship between physical frailty and social activity using a taxonomy of activity levels among community-dwelling older adults in Japan. METHODS: This cross-sectional observational study analyzed data from 12,788 older adults (7001 women, mean age: 73.8 years, standard deviation = 5.9; range: 60–96 years) from the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes. Physical frailty was assessed using the following components: slow walking speed, muscle weakness, exhaustion, low activity, and weight loss. We asked participants about seven social activities that included social participation and engagement and examined their relationship to physical frailty. RESULTS: Physical frailty was independently associated with all social activities. Exercise circle activity, which includes a level of social participation, was strongly associated with physical pre-frailty and physical frailty. Results of sub-analyses indicated that the level of social engagement was independently associated with physical frailty in the older group (over 75 years) but not in the younger group (60–74 years). CONCLUSIONS: Our results indicate that the strength of the association between social activity and physical frailty differs by the level of social participation. Given the increasingly high prevalence of physical frailty in Japan and its strong association with numerous adverse health outcomes, the relationship between physical frailty and levels of social participation may assist in developing measures to prevent the incidence and progression of physical frailty. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-03563-w.