Social frailty: a most important risk factor of frailty and sarcopenia in community-dwelling elderly

Aim: To examine the association between social frailty and new onset of frailty and sarcopenia, which are defined by Cardiovascular Health Study index and Asian working group of sarcopenia, respectively, in Japanese community-dwelling older adults. Methods: Large-scale longitudinal surveys were performed in annually from 2012 to 2014. The inclusion criteria consisted of randomly selected community-dwelling older adults aged ≥65 years who were non eligible for long-term care and were robust group at baseline assessment. 1,211 elderly were included in this study. Social frailty were operationally defined using a deficit accumulation model referred to previous study in Japan. Cox proportional hazard modeling were used to identify the associations between social frailty and onset of frailty and of sarcopenia. Results: 9.7% of participants experienced having frailty, and 5.5% experienced having sarcopenia during the follow-up period. Baseline prevalence of social prefrailty (1/5score) was 31% and it of social frailty (≥2/5) was 20%. Although there were no significant association with social prefrailty, those who with social frailty were found to be significantly at risk of future frailty and sarcopenia (hazard ratio 2.25, 95% confidence interval 1.3–3.9 for frailty; hazard ratio 1.55, 95% confidence interval 1.1–2.8 for sarcopenia, respectively), although adjusted by confounding factors (such as age, instrumental activity of daily living). Conclusion: Our research showed strong impact of social frailty on the risk of new onset of frailty and sarcopenia in disability-free community-dwelling older adults. Therefore, to prevent physical frailty in community setting, early interventions for social frailty via multi-dimensional approaches may be indispensable.