Life satisfaction as a protective factor against frailty among Japanese adults aged 60 and older: A cohort study

OBJECTIVES: Subjective well-being is linked to healthy aging as it decreases disease-related risk factors. Frailty is associated with biological factors such as inflammatory markers. However, the relationship between life satisfaction, a type of subjective well-being, and the onset of frailty is not sufficiently clear. This study investigated the relationship between life satisfaction and the onset of frailty among Japanese adults aged 60 years and older. DESIGN: A prospective cohort study was conducted. SETTING AND PARTICIPANTS: The sample comprised 1760 individuals aged ≥60 years living in Japan. METHODS: A baseline assessment was followed by a further assessment 2.5 years later. The main outcome, frailty, was defined as a score of 7 or more on the Kihon checklist. The independent variable was score on a life satisfaction scale. A logistic regression model was used to examine the relationship between the onset of frailty and quartiles on the life satisfaction scale, and odds ratios and 95 % confidence intervals were calculated. RESULTS: A total of 216 participants (12.2 %) developed frailty during the follow-up. Score on the life satisfaction scale at baseline for all participants was 39.7 ± 5.0. The odds ratio (95 % confidence intervals) for life satisfaction scale quartiles for the onset of frailty was 0.50 (0.33-0.75) for the Q2 group, 0.45 (0.28-0.72) for the Q3 group, and 0.43 (0.26-0.67) for the Q4 group, compared with the Q1 (lowest life satisfaction score) group. CONCLUSIONS AND IMPLICATIONS: The results suggest that high life satisfaction is a protective factor against frailty. Increasing the life satisfaction of Japanese adults aged 60 years and older may contribute to the prevention of frailty.