Relationship between social engagement and diabetes incidence in a middle-aged population: Results from a longitudinal nationwide survey in Japan

Aims/Introduction: Social engagement can positively affect health status, but its effect on diabetes incidence remains unclear. The present study aimed to assess the relationship between social engagement and diabetes incidence in a middle-aged Japanese population. Materials and Methods: We analyzed data on 31,615 people aged 50–59 years from a prospective national survey carried out in Japan from 2005 to 2013. Diabetes incidence was measured by asking respondents annually whether they had been diagnosed with diabetes by a physician in the previous year. We used the complementary log–log model for interval-censored survival time analysis. Social engagement was assessed at baseline as participation in social activities, having the companionship of friends, living with someone and employment status. Covariates including sex, age, health status and health behaviors were also measured at baseline. Results: After adjusting for covariates measured at baseline, the effect size of social engagement on diabetes incidence was the same as or larger than that of the covariates. Respondents who participated in social activities (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.87–0.92), had the companionship of friends (HR 0.97, 95% CI: 0.95–1.00), lived with someone (HR 0.85, 95% CI: 0.82–0.89) and were employed (HR 0.94, 95% CI: 0.92–0.96) were significantly less vulnerable to diabetes than were those who did not. Conclusions: The present study found a prospective association between social engagement and diabetes incidence among a middle-aged population. Future strategies to prevent diabetes in Japan should focus on both social and personal factors.