Association Between Community-Level Social Participation and Self-reported Hypertension in Older Japanese: A JAGES Multilevel Cross-sectional Study

BACKGROUND Many factors are associated with hypertension development. We focused on social participation as an aspect of social capital and investigated the contextual relationship between community-level social participation and hypertension using multilevel regression analyses. METHODS We used cross-sectional data from the 2016 Japan Gerontological Evaluation Study-a population-based study of functionally independent adults aged 65 years or older. The sample comprised 116,013 participants nested in 818 communities. Hypertension and social capital were defined by questionnaires. Social capital was assessed at both the individual and the community levels in 3 dimensions: civic participation (as an index of social participation), social cohesion, and reciprocity. RESULTS The prevalence rate of hypertension was 43.7%, and 44.1% of the respondents were involved in civic participation. Community-level civic participation, but not social cohesion or reciprocity, was negatively associated with hypertension in the total population (prevalence ratio (95% confidence interval): 0.98 (0.96-0.99), P = 0.004) and female group (0.97 (0.95-0.99), P = 0.015), and the association neared significance in the male group (0.98 (0.96-1.005), P = 0.13) after adjustment for individual-level social capital dimensions including civic participation, individual-level covariates, and population density as a community-level covariate. The interaction between community-level civic participation and sex in relation to hypertension was significant (P = 0.012). CONCLUSIONS We found a contextual preventive relationship between community-level civic participation and hypertension. The design of the contextual characteristics of communities by the promotion of social participation may help reduce the prevalence of hypertension in older people.