Spatial Social Polarization and Cardiometabolic Disease Prevalence and Incidence: What Is the Role of the Neighborhood Environment?

This study examines the spatial polarization of income and racial-ethnic groups as predictors of prevalent and incident cardiometabolic disease and tests the extent to which local environmental features act as mediators. Spatial income and racial polarization are defined using the Index of Concentration at the Extremes. Using two waves of data from the Midlife in the United States study, generalized Poisson regression model results indicate that county- and tract-level income polarization are independently associated with prevalence and incidence of cardiometabolic disease. Results from path models showed that more income-privileged counties and tracts generally had greater parkland availability, lower social risks, less air pollution, fewer extreme heat days, and more tree canopy cover-but lower walkability. However, associations between income polarization and cardiometabolic disease are not substantively attenuated when accounting for these tract-level features. The findings show how income polarization locally and regionally patterns both environmental inequities and cardiometabolic disease.