Historic Redlining and Impact of Structural Racism on Diabetes Prevalence in a Nationally Representative Samples of US Adults

Objective: This study investigated direct and indirect relationships between historic redlining and prevalence of diabetes in a national sample. Research Design and Methods: Using a previously validated conceptual model, we hypothesized pathways between structural racism and prevalence of diabetes via discrimination, incarceration, poverty, substance use, housing, education, unemployment, and food access. We combined census tract level data including diabetes prevalence from the CDC PLACES 2019 database, redlining using historic Home Owners’ Loan Corporation (HOLC) maps from the Mapping Inequality project, and census data from Opportunity Insights database. HOLC grade (a score between 1=best and 4=redlined) for each census tract was based on overlap with historically HOLC graded areas. The final analytic sample consisted of 11,375 US census tracts. Structural equation modeling was used to investigate direct and indirect relationships adjusting for 2010 population. Results: Redlining was directly associated with higher crude prevalence of diabetes within a census tract (r=0.01, p=0.008) after adjusting for the 2010 population (c2(54)=69900.95, p<0.001, RMSEA=0, CFI=1). Redlining was indirectly associated with diabetes prevalence via incarceration (r=0.06, p<0.001), poverty (r= -0.10, p<0.001), discrimination (r=0.14, p<0.001); substance abuse (measured by binge drinking r= -0.65, p<0.001 and smoking r=0.35, p<0.001), housing (r=0.06, p<0.001), education (r=-0.17, p<0.001), unemployment (r= -0.17, p<0.001), and food access (r=0.14, p<0.001) after adjusting for the 2010 population. Conclusions: Redlining has significant direct and indirect relationships with diabetes prevalence. Incarceration, poverty, discrimination, substance use, housing, education, unemployment, and food access may be possible targets for interventions aiming to mitigate the impact of structural racism on diabetes.