LAUSR

Background: Stark regional and racial disparities in diabetes prevalence exist in the US. Community-level factors (e.g., median income) have been associated with higher diabetes prevalence. However, few studies have investigated how community-level spatial polarization, specifically in race and income, may relate to diabetes burden. Objective: To investigate the association between the Index of Concentration at the Extremes (ICE), a measure that reflects polarization in race and income at the community-level, and individual-level diabetes prevalence. Methods: This analysis included 24,752 Black and White adults age ≥ 45 years at baseline (2003-2007) from the REGARDS Study. The ICE measure quantifies the concentration of community affluence and poverty in a census tract using both income and race jointly, with values ranging from -1 (most deprived) to +1 (most privileged). Diabetes was defined as fasting glucose ≥ 126 mg/dL or random glucose ≥ 200 mg/dL or use of diabetes medication. Modified Poisson regression was used to obtain prevalence ratios and 95% CI for the association of ICE quartiles with prevalent diabetes. Results: The overall prevalence of diabetes was 21% and was highest for adults living in the most deprived census tracts (28.3%) and lowest for those living in the most privileged census tracts (12.5%). The association between ICE and prevalent diabetes was graded in crude analyses but attenuated after adjustment for individual-level sociodemographic, lifestyle and clinical factors (Table). Conclusion: Communities with greater polarization in race and income had a higher burden of diabetes. This association was mostly explained by individual-level socioeconomic and lifestyle factors. Further investigation of community-level attributes and how they relate to individual-level factors that increase diabetes risk is needed.