Abstract 06: Residential Segregation and Thrombo-Inflammatory Biomarkers Related to Hypertension in Black and White Americans

Abstract

Background: Thrombo-inflammation is involved in hypertension pathogenesis. Black people have higher thrombo-inflammatory biomarkers and hypertension burden than White people. It is unclear whether residential segregation, a driver of health inequities, has a differential impact on thrombo-inflammation in Black and White Americans. Hypothesis: Higher residential segregation is associated with adverse levels of thrombo-inflammatory biomarkers, and this association is greater among Black relative to White adults. Methods: This cross-sectional study included 4,362 participants of the biracial REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. County-level segregation was measured with the (1) dissimilarity index (DI, the difference in racial distribution of census tracts relative to their county), (2) isolation index (ISI, the degree to which Black people are exposed only to one another in a county), and (3) interaction index (ITI, the degree to which Black people are exposed to White people in a county). Linear regression was used to assess correlations of residential segregation indices with 7 thrombo-inflammatory biomarkers associated with hypertension risk: C-reactive protein (CRP), D-dimer, E-selectin, Factor IX, interferon (IFN)-γ, interleukin (IL)-6, and tumor necrosis factor (TNF)-α. Results: Worse ISI, ITI, and DI were associated with adverse levels of most biomarkers even with Bonferroni adjustment (Table). For example, CRP was 12% (95% CI: 9-16%) higher per SD higher ISI, 5%(95% CI: 1- 8%) higher per SD higher DI, and 9% (95% CI: 6-12%) higher per SD lower ITI. None of the associations differed significantly by race (p race* residential segregation index >0.1). Conclusions: Several thrombo-inflammatory biomarkers important in hypertension were more adverse with greater residential segregation by three metrics, regardless of race. This indicates that residential segregation, a manifestation of structural racism, may become embodied in thrombo-inflammatory processes.