Abstract Body: Introduction:
Development of hypertension is linked to thrombo-inflammation. In the U.S., Black women have the highest hypertension prevalence of any race-gender group, and Black people have higher thrombo-inflammatory responses than White people. Evidence on residential segregation— a manifestation of structural racism and a key driver of health inequities— and thrombo-inflammation is limited. This study examined race and/or gender differences in the association of a measure of residential segregation and hypertension-related thrombo-inflammatory biomarkers.

Methods:
We included 4,362 Black and White participants of the REasons for Geographic And Racial Differences in Stroke study. Residential segregation was measured with the delta index (the proportion of Black people that would need to move across census tracts to achieve a uniform density in a county). Regression models assessed associations of the delta index with 8 thrombo-inflammatory biomarkers: C-reactive Protein, D-dimer, E-selectin, factor IX, interferon-γ, interleukin (IL)-6, and tumor necrosis factor-α, and IL-1β. Racial and/or gender differences in associations were tested.

Results:
The delta index was only associated with IL-1β. The figure shows that each SD higher delta index was associated with 39% lower odds of being in the top versus the bottom tertile of IL-1β (odds ratio: 0.61, 95% confidence interval: 0.38, 0.95). There were no significant racial and/or gender differences in associations.

Discussion:
A measure of residential segregation, the delta index, was associated with lower IL-1β in Black and White Americans. This suggests that aspects of living in majority Black counties may buffer thrombo-inflammatory responses associated with IL-1β.