Abstract P150: Residential Segregation and Hypertension Risk in Black and White Americans

Introduction:Black adults experience the highest hypertension burden of any American group. Evidence indicates social factors adversely affecting Black people explain some of the excess hypertension burden. It’s unclear whether residential segregation, a key cause of health inequities, has a differential impact on Black and White people.Hypothesis:The magnitude of the association of residential segregation and risk of incident hypertension will be greater in Black than White people.Methods:Our sample included 6,143 Black and White REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants without prevalent hypertension (2003-7), and with a follow-up visit 9.3 years later. Baseline county-level segregation was measured with the (1) dissimilarity index (DI, the difference in race 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). Modified Poisson regression estimated the risk ratios (RR) of incident hypertension per SD increment of baseline residential segregation.Results:The mean (SD) age was 61(8) years for Black people and 62(8) years for White people. Hypertension incidence was 46% for Black people and 33% for White people. There was noassociation of any of the three measures of residential segregation (DI, ISI and ITI) with incident hypertension, with RRs all around 1.0 (Figure).Conclusions:Three measures of residential segregation were not associated with incident hypertension risk in Black and White participants of the REGARDS cohort. Findings differ from a previous study that reported that a measure of racial clustering was associated with higher risk of hypertension in Black people. Taken together, findings suggest that, in Black people, different domains of residential segregation capture factors related differently to hypertension development.