Neighbourhood racial/ethnic residential segregation and cardiometabolic risk: the multiethnic study of atherosclerosis

Racial residential segregation has been linked to adverse health outcomes, but associations may operate through multiple pathways. Prior studies have not examined associations of neighbourhood-level racial segregation with an index of cardiometabolic risk (CMR) and whether associations differ by race/ethnicity.

We used data from the Multi-Ethnic Study of Atherosclerosis to estimate cross-sectional and longitudinal associations of baseline neighbourhood-level racial residential segregation with a composite measure of CMR. Participants included 5015 non-Hispanic black, non-Hispanic white and Hispanic participants aged 45-84 years old over 12 years of follow-up (2000-2012). We used linear mixed effects models to estimate race-stratified associations of own-group segregation with CMR at baseline and with the rate of annual change in CMR. Models were adjusted for sociodemographics, medication use and individual-level and neighbourhood-level socioeconomic status (SES).

In models adjusted for sociodemographics and medication use, high baseline segregation was associated with higher baseline CMR among blacks and Hispanics but lower baseline CMR among whites. Individual and neighbourhood-level SES fully explained observed associations between segregation and CMR for whites and Hispanics. However, associations of segregation with CMR among blacks remained (high vs low segregation: mean difference 0.17 SD units, 95% CI 0.02 to 0.32; medium vs low segregation: mean difference 0.18 SD units, 95% CI 0.03 to 0.33). Baseline segregation was not associated with change in CMR index scores over time.

Associations of own-group racial residential segregation with CMR varied by race/ethnicity. After accounting for SES, living in a more segregated neighbourhood was associated with greater risk among black participants only.