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

BACKGROUND: 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.
METHODS: 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).
RESULTS: 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.
CONCLUSION: 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. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.