Impact of residential segregation on CV risk varied by race, ethnicity

The association between residential segregation and CV risk varied by race or ethnicity, according to new findings from the Multi-Ethnic Study of Atherosclerosis.

According to the study background, previous research had suggested that neighborhood-level racial and ethnic segregation is linked to health, but the impact of neighborhood-level segregation on CVD had not been studied prospectively.

“Despite discrimination and other exclusionary housing practices having been outlawed for >50 years, racial/ethnic residential segregation in US metropolitan areas remains high; the average white individual lives in a neighborhood that is 75% white, whereas the average black and Hispanic individuals, who make up approximately 13% and 16% of the US population, respectively, live in neighborhoods that are only 35% white,” researchers wrote in Circulation.

Kiarri N. Kershaw, PhD, and colleagues analyzed 1,595 non-Hispanic black adults, 2,345 non-Hispanic white adults and 1,289 Hispanic adults from the Multi-Ethnic Study of Atherosclerosis who were aged 45 to 84 years and free from CVD at baseline.

They assessed own-group residential segregation by measuring how a neighborhood’s racial and ethnic composition deviates from that of surrounding communities. The researchers estimated HRs for incident CVD, defined as first definite angina, probable angina followed by revascularization, MI, resuscitated cardiac arrest, CHD death, stroke or stroke death, during a median 10.2 years of follow-up.

Results differed by race, ethnicity

For black adults, after adjustment for demographics, each standard deviation increase in black segregation was associated with a 12% increased risk for developing CVD (HR=1.12; 95% CI, 1.02-1.22). Adjustment for neighborhood-level characteristics, individual socioeconomic position and CVD risk factors did not change the results (HR=1.12; 95% CI, 1.02-1.23).

For white adults, higher white segregation was associated with lower CVD risk after adjustment for demographics (HR=0.88; 95% CI, 0.81-0.96), but the association was attenuated after adjustment for neighborhood characteristics (HR=0.91; 95% CI, 0.81-1.02), according to the results.

The researchers reported no association between neighborhood segregation and CVD for Hispanic adults (HR=1; 95% CI, 0.95-1.05). Adjustment for time-varying segregation and covariates did not change the results.

“Our findings suggest that associations of segregation with CVD risk vary by race/ethnic group, reflecting differences in the processes that lead to segregation across these different groups and in the consequences of segregation for CVD-relevant exposures,” Kershaw, from the department of preventive medicine at Northwestern University Feinberg School of Medicine, and colleagues wrote. “A better understanding of the impact of segregation on CVD risk, and the individual- and neighborhood-level pathways linking segregation to CVD, as well, may help guide the efforts to prevent CVD and reduce racial/ethnic disparities in [CV] outcomes.”

Implications for research, policies

In a related editorial, Adolfo Correa, MD, PhD, from the department of medicine at the University of Mississippi Medical Center, and colleagues noted that this study highlighted four important points: “(1) knowledge and knowledge gaps related to residential segregation and CVD disparities; (2) value of new developments in measuring neighborhood residential segregation; (3) opportunities for future research in residential segregation and CVD outcomes; and (4) implications for research and policies regarding residential segregation as a contributor to CVD disparities by race/ethnicity.”

For more information:

Correa A. Circulation. 2015;131:124-127.

Kershaw KN. Circulation. 2015;131:141-148.

Disclosure: The researchers and editorial authors report no relevant financial disclosures.