Associations between Historical and Contemporary Measures of Structural Racism and Leukocyte Telomere Length: The Multi-Ethnic Study of Atherosclerosis (MESA)

We assessed the link between two manifestations of structural racism—historical redlining and contemporary racial residential segregation—and baseline and 10-year changes in Leukocyte Telomere Length (LTL). We used data on Black and Hispanic/Latinx participants from Exams I and V of the Multi-Ethnic Study of Atherosclerosis Stress Ancillary Study (N=741, age range=45-84 years). LTL was defined as the ratio of telomeric DNA to a single copy gene (T/S), and 10-year changes were adjusted for regression to the mean. We used 1930s Home Owners' Loan Corporation maps to assign three historical redlining grades (A&B: best/still desirable, C: declining, D: hazardous/redlined) to participants' neighborhoods (census-tracts) at baseline. The Getis-Ord Gi* statistic was used to evaluate census-tract level baseline residential segregation (low/moderate/high). In mixed-effects regression models accounting for neighborhood clustering, individual characteristics, and current neighborhood environments, those living in highly segregated Black neighborhoods had 0.08 shorter baseline LTL (95% CI: -0.13, -0.04), than those residing in the least segregated neighborhoods. We did not find a relationship between residing in segregated neighborhoods and 10-year LTL changes, and associations examining the relationship between residing in historically redlined neighborhoods and both baseline and 10-year changes in LTL were null. Across discriminatory disinvestment trajectories examined, individuals residing in highly segregated but non-redlined neighborhoods had 0.6 shorter baseline LTL than individuals residing in non-redlined neighborhoods with low/moderate segregation (95% CI: -0.12, -0.01). Our results highlight the impact of racial segregation on cellular aging and underscore the need to ameliorate structural inequities within segregated neighborhoods.