Racial inequities in the incidence of major adverse cardiovascular events in ELSA-Brasil cohort: the mediating role of weathering

BACKGROUND: The weathering hypothesis proposes that chronic exposure to social disadvantage leads to earlier onset of age-related diseases, explaining, in part, greater CVD disadvantages of racialized groups. The investigation of such a hypothesis is incipient in Brazil, a society strongly marked by racism. We investigated whether racism is associated with incidence of major adverse cardiovascular events (MACE) and the extent to which weathering explained this association in Brazilian adults. METHOD: The study includes 10,983 individuals from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), free from CVD at baseline (2008-2010). We use self-reported race/color (White, Brown, and Black) as a social marker of racism as exposure. Weathering was the mediator, defined as the difference between biological and chronological age (obtained by combining nine biomarkers and the Klemera and Doubal method). MACE incidence (fatal and non-fatal coronary syndrome, coronary revascularization, stroke, and heart failure) was the outcome. Sociodemographic and behavioral factors, depression, and racial discrimination were the confounders. Marginal structural models estimated the total (TE) and the controlled direct (CDE) effects of the exposure on outcome. RESULTS: The mean follow-up period was 4.1 years. Black and Brown individuals showed, on average, greater weathering than White individuals. MACE incidence was 63 % higher among Black than White individuals [TE = HR(95 %CI):1.63(1.01-2.65)]. The CDE indicated that weathering mediates the association after weighting [CDE=HR(95 %CI):1.05(0.61-1.79)]. There was no association among Brown individuals. CONCLUSION: Our results corroborate the weathering hypothesis by showing that accelerated biological aging is a major driver of racial inequalities in MACE incidence in Brazilian adults.