Social, Behavioral, and Metabolic Risk Factors and Racial Disparities in Cardiovascular Disease Mortality in U.S. Adults : An Observational Study

Background: Cardiovascular disease (CVD) mortality is persistently higher in the Black population than in other racial and ethnic groups in the United States.

Objective: To examine the degree to which social, behavioral, and metabolic risk factors are associated with CVD mortality and the extent to which racial differences in CVD mortality persist after these factors are accounted for.

Design: Prospective cohort study.

Setting: NHANES (National Health and Nutrition Examination Survey) 1999 to 2018.

Participants: A nationally representative sample of 50 808 persons aged 20 years or older.

Measurements: Data on social, behavioral, and metabolic factors were collected in each NHANES survey using standard methods. Deaths from CVD were ascertained from linkage to the National Death Index with follow-up through 2019.

Results: Over an average of 9.4 years of follow-up, 2589 CVD deaths were confirmed. The age- and sex-standardized rates of CVD mortality were 484.7 deaths per 100 000 person-years in Black participants, 384.5 deaths per 100 000 person-years in White participants, 292.4 deaths per 100 000 person-years in Hispanic participants, and 255.1 deaths per 100 000 person-years in other race groups. In a multiple Cox regression analysis adjusted for all measured risk factors simultaneously, several social (unemployment, low family income, food insecurity, lack of home ownership, and unpartnered status), behavioral (current smoking, lack of leisure-time physical activity, and sleep <6 or >8 h/d), and metabolic (obesity, hypertension, and diabetes) risk factors were associated with a significantly higher risk for CVD death. After adjustment for these metabolic, behavioral, and social risk factors separately, hazard ratios of CVD mortality for Black compared with White participants were attenuated from 1.54 (95% CI, 1.34 to 1.77) to 1.34 (CI, 1.16 to 1.55), 1.31 (CI, 1.15 to 1.50), and 1.04 (CI, 0.90 to 1.21), respectively.

Limitation: Causal contributions of social, behavioral, and metabolic risk factors to racial and ethnic disparities in CVD mortality could not be established.

Conclusion: The Black-White difference in CVD mortality diminished after adjustment for behavioral and metabolic risk factors and completely dissipated with adjustment for social determinants of health in the U.S. population.

Primary Funding Source: National Institutes of Health.