Social, behavioral, and metabolic risk factors for racial disparities in cardiovascular disease mortality in US adults

Abstract

Abstract Background Cardiovascular disease (CVD) mortality is persistently higher in the Black population than in other race and ethnicity groups in the US. Purpose To determine whether social, behavioral, and metabolic risk factors mediate racial disparities in CVD mortality and to assess the contribution of these risk factors to CVD mortality in the US general population. Methods A nationally representative sample of 50,808 individuals aged ≥20 years from National Health and Nutrition Examination Surveys (NHANES) 1999-2018 were included in the analysis. Data on social, behavioral, and metabolic factors were collected in each NHANES survey using standard methods. CVD deaths 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, 2,598 CVD deaths were confirmed. In a multivariable Cox regression model stratified by NHANES cycle and adjusted for age, sex, race, and social, behavioral, and metabolic risk factors simultaneously, individuals who were unemployed, had a lower family income, did not own a home, were not married nor living with a partner, were current smokers, reported no leisure-time physical activity, slept <6 or >8 hours/day, had obesity, hypertension, or diabetes, or had an albumin-to-creatinine ratio ≥30 mg/g or estimated-glomerular filtration rate <60 ml/min/1.73 m2 were at significantly higher risk for CVD mortality. After adjusting for these risk factors, hazard ratios (95% CI) of CVD mortality for Black individuals compared to White individuals decreased from 1.54 (1.34-1.77) to 0.86 (0.75-1.00). Social risk factors explained 72.9% Black-White differences in CVD mortality in a multivariable mediation analysis. The population attributable fractions (95% CI) for the top five risk factors for CVD mortality were 12.5% (5.6-19.3%) for hypertension, 10.6% (6.9-14.3%) for albuminuria, 9.4% (5.3-13.6) for physical inactivity, 9.1% (4.6-13.7%) for family income-to-poverty ratio <300%, and 7.2% (4.5-9.9%) for estimated-glomerular filtration rate <60 ml/min/1.73 m2 in the US general population. Conclusion Social, behavioral, and metabolic risk factors fully explained the Black-White difference in CVD mortality. Hypertension, albuminuria, physical inactivity, low family income, and reduced kidney function are leading risk factors for CVD mortality in the US population.