After Adjusting for Social Determinants of Health, Cardiovascular Disease Mortality Differences Disappear Between Black, White Populations

After adjusting for behavioral and metabolic risk factors, the differences in cardiovascular disease (CVD) mortality between Black and White individuals lessened, and completely disappeared after adjustments were made for social determinants of health in the US population, according to the results of a study in Annals of Internal Medicine.¹

Because CVD mortality is generally higher in Black populations compared to other racial and ethnic groups in the United States, investigators of the study aimed to determine to which degree social, behavioral, and metabolic risk factors contributed to the racial differences.¹

“For so many years we have focused on smoking, diet, physical activity, obesity, hypertension, diabetes, and high cholesterol, and we know those are important for the prevention of cardiovascular disease, but it surprised me that the Black-White difference in [CVD] mortality is mainly due to social factors,” Jiang He, MD, PhD, the Joseph S. Copes Chair in Epidemiology at Tulane’s School of Public Health and Tropical Medicine, said in a statement.²

Investigators included health data from the National Health and Nutrition Examination Survey from 1999 to 2018, with 50,808 individuals aged 20 years and older. Clinical risk factors included obesity, diabetes, hypertension, and high cholesterol, and lifestyle risk factors included smoking, unhealthy diet, lack of exercise, and too little or too much sleep. Social risk factors included unemployment, low family income, food insecurity, low education, no regular access to health care, no private health insurance, not owning a home, and not married or living with a partner.²

There was an average of 9.4 years of follow-up data and 2589 deaths reported. Investigators found that the age- and sex-standardized rates of CVD mortality were 484.7 deaths per 100,000 person-years for individuals who are Black, 384.5 deaths per 100,000 person-years for those who are White, 292.4 deaths per 100,000 person-years for those who are Hispanic, and 255.1 per 100,000 person-years for those in other racial groups.¹

Using a multiple Cox regression analysis, investigators found that when the analysis was adjusted for all risk factors simultaneously, they were associated with a significantly higher risk for CVD death. Furthermore, when the adjustments were made for metabolic, behavioral, and social risk factors separately, the hazard ratios for CVD mortality for Black individuals went from 1.54 to 1.34 and for White individuals went from 1.31, and 1.04.¹

The study authors found that when adjusted for age and sex, Black individuals had a 54% higher CVD mortality risk compared to White individuals but dropped to 34% and 31% when adjusted for clinical and lifestyle risk factors, respectively.² However, they also found that the CVD mortality completely disappeared after adjusting for social risk factors, according to the statement.²

Investigators noted that the limitations of the study included that the causal contributions of these factors for racial and ethnic disparities could not be established for CVD mortality.¹

The study investigators also emphasized the importance of well-paying jobs, health care access, and social support to help social determinants of health.²

“It is essential to develop novel community-based interventions for reducing cardiovascular disease risk in Black populations,” He said in the statement.²

References

1. He J, Bundy JD, Geng S, Tian L, et al. Social, behavioral, and metabolic risk factors and racial disparities in cardiovascular disease mortality in US adults: an observational study. Ann Intern Med. 2023;10.7326/M23-0507. doi:10.7326/M23-0507
2. Why are Black adults at greater risk of death from heart disease? Study blames social factors. EurekAlert. News release. August 14, 2023. Accessed August 15, 2023. https://www.eurekalert.org/news-releases/998429