Findings from a new Northwestern Medicine study rebut the idea that Black individuals’ higher risk of cardiovascular disease is because of biological differences.
“The key take-home message is that racial differences in cardiovascular disease are not due to race itself, which is a social concept that is not related to biology.”
Black adults are at significantly higher risk (1.6-2.4 times) for cardiovascular disease than white adults. The new study found these large differences can be explained by differences in social determinants of health (like education or neighborhood-level poverty), clinical factors (like blood pressure) and lifestyle behaviors (like dietary quality).
“The key take-home message is that racial differences in cardiovascular disease are not due to race itself, which is a social concept that is not related to biology,” said corresponding author Dr. Nilay Shah, assistant professor of cardiology and epidemiology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. “Rather, these differences in cardiovascular disease can be explained by differences in social and clinical factors. Clinicians should be evaluating the social determinants that may be influencing the health of their patients.
“The data from this study starts to identify what contributes to the higher burden of heart disease experienced by Black adults, and how much each factor matters.”
The study was published May 24 in Circulation, the flagship journal of the American Heart Association.
A breakdown of the findings
Black women had a 2.4-times higher risk for cardiovascular disease compared with white women. The study found that clinical factors, neighborhood-level factors and socioeconomic factors explained the largest components of the higher risk experienced by Black women.
Black men had a 1.6-times higher risk for cardiovascular disease compared with white men. The study found that clinical factors, socioeconomic factors and lifestyle behaviors explained the largest components of the higher risk experienced by Black men.
“The findings of significantly higher risk in non-Hispanic Black adults compared with non-Hispanic white adults is not surprising—this is well-known,” said senior author Dr. Sadiya Khan, assistant professor of cardiology and epidemiology at Feinberg and a Northwestern Medicine physician. “But it was surprising that the risk for cardiovascular disease was the same once social and clinical factors were considered over time. This finding is really important to rebut that there is an unexplained or genetic reason that Black individuals have higher risk.”
The study’s findings are important because they show that disparities in heart disease experienced by Black adults could be reduced by improving preventive care of heart disease risk factors and addressing social determinants, Shah said. The data provide a guide to identify strategies that may be particularly effective at reducing the persistent differences and disparities in heart disease that exist in the U.S.
“It is important to note that clinical risk factors, lifestyle and depression are not independent of socioeconomic status and neighborhood segregation,” Khan said. “Future research needs to go upstream to target social determinants of cardiovascular health. Our study lays groundwork to help inform community-engaged interventions that ensure equal opportunities for all people to have access to high-quality foods, environments and health care.”
The study evaluated data from about 5,100 Black and white adults who participated in the CARDIA (Coronary Artery Risk Development in Young Adults) Study at four locations in the U.S. (Chicago; Minneapolis, Minn.; Oakland, Calif.; and Birmingham, Ala.). The participants enrolled around 1985 and have been followed for over 30 years. The scientists evaluated the information participants provided starting from the time of their enrollment to determine the role of social and clinical factors in the differences in cardiovascular disease experienced by Black compared with white adults over the course of 30 years of follow-up.
Other Northwestern co-authors include Norrina Allen, Dr. Donald Lloyd-Jones, Mercedes Carnethon, Kiarri Kershaw, Lucia Petito and Hongyan Ning.
Funding for the study was provided by the National Heart, Lung, and Blood Institute (NHLBI) (grant K23HL157766); the National Institutes of Health (grants P30AG059988 and P30DK092939); and the American Heart Association (grant 19TPA34890060). The CARDIA study is conducted and supported by the NHLBI in collaboration with the University of Alabama at Birmingham (grants HHSN268201800005I and HHSN268201800007I), Northwestern University (grant HHSN268201800003I), University of Minnesota (grant HHSN268201800006I) and Kaiser Foundation Research Institute (grant HHSN268201800004I).