Study finds ethnic differences in coronary heart disease risk within diverse population

In a study of more than 1.3 million Kaiser Permanente members in Northern California that stretched over 10 years, researchers found that blacks, Latinos and Asians generally had lower risk of coronary heart disease compared to whites. The study was published today in American Journal of Preventive Medicine.

"Racial and ethnic differences in diabetes, cardiovascular-disease risk factors and their outcomes, especially in blacks, are well documented, but population health estimates are often confounded by differences in access to high-quality health care," said lead author Jamal S. Rana, MD, PhD, of the Division of Cardiology and Clinical Adjunct with Division of Research at Kaiser Permanente Northern California.

The findings echo those of a 2014 study published in the New England Journal of Medicine, which showed that racial disparities between black and white Medicare beneficiaries covered by Kaiser Permanente in the western United States have been nearly eliminated for cardiac risks and diabetes markers, even as these disparities persisted among patients in managed health care systems in other regions of the United States.

In the study just published, "we were able to evaluate ethnic differences in risk of future coronary heart disease within a diverse population, which included not only black, but also large Asian and Latino populations, with uniform access to care in an integrated health care delivery system," Rana noted. "The results in our report may reflect, not only access to high quality heart disease care, but also systematic efforts by the health plan to improve risk-factors such as high blood pressure and promote smoking cessation across its member population."

The ethnic composition of the study cohort of 1,344,899 members was 64 percent white (868,301 members), 14 percent Asian (190,439 members), 13 percent Latino (169,886 members) and 9 percent black (116,273 members). More than 10 percent of Latinos and almost 20 percent of blacks were from economically disadvantaged neighborhoods. Members were aged 30 to 90 years, included both men and women, and were followed from 2002 through 2012.

Researchers evaluated the ethnic differences in risk of future coronary heart disease in patient populations distinguished by the presence or absence of diabetes and prior coronary heart disease in four clinical risk categories:

• 1) No diabetes with no prior coronary heart disease;

  2) No diabetes with prior coronary heart disease;

  3) Diabetes with no prior coronary heart disease; and

  4) Diabetes with prior coronary heart disease.

Blacks, Latinos and Asians without any prior history of coronary heart disease had lower risk of coronary heart disease compared with whites, regardless of whether they also had diabetes.

Among members with prior coronary heart disease and no diabetes, blacks had slightly increased risk of future heart disease compared to whites. However, no such increased risk was noted in the highest risk group with both prior history of heart disease and diabetes. Latinos did not have any difference in risk compared to whites in both of these groups, and Asians had decreased risk.

"Our findings are very encouraging. It is a complex issue, and further research is needed to address the differences in health status and outcomes related to race and ethnicity across the country," Rana noted. "These findings may inform policy development and interventions designed to identify and eliminate racial and ethnic disparities."