A recent epidemiologic study of patients with systemic lupus erythematosus (SLE) investigated racial and ethnic differences in the risk for cardiovascular disease (CVD). Among SLE patients enrolled in Medicaid, the risk for myocardial infarction (MI) was lower in Hispanics and Asians compared with whites, and the risk of stroke was higher in blacks and Hispanics compared with whites.1
“The risk of CVD is known to be greatly elevated among SLE patients and is the major cause of death in SLE,” says Medha Barbhaiya, MD, MPH, an assistant attending physician at the Hospital for Special Surgery and an assistant professor at Weill Cornell Medical College in New York City. “It is also known that Hispanic, Asian and African Americans in the United States have higher incidence of SLE than whites, and often more severe disease. However, the role of patient race and ethnicity in relation to risk of CVD previously has not been well understood.”
The Study
The researchers used the Medicaid Analytic eXtract to identify patients between 18 and 65 years old with an SLE diagnosis and at least 12 months of continuous enrollment. The study ran from 2000–2010. The researchers followed the subjects from their SLE index date to their first CVD event, MI or stroke (if any), or death, disenrollment, loss to follow-up or end of the follow-up period. Of the 65,788 SLE patients enrolled, 93% were women, roughly 42% were black, 48% were white, 16% were Hispanic, 3% were Asian, and 1% were Native American/Alaskan Native. The mean follow-up time was 3.8 years.
CVD rates were highest among blacks, with an incidence rate (IR) of 10.57, and lowest among Asians, with an IR of 6.63. After multivariable adjustment, the risk of CVD events was elevated among blacks, with a hazard ratio (HR) of 1.14, compared with whites. When examining MI or stroke risk separately, Hispanics and Asians had a lower risk, with an HR of 0.61 and 0.57, respectively, compared with white SLE patients enrolled in Medicaid. Blacks and Hispanics had a higher risk for stroke than whites, with an HR of 1.31 and 1.22, respectively. Among all patients, the annual CVD event IR per 1,000 person-years measured 9.31. All rates came with a 95% CI.