Current use of corticosteroids increases cardiovascular events (CVE) risk in patients with systemic lupus erythematosus (SLE), but past use, in the absence of current use, does not, a study found.
In a study of 1,874 SLE patients, investigators Laurence S. Magder, PhD, of the University of Maryland in Baltimore, and Michelle Petri, MD, MPH, of Johns Hopkins University in Baltimore, found that the rate of CVEs was 2.66 times higher than would be expected in the general population with similar levels of traditional risk factors, according to an online report in the American Journal of Epidemiology. After adjusting for age, the excess risk was not associated with SLE duration but was associated with current disease activity and anti-double-stranded DNA.
Consistent with previous studies, the excess risk was more strongly associated with the current dose of corticosteroid than with cumulative past dose, suggesting a short-term impact of corticosteroid use on CVE risk.
Compared with patients not currently using corticosteroids, those currently taking daily doses of 10-19 mg and 20 mg or more had a significant twofold and fivefold increased risk of CVEs, respectively, after adjusting for age.
During 9,485 person-years of follow-up, the investigators observed 134 CVEs, for a rate of 14.1 per 1,000 person-years.
The researchers defined CVEs as the occurrence of myocardial infarction, clinically definite angina, thrombotic stroke, percutaneous coronary intervention, coronary artery bypass procedure, or claudication.
Drs. Magder and Petri noted that three previous studies of other large non-SLE cohorts also found that current, but not past, use of corticosteroids was associated with higher CVE rates. These studies showed that the increased risk was highest among subjects with the higher current doses.
“Our findings, along with these previous consistent findings, suggest that there is an acute impact of corticosteroids on CVE risk,” the authors wrote.
It is also possible that current use of corticosteroids “is merely a marker for a flare of disease activity that is the real cause of the increased CVE risk,” they stated. The investigators noted, however, that in multivariable analysis, the association between current corticosteroid use and CVE risk persisted after controlling for the disease activity level measured at the time of the corticosteroid prescription decision.
Another plausible explanation for the association is an effect of corticosteroids on traditional risk factors, such as blood pressure (BP) or serum lipids, they observed. They pointed out, however, that the effect of corticosteroid use on CVE risk persisted after controlling for BP and serum cholesterol, suggesting that the association is independent of the effect of corticosteroids on these risk factors.