Doctors have long suspected that people with lupus have a heightened risk of heart attack. Now, two major studies reveal more early signs of atherosclerosis in the blood vessels of people with the autoimmune disease than in healthy participants.
Inflammation is the logical link between heart disease and systemic lupus erythematosus, the condition’s formal name. A raft of studies over the past decade has tied inflammation to subtle artery injuries that can lead to atherosclerosis (SN: 4/20/02, p. 244: Available to subscribers at Cardiac Culprit: Autopsies implicate C-reactive protein in fatal heart attacks); 12/6/03, p. 366: Available to subscribers at Two markers may predict heart risk). In lupus patients, the immune system seems to assault its own tissues, sending inflammatory proteins to the skin and elsewhere. This gives rise to the rash, joint pain, fatigue, fever, anemia, and organ failure that mark the disease.
In one of the new studies, researchers used ultrasound to examine the neck arteries of 197 lupus patients and 197 apparently healthy individuals of matching age, gender, race, and blood pressure. The ultrasound revealed that 37 percent of lupus patients, but only 15 percent of the control group, had small atherosclerotic plaques along the inside lining of the carotid arteries.
The result was more dramatic when the authors accounted for differences in the two groups, such as cholesterol-test results and whether the participants smoked, says study coauthor Mary J. Roman, a cardiologist at Weill Medical College of Cornell University in New York. In that analysis, the lupus patients were five times as likely as the others to have budding atherosclerosis, she and her colleagues report in the Dec. 18 New England Journal of Medicine.
In the other new study, researchers used computerized tomography to spot calcium build-up in coronary arteries. Such deposits can reveal hidden atherosclerosis (SN: 9/13/03, p. 174: Available to subscribers at Coronary calcium may predict death risk).
Rheumatologist C. Michael Stein of Vanderbilt University School of Medicine in Nashville and his colleagues report in the same journal that 20 of 65 lupus patients, but only 6 of 69 healthy volunteers, had calcium deposits in a coronary artery. The difference held up even when the team accounted for known heart attack risk factors.
Many lupus patients take anti-inflammatory medication to suppress flare-ups of their symptoms. Roman and her colleagues found that lupus patients free of plaques in their carotid arteries were more likely to have taken strong anti-inflammatory drugs, such as prednisone, than were patients who had plaques. The studies contradict a widely held opinion that long-term use of prednisone and other steroids accelerates atherosclerosis, says physician Bevra Hannahs Hahn of the University of California, Los Angeles in the same issue.
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Hahn says the two new studies indicate that “more aggressive control of [lupus] might help prevent atherosclerosis.”
Curiously, Roman says, blood analyses of participants in her study didn’t show excess inflammatory proteins in lupus patients compared with other volunteers. Therefore, while the findings solidify the link between lupus and atherosclerosis, she says, they don’t pin down inflammation as its cause.
Inflammatory proteins are ephemeral, flooding the system during a lupus flare-up but subsiding otherwise, Stein says. It could be that lupus patients in the throes of a flare-up were unlikely to volunteer for these studies, he adds.
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