In fact, this tendency for early heart attacks and strokes has been known for decades, yet researchers haven't understood why it happens, writes lead researcher Mary J. Roman, MD, a cardiologist with the Weill Medical College of Cornell University in New York.
Roman has conducted two studies of this pattern; her third and most recent study appears in this week's New England Journal of Medicine.
Some studies have pointed toward traditional risk factors -- high blood pressure, high cholesterol, and diabetes -- as the cause of early heart disease and stroke, worsened or provoked by steroids used to treat lupus, writes Roman. However, recent evidence suggests that lupus itself -- because it is a chronic immune disorder that triggers inflammation -- may cause artery damage and plaque buildup that can lead to clogged arteries that can cause a heart attack or stroke.
Higher Risk in Under-40 Patients
In Roman's current study of nearly 400 people, half with lupus and half without, those with lupus had more artery plaque. Plaque buildup was exceptionally more common in lupus patients under 40.
- Under-40 lupus patients were nearly six times as likely to have plaque buildup than patients without lupus. Older patients showed a similar trend.
- Plaque buildup and clogged arteries were significantly more common among lupus patients than those without lupus -- 37% vs. 15%. This pattern of increased plaque buildup could not be attributed to traditional risk factors like smoking, blood pressure, or cholesterol level.
- Lupus patients with artery plaque tended to be older, had lupus longer, and had more severe lupus, higher blood pressure, and higher LDL "bad" cholesterol levels than those lupus patients without plaque.
- Medications made a difference in artery plaque levels. Lupus patients with more plaque tended to take prednisone less frequently, and in lower doses; they also took less Cytoxan and Plaquenil, also used to treat lupus.