People with systemic lupus erythematosus (SLE) have a more than twofold increased risk of cardiovascular disease, according to a new study.

Lupus is a chronic “autoimmune” disease in which the immune system confuses its own healthy tissues with foreign tissues and sometimes attacks both. The condition can manifest as a skin rash or arthritis and may lead to damage to the kidneys, heart, lungs and brain to varying degrees. The disorder disproportionately affects women.

“Despite improved life expectancy in the past few decades,” increased heart-related illness and death among people with lupus has been documented in several studies, Dr. A. Elisabeth Hak, from Erasmus MC University Medical Center, Rotterdam, the Netherlands, and colleagues note in the journal Arthritis Care and Research.

Hak’s team examined ties between lupus and cardiovascular disease among women participating in the Nurses’ Health Study. A total of 119,332 women who were free of cardiovascular disease and lupus in 1976 were included in the study and were followed until 2004.

Over 28 years of follow-up, there were 8,169 cardiovascular “events,” such as heart attack, stroke. Lupus was confirmed in 148 women and 20 of these women experienced a cardiovascular event.

After allowing for multiple factors, having lupus was associated with a 2.26-fold increased risk of suffering a cardiovascular event.

The investigators point out that the increased risk of cardiovascular disease in lupus patients is probably caused by a combination of factors. While traditional cardiovascular disease risk factors are more prevalent in people with lupus, this does not fully explain the risk. It is unclear whether lupus itself or its treatment increases the risk.

SOURCE: Arthritis Care and Research, October 15, 2009.