Rheumatoid arthritis, lupus, and related autoimmune disorders are caused by a misguided immune system. Certain white blood cells, which ordinarily protect the body from infection, attack its tissues instead.
Although it's not clear how these conditions are linked to cardiovascular disease, it believed that it might be a result of inflammation.
In people with rheumatoid arthritis and lupus inflammation turns against the body and damages joints and other tissues.
In heart disease, inflammation kicks off artery-clogging atherosclerosis, keeps it smouldering, and influences the formation of clots, the main cause of heart attacks and strokes.
The study suggests that controlling rheumatoid arthritis or lupus with medications used for treating inflammation may help in reducing the excess risk of heart disease.
The study appears in the August 2008 issue of the Harvard Heart Letter.