Study finds new risk factor for stroke and heart attack
Researchers studying risk factors for stroke and heart attack have identified antibodies that seem to double the risk of both health problems in men, independent of other risk factors. Their study, published in the August issue of Stroke, is the first prospective study to show increased risk of ischemic stroke and heart attack among men with these particular antibodies, known as Beta-2 Dependent Anticardiolipin Antibodies (B2GP1-dependent aCL).
Dr. Robin L. Brey, associate professor of medicine at the Health Science Center, said this study will help researchers determine whether people with these antibodies should be treated differently after they have a heart attack or a stroke.
"Now that we have proof that these antibodies are markers for increased risk, we can turn our attention to how they are associated with stroke and heart attack. We need to explore whether these antibodies cause stroke or heart attack, and try to better understand the mechanism, if they are found to be causative," said Dr. Brey, the study's lead author. "The next step will be to use information about mechanism to develop better strategies to decrease stroke and heart attack risk for people with these antibodies."
The 20-year study of men from Japanese ancestry showed that men with the antibodies had a twofold increased risk of stroke, and a nearly double increased risk of heart attack, when adjusted for other risk factors.
"Our study found that the risk of stroke and heart attack associated with these antibodies was similar to the increased risk from other conditions, such as hypertension and diabetes," said Dr. Steven J. Kittner, professor of neurology at the University of Maryland School of Medicine and a neurologist at the Baltimore VA Medical Center. Dr. Kittner is the study's senior author.
While it is clear that uncontrolled hypertension, diabetes, high cholesterol and smoking increase the risk of cardiovascular disease, the researchers say they do not know all of the predisposing risk factors. Many people who suffer from a stroke or heart attack did not seem to be at high risk based on the known factors.
Our bodies form antibodies after they are exposed to infection. The role of inflammation and infection in cardiovascular disease is a major focus of research, as part of the effort to better prevent, predict and treat heart disease and stroke.
The B2GP1-dependent aCL antibodies were found in about 12 percent of men in the study who did not have cardiovascular disease, but they were prevalent in 17 percent of men who had a stroke and 16 percent of those who had a heart attack. Scientists do not know which type of infection, if there is one, may be responsible for these particular antibodies.