Study suggests non-genetic factors may be what increases risk.
People who have migraines have a greater risk for heart disease, but their genes may not be to blame for the connection, new research suggests.
Scientists looked at two large studies that pinpointed genetic variations that can increase the risk for migraine and heart disease. The first study included almost 20,000 people with migraine and more than 55,000 people who didn't have these severe headaches. The second study involved more than 21,000 people with heart disease and just over 63,000 people who didn't.
Led by Dr. Aarno Palotie, of the Broad Institute of MIT and Harvard in Boston, the researchers tried to find shared genetic variants in people with migraines and heart disease.
But they found no common gene variations between migraine with aura and heart disease -- even though evidence suggests these patients have a greater risk for heart disease than those with migraine without aura.
Migraine without aura and heart disease, however, do share some genetic variations. But the shared variations seem to help protect against heart disease, the study published in the July 2 issue of the journal Neurology Genetics revealed.
"In other words, people with migraine without aura seem to have a lower load of genetic factors increasing the risk of heart disease," Dr. Anne Ducros, of the University of Montpellier in France, who wrote an editorial accompanying the study, said in a news release from the American Academy of Neurology.
"We now need to understand why people with migraine who are born with a protective or neutral genetic risk for heart disease end up with an increased risk for heart problems," Ducros said.
Genetic factors not included in these studies could affect the risk for heart disease among those with migraine, Ducros added. Factors other than genetics could also be involved in the increased risk of heart disease, such as obesity, lack of exercise, smoking and depression, she suggested.