These headaches were associated with an increased risk for several heart problems, including heart attack, stroke, atrial fibrillation (a type of irregular heart rhythm) and blood clots that start in a person's veins, according to the study, which was published today (Jan. 31) in the journal The BMJ.
Migraines are primarily considered a headache disorder (as opposed to a heart issue), with symptoms such as an intense pulsing or throbbing pain, nausea, and sensitivity to light and sound. However, this is not the first study to link migraine headaches and heart problems, said study lead author Dr. Kasper Adelborg, a cardiologist at Aarhus University Hospital in Denmark. Previous studies have suggested a link between migraines and the risk of stroke and heart attack, particularly among women, he said.
The new study confirmed this link and also found that migraines were associated with an increased risk of other heart problems, such as blood clots and atrial fibrillation, Adelborg told Live Science. In addition, because the new analysis included a large number of people, the findings can provide researchers with clues about how migraines affect cardiovascular problems at a population level, Adelborg said.
In the study, the researchers looked at data from about 51,000 people in Denmark who had migraines and about 510,000 people who did not. People in the migraine group had been first diagnosed by age 35, on average, and 71 percent of them were women, according to the findings.
After 19 years of follow-up, the study determined that people with migraines had a 1.5-fold increased risk of heart attack and a twofold increased risk of stroke, compared with people who did not have the headaches, Adelborg said. The study also found that for people with migraines, the risk of blood clots was 1.6 times greater and the risk of atrial fibrillation was 1.3 times greater, compared with people who were migraine-free.
In addition, researchers found that the associations between migraines and several of the cardiovascular problems were stronger in women than in men. The association was also stronger in people who had migraines with an "aura," a phenomonen that can precede the headache and that includes visual disturbances such as seeing flashing lights or having blind spots in one eye.
The head-heart connection?
There are several reasons why migraines may be tied to cardiovascular problems, the researchers said. One potential mechanism may involve the sudden constriction of blood vessels in the brain that is thought to lead to migraines; this may also make a person more vulnerable to stroke, Adelborg said. (When blood vessels suddenly constrict, it is more difficult for blood to flow, which could lead to a lack of blood in parts of the brain.)
Another possible explanation may be that people who have migraines are less active and need to rest when episodes strike, which could increase the risk of blood clots, he said.
Though the exact mechanisms for the link remain unclear, a mounting body of evidence supports considering migraines to be strong and persistent risk factors for most cardiovascular diseases in both men and women, Adelborg said. Although the risk of heart problems among people with migraines in the study was low at an individual level, this still translates into a substantial increase in heart disease risk at a population level, because migraine is a very common condition, he said.
One limitation of the research is that the average age of the study population was 35, which is young for heart-related problems, even though the follow-up period lasted nearly two decades, Adelborg said. Future research will need to determine whether prevention strategies for migraines can also reduce the risk of cardiovascular disease, he said.
Originally published on Live Science