After more than 20 years of follow-up, researchers found there was an association between migraine and cardiovascular disease and mortality, according to a prospective cohort study of more than 100,000 female nurses in the U.S.

Lead researcher Tobias Kurth, MD, of Brigham and Women’s Hospital and Harvard University in Boston, and colleagues published their results in The BMJ on May 31.

The researchers noted that approximately one-fifth of the U.S. population have migraine, which is three to four times more common in women than in men. They added that previous research showed that migraine was consistently linked with an increased risk of stroke.

In this study, the researchers analyzed 115,541 women who were between 25 and 42 years old when they enrolled in the Nurses’ Health Study II.

The women were free of angina and cardiovascular disease at baseline and were followed from 1989 through June 2011. They completed a self-administered questionnaire at baseline and every two years and provided information on their reproductive factors, lifestyle factors and medical history. 

Of the women, 15.2 percent said a physician had diagnosed them as having a migraine at baseline. The mean age was approximately 35 years old.

During the follow-up period, there were 1,329 major cardiovascular disease events, which included MI, stroke and fatal cardiovascular disease. In addition, 223 women died from cardiovascular disease.

After adjusting for potential confounding factors, the researchers found migraine was associated with an increased risk for major cardiovascular disease (hazard ratio [HR], 1.50), MI (HR, 1.39), stroke (HR, 1.62), angina/coronary revascularization procedures (HR, 1.73) and cardiovascular disease mortality (HR, 1.37) compared with women without migraine.

The researchers said the results were similar to findings from the Women’s Health Study, a prospective cohort study of female health professionals who were at least 45 years old. That study found migraine was associated with an increased risk of major cardiovascular disease events (HR, 1.42) and cardiovascular disease mortality (HR, 1.42).

This study had a few limitations, according to the researchers, including that the women self-reported their physician diagnosed migraine status. They also had no information on the presence or absence of migraine aura, which previous research found was the subgroup with the highest risk of cardiovascular disease.

In addition, they said there may have been residual confounding factors such as markers of inflammation or genetic factors. Further, the study only enrolled female nurses in the U.S. between 25 and 42 years old, so the results may not be generalizable to other populations.

“The results of our study support the findings of other population based studies linking migraine with increased risk of cardiovascular disease,” the researchers wrote. “Although most studies link migraine with aura with increased risk of ischemic stroke, emerging evidence indicates that this risk extends to other cardiovascular disease as well. Our data support consideration of a history of migraine as a marker for increased risk of any cardiovascular disease event.”