Researchers have found that those experiencing occasional migraine attacks are likelier to develop chronic migraine in the future if they also have asthma.
University of Cincinnati's Vincent Martin, M.D. and colleagues explained that having asthma is a strong predictor for chronic migraine attacks in the future. According to Richard Lipton, M.D., asthma and migraine are both disorders involving inflammation and activation of smooth muscle in either the airways or the blood vessels so it is possible that asthma-related inflammation could lead to migraine attacks worsening.
Analyzing data from the American Migraine Prevalence and Prevention Study, the researchers went through information from around 4,500 individuals who experienced less than 15 headaches in a month or had episodic migraine. Participants filled out written questionnaires in 2008 and 2009 and were separated into two groups: one with episodic migraine, but didn't have asthma and the other with episodic migraine and asthma.
As the questionnaires asked for details regarding headache frequency, they were able to help the researchers identify which of the participants progressed to chronic migraine. Other details provided by participants include smoking and depression status and medication usage.
After a year of follow-up, the researchers saw that chronic migraine developed in 5.4 percent of participants who had asthma and 2.5 percent in those without. Martin added that participants with both asthma and episodic migraine at baseline were at least two times likelier to develop chronic migraine within one year compared to participants from the other group.
"The strength of the relationship is robust," said Martin, adding that asthma is a stronger predictor compared to depression, which earlier studies have discovered to be a potent condition associated with future chronic migraine development.
One of the reasons the researchers are looking into to explain the relationship between asthma and migraine is that those with asthma may have overactive parasympathetic nervous systems, which makes them more vulnerable against both asthma and migraine attacks. On the other hand, it is also possible for shared genetic or environmental factors being at play.
Asthma is present in about 8 percent of adults in the U.S. while around 12 percent of the American population experience migraines, although the latter is three times more common in women than in men. Chronic migraine is defined as having headaches for at least 15 days in a month. About a percent of the U.S. population miss out on social events and work because of chronic migraine.
The study was published online in the American Headache Society's journal, Headache.
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