CINCINNATI, Nov. 30 (UPI) -- People who have occasional migraines and asthma are twice as likely as those without the breathing condition to develop chronic migraine attacks, according to a new study.
Researchers at the University of Cincinnati and Montefiore Headache Center explored the link between migraines and asthma because they are similarly caused by inflammation, either of the blood vessels or airways. They theorize that if one is not directly caused by the other, they may be caused by the same allergens, suggesting allergies in some patients be treated more aggressively.
About 12 percent of the U.S. population gets migraine headaches, which are about three times more common in women than men, according to the National Institute for Neurological Disorders and Stroke. People with chronic migraine get headaches 15 or more days per month. The Centers for Disease Control and Prevention reports about 7 percent of American adults have asthma.
"If you have asthma along with episodic or occasional migraine, then your headaches are more likely to evolve into a more disabling form known as chronic migraine," Dr. Vincent Martin, a professor of medicine at the University of Cincinnati, said in a press release. "The strength of the relationship is robust -- asthma was a stronger predictor of chronic migraine than depression, which other studies have found to be one of the most potent conditions associated with the future development of chronic migraine."
Researchers analyzed data on 4,446 people with a mean age of 50.4 years, with 80.8 percent of participants being women. The participants were split into two groups, people with asthma and people without it, and completed surveys in 2008 and 2009. The researchers asked about episodic migraines, frequency of headaches, medication usage, depression and smoking status.
In the first survey, 17 percent of participants reported having asthma. Overall, 2.9 percent of people who completed the 2008 survey reported they developed chronic migraine by the 2009 survey. Of these participants, 5.4 percent had asthma in 2008, versus 2.5 percent who did not have it.
Previous studies have shown people with asthma are more likely to have allergies, and people with allergies are more likely to have headaches, researchers said. An overactive parasympathetic nervous system may contribute to the potential of developing one or both conditions, which they said is also a reaction to allergens in the environment.
"If allergies are the trigger it begs the question: Should we treat allergies more aggressively in these patients?" Martin said.
The study is published in the journal Headache.