Individuals with asthma who also experience episodic or occasional migraine may be more likely to develop chronic migraine, according to a National Headache Foundation-sponsored study, recently published online in the journal Headache.

“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,” said Vincent Martin, MD, professor of medicine in UC’s Division of General Internal Medicine, co-director of the Headache and Facial Pain Program at the UC Neuroscience Institute and lead author in the study. Dr. Martin is Vice President of the National Headache Foundation.

Researchers from the University of Cincinnati (UC), Montefiore Headache Center, Albert Einstein College of Medicine, and Vedanta Research studied 4,500 individuals who experienced episodic migraine or fewer than 15 headaches per month in 2008. They analyzed data from the American Migraine Prevalence and Prevention (AMPP) Study which was undertaken during 2008 and 2009Study participants completed written questionnaires in both years.  Based on responses to the 2008 questionnaire, patients were divided into two groups—one with episodic migraine and coexisting asthma and another with episodic migraine and no asthma. They were questioned about medication usage, depression, and smoking status. The 2008 and 2009 questionnaires included questions about frequency of headaches, which enabled the authors to identify the participants who had progressed to chronic migraine.

After one year of follow-up, researchers found that new onset chronic migraine developed in 5.4 percent of participants who were also suffering from asthma, and in 2.5 percent of individuals without asthma.

“The strength of the relationship is robust,” Martin said. “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 future development of chronic migraine.”

About 12 percent of the U.S. population experiences migraine, according to Martin. Individuals with chronic migraine have headaches 15 or more days per month. Chronic migraine affects about 1 percent of the U.S. population and takes a severe toll on sufferers who often miss work and social events.

There are various theories as to why asthma may have a predictive role in chronic migraine development for individuals with episodic or occasional migraine. Martin said asthmatic patients are more likely to also have allergies and prior studies have shown that allergies may increase the number of headaches, particularly if the individual has hay fever.

Other possibilities, according to Martin, include patients with asthma who may have an overactive parasympathetic nervous system that predisposes them to attacks of both migraine and asthma. He said it is also possible that asthma may not directly cause chronic migraine, but that a shared environmental or genetic factor, like air pollution which has been known to trigger both asthma and migraine attacks, may play a role.

Martin suggested that physicians may consider prescribing preventive medications for migraine at an earlier stage in patients who suffer from asthma and occasional migraine in order to avoid chronic migraine.

“If allergies are the trigger, it begs the question, should we treat allergies more aggressively in these patients?” said Martin.

The AMPP Study was funded through research grants to the National Headache Foundation from McNeil-Janssen Scientific Affairs LLC, Raritan, N.J. The AMPP study database was donated by the McNeil-Janssen Scientific Affairs LLC to the National Headache Foundation for use in various projects. There are no financial conflicts of interest declared by the study authors.