To delineate the relationship between headache frequency and associated health conditions in people with migraine. vs a control sample without migraine.

Prior work has compared rates of associated health problems in persons with and without migraine and between episodic migraine (EM) and chronic migraine (CM) groups. 

A systematic US sample of people with and without migraine were identified in the MAST Study using ICHD-3 beta criteria.. Health conditions were assessed  based on self-reported healthcare professional diagnosis. Health problems included  cardiovascular and metabolic conditions, respiratory conditions, inflammatory and pain conditions as well as neurologic and psychiatric disorders. The migraine cohort was stratified based on monthly headache days (MHD) into 5 groups: 1-4, 5-9, 10-14, 15-20 and ≥21 MHDs. Logistic regression modeling calculated the odds ratios (OR) and 95% confidence intervals for the presence of selected conditions in each MMD group compared to controls, adjusting for sociodemographics.

The sample included 15,133 participants who met criteria for migraine (73.0% women, mean age 43.1) and 77,453 non-migraine controls (46.4% women, mean age 52.4). As MHD frequency increased the odds of having many associated health conditions also increased.  For example, Insomnia: 1-4 MHDs OR=2.94, 5-9 MHDs OR=4.49, 10-14 MHDs OR=6.17,15-20 MHDs OR=6.50, ≥21 MHDs OR=7.91. A similar pattern was observed for gastric ulcer: 1-4 MHDs OR=2.61, 5-9 MHDs OR=3.31, 10-14 MHDs OR=4.43, 15-20 MHDs OR=4.28, ≥21 OR=5.91; and other conditions such as anxiety, depression and epilepsy. All ORs were significant (p<.001).

Increasing MHD frequency is associated with increased risk of other health conditions in persons with migraine. Findings may be due to direct causality or reverse causality, shared risk factors or potential detection bias.  Exploration of the pathways that drive these comorbidities may lead to insights that clarify pathophysiology and improve treatment.