Various migraine subgroups based on comorbidities can predict the risk for the progression of episodic migraine to chronic migraine, according to study results in Neurology.
Patients with episodic migraine who reported ≥1 comorbidity and responded to the internet-based CaMEO Study (NCT01648530), which was designed to assess a range of data including migraine characteristics and progression, as well as comorbidities, were included in this analysis. Researchers assessed the onset of chronic migraine <4 episodes over a 12-month period in these patients. A total of 8 subgroups of migraine classes were identified by latent class analysis and included: many comorbidities/most comorbidities (class 1); respiratory/psychiatric (class 2); respiratory/pain (class 3); respiratory (class 4); psychiatric (class 5); cardiovascular (class 6); pain (class 7); few comorbidities/fewest comorbidities (class 8).
A total of 8658 people with episodic migraine from the CaMEO Study Comorbidities/Endophenotype module were included. Using class 8 (few comorbidities) as a reference, researchers found that all comorbidity classes were associated with significantly higher hazard ratios (HRs) in regards to the risk for progression of episodic to chronic migraine. The HR for chronic migraine onset was 5.34 (95% CI, 3.89–7.33; P ≤.001) for most comorbidities, whereas the HR was 1.53 (95% CI, 1.17–2.01; P <.05) for the respiratory class. The second highest HR for chronic migraine onset was noted in a combination of respiratory and pain comorbidities (HR, 3.64; 95% CI, 2.67–4.98).
After adjustment for covariates such as headache-related disability, medication overuse, and allodynia, results demonstrated an attenuated association between comorbidity classes and the progression to chronic migraine. For example, HR for progression to chronic migraine decreased from 5.34 to 3.95 for most comorbidity classes when data was adjusted for headache-related disability. Other adjustments demonstrated similar attenuations, although to a lesser degree.
Limitations of the study included the low response rates to the initial survey invitation, as well as the reliance on self-reported diagnoses of comorbidities.
The researchers concluded that the next step will be to externally validate comorbidity classes “to determine whether we can predict treatment responses to different types of treatment based on comorbidity class.”
Disclosure: This clinical trial was supported by Allergan plc. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Lipton RB, Fanning KM, Buse DC, et al. Migraine progression in subgroups of migraine based on comorbidities: Results of the CaMEO Study [published online November 5, 2019]. Neurology. doi: 10.1212/WNL.0000000000008589