People with migraines appeared to have a higher likelihood of COVID-19 infection and subsequent symptoms of the disease, but they were less likely to receive health care, according to a study presented at the American Headache Society's 2021 annual meeting.
"These data suggest that people with migraine are either more susceptible to contracting COVID-19, or that they may be more sensitive to the development of symptoms once COVID-19 has been contracted, or both," Robert Shapiro, MD, PhD, professor of neurological science at the University of Vermont, Burlington. "Further, once COVID-19 has been contracted, people with migraine may be less likely to develop serious COVID-19 outcomes, or they may be less likely to seek health care for COVID-19, or both."
In providing background information, Shapiro noted previous research showing that headache is associated with a positive prognosis in COVID-19 inpatients, including lower IL-6 levels throughout the disease course, a 1-week shorter disease course, and a 2.2 times greater relative risk of survival.
Yet in a study across 171 countries, a higher population prevalence of migraine is associated with higher COVID-19 mortality rates. It's unclear what conclusions can be drawn from that association, however, said Deborah I. Friedman, MD, MPH, professor of neurology and ophthalmology at University of Texas, Dallas, who was not involved in the research.
Shapiro suggested a theoretical possibility, noting that two genes linked to migraine susceptibility – SCN1A and IFNAR2 – are among 15 host loci also associated with COVID-19 outcomes. Further, Shapiro noted in his background information, COVID-19 is linked to lower serum calcitonin gene-related peptide levels.
For the study, Shapiro and colleagues analyzed data from U.S. adults who responded to the National Health and Wellness Survey from April to July 2020. The researchers limited their analysis to the 41,155 participants who had not received the flu vaccine in 2020 since previous research has suggested reduced morbidity among those with COVID-19 who had been vaccinated against the flu. In this group, 4,550 participants had ever been diagnosed by a doctor with migraine (11%) and 36,605 participants had not (89%).
The majority of those with a history of migraine were female (78%), compared with the overall sample (50% female), and tended to be younger, with an average age of 39 compared with 45 for those without migraine (P < .001).
Among those with a previous migraine diagnosis, 3.8% self-reported having had a COVID-19 infection, compared with infection in 2.4% of those without a history of migraine (P < .001). That translated to a 58% increased risk of COVID-19 infection in those with migraine history, with a similar rate of test positivity in both groups (33.7% with migraine history vs. 34.5% without). Test negativity was also similar in both groups (15.9% vs. 17.8%).
Of 360 respondents who had tested positive for COVID-19, the 60 with a history of migraine reported more frequent symptoms than those without migraine. The increased frequency was statistically significant (P < .001 unless otherwise indicated) for the following symptoms:
Difficulty breathing or shortness of breath (P = .005).
Headache, sore throat, and/or congestion.
Loss of smell and taste.
Chills and body aches.
Persistent pain or pressure in the chest.
Confusion or inability to arouse.
Digestive issues (P = .005).
Bluish lips or face.
For several of these symptoms – such as headache/sore throat/congestion, persistent pain or pressure in the chest, confusion/inability to arouse, and digestive issues – more than twice as many respondents with migraine reported the symptom, vs. those without migraine.
Changes in Health Care Utilization
"I think that people with migraine are aware of their bodies and aware of their symptoms more than the average person," Friedman said. Yet those with migraine were less likely to use health care while diagnosed with COVID-19 than were those without migraine. Migraine sufferers with a COVID-19 infection were 1.2 times more likely to visit a health care provider than were those without an infection, but the similar relative risk was 1.35 greater for those with COVID-19 infections and no migraines.
Similarly, those with a migraine history were more than twice as likely to visit the emergency department when they had a COVID-19 vaccine infection than were those without an infection (RR = 2.6), but among those without a history of migraine, respondents were nearly five times more likely to visit the emergency department when they had a COVID-19 infection than when they didn't (RR = 4.9).
Friedman suggested that the lower utilization rate may have to do with the nature of migraine itself. "There are people with migraine who go to the emergency room all the time, but then there's most of the people with migraine, who would rather die than go to the emergency room because with the light and the noise, it's just a horrible place to be if you have migraine," Friedman said. "I think the majority of people would prefer not to go to the emergency room if given the choice."
Increased likelihood of hospitalization among those with migraine and a COVID-19 infection was 4.6 compared with those with a migraine and no infection; the corresponding hospitalization risk for COVID-19 among those without migraine was 7.6 times greater than for those with no infection. All these risk ratios were statistically significant.
Shapiro then speculated on what it might mean that headache is a positive prognostic indicator for COVID-19 inpatients and that migraine population prevalence is linked to higher COVID-19 mortality.
"A hypothesis emerges that headache as a symptom, and migraine as a disease, may reflect adaptive processes associated with host defenses against viruses," Shapiro said. "For example, migraine-driven behaviors, such as social distancing due to photophobia, in the setting of viral illness may play adaptive roles in reducing viral spread."
The researchers did not receive external funding. Shapiro has consulted for Eli Lilly and Lundbeck. Friedman reports grant support and/or advisory board participation for Allergan, Biohaven Pharmaceuticals, Eli Lilly, Impel NeuroPharma, Invex, Lundbeck, Merck, Revance Therapeutics, Satsuma Pharmaceuticals, Teva Pharmaceuticals, Theranica, and Zosano Pharma.