Long-term exposure to air pollutants and new-onset migraine: A large prospective cohort study

Short-term exposure to air pollutants increases the risk of migraine, but the long-term impacts of exposure to multiple pollutants on migraine have not been established. The aim of this large prospective cohort study was to explore these links. A total of 458,664 participants who were free of migraine at baseline from the UK Biobank were studied. Cox proportional hazards models were used to estimate the risk of new-onset migraine from combined long-term exposure to four pollutants, quantified as an air pollution score using principal component analysis. During a median (IQR) follow-up of 12.5 (11.8, 13.2) years, a total of 5417 new-onset migraine cases were documented. Long-term exposure to multiple air pollutants was associated with an increased risk of new-onset migraine, as indicated by an increased in the SDs of PM2.5 (hazard ratio (HR): 1.04, 95% CI: 1.01–1.06, P = 0.009), PM10 (HR: 1.07, 95% CI: 1.04–1.10, P < 0.001), NO2 (HR: 1.10, 95% CI: 1.07–1.13, P < 0.001) and NOx (HR: 1.04, 95% CI: 1.01–1.07, P = 0.005) in the main model. The air pollution score showed a doseresponse association with an increased risk of new-onset migraine. Similarly, compared with those of the lowest tertile, the HRs (95% CI) of new-onset migraine were 1.11 (95% CI: 1.04–1.19, P = 0.002) and 1.17 (95% CI: 1.09–1.26, P < 0.001) in tertiles 2 and 3, respectively, according to the main model (P trend < 0.001). Long-term individual and joint exposure to multiple air pollutants is associated with an increased risk of new-onset migraine.