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

Abstract

BackgroundsShort-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. MethodsA 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. ResultsDuring 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). ConclusionLong-term individual and joint exposure to multiple air pollutants is associated with an increased risk of new-onset migraine.