High risk of MS in Iranian immigrants in Gothenburg, Sweden

Abstract

Background: In this study we investigated the risk of multiple sclerosis (MS) in migrants who had moved from Iran to Gothenburg, Sweden. Methods: Patients born in Iran were retrieved from a population-based cohort, which included 534 MS and clinically isolated syndrome patients, born 1959—1990, aged 10—39 years at disease onset in Gothenburg. The expected versus observed number of migrants from Iran was calculated. Results: The MS risk in the Iranian migrants in Gothenburg was several times higher than in Isfahan, Iran (hazard ratio 3.88, 95% confidence interval 2.17—6.40). Compared with the general population of Gothenburg, the observed number of 17 Iranian patients was higher than the expected value of 9.89 (hazard ratio 1.72, 95% confidence interval 1.00—2.75). Conclusion: Migration from a medium-risk to a high-risk area may increase the MS risk to that of the high-risk area.