title: The risk of type 1 diabetes among offspring of immigrant mothers in relation to the duration of residency in Sweden.
abstract: OBJECTIVE
  The risk for type 1 diabetes mellitus (T1DM) is increased in the second compared with the first generation of immigrants in Sweden. We investigated the effect of the mother's duration of stay in Sweden on the risk of T1DM in the offspring.
  
  
  METHODS
  Using data from national registries, we identified all subjects with T1DM among 984,798 children born in Sweden (aged 0-18 years) between 1992 and 2009. Incidence rate ratios (IRRs) with 95% CI were estimated using Poisson regression.
  
  
  RESULTS
  Offspring of mothers living in Sweden for up to 5 years had a 22% lower risk of T1DM (adjusted IRR 0.78, 95% CI 0.63-0.96) compared with offspring of mothers living in Sweden for 11 years or more. The risk increased with the mother's duration of stay in Sweden.
  
  
  CONCLUSIONS
  Our findings support the hypothesis that immigration to Sweden is associated with exposure to new environmental factors that contribute to the development of T1DM in genetically susceptible individuals.
authors: Department of Environmental Medicine, Division of Epidemiology, Unit of Cardiovascular Epidemiology, Karolinska Institutet, Stockholm, Sweden.
authors: Hozan Ismael
authors: HI
authors: Hussen
authors: Department of Environmental Medicine, Division of Epidemiology, Unit of Cardiovascular Epidemiology, Karolinska Institutet, Stockholm, Sweden Centre for Epidemiology and Social Medicine, Health Care Services, Stockholm County Council, Stockholm, Sweden.
authors: Tahereh
authors: T
authors: Moradi
authors: Department of Medicine, Clinical Epidemiology Unit, Karolinska University Hospital, Stockholm, Sweden martina.persson@ki.se.
authors: Martina
authors: M
authors: Persson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D004641:Emigration and Immigration / Q000706:statistics & numerical data; D004812:Epidemiologic Methods; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007396:Internship and Residency / Q000706:statistics & numerical data; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors