title: Incidence of type 1 diabetes in childhood before and after the reunification of Germany--an analysis of epidemiological data, 1960-2006.
abstract: OBJECTIVE
  To examine the impact of rapidly changing environmental factors on the incidence of type 1 diabetes mellitus (T1D).
  
  
  METHODS
  We compared the frequency of T1D in children before and after the reunification of Germany by means of the registries of the German Democratic Republic (GDR, 1960-1989) and of Baden-Wuerttemberg (BW, 1987-2006). The number of cases of diabetes onset in East Germany after the reunification was predicted by a mathematical model. The observed incidence rate in the Eastern part of Germany after the reunification was taken from the literature 1.
  
  
  RESULTS
  In Germany, the incidence rate of T1D in children aged 0-14 was 7.2/100 000/year (95%-CI 6.9-7.5, GDR, 1980-1987), and 10.4/100 000/year (95%-CI 9.5-11.4, BW, 1987-1994). For the whole observation period (1960-2006), the observed incidence rates y could be described by the square of a linear function [GDR: y=(1.86 + 0.040 * (year - 1960))²; r²=0.85; BW: y=(3.03 + 0.085 * (year - 1987))², r²=0.89]. The mean rise in incidence before the reunification was less than half the mean rise after the reunification (mean slope: BW 0.085, 95%-CI 0.080-0.090 vs. GDR 0.040, 95% CI 0.036-0.044). The observed incidence for East Germany after 1989 was higher than the prediction on the basis of the GDR -registry (GDR 12.3/100 000/year vs. Saxony 15.7/100 000/year, 95%-CI 14.2-17.3, n=412; 1999-2003).
  
  
  CONCLUSIONS
  We conclude that the basis for the disease progress is a genetic predisposition. Environmental factors may modify changes in incidence of type 1 diabetes but do not determine the overall risk.
authors.affiliation: Paediatric Endocrinology and Diabetes, University Children's Hospital Tuebingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Ehehalt
authors.forename: A
authors.initials: A
authors.lastname: Neu
authors.forename: D
authors.initials: D
authors.lastname: Michaelis
authors.forename: P
authors.initials: P
authors.lastname: Heinke
authors.forename: A M
authors.initials: AM
authors.lastname: Willasch
authors.forename: K
authors.initials: K
authors.lastname: Dietz
mesh_terms: D000293:Adolescent; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003148:Communism; D003709:Democracy; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D005858:Germany / Q000453:epidemiology; D005859:Germany, East / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008954:Models, Biological; D012042:Registries; D012922:Social Change