title: Risk of renal disease in patients with both type 1 diabetes and coeliac disease.
abstract: OBJECTIVE
  Our aim was to study the risk of renal disease in patients with type 1 diabetes (T1D) and coexisting coeliac disease (CD).
  
  
  METHODS
  Individuals with T1D were defined as having a diagnosis of diabetes recorded at ≤30 years of age in the Swedish Patient Register between 1964 and 2009. Individuals with CD were identified through biopsy reports with villous atrophy (Marsh stage 3) from 28 pathology departments in Sweden between 1969 and 2008. We identified 954 patients with both T1D and CD. For each patient with T1D + CD, we selected five age- and sex-matched reference individuals with T1D only (n = 4,579). Cox regression was used to estimate the following risks: (1) chronic renal disease and (2) end-stage renal disease in patients with CD + T1D compared with T1D patients only.
  
  
  RESULTS
  Forty-one (4.3%) patients with CD + T1D and 143 (3.1%) patients with T1D only developed chronic renal disease. This corresponded to an HR of 1.43 for chronic renal disease (95% CI 0.94, 2.17) in patients with CD + T1D compared with T1D only. In addition, for end-stage renal disease there was a positive (albeit statistically non-significant) HR of 2.54 (95% CI 0.45, 14.2). For chronic renal disease, the excess risk was more pronounced after >10 years of CD (HR 2.03, 95% CI 1.08, 3.79). Risk estimates were similar when we restricted our cohort to the following T1D patients: (1) those who had an inpatient diagnosis of T1D; (2) those who had never received oral glucose-lowering medication; and (3) those who had not received their first diabetes diagnosis during pregnancy.
  
  
  CONCLUSIONS
  Overall this study found no excess risk of chronic renal disease in patients with T1D and CD. However, in a subanalysis we noted a positive association between longstanding CD and chronic renal disease in T1D.
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden, kaziwe.mollazadegan@live.se.
authors.forename: Kaziwe
authors.initials: K
authors.lastname: Mollazadegan
authors.forename: Michael
authors.initials: M
authors.lastname: Fored
authors.forename: Sigrid
authors.initials: S
authors.lastname: Lundberg
authors.forename: Johnny
authors.initials: J
authors.lastname: Ludvigsson
authors.forename: Anders
authors.initials: A
authors.lastname: Ekbom
authors.forename: Scott M
authors.initials: SM
authors.lastname: Montgomery
authors.forename: Jonas F
authors.initials: JF
authors.lastname: Ludvigsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002446:Celiac Disease / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012042:Registries; D012306:Risk; D013548:Sweden; D055815:Young Adult