title: The long-term renal and retinal outcome of childhood-onset Type 1 diabetes.
abstract: OBJECTIVE
  To quantify the influence of childhood onset on long-term renal and retinal outcome in Type 1 diabetes.
  
  
  METHODS
  We used a population-based diabetes register to identify all Type 1 patients diagnosed before age 15 from 1960 to 1982 and resident in a defined catchment area in 1999. Those diagnosed before age 5, aged 5-9 and 10-14 years were compared with a reference group diagnosed at age 21-25 years over the same period.
  
  
  RESULTS
  Compared with adult-onset controls, proteinuria occurred earlier (P = 0.02) and nephropathy outcome was worse (P = 0.008) in childhood-onset diabetes. The risk of developing microalbuminuria was greater in childhood-onset diabetes: odds ratio 2.6 (95% confidence interval 1.4-4.9, P = 0.003). The relative risk of established nephropathy was 3.8 (1.5-9.4, P = 0.005) with childhood onset. The number developing background retinopathy did not differ with age at onset but younger onset patients were more likely to need laser treatment: relative risk 2.1 (1.1-3.8, P = 0.02). This maintained visual outcome which was not significantly different between the various age at onset groups.
  
  
  CONCLUSIONS
  Patients with onset of Type 1 diabetes before age 15 have substantially worse renal outcome and require more laser treatment than adult-onset patients. Differences between those with onset before age 5, onset at 5-9 and 10-14 years are small compared with the difference between childhood onset and adult onset. Events in the teenage years therefore appear to have a major adverse effect on the risk of developing long-term microvascular complications.
authors.affiliation: University of Wales College of Medicine, Wrexham Academic Unit, Wrexham, UK. john.harvey@new-tr.wales.nhs.uk
authors.forename: J N
authors.initials: JN
authors.lastname: Harvey
authors.forename: B
authors.initials: B
authors.lastname: Allagoa
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000419:Albuminuria / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000503:physiopathology / Q000652:urine; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000503:physiopathology / Q000652:urine; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology / Q000652:urine; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011379:Prognosis; D011507:Proteinuria / Q000175:diagnosis; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D016019:Survival Analysis; D013997:Time Factors