title: Risk factors for progression to proliferative diabetic retinopathy in the EURODIAB Prospective Complications Study.
abstract: OBJECTIVE
  Proliferative diabetic retinopathy (PDR), a leading cause of blindness, cannot be totally prevented by optimizing metabolic and blood pressure control and responds to no specific treatment other than partially destructive retinal photocoagulation. Recognizing risk factors using large-scale epidemiological studies could help identify targets for treatment. The EURODIAB Prospective Complications Study (PCS) includes the largest cohort so far of patients with Type I (insulin-dependent) diabetes mellitus.
  
  
  METHODS
  Baseline data were collected between 1989 and 1991 on 3250 patients who were recalled for follow-up. Physical examination, biochemical tests and assessment of complications were done on both occasions. In particular, 1249 patients had retinal photographs taken both basally and after an average of 7.3 years.
  
  
  RESULTS
  Proliferative retinopathy had developed in 157 patients (cumulative incidence 17.3/1000 patient-years; 95%-CI: 13.6-21.1). HbA(1c) (standardized regression estimate--SRE = 3.03, CI 2.49-3.69), diabetes duration (1.71, 1.42-2.06), age at diagnosis < 12 (1.66, 1.11-2.50), diastolic blood pressure less than or equal to 83 (1.50, 1.03-2.20) and waist-to-hip ratio (1.50, 1.03-2.20) were all independent predictors for progression to PDR when entered simultaneously into a logistic regression model. Including retinopathy at baseline maintained the effects of metabolic control and pre-pubertal onset only. Including the albumin excretion rate maintained the effect of control but reduced SRE for pre-pubertal onset to 1.49 (0.94-2.33). There was no evidence for a threshold effect for HbA(1c)concentrations at baseline and progression to proliferative retinopathy.
  
  
  CONCLUSIONS
  Metabolic control and duration of diabetes are strong indicators of progression to proliferative retinopathy. Onset of diabetes before puberty could be an additional independent risk factor.
authors.affiliation: Diabetic Retinopathy Centre, Department of Internal Medicine, University of Turin, Corso AM Dogliotti 14, 10126 Turin, Italy. massimo.porta@unito.it
authors.forename: M
authors.initials: M
authors.lastname: Porta
authors.forename: A K
authors.initials: AK
authors.lastname: Sjoelie
authors.forename: N
authors.initials: N
authors.lastname: Chaturvedi
authors.forename: L
authors.initials: L
authors.lastname: Stevens
authors.forename: R
authors.initials: R
authors.lastname: Rottiers
authors.forename: M
authors.initials: M
authors.lastname: Veglio
authors.forename: J H
authors.initials: JH
authors.lastname: Fuller
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001794:Blood Pressure; D001824:Body Constitution; D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy; D003930:Diabetic Retinopathy / Q000453:epidemiology / Q000473:pathology* / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors
chemical_list: D006442:Glycated Hemoglobin