title: Changing impact of modifiable risk factors on the incidence of major outcomes of type 1 diabetes: the Pittsburgh Epidemiology of Diabetes Complications Study.
abstract: OBJECTIVE
  The incidence of type 1 diabetes complications appears to be decreasing, but relative contributions of risk factors are unclear. We thus estimated the effect of modifiable risk factors on the incidence of a composite end point, major outcomes of diabetes (MOD).
  
  
  METHODS
  The Pittsburgh Epidemiology of Diabetes Complications (EDC) Study was used to derive two cohorts based on diabetes diagnosis year (1960-1969 and 1970-1980). Baseline exam data in the current analysis for the 1960s group were collected in 1986-1988 and for the 1970s in 1996-1998. Each group was followed for 8 years for MOD incidence (diabetes-related death, myocardial infarction, revascularization procedure/blockage ≥50%, stroke, end-stage renal disease, blindness, and amputation). Assessed risk factors include the following: HbA1c, hypertension, microalbuminuria, BMI, hypercholesterolemia, and smoking. Accelerated failure time models were used to estimate the acceleration factor.
  
  
  RESULTS
  MOD incidence decreased in the 1970s cohort (15.8% [95% CI 11.6-21.4]) compared with the 1960s (22.6% [17.0-29.1]) over the 8-year follow-up (P = 0.06). Hypertension and microalbuminuria were associated with significantly accelerated MOD incidence in both cohorts (P < 0.01 for both). High HbA1c (P = 0.0005), hypercholesterolemia (P = 0.01), and current smoking (P = 0.003) significantly accelerated the incidence of MOD in the 1960s but not 1970s cohort. BMI was not associated with MOD in either cohort.
  
  
  CONCLUSIONS
  These results suggest that hypertension and microalbuminuria remain important predictors of complications that are not being adequately addressed.
authors.affiliation: Corresponding author: Trevor J. Orchard, orchardt@edc.pitt.edu.
authors.forename: Rachel G
authors.initials: RG
authors.lastname: Miller
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Secrest
authors.forename: Demetrius
authors.initials: D
authors.lastname: Ellis
authors.forename: Dorothy J
authors.initials: DJ
authors.lastname: Becker
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Orchard
mesh_terms: D000293:Adolescent; D000328:Adult; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D048909:Diabetes Complications / Q000150:complications / Q000453:epidemiology*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D010414:Pennsylvania / Q000453:epidemiology; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult