title: HbA1c, fasting plasma glucose and the prediction of diabetes: Inter99, AusDiab and D.E.S.I.R.
abstract: BACKGROUND
  With diabetes defined by HbA1c≥6.5% and/or FPG≥7.0mmol/l and/or diabetes treatment, we investigated HbA1c and fasting plasma glucose (FPG) thresholds/change-points above which the incidence of diabetes increases.
  
  
  METHODS
  Data are Danish (Inter99), Australian (AusDiab) and French (D.E.S.I.R.), with respectively 4930, 6012 and 3784 non-diabetic participants.
  
  
  RESULTS
  Diabetes incidences at 5 years for Inter99 and AusDiab and at 6 years for D.E.S.I.R. were 2.3%, 3.1% and 2.4% respectively and incidences increased with baseline HbA1c and FPG. As HbA1c distributions differed between cohorts, HbA1c was standardized on D.E.S.I.R. data. Change-points where diabetes incidence increased were identified for HbA1c (%) after standardization: 5.1 (4.9-5.6) (Inter99), 5.4 (5.1-5.6) (AusDiab), 5.3 (5.1-5.7) (D.E.S.I.R.); for FPG change-points (mmol/l) were 5.1 (…-6.1) (Inter99), 5.5 (5.2-5.8) (AusDiab), no change-point for D.E.S.I.R. Using current diabetes risk criteria HbA1c≥5.7% and/or FPG≥5.6mmol/l to screen for diabetes provided high sensitivity (over 89%) and positive predictive values: 4.3%, 6.9%, and 5.9% respectively.
  
  
  CONCLUSIONS
  HbA1c and FPG change-points predicting incident diabetes did not always exist, differed across studies, when available were generally lower than current criteria with wide confidence intervals. Using jointly HbA1c≥5.7% and/or FPG≥5.6mmol/l as a criterion for the risk of incident diabetes is appropriate.
authors: Université Paris Sud 11, UMRS 1018, Villejuif, France. soraya.soulimane@inserm.fr
authors: Soraya
authors: S
authors: Soulimane
authors: Dominique
authors: D
authors: Simon
authors: Jonathan
authors: J
authors: Shaw
authors: Daniel
authors: D
authors: Witte
authors: Paul
authors: P
authors: Zimmet
authors: Sylviane
authors: S
authors: Vol
authors: Knut
authors: K
authors: Borch-Johnsen
authors: Dianna
authors: D
authors: Magliano
authors: Dorte
authors: D
authors: Vistisen
authors: Beverley
authors: B
authors: Balkau
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D005215:Fasting / Q000097:blood*; D005260:Female; D005602:France / Q000453:epidemiology; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human