title: Predicting the 20-year diabetes incidence rate.
abstract: BACKGROUND
  The long-range prediction from clinical variables of the onset of diabetes is important to patients and clinicians. Our objective was to evaluate the efficacy of various glucose-related clinical measurements in predicting the 20-year risk of developing type 2 diabetes (T2DM) in an elderly population.
  
  
  METHODS
  In a prospective study, 672 men and women aged 59-92 years, who were not diabetic in 1980 and were part of a nationwide longitudinal randomized study, were followed-up in 2000-2003. Fasting glucose, 1- and 2-h post-oral glucose tolerance and insulin were measured in 1980 and 2000-2003.
  
  
  RESULTS
  A group of 174 (25.9%) survivors had progressed to diabetes during the 20-year follow-up. Fasting glucose values were a good predictor for diabetes. With the 100 mg/dL cut-off of impaired fasting glucose (IFG), a 2-4-times higher predictive sensitivity followed the dramatic increase in IFG prevalence compared to the 110 mg/dL cut-off, but at a cost of reduced specificity and positive predictive value (PPV). By receiver operating curve (ROC) analysis, a 1-h post-load glucose was similar to 2 h and fasting glucose in prediction of the 20-year incidence of diabetes, and classifying correctly the 77, 74 and 73% of the group, respectively. In adjusted logistic regressions, 2.28, 1.78 and 1.69-folds increased the 20-year risk, and were associated with each SD increment of the respective glucose values (p < 0.001).
  
  
  CONCLUSIONS
  Although the best population-based strategy for the diagnosis of T2DM would be the combination of fasting glucose followed by post-load glucose, for the purposes of long-term prediction of T2DM risk, fasting glucose is sufficient.
authors.affiliation: Unit for Cardiovascular Epidemiology, The Gertner Institute for Epidemiology and Health Policy Research, Tel-Hashomer, Israel. rachel@gertner.health.gov.il
authors.forename: Rachel
authors.initials: R
authors.lastname: Dankner
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Abdul-Ghani
authors.forename: Yariv
authors.initials: Y
authors.lastname: Gerber
authors.forename: Angela
authors.initials: A
authors.lastname: Chetrit
authors.forename: Julio
authors.initials: J
authors.lastname: Wainstein
authors.forename: Itamar
authors.initials: I
authors.lastname: Raz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D016019:Survival Analysis; D017741:Survivors