title: Annual incidence and relative risk of diabetes in people with various categories of dysglycemia: a systematic overview and meta-analysis of prospective studies.
abstract: BACKGROUND
  Several estimates of the risk of progression to diabetes in people with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) have been reported.
  
  
  OBJECTIVE
  To provide an estimate of the risk of progression to diabetes and regression to normoglycemia in these populations.
  
  
  METHODS
  Systematic overview and meta-analysis of prospective cohort studies published from 1979 until 2004.
  
  
  METHODS
  Global cohort studies.
  
  
  METHODS
  People with IFG or IGT detected by a screening oral glucose tolerance test.
  
  
  METHODS
  Fasting and post-load plasma glucose levels.
  
  
  RESULTS
  The absolute annual incidence of diabetes in individuals with various categories of IFG or IGT varied from 5 to 10%. Compared to normoglycemic people the meta-analyzed relative risk and 95% confidence interval for diabetes was: 6.35 (4.87-7.82) in people with IGT; 5.52 (3.13-7.91) in people with isolated IGT; 4.66 (2.47-6.85) in people with IFG; 7.54 (4.63-10.45) in people with isolated IFG; and 12.13 (4.27-20.00) in people with both IFG and IGT. People with IGT were 0.33 times as likely to be normoglycemic after 1 year compared to people with normal glucose tolerance (95% CI 0.23-0.43).
  
  
  CONCLUSIONS
  Studies that used differing criteria for IFG and IGT were included, and participants were classified on the basis of only one test.
  
  
  CONCLUSIONS
  IFG and IGT are associated with similar, high relative risk for incident diabetes. The combined abnormality of IFG plus IGT is associated with the highest relative risk.
authors.affiliation: Department of Medicine, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada. gerstein@mcmaster.ca
authors.forename: Hertzel C
authors.initials: HC
authors.lastname: Gerstein
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Santaguida
authors.forename: Parminder
authors.initials: P
authors.lastname: Raina
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Morrison
authors.forename: Cynthia
authors.initials: C
authors.lastname: Balion
authors.forename: Dereck
authors.initials: D
authors.lastname: Hunt
authors.forename: Hossein
authors.initials: H
authors.lastname: Yazdi
authors.forename: Lynda
authors.initials: L
authors.lastname: Booker
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood / Q000145:classification / Q000453:epidemiology*; D018149:Glucose Intolerance / Q000097:blood / Q000145:classification / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D012016:Reference Values; D012306:Risk
chemical_list: D001786:Blood Glucose