title: Screening for diabetes mellitus--a two-step approach in individuals with impaired fasting glucose improves detection of those at risk of complications.
abstract: OBJECTIVE
  To compare the new American Diabetes Association (ADA) fasting plasma glucose (FPG) criteria to the 1985 World Health Organization (WHO) 2-h post glucose (2hPG) criteria when used for screening of those with no prior history of diabetes mellitus.
  
  
  METHODS
  The study included 3,407 subjects without a history of diabetes in whom both FPG and 2hPG were available from the 1992 Singapore National Health Survey. The agreement (kappa) between FPG and 2hPG for the diagnosis of DM was assessed. The optimal cut-off of FPG for the detection of individuals with 2hPG > or = 11.1 mmol/l was determined by receiver-operating characteristics analysis.
  
  
  RESULTS
  The prevalence of diabetes diagnosed by FPG alone was 7.3% compared to 8.4% diagnosed by 2hPG. The prevalence of impaired fasting glucose was 8.0%. FPG and 2hPG showed moderate agreement (kappa = 0.646, 95% confidence interval 0.584-0.708). Age, ethnic group and obesity did not affect the degree of agreement. Of those with 2hPG > or = 11.1 mmol/l, 40.8% had FPG in the non-diabetic range while 24.8% of those with FG > or = 7.0 mmol/l had 2hPG in the non-diabetic range. The optimal FPG for the detection of 2hPG > or =11.1 mmol/l was 6.1 mmol/l. Oral glucose tolerance tests (OGTT) in those with 6.0 mmol/ < FPG < 7.0 mmol/l resulted in the diagnosis of diabetes in 90.7% of individuals at risk of microvascular complications.
  
  
  CONCLUSIONS
  FPG provides a simple screening test for diabetes, which shows moderate agreement with the 2hPG. A two-step strategy of OGTT in those with impaired fasting glucose improves the detection of at-risk individuals. However, diabetes should not be diagnosed on a single test. The test should be repeated on another day if an individual tests positive for diabetes.
authors.affiliation: Department of Endocrinology, Singapore General Hospital, Singapore. eshyong@pacific.net.sg
authors.forename: E S
authors.initials: ES
authors.lastname: Tai
authors.forename: S C
authors.initials: SC
authors.lastname: Lim
authors.forename: B Y
authors.initials: BY
authors.lastname: Tan
authors.forename: S K
authors.initials: SK
authors.lastname: Chew
authors.forename: D
authors.initials: D
authors.lastname: Heng
authors.forename: C E
authors.initials: CE
authors.lastname: Tan
mesh_terms: D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis*; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology*; D005006:Ethnicity; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000175:diagnosis*; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012846:Singapore / Q000453:epidemiology; D014481:United States; D014837:Voluntary Health Agencies; D014944:World Health Organization
chemical_list: D001786:Blood Glucose