title: CDT, GGT, and AST as markers of alcohol use: the WHO/ISBRA collaborative project.
abstract: BACKGROUND
  Estimates of the performance of carbohydrate deficient transferrin (CDT) and gamma glutamyltransferase (GGT) as markers of alcohol consumption have varied widely. Studies have differed in design and subject characteristics. The WHO/ISBRA Collaborative Study allows assessment and comparison of CDT, GGT, and aspartate aminotransferase (AST) as markers of drinking in a large, well-characterized, multicenter sample.
  
  
  METHODS
  A total of 1863 subjects were recruited from five countries (Australia, Brazil, Canada, Finland, and Japan). Recruitment was stratified by alcohol use, age, and sex. Demographic characteristics, alcohol consumption, and presence of ICD-10 dependence were recorded using an interview schedule based on the AUDADIS. CDT was assayed using CDTect and GGT and AST by standard methods. Statistical techniques included receiver operating characteristic (ROC) analysis. Multiple regression was used to measure the impact of factors other than alcohol on test performance.
  
  
  RESULTS
  CDT and GGT had comparable performance on ROC analysis, with AST performing slightly less well. CDT was a slightly but significantly better marker of high-risk consumption in men. All were more effective for detection of high-risk rather than intermediate-risk drinking. CDT and GGT levels were influenced by body mass index, sex, age, and smoking status.
  
  
  CONCLUSIONS
  CDT was little better than GGT in detecting high- or intermediate-risk alcohol consumption in this large, multicenter, predominantly community-based sample. As the two tests are relatively independent of each other, their combination is likely to provide better performance than either test alone. Test interpretation should take account sex, age, and body mass index.
authors.affiliation: Drug and Alcohol Department, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050, Sydney, Australia. katec@med.usyd.edu.au
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Conigrave
authors.forename: Louisa J
authors.initials: LJ
authors.lastname: Degenhardt
authors.forename: John B
authors.initials: JB
authors.lastname: Whitfield
authors.forename: John B
authors.initials: JB
authors.lastname: Saunders
authors.forename: Anders
authors.initials: A
authors.lastname: Helander
authors.forename: Boris
authors.initials: B
authors.lastname: Tabakoff
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000097:blood* / Q000378:metabolism; D000437:Alcoholism / Q000097:blood* / Q000201:enzymology; D001219:Aspartate Aminotransferases / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014168:Transferrin / Q000031:analogs & derivatives* / Q000378:metabolism*; D014944:World Health Organization; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D014168:Transferrin; C056759:carbohydrate-deficient transferrin; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases