Improved diagnostic classification of alcohol abusers by combining carbohydrate-deficient transferrin and gamma-glutamyltransferase.

BACKGROUND

Biochemical markers can provide objective evidence of high alcohol consumption. However, currently available markers have limitations in their diagnostic performance.

METHODS

The diagnostic values of the most frequently used markers [carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume] were studied in an analysis of six different clinical studies (n = 1412) on alcohol abusers and social drinkers. The purpose of the analyses was to determine whether a combination of markers would improve the diagnosis of subjects.

RESULTS

Discrimination between alcohol abusers and social drinkers, as measured by the areas under nonparametric ROC plots, was significantly better (P<0.001) for the new combined marker [gamma-CDT = 0.8. ln(GGT) + 1.3. ln(CDT)] than for any of the separate markers or combination of CDT or GGT with other markers. The cutoff values for gamma-CDT (6.5) can be taken to be the same among males and females.

CONCLUSIONS

The combined variable gamma-CDT is a powerful tool to discriminate alcohol abusers from social drinkers and is recommended for clinical use.