Enhanced clinical utility of gamma-CDT in a general population

Background: The use of a combination of markers to detect excessive alcohol consumption has been reported to provide better sensitivity in the diagnos is of alcohol abuse than single markers. However, the optimal combination o f markers for the diagnosis of alcohol abuse has not yet been found. The ai m of this study was to compare the diagnostic value of carbohydrate-deficie nt transferrin (CDT) and gamma-glutamyltransferase (GGT) to discriminate am ong heavy drinkers (>280 g/week), moderate drinkers (105-280 g/week), and l ight drinkers (<105 g/week). Their mathematical combination, named gamma-CD T, which has been found to be a strong marker of alcohol abuse in a former study, was also evaluated. Methods: The study was conducted in a group of 6962 subjects (3974 males an d 2988 females), between the ages of 25 and 74 years, who participated in a large cross-sectional risk factor survey carried out in five geographic ar eas in Finland. In each study area, an age- and gender-stratified random sa mple was drawn from the general population. Sensitivity, specificity, posit ive and negative predictive values, and receiver operating characteristic c urves were used to evaluate the performance of CDT, GGT, and gamma-CDT. Results: For both sexes, the combined marker had the highest specificity (9 5%) and sensitivity in detecting heavy drinkers. In all cases, gamma-CDT ha d the highest area under ROC plots. Our results also showed that GGT and CD T have similar, and rather low, sensitivity but high specificity in a gener al population. Conclusions: Compared with single markers, a significant improvement of sen sitivity was obtained when the combination of both markers was used, especi ally in females.