Carbohydrate-deficient transferrin and γ-glutamyltransferase for the detection and monitoring of alcohol use:: Results from a multisite study

Background: The purpose of this article is to evaluate the biological marker of heavy alcohol use, carbohydrate-deficient transferrin (CDT), in contrast to the older and more widely used gamma-glutamyltransferase (GGT) for the detection and monitoring of heavy alcohol use. Methods: In this report, CDT and GGT sensitivity and specificity for heavy alcohol intake are examined in a large multisite study in which 444 recently admitted inpatient alcoholics were compared with 204 matched social drinker controls. In addition, changes in these biomarkers were evaluated during an initial abstinence period and biweekly over 14 weeks of monitoring to compare changes in CDT and GGT during continued abstinence or relapse. Results: CDT and GGT were comparable in identifying heavy alcohol consumption in men, but GGT appeared to be better for women, For both genders, when these markers were combined, there was better sensitivity than when used alone. CDT and GGT both decreased during 4 weeks of abstinence. When we used a 30% increase from baseline abstinent levels as an indicator, CDT appeared marginally better than GGT at indicating relapse in men but not in women. For men in particular, relapse over the course of the study was best identified by evaluating changes (30% increase) in both markers simultaneously. Conclusions: These results support the utility, of CDT, especially when used in conjunction with GGT. as an aid in detecting and monitoring heavy alcohol consumption.