Utility of biological markers during outpatient treatment of alcohol-dependent subjects: carbohydrate-deficient transferrin responds to moderate changes in alcohol consumption

A group of 25 alcohol-dependent subjects in outpatient treatment were monitored for a period of 4 weeks. They were weekly interviewed for their alcohol consumption and their serum levels of carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GT) were analyzed. The majority of the patients reported an excessive and fairly constant alcohol intake during the observation period. When selecting those patients that reported periods of 1 or 2 weeks with moderate changes in alcohol consumption, corresponding changes in CDT were demonstrated. Thus, of 14 patients reporting an increased alcohol consumption for 2 weeks (mean values increased from 57 to 101 g/day), 11 showed an increase in CDT at the end of the period. The mean CDT value of all 14 increased from 5.5 to 6.7% (p < 0.05). Slight, but not significant, increases were noted in GT, indicating that CDT is more sensitive than GT in detecting increased alcohol consumption. Furthermore, of 17 patients that reported decreased alcohol consumption for one or several weeks, 14 showed decreased CDT and GT values. The mean values of all 17 were reduced from 5.1% to 4.5% (CDT) and from 126 units/liter to 97 units/liter (GT) (p < 0.05 for both parameters). The results indicate that CDT responds to moderate changes in alcohol consumption in alcohol-dependent patients and may thus be useful as a corrective tool to self-reports of alcohol consumption during outpatient treatments.