LONGITUDINAL COMPARISON OF CARBOHYDRATE-DEFICIENT TRANSFERRIN AND GAMMA-GLUTAMYL-TRANSFERASE - COMPLEMENTARY MARKERS OF EXCESSIVE ALCOHOL-CONSUMPTION

The utility of carbohydrate-deficient transferrin (CDT) and gamma-glut amyl transferase (GGT) as biochemical markers of excessive alcohol con sumption was studied in alcohol-dependent subjects. Serum samples were collected once weekly from 10 male out-patients undergoing a 6-month alcohol treatment programme. Frequency of relapse into drinking (defin ed as any intake of alcoholic beverage) was assessed by self-reports d uring patient interviews three times per week and by daily determinati on of the 5-hydroxytryptophol level in urine; A marked decrease in mea n CDT and GGT values was observed during the initial month. Only one p atient remained totally abstinent throughout the observation period, w hile four had sporadic relapses (2-5 days with alcohol consumption). B oth CDT and GGT remained below the respective reference limits in thos e patients. The other five patients drank more frequently (range 22-57 days) and increased their mean levels of CDT and GGT after the initia l decrease. As determined from the values at admission and during the course of the study, CDT appeared to be the most sensitive marker in s ix out of the 10 patients. In one patient, both markers were affected in a parallel way, whereas two of those with frequent relapses respond ed to alcohol consumption with a marked increase in GGT, but with no o r only a slight increase in CDT. One patient did not show any abnormal CDT or GGT values. In 54 female and 60 male serum samples collected a t random from patients during admission at an alcohol detoxification u nit, 35% and 58% of the CDT values exceeded the reference limits for f emales and males, respectively. For GGT, 59% of the female and 67% of the male values were above cut-off. Carbohydrate-deficient transferrin and GGT were not significantly correlated. Taken together, the presen t results indicate that measurement of both CDT and GGT will increase the possibility of identifying excessive alcohol consumption. By follo wing changes in CDT and GGT values during a period of alcohol withdraw al, the most sensitive individual marker can be determined. This in tu rn allows for improved detection of relapse into heavy drinking during long-term monitoring of out-patients.