The relationship between serum gamma-glutamyl transpeptidase level and reported alcohol consumption in healthy men.

Abstract

The value of serum .gamma.-glutamyl transpeptidase (GTP) as a screening test for alcoholism was investigated in 260 healthy men (aged 21-68; mean age 45). Data on alcohol intake during the 7 days preceding the test were obtained by structured interview (131 men) or self-administered questionnaire (containing the same questions as the interview, completed by 129 men); data on drinking were also obtained from standard medical history forms of 209 of the men. When the GTP levels of the 260 men were plotted against their alcohol consumption, the scatter was so great that no meaningful regression line could be fitted; the Pearson product-moment correlation was .095 (not significant). Above a weekly consumption of 80 g of alcohol, GTP levels changed little with increasing alcohol intake. The usefulness of the test in detecting heavy drinking is questioned. The drinking data obtained by the 3 methods were compared: there was no significant difference in the distributions of alcohol consumption reported in the interview and questionnaire; the men reported a higher mean weekly consumption in the interview than in the questionnaire (175 vs. 143 g of alcohol); and fewer men reported heavy drinking in the medical history form than in the interview or questionnaire.