Causes of elevated serum gamma-glutamyl transferase in patients attending outpatient somatic clinics and district health centres.

In this study of 1985 patients in somatic outpatient care (medicine, surgery, orthopedics, emergency and primary health care clinics), 231, or 11.6%, were found to have an elevated serum GT value (above 0.9 mukat/l). Alcohol was the cause of this in approximately one third of the cases, while diseases and drugs were the underlying cause in the other cases. In the population, there were 208 alcohol-overconsuming patients (163 men and 45 women) and 28 patients had a serum GT elevation which led to detection of a previous unknown alcohol problem or excessive consumption. The mean and median value for serum GT for the alcohol patients was markedly higher than in the non-alcohol-overconsuming group. The sensitivity for serum GT (with a value of 0.9) as regards alcohol consumption was 40%. The GT test screened 4.2% of patients with excessive alcohol consumption of which one third were "hidden".