Sex differences in gamma-glutamyltransferase in people aged 40-42 years in two Norwegian counties.

Gamma-glutamyltransferase (GGT) is widely used as a marker of alcohol intake, although it is documented that other factors are also associated with serum levels of GGT. The total population of men and women aged 40-42 years in two Norwegian counties was invited to participate in a health survey program. GGT was measured in 8116 men and 8689 women--67 % of the eligible population. In sex-specific multiple regression analyses, GGT showed a positive association with body mass index (BMI), cholesterol, ln triglycerides, systolic blood pressure, and number of drinks per 2 weeks for both men and women. Glucose and 'years of smoking' were significant in women only. Cups of boiled coffee per day and physical activity in spare time were inversely associated with GGT level for both men and women. A significant positive interaction between alcohol intake and BMI was observed for men but not for women. The use of GGT as a marker of alcohol consumption in middle-aged persons should take into account sex, BMI and drinking of boiled coffee. Copyright 2002 Elsevier Science Irealnd Ltd.