THE TROMSØ STUDY

TLDR

Gamma‑glutamyltransferase levels are influenced by factors stronger than alcohol consumption within their normal range. The study measured gamma‑glutamyltransferase in 10,942 men and 10,840 women aged 12–62 in a national heart survey. In the Tromsø population, gamma‑glutamyltransferase was low and right‑skewed, with median 17 U/L in men and 12 U/L in women; it was strongly associated with BMI, alcohol, cholesterol, and other metabolic and lifestyle factors, while coffee, time of day, and physical activity were negatively associated.

Abstract

Gamma-glutamyltransferase was measured in 10,942 males aged 12–62 years and 10,840 females aged 12–59 years screened in a hearth survey program. The distribution was right-skewed, with medians of 17 and 12 units/liter for males and females, respectively. Fewer than 5.5% of the males and 1.5% of the females had values exceeding 50 units/liter, reflecting the modest use of alcohol in Norway. In sex-specific multiple regression analyses, gamma-glutamyltransferase showed a strong positive association with body mass index, alcohol use, and total serum cholesterol and a somewhat weaker positive association with serum triglycerides, high density lipoprotein cholesterol, heart rate, Mood pressure, use of analgesics, and time since last meal. Strong negative associations were found for coffee consumption, hour of the day at which the examination was performed and, In males, physical activity. In females, use of oral contraceptives and menopause were positively associated with gamma-glutamyltransferase, whereas pregnant females had lower values. In conclusion, the gamma-glutamyltransferase level in the Tromse population was low, with marked and consistent sex differences which probably are physiologic. Within its normal range, gamma-glutamyltransferase has many other, even stronger determinants than alcohol consumption.