Distribution, Determinants, and Prognostic Value of γ-Glutamyltransferase for All-Cause Mortality in a Cohort of Construction Workers from Southern Germany

Background.Serum γ-glutamyltransferase (GGT) is commonly measured as a marker of hepatobiliary disorders in clinical practice, but little is known about its distribution and prognostic value for all-cause mortality. Methods.Distribution and determinants of serum GGT levels were assessed among 8,043 construction workers ages 25–64 who underwent occupational health examinations in six centers in Southern Germany from 1986 to 1988. Study participants were followed for all-cause mortality until 1994. Results.Serum GGT levels were considerably higher in this cohort than among male employees examined in a national survey conducted during the same period. The factors most strongly related to serum GGT were self-reported alcohol consumption, body mass index, diabetes, and hypertension, but relations of GGT levels were also found with nationality, occupation, and smoking. There was a strong dose–response relation between serum GGT levels and all-cause mortality (Pvalue for trend <0.001). Compared with men with GGT levels below 15 U/liter (measured at 25°C), relative risks (95% CI) were 1.46 (0.86–2.49), 1.78 (1.08–2.94), 2.09 (1.26–3.45), and 3.44 (2.20–5.38) for men with GGT levels of 15–19, 20–29, 30–49, and ≥50 U/liter, respectively. This relation was reduced but not eliminated by control for body mass index, diabetes, hypertension, alcohol consumption, and other covariates in multivariable analysis. Conclusion.Serum GGT is a strong risk indicator of all-cause mortality.