Letter Regarding Article by Ruttmann et al, “γ-Glutamyltransferase as a Risk Factor for Cardiovascular Disease Mortality: An Epidemiological Investigation in a Cohort of 163 944 Austrian Adults”

Abstract

To the Editor: In their article, Ruttmann et al1 showed that γ-glutamyltransferase(GGT) was independently associated with cardiovascular (CV) mortality. GGT was significantly correlated with components of the metabolic syndrome,2 including uric acid level, but waist circumference was not measured. Measurement of GGT activity is a very commonly used diagnostic test for liver dysfunction, and it increases with alcohol consumption and steatosis. Elevation of hepatic enzyme activities occurs frequently in patients with multiple CV risk factors. Indeed, we have shown that approximately one fourth of a population of 8501 dyslipidemic patients3 displayed hepatic enzymatic elevations. We found correlation coefficients similar to those reported by Ruttmann et al1 when GGT, aspartate aminotransferase, or alanine aminotransferase was selected. In subgroup analysis, the relation between waist circumference, body mass index (BMI), and GGT (n=1911) was …