Background: The metabolic syndrome is associated with insulin resistance and elevated serum gammaglutamyltransferase(GGT). Elevated serum GGT is a well known biological indicator of alcohol consumption. The authors analyzed the associations between serum GGT with alcohol consumption and with each metabolic components. The association between serum GGT and
insulin resistance was also analyzed.
Methods: The subjects were classified into three categories according to alcohol consumption. Elevated serum GGT was defined as serum GGT ≥ 56 IU/L in men and ≥ 21 IU/L in women. Insulin resistance was defined as Homeostasis model assessment-insulin resistance (HOMA-IR) ≥ 2.60.
Results: The frequency of metabolic components had a tendency to differ according to alcohol consumption.
However, the effect of alcohol consumption on metabolic components was not statistically significant after adjusting for age, smoking, body mass index and regular exercise.
Severe alcohol consumption was the strongest factor causing GGT elevation in men by odds ratio of 4.00. While for women, fatty liver was the main cause of elevated GGT level with odds ratio of 3.37 (P < 0.001). Hypertension, hypertriglyceridemia and abdominal obesity significantly elevated serum GGT level in men; diabetes mellitus, hypertriglyceridemia and insulin resistance caused GGT level elevation in women after adjusting for age, alcohol consumption, smoking, body mass index, regular exercise and fatty liver.
Conclusion: The main attributing factor of serum GGT elevation was insulin resistance in women, and for men it was high alcohol consumption. Further studies are warranted for clarification of the relationships.

Keywords: Gamma-glutamyltransferase, Insulin resistance, Metabolic syndrome

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