Relations of Serum gamma-glutamyltransferase Levels to Incidence of the Metabolic Syndrome

Background: The metabolic syndrome is a cluster of risk factors for cardiovascular diseases. Recently, serum gamma-glutamyltransferase (GGT) has been suggested as a predictor for development of the metabolic syndrome. Therefore, we investigated the association between serum GGT levels and the incidence of the metabolic syndrome in the Korean healthy adults with normal serum GGT with a 3 year follow-up. Methods: The study subjects consisted of 741 individuals who visited the Center for Health Promotion in Pusan National University Hospital for a medical checkup in 2002 to 2005. Among 741 subjects, 312 were excluded: 71 were positive for HBsAg, 17 were positive for Anti-HCV Ab, 40 showed GGT higher levels than limit of reference range, and 224 had metabolic syndrome. The final subjects were 429 individuals. We measured serum GGT levels, lipid profiles, fasting glucose, blood pressure and their metabolic components. Results: As the quartile of serum GGT increased, 3 year follow-up incidence of the metabolic syndrome was increased. Logistic regression analysis adjusting for sex, age, and alcohol drinking status showed that the odds ratio (95% confidence Interval, P-value) of each GGT quartile was 2.28 (0.58 similar to 9.01, P=0.240), 1.53 (0.36 similar to 6.66, P=0.564), 4.56 (1.08 similar to 19.32, P=0.040), respectively. Conclusion: These results showed that the serum GGT was closely related to the metabolic syndrome. In Korean adults without the metabolic syndrome, the serum GGT levels within normal limit were associated with an increased risk of incident, metabolic syndrome.