Abstract: Objective To explore the association of γ-glutamyltransferase (GGT) with metabolic syndrome (MS) and its components and to provide scientific evidence for diagnosis of MS by GGT level in clinical practice.Methods Purposive sampling was used to extracted medical records of 23 269 persons taking physical examination at Beijing Xiaotangshan Hospital from January through December of 2012.Pearson correlation analysis was adopted to analyze the correlation between GGT and components of MS.Binary logistic analysis was applied to evaluate the risk of MS in relation to GGT level among the participants with various GGT level (divided into quartiles of<13.0,13.0-19.0,19.1-31.0,and >31.0 U/L).Receiver operating characteristic (ROC)analysis was applied to determine an optimal cut-off value of GGT for the diagnosis of MS.Results The GGT level in the participants with MS was significantly higher than that in those without MS (40.96±41.74 vs.24.10±24.86,t=-27.048;P<0.01).Pearson analysis showed that there were positive significant correlations between GGT level and body mass index,systolic blood pressure,diastolic blood pressure,fasting plasma glucose,and triglyceride (all P<0.01)and a significant inverse correlation between GGT level and high density lipoprotein (P<0.01)after adjusting for age and sex.The results of binary logistic analysis revealed that the risk of MS increased with the increment of GGT level,with the odds ratios (95%confidence intervals) of 1.247 (1.133-1.374)for the participants with GGT of 13.0-19.0/L,2.375 (2.166-2.605)for 19.1-31.0/L,and 4.729 (4.323-5.173)for >31.0/L 9,after adjusting for age and gender,respectively.ROC analyses revealed that for the prediction of MS with GGT level among the male and female participants,the mean area under the curve was 0.687 and 0.747 and the optimal cut-off value of GGT are 24.5 and 13.5 U/L,with the sensitivity of 0.715 and 0.806 and the specificity of 0.563 and 0.580,respectively.Conclusion The GGT level correlates to MS and its components and increased GGT level may increase the risk of MS,suggesting that GGT could be used as a predictor of MS.