DPP4 and metabolic syndrome: Within a model including BMI HDL-C, TG, SBP, FBG and ACR, DPP4 activity did significantly increase the area under the ROC curve, thereby demonstrating that in Chinese population, plasma DPP4 activity may increase the predictive ability for identification of subjects at risk for developing new-onset metabolic syndrome beyond that of the information provided by the components of the metabolic syndrome.