Increased plasma DPP4 activity is predictive of prediabetes and type 2 diabetes onset in Chinese over a four-year period: result from the China National Diabetes and Metabolic Disorders Study.

Context: The significance of associations between prediabetes, type 2 diabetes, and dipeptidyl peptidase-4 (DPP4) activity in a Chinese population is not clear.

Objective: The objective of the study was to determine whether DPP4 activity and active glucagon-like peptide-1 (GLP-1) were predictive of the onset of prediabetes and type 2 diabetes.

Design, Setting, And Patients: This was a 4-year follow-up study conducted in Sichuan, China. A total of 474 Chinese women and men aged 18-70 years were studied.

Main Outcome Measures: All subjects were divided into 3 groups (normal glucose tolerance, prediabetes, and type 2 diabetes) on the basis of their glucose metabolism status after 4 years. The DPP4 activity, active GLP-1, and glucagon were measured at baseline and 4 years later.

Results: The baseline DPP4 activity was significantly higher in subjects who had progressed to prediabetes or type 2 diabetes compared with subjects who remained normoglycemic (P < .01). In a multiple linear regression analysis, baseline DPP4 activity and active GLP-1 were independent predictors of an increase in insulin resistance over a 4-year period (P < .05). Cox proportional hazards models revealed that DPP4 activity independently predicted the risk of developing prediabetes [relative risk 2.77 (95% confidence interval 1.38-5.55), P < .01] and type 2 diabetes [5.10 (95% confidence interval 1.48-17.61), P < .05] after adjustment for confounding risk factors.

Conclusions: DPP4 activity is an important predictor of the onset of insulin resistance, prediabetes, and type 2 diabetes in apparently healthy Chinese individuals. This finding may have important implications for understanding the etiology of diabetes.