Baseline serum N-glycans as a predictor for the efficacy of metformin in newly diagnosed patients with type 2 diabetes mellitus

Objective: To evaluate the predictive power of serum N-glycans for efficacy of metformin in patients with type 2 diabetes mellitus (T2DM). Methods: A total of 155 healthy controls and 220 newly diagnosed T2DM patients treated with metformin for 3 months were enrolled. Serum N-glycan profile was determined by DNA sequencer-assisted fluorophore-assisted carbohydrate electrophoresis (DSA-FACE). Logistic regression analysis was used to establish the N-glycan model, and receiver operating characteristic curve (ROC) analysis was used to analyze the predictive power of the N-glycan model for metformin efficacy. Results: The abundance of N-glycan peak 2 at baseline had a significant difference between the good (fasting plasma glucose < 7 mmol/L, glycated hemoglobin A1c < 6.5% and 2-h post-prandial plasma glucose < 11.1 mmol/L) and poor (other patients) response groups post-treatment, which may be a biomarker for predicting metformin efficacy. The area under ROC (AUROC) of peak 2 (0.635) for the predictive model of good response was greater than CP2h/FCP (C-peptide 2h/fasting C-peptide) (0.594). Peak 2 combined with other 11 N-glycans at baseline was used for establishing the predictive model to distinguish the good response from the poor response patients (AUROC = 0.719, sensitivity = 55.0% and specificity = 83.4%). Conclusion: Serum N-glycans may have potential value as biomarkers for predicting efficacy of metformin in T2DM patients.