N-glycan as new potential biomarker for predicting treatment response in patients with type 2 diabetes mellitus.

Aims: To investigate the N-glycans related to the metformin efficacy in patients with type 2 diabetes mellitus (T2DM).

Materials and methods: We enrolled 141 healthy controls and 195 newly diagnosed T2DM patients treated with metformin for 3 months. Serum N-glycan profile was determined by DNA sequencer - assisted fluorophore-assisted carbohydrate electrophoresis (DSA-FACE). The N-glycan model was established by logistic regression analysis. Receiver operating characteristic curve (ROC) analysis was used to analyze the predictive power of the N-glycan model for metformin efficacy.

Results: The abundances of several N-glycans in serum of T2DM patients at baseline were significantly different from those of healthy controls and tended to recover the N-glycan of controls after 3 months treatment. Serum N-glycans changes were more significant in the good response group (FPG <7 mmol/L) after metformin treatment. In addition, the abundance of peak9 at baseline had an opposite tendency between HbA1c increased and decreased groups post-treatment, which could be a biomarker for predicting metformin efficacy. Peak9 combined with other 11 N-glycans at baseline was used to establish the predictive model to distinguish non-response from response patients (AUROC = 0.780, sensitivity = 70.6% and specificity = 77.5%).

Conclusions: Serum N-glycans may have potential value as biomarkers for indicating the efficacy of metformin.