Effects of insulin therapy on glucagon in patients with newly diagnosed type 2 diabetes

The aim of this study was to investigate the effects of insulin therapy on glucagon in patients with newly diagnosed Type 2 Diabetes (nd-T2DM patients). We recruited 93 nd-T2DM patients, including 45 nonobese patients and 48 obese patients. A 100 g bread meal test was performed before and after insulin therapy, and glucagon levels were measured before and after the experiment. Compared with the control group, the serum glucagon levels before treatment in both the obese and non-obese nd-T2DM patients were significantly higher (P=0.001). After treatment, the serum glucagon levels in the nd-T2DM patients had significantly decreased (P=0.001), but they were still higher than those in the control group (P=0.001). Additionally, the area under the curve of serum glucagon and postprandial glucagon levels in the non-obese nd-T2DM patients decreased significantly (P=0.001 and P<0.01, respectively). The serum glucagon level in the obese nd-T2DM patients decreased non-significantly (P>0.05). Insulin therapy improved serum glucagon levels in nd-T2DM patients. The serum glucagon level in the non-obese ndT2DM patients improved significantly, but that in the obese nd-T2DM patients did not. The CP levels in the non-obese T2DM group at 30 min (P=0.003), 60 min (P=0.001), 120 min (P=0.001), and 180 min (P=0.001) after treatment had significantly increased compared to that before treatment. The CP levels in the obese T2DM group at 120 min (P=0.001) and 180 min (P=0.001) after treatment had significantly increased compared to that before treatment. This improvement might be related with a potential association between T2DM and obesity.