Abstract:

Objective To investigate the changes of plasma somatostatin, glucagon-like peptide-1 (GLP-1) and glucagon in patients with type 2 diabetes in early stage. Methods Forty-nine patients with diabetes in early stage (diabetes group) and 21 normal controls (control group) were selected. Oral glucose tolerance tests (OGTT) were performed, the fasting plasma somatostatin, GLP-1 and glucagon and those 2 h after glucose load were measured, the increase ratios were calculated, and the correlation was analysed. Results The fasting plasma somatostatin, GLP-1 and glucagon and plasma somatostatin and GLP-1 2 h after glucose load in diabetes group were significantly lower than those in control group (P<0.05), and plasma somatostatin, GLP-1 and glucagon 2 h after glucose load were higher than fasting ones in both groups. The increase ratios of plasma somatostatin and glucagon in diabetes group were significantly higher than those in control group (P<0.05), and there was no significant difference in the increase ratio of plasma GLP-1 between two groups (P>0.05). The increase ratio of plasma somatostatin was significantly positively related to that of plasma GLP-1 in diabetes group (r＝0.367, P＝0.015). Conclusion The reduction of inhibition of somatostatin on GLP-1 may be the compensatory response in patients with type 2 diabetes in early stage. In the early stage of type 2 diabetes, improper increase of glucagon secretion has already existed, and plasma glucose and insulin may play a more important role than GLP-1.

Key words: type 2 diabetes, somatostatin, glucagon-like peptide-1, glucagon