Incretin secretion is not restored by short-term strict glycaemic control in Korean hyperglycaemic patients with type 2 diabetes

Abstract

AimsTo determine whether short-term strict glycaemic control could restore incretin secretion in type 2 diabetic patients. The factors associated with incretin levels were also investigated. MethodsA meal tolerance test (MTT) was performed in eighteen poorly controlled (pDM) and fifteen well controlled (wDM) diabetic patients. Fourteen patients in the pDM group underwent follow-up MTT after strict glycaemic control. The secretions of intact glucagon-like peptide-1 (iGLP-1) and total glucose-dependent insulinotropic polypeptide (tGIP) during MTT were calculated by total and incremental area under the curve (TAUC and IAUC) values. ResultsPosttreatment HbA1c level was significantly improved in the pDM group (11.2±0.9 to 7.9±0.9%). However, the secretion of incretin hormones was not increased in the posttreatment pDM group (TAUCiGLP-1, 3612±587 to 2916±405pmol/Lmin; TAUCtGIP, 9417±1099 to 8338±903pmol/Lmin). IAUCiGLP-1 was negatively correlated (r=−0.446, P=0.011) and independently associated (β=−137.2, P=0.027) with insulin resistance assessed by homeostasis model assessment. ConclusionsIncretin secretion is not restored by short-term strict glycaemic control. Decreased incretin secretion seems to develop early in the course of type 2 diabetes with increasing insulin resistance, but not to be influenced by glycaemic status.