Objective: To study the changes of plasma glucagon-like peptide-1 (GLP-1), serum peptide-YY (PYY) and Ghrelin and their secretion functions in patients with newly diagnosed type 2 diabetes mellitus (T2DM).
Method: A total of 102 subjects were enrolled, including 32 normal-glucose-tolerance controls (NGT) and 70 patients with newly diagnosed T2DM. Height, body mass, waist circumference (WC) and hip circumference were measured. The plasma lipids and 0 h, 1/2 h, 2 h plasma glucose, insulin (INS), GLP-1, serum PYY and Ghrelin in a standard meal test in each subject were detected, and body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), insulin sensitivity index (ISI), homeostasis model assessment of beta cell function (HOMA-B) and early insulin secretion function index (DeltaI30/DeltaG30) were calculated. All these variables were compared between the two groups.
Results: Compared with those in NGT group, the WC, fasting plasma glucose (FPG), postprandial plasma glucose (2 h-PG), triglyceride (TG), HOMA-IR were significantly higher (P 0.05), while INS(30), HOMA-B, ISI, DeltaI30/DeltaG30 were significantly lower in T2DM group (P<0. 05). In addition, in T2DM group, 0 h, 1/2 h, 2 h plasma GLP-1 and serum PYY and the area under the curve (AUC) of GLP-1 (GLP-lAuc ) and PYY (PYYAc) in standard meal test were significantly lower (P<0. 05), but the serum Ghrelin and GhrelinA, were significantly higher (P<0. 05). Meanwhile, the secretory peak of GLP-1 and PYY after standard meal in T2DM patients all disappeared. In T2DM group, PYYAUC and TG were negatively correlated (P<0.05), the fasting serum Ghrelin level was negatively associated with total cholesterol (TC), and GhrelinAuc was positively associated with HOMA-B, but negatively with the low-density lipoprotein cholesterol (LDL-C) and FPG (P(<0. 05).
Conclusion: Patients with newly diagnosed T2DM have decreased fasting and postprandial GLP-1 and PYY levels, along with changes of their secretion mode and increased levels of Ghrelin.