Background: Preptin is a novel hormone that is co-secreted with insulin and amylin from the pancreatic beta-cells. Preptin increases glucose-mediated insulin secretion, while the binding of endogenous preptin by antipreptin antibodies decreases glucose-mediated insulin secretion. Thus, it appears to act as a physiological amplifier of glucose-mediated insulin secretion. Aim. In this study, we investigate whether plasma preptin levels are different in non-diabetic subjects and patients with impaired glucose tolerance (IGT) or type 2 diabetes mellitus (T2DM).
Method: Fifty patients with T2DM, 56 subjects with IGT, and 54 sex- and age-matched normal controls participated in the study. Plasma preptin levels were measured with a radioimmunoassay. The relationships between plasma preptin levels and anthropometric and metabolic parameters were also assessed.
Results: Plasma preptin levels were higher in patients with T2DM compared to patients with IGT and controls (456+/-14 versus 416+/-13 and 398+/-13 ng/L, P<0.05 and P<0.01, respectively). Plasma preptin levels were lower in males than females (403+/-10 versus 432+/-10 ng/L, P<0.05). Fasting plasma preptin levels correlated positively with diastolic blood pressure (DBP) (r=0.20, P<0.01), triglyceride (TG) (r=0.24, P<0.01), total cholesterol (TC) (r=0.24, P<0.01), high-density lipoprotein cholesterol (HDL-C) (r=0.18, P<0.05), free fatty acids (FFA) (r=0.21, P<0.01), 2-h blood glucose after glucose overload (2hOGTT) (r=0.18, P<0.05), glycosylated haemoglobin (HbA(1)c) (r=0.19, P<0.01), and homeostasis model assessment-insulin resistance index (HOMA(IR)) (r=0.13, P<0.05) in simple regression analysis of pooled data, while in multiple stepwise regression analysis, only DBP, TG, HDL-C, and FFA were independently related with plasma preptin levels.
Conclusion: The present work suggests a potential role of preptin in the pathogenesis of T2DM.