Relationship between serum adipsin and the first phase of glucose‐stimulated insulin secretion in individuals with different glucose tolerance

AIMS/INTRODUCTION: To detect serum adipsin levels in individuals with different glucose tolerance, and investigate the relationship between adipsisn and the first phase of insulin secretion. MATERIALS AND METHODS: A total of 56 patients with newly diagnosed type 2 diabetes mellitus, 36 patients with impaired glucose tolerance (IGT) and 45 individuals with normal glucose tolerance were enrolled. Intravenous glucose tolerance tests were carried out to evaluate pancreatic β‐cell function. The serum levels of adipsin, interleukin‐1β and high‐sensitivity C‐reactive protein were assayed. RESULTS: Serum adipsin levels were significantly lower in the type 2 diabetes mellitus and the IGT patients than those in the normal glucose tolerance group (P < 0.05). The acute insulin response and area under the curve showed a progressive decrease in the normal glucose tolerance and IGT groups, and decreased to the lowest levels in the type 2 diabetes mellitus group (P < 0.05). Adipsin was found to be negatively correlated with waist‐to‐hip ratio, free fatty acid, fasting plasma glucose, 2‐h postprandial plasma glucose, glycated hemoglobin, homeostasis model assessment of insulin resistance, interleukin‐1β and high‐sensitivity C‐reactive protein (P < 0.05 or P < 0.001), and positively correlated with homeostasis model assessment of β‐cell function, high‐density lipoprotein cholesterol, the area under the curve of the first phase insulin secretion and acute insulin response (P < 0.05 or P < 0.001). Stepwise multiple regression analysis showed that homeostasis model assessment for β‐cell function and acute insulin response were independently related to adipsin (P < 0.05). CONCLUSIONS: Serum adipsin levels were lower in type 2 diabetes mellitus and IGT patients, and correlated with the first phase of insulin secretion. Adipsin might be involved in the pathology of type 2 diabetes mellitus.