Increased Serum Nesfatin-1 Levels in Patients with Impaired Glucose Tolerance

Abstract

Purpose: Nesfatin-1 is a recently discovered energy-regulating peptide, widely expressed in both central and peripheral tissues. It is involved in various functions, such as the stimulation of hypothalamic-pituitary-adrenal axis and sympathetic nervous system, influencing visceral functions, water intake, and regulation of temperature and emotions. It exerts a direct glucose-dependent insulinotropic action on the beta cells of pancreatic islets. The current study evaluated nesfatin-1 levels and insulin response to glucose load in patients with impaired glucose tolerance (IGT) and in healthy subjects. Material and Method: Of those patients who underwent the oral glucose tolerance test (OGTT), 14 with IGT and 13 body mass index-(BMI) and age-matched healthy subjects as controls were included in the study. Blood samples were taken at 0, 60 and 120 min, and the glucose, insulin, and nesfatin-1 levels were measured. Results: The basal levels of glucose, insulin, and nesfatin-1 were significantly higher in the patients with IGT than in controls. Two-way repeated measures ANOVA revealed that change in time (CIT) for glucose and insulin during an OGTT was significant (p<0.001 and p<0.001, respectively). CIT for glucose and insulin was significantly different between the IGT patients and the controls (p<0.001 and p=0.003, respectively). CIT for nesfatin-1 was not significant (p=0.406) and did not differ significantly between the two groups (p=0.331). Discussion: The elevated levels of basal nesfatin-1 were observed in the patients with IGT. There was no change in the absolute nesfatin-1 levels in response to glucose load in either group. The increase in the levels of basal nesfatin-1 may reflect a compensatory mechanism to regulate the impaired glucose metabolism in the IGT patients, which is later underwhelmed with the onset of diabetes.