Postprandial glucose-dependent insulinotropic polypeptide and insulin responses in patients with chronic pancreatitis with and without secondary diabetes

Objective: To study GIP and insulin release after a test meal in patients with chronic pancreatitis with and without secondary diabetes mellitus. Methods: 28 patients with chronic pancreatitis were classified in groups I and II according to the presence or absence of secondary diabetes mellitus. Twelve healthy subjects were included as controls. After a test meal plasma GIP levels and serum insulin levels were determined at 0, 30, 60, 120 and 180 min. Results: A significant diminished GIP response was found in the groups of patients with respect to the control group. No association could be detected with severity of pancreatic insufficiency, Higher values of GIP were demonstrated at 60 and 120 min in patients without diabetes than in patients with it. Conclusions: An abnormal GIP response is present in cases of chronic pancreatitis irrespective of the presence or severity of pancreatic insufficiency. This response is further affected if secondary diabetes mellitus is present.