Pancreatic polypeptide response to a mixed meal is blunted in pancreatic head cancer associated with diabetes mellitus

Introduction: Pancreatic polypeptide (PP) is a hormone secreted by islet cells of the ventral pancreas. It has been proposed that a blunted PP response to a mixed meal can distinguish diabetes mellitus (DM) secondary to pancreatic disease from other types of DM. We performed a proof of concept study to determine if PP response to a mixed meal discriminates DM secondary to pancreatic cancer (PaCDM) from type 2 DM (T2DM). Methods: We studied 18 subjects with new onset DM (PaCDM (n = 9) and T2DM (n = 9); matched for age and gender). Serum PP levels were measured at 0, 30, and 60 min following a mixed meal. Increases in PP levels from baseline were compared using the-Wilcoxon test. Results: In PaCDM the PP increase following a mixed meal was less than T2DM at 30 min (median 60.0%, IQR, 33.0-119.8 vs. 134.5%, IQR, 117.5-265.9; p = 0.03), but statistically similar at 60 min (median 55.8%, interquartile range (IQR) 23.7-121.5 vs. 100.0%, IQR, 47.7-202.5; p = 0.17). In PaCDM subjects, the PP increase over baseline was smaller in those with a tumor located in the pancreatic head (n = 6) compared to the body/tail (n = 3) at 30 min (41.3% vs. 158.7%, p = 0.02) and at 60 min (37.4% vs. 167.4%,p = 0.04). Conclusions: Subjects with PaCDM have a blunted PP response to a mixed meal compared to T2DM. However, the blunted PP response is only observed in those PaC subjects with a tumor located in the head of the pancreas. Confirmation in larger studies may suggest this could be used to aid screening for sporadic PaC. Copyright (C) 2015, IAP and EPC. Published by Elsevier India, a division of Reed Elsevier India Pvt. Ltd. All rights reserved.