Changes in post-oral glucose challenge pancreatic polypeptide hormone levels following metabolic surgery: A comparison of gastric bypass and sleeve gastrectomy

Abstract

Background: Pancreatic polypeptide (PP) hormone is a 36-amino-acid peptide released from the pancreas, the serum levels of which have been shown to rise upon food intake. The underlying mechanism for metabolic surgery in the treatment of patients with type 2 diabetes mellitus (T2DM) remains intriguing. We compared post-oral glucose challenge PP levels between patients undergoing laparoscopic gastric bypass (GB) and sleeve gastrectomy (SG) at 1 year after surgery.

Methods: This hospital-based, prospective study followed up a total of 12 laparoscopic GB and 12 laparoscopic SG patients and evaluated their glucose homeostasis. One year after metabolic surgery, 75-g oral glucose tolerance tests (OGTTs) were performed in the patients in the GB and SG groups and the blood levels of PP were evaluated.

Results: The laparoscopic GB group had stable serum PP levels within 120 min after OGTT; however, the levels were significantly higher in the laparoscopic SG group at 30 min after OGTT. The patients with complete T2DM remission did not exhibit significantly different PP levels at fasting and post-OGTT than those in patients without remission after GB. Similarly, after SG, patients with T2DM remission did not show significantly different PP levels at fasting and post-OGTT than those in patients without T2DM remission.

Conclusions: No significant difference was found in plasma PP levels after OGTT in T2DM patients that received either GB or SG, or in T2DM remitters or non-remitters 1 year after metabolic surgery.

Keywords: Gastric bypass; Oral glucose tolerance test; Pancreatic polypeptide; Sleeve gastrectomy; Type 2 diabetes mellitus.