Early changes in incretin secretion after laparoscopic duodenal-jejunal bypass surgery in type 2 diabetic patients

Background: A stomach-preserving duodenal-jejunal bypass (DJB) has been used for the treatment of type 2 diabetes mellitus (DM) since Rubino et al. first reported a prospective trial. However, there has been no report on changes in incretin secretion after DJB. We aimed to investigate whether DJB changes incretin secretion in nonmorbidly obese type 2 diabetic patients. Methods: The inclusion criteria in this prospective study were: patient age of 20-65 years, body mass index of <30 kg/m², a history of type 2 DM for ≤10 years, and fasting C-peptide ≥0.3 nmol/l. Six patients with type 2 DM without morbid obesity underwent DJB. Fasting plasma glucose and glycated hemoglobin (HbA1c) were measured. An oral glucose tolerance test (OGTT) was performed with measurement of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), insulin, C-peptide, and glucagon. The study subjects were followed up for 6 months. Results: The body weight of patients declined after surgery. The area under the curve (AUC) of glucose, peak glucose levels during OGTT, and HbA1c also declined until 3 months postoperatively. The AUC of C-peptide and insulin tended to increase postoperatively. The AUC of glucagon had a significant increase at 6 months postoperatively. The AUC of active GLP-1 increased at 1 month and at 6 months postoperatively. There was no change in the AUC of total GIP. Conclusion: Our data suggest that DJB increases GLP-1 secretion in nonmorbidly obese type 2 diabetic patients. However, long-term data are needed to confirm this finding.