OBJECTIVE: This study aims to investigate the relationship between gastric emptying, postprandial GLP-1 and insulin sensitivity after pancreaticoduodenectomy (PD).

BACKGROUND: Abnormal glucose regulation is highly prevalent in patients with pancreatic neoplasm and resolves in some after PD, the cause of which is unclear. The procedure is carried out with pylorus preservation (PPPD) or with distal gastrectomy (Whipple procedure). Accelerated gastric emptying and ensuing enhanced release of glucagon-like peptide-1 (GLP-1) conceivably play a role in glucose metabolism after PD. It was the purpose of this study to shed light on the relationship between gastric emptying, GLP-1 and glycemic control after PPPD and the Whipple procedure.

METHODS: A 75-g oral glucose tolerance test was carried out in 13 patients having undergone PPPD and in 13 after the Whipple procedure, median age 61 (range, 32-70) years, following an interval of 23 (range, 5-199) months. Gastric emptying was measured by the paracetamol absorption method. Plasma concentrations of glucose, insulin, GLP-1 and paracetamol were measured at baseline, 10, 20, 30 60, 90, 120, 150 and 180 min. Homeostasis model assessment-estimated insulin resistance (HOMA-IR) and oral glucose insulin sensitivity were calculated from glucose and insulin concentrations.

RESULTS: Patients with Whipple procedure as compared to PPPD had accelerated gastric emptying (p = 0.01) which correlated with early (0-30 min) integrated GLP-1 (AUC30; r (2) = 0.61; p = 0.02) and insulin sensitivity (r (2) = 0.41; p = 0.026) and inversely with HOMA-IR (r (2) = 0.17; p = 0.033). Two of 13 Whipple patients (15 %) as compared to seven of 13 after PPPD (54 %) had postload glucose concentrations (i.e. 120 min postmeal) ≥200 mg/dl (p < 0.05). None of 13 (0 %) after Whipple procedure but four of 13 patients (31 %) after PPPD had fasting glucose concentrations ≥126 mg/dl (p < 0.05) CONCLUSIONS: Gastric emptying was accelerated after Whipple procedure as compared to patients who have undergone PPPD, resulting in higher postprandial GLP-1 concentrations and insulin sensitivity and improved glycemic control.