REVERSIBILITY OF SECRETION OF GASTRIC-INHIBITORY POLYPEPTIDE IN LONG-TERM SURVIVORS AFTER PANCREATICODUODENECTOMY

To elucidate serial changes in GIP and insulin secretion late after radical pancreatoduodenectomy (PD) in patients with pancreatic head cancer, plasma levels of GIP and insulin were measured during oral glucose administration before, early after (mean 50.2 days) and late after (mean 14.9 months) the operation. Basal plasma levels of GIP in the patients (n=6) were not different among these three studies. The levels did not differ from those in normal controls (n=9). GIP secretion in response to oral glucose before PD were significantly greater than normal controls. The GIP secretion early after PD were significantly less than that before PD. Late after PD, the GIP secretion were significantly greater than that early after PD. An insulinogenic index was calculated in each patient as integrated incremental IRI over integrated incremental glucose for 180 minutes. The indices in response to glucose ingestion before PD were significantly less than those of controls. The indices early after PD were significantly smaller than those before PD. Late after PD, the indices did not differ from those early after PD. In conclusion, in long-term survivors after radical pancreatoduodenectomy for pancreatic head cancer, GIP secretion in response to glucose ingestion recovered but the pancreas may not respond adequately to the stimulation of GIP.