Hyperglycemia reduces gastric secretory and plasma pancreatic polypeptide responses to modified sham feeding in...

We have investigated the effect of acute stable hyperglycemia on gastric acid secretion and serum gastrin and pancreatic polypeptide (PP) release. Gastric acid output was measured under basal conditions and in response to modified sham feeding (MSF) in 7 healthy volunteers on two separate occasions: during normoglycemia (serum glucose 5 mmol/l) and during hyperglycemia (serum glucose 15 mmol/l). PP secretion was determined as an indirect measure of vagal-cholinergic tone. Basal acid output during hyperglycemia (4.7 +/- 1.0 mmol/h) was not significantly different from euglycemia (5.4 +/- 0.6 mmol/h), but MSF-stimulated acid output during hyperglycemia (14.7 +/- 3.3 mmol/90 min) was significantly (p < 0.05) reduced compared to euglycemia (24.7 +/- 3.2 mmol/90 min). Serum gastrin levels were not affected by MSF. During hyperglycemia, the integrated PP secretion in response to MSF (235 +/- 95 pmol/l.90 min) was significantly (p < 0.05) reduced compared to euglycemia (434 +/- 71 pmol/l.90 min). This study indicates that (1) serum glucose affects cephalic-stimulated gastric acid secretion, and (2) PP secretion after MSF is significantly reduced during hyperglycemia suggesting impaired vagal-cholinergic activity during hyperglycemia.