HYPERGLYCEMIA REDUCES GASTRIC SECRETORY AND PLASMA PANCREATIC-POLYPEPTIDE RESPONSES TO MODIFIED SHAM FEEDING IN HUMANS

We have investigated the effect of acute stable hyperglycemia on gastr ic acid secretion and serum gastrin and pancreatic polypeptide (PP) re lease. 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/1). PP secretion was dete rmined as an indirect measure of vagal-cholinergic tone. Basal acid ou tput during hyperglycemia (4.7 +/- 1.0 mmol/h) was not significantly d ifferent from euglycemia (5.4 +/- 0.6 mmol/h), but MSF-stimulated acid output during hyperglycemia (14.7 +/- 3.3 mmol/90 min) was significan tly (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 . 9 0 min) was significantly (p < 0.05) reduced compared to euglycemia (43 4 +/- 71 pmol/l . 90 min). This study indicates that (1) serum glucose affects cephalic-stimulated gastric acid secretion, and (2) PP secret ion after MSF is significantly reduced during hyperglycemia suggesting impaired vagal-cholinergic activity during hyperglycemia.