Effect of acute hyperglycemia on basal, secretin and secretin + cholecystokinin stimulated exocrine pancreatic secretion in humans

Abstract

Pancreatico-biliary secretion is reduced during acute hyperglycemia. We investigated whether alterations in pancreatico-biliary flow or volume output are responsible for the observed reduction in duodenal output of pancreatic enzymes and bilirubin during hyperglycemia. Eight healthy subjects were studied on two occasions during normoglycemia and hyperglycemia (15 mmol/l). Pancreatico-biliary output was measured by aspiration using a recovery marker under basal conditions (60 min), during secretin infusion (0.1 CU/kg.h) for 60 min and during secretin + CCK (0.5 IDU/kg.h) infusion for 60 min. Secretin was infused to stimulate pancreatico-biliary flow and volume output. Secretin significantly (P < 0.005–P < 0.05) increased volume and bicarbonate output and CCK significantly (P < 0.01) increased the output of bilirubin, pancreatic enzymes, bicarbonate and volume, both during normoglycemia and hyperglycemia. During hyperglycemia basal, secretin stimulated and secretin + CCK stimulated total pancreatico-biliary output were significantly (P < 0.005–P < 0.05) reduced compared to normoglycemia. The incremental outputs, however, were not significantly different between hyper- and normoglycemia. Pancreatic volume output was significantly (P < 0.05) reduced during hyperglycemia compared to normoglycemia under basal conditions (31 ± 16 ml/h versus 132 ± 33 ml/h) during secretin infusion (130 ± 17 ml/h versus 200 ± 34 ml/h) and during secretin + CCK infusion (370 ± 39 ml/h versus 573 ± 82 ml/h). Plasma PP levels were significantly (P < 0.05) reduced during hyperglycemia. It is concluded that 1) hyperglycemia significantly reduces basal pancreatico-biliary output 2) the incremental pancreaticobiliary output in response to secretin or secretin + CCK infusion is not significantly affected during hyperglycemia, 3) a reduction in volume output contributes to the inhibitory effect of hyperglycemia on pancreatico-biliary secretion, 4) hyperglycemia reduces PP secretion suggesting vagal-cholinergic inhibition of pancreatico-biliary secretion and volume during hyperglycemia.