The effect of acute hyperglycaemia on small intestinal motility in normal subjects

The effects of hyperglycaemia on postprandial small intestinal motor activity are unclear. Duodenal and jejunal pressures and duodeno-caecal transit were measured in eight healthy male volunteers during euglycaemia (blood glucose 4-6 mmol/l) and hyperglycaemia (blood glucose 12-15 mmol/l). Duodenal and jejunal pressures were recorded with a manometric assembly during intraduodenal infusion of 100 ml nutrient liquid comprising 14% protein, 31.5% fat and 54.5% carbohydrate together with 15 g lactulose. Duodeno-caecal transit was determined by a breath hydrogen technique. The number of duodenal (p < 0.05) and jejunal (p < 0.01) pressure waves, excluding phase III episodes was reduced during hyperglycaemia compared to euglycaemia. Hyperglycaemia was associated with earlier onset of phase III activity (30 +/- 12 vs 132 +/- 20 min; p < 0.05). Duodeno-caecal transit was slower during hyperglycaemia when compared to euglycaemia (114 +/- 17 vs 49 +/- 6 min, p < 0.01). We conclude that induced hyperglycaemia has major effects on postprandial small intestinal motility. The reduction in duodenal and jejunal motor activity is likely to explain the retardation of small intestinal transit during hyperglycaemia.