Enteroglucagon release in disaccharide malabsorption induced by intestinal alpha-glucosidase inhibition

To study the effects of acarbose, an alpha-glucosidase inhibitor, on saccharide absorption and pancreatic and gut hormone release, we loaded 50 g glucose (GTT), maltose (MTT), and sucrose (STT) to 12 healthy male volunteers with and without acarbose (0, 100, or 300 mg) in a double-blind protocol. Oral load of 300 mg acarbose did not inhibit absorption of 50 g glucose; neither did it alter subsequent responses of insulin and glucagons. Maltose absorption was not influenced by acarbose up to 300 mg. However, insulin response was reduced and eteroglucagon response was enhanced by acarbose. Acarbose 100 mg markedly decreased absorption of sucrose, resulting in inhibition of plasma elevation of glucose and insulin and in enhancement of enteroglucagon release. Oral load of 30 g lactulose, nonabsorbable disaccharide, could reproduce the acarbose-induced enteroglucagon release. An increase in osmotic pressure due to retention of unabsorbed carbohydrate in the distal small intestine and proximal colon may explain the acarbose-induced enteroglucagon release and diarrhea that results from STT with acarbose.