Malnutrition after gastric surgery. Association with exaggerated distal intestinal hormone release.

This study was designed to investigate the mechanism of excessive weight loss following gastric surgery. Twelve weight-stable and six weight-losing postoperative subjects were studied. The weight-losing subjects had lesser body mass based upon anthropometric measurements. All weight-losing subjects and six weight-stable subjects excreted excess breath hydrogen after a standard meal. The quantities of hydrogen excreted by the weight-losing subjects and weight-stable subjects with positive tests were not different, implying similar degrees of carbohydrate malabsorption. Peak breath hydrogen concentration occurred earlier in weight-losing subjects than in weight-stable subjects (2 vs 5 hr), indicating more rapid oral-cecal transit of the test meal in weight-losing subjects. Analyses of postprandial blood samples for eight different gastrointestinal hormones demonstrated exaggerated postprandial elevations in the concentrations of enteroglucagon and neurotensin. The results of these studies demonstrate close correlations between excessive weight loss after gastric surgery, rapid gastrointestinal transit as measured by excess breath hydrogen excretion, and increased release of hormones from the distal intestine. We conclude that these hormones are secreted in excess due to the rapid gastrointestinal transit and that rapid gastrointestinal transit may play a role in excessive weight loss after gastric surgery.