The effect of severe undernutrition, and subsequent refeeding on digestivefunction in human patients

Background Severe undernutrition may adversely affect gut function. Aims To investigate the effects of severe undernutrition and subsequent ref eeding on human digestive function. Methods Severely undernourished patients (body mass index (BMI)<17 kg/m(2)) were studied before, and after a period of intensive nutritional support. Standard intestinal absorption tests (faecal fat and urinary xylose excreti on), pentagastrin-stimulated acid secretion, and cholecystokinin octapeptid e (CCK-8)-stimulated pancreatic enzyme secretion tests were performed. In a ddition, duodenal biopies were taken to assess gut mucosal morphology. Find ings were evaluated in comparison to a group of normal healthy volunteers. Results Mean BMI of the patients prior to nutritional support was 13.41 kg/ m(2), with improvement to 16.12 kg/ m(2) after. Duodenal histology showed e vidence of villous atrophy in six of 14 (43%) undernourished patients. Mean xylose excretion following a 5 g oral dose was 0.62 g/5 h in the group of undernourished patients prior to nutritional support (normal >1 g/5 h), wit h improvement to 1.40 g/ 5 h (P< 0.01) after feeding. Maximal gastric acid output was significantly impaired in the undernourished group, as compared to the controls (6.94 mEq/l vs 25.53 mEq/l, P < 0.02), with a significant i mprovement to 12.30 mEq/l (P< 0.05) following nutritional support. Pancreat ic enzyme output was significantly reduced (amylase 830.9 U/h vs 2304 U/h, P< 0.01; lipase 38.0 U/h vs 118.6 U/h, P< 0.01; trypsin 119.7 U/h vs 341.4 U/h, P< 0.01). Following a period of nutritional support there was a signif icant improvement in amylase and lipase outputs to 1819 U/h and 85.5 U/h, r espectively (P< 0.01). These levels were not significantly different from t he normal controls. Trypsin output, however, remained significantly impaire d at 174.3 U/h (P< 0.01). Conclusions Severe undernutrition is associated with significant impairment of digestive function, with improvement occurring following nutritional su pport. These changes may affect initial tolerance to enteral feeding, parti cularly in those patients with co-existent gut disease. Eur J Gastroenterol Hepatol 12:191-196 (C) 2000 Lippincott Williams & Wilkins.