title: The effect of severe undernutrition, and subsequent refeeding on digestive function in human patients.
abstract: BACKGROUND
  Severe undernutrition may adversely affect gut function.
  
  
  OBJECTIVE
  To investigate the effects of severe undernutrition and subsequent refeeding on human digestive function.
  
  
  METHODS
  Severely undernourished patients (body mass index (BMI) < 17 kg/m2) were studied before, and after a period of intensive nutritional support. Standard intestinal absorption tests (faecal fat and urinary xylose excretion), pentagastrin-stimulated acid secretion, and cholecystokinin octapeptide (CCK-8)-stimulated pancreatic enzyme secretion tests were performed. In addition, duodenal biopies were taken to assess gut mucosal morphology. Findings 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/m2, with improvement to 16.12 kg/m2 after. Duodenal histology showed evidence 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), with 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 improvement to 12.30 mEq/l (P < 0.05) following nutritional support. Pancreatic 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 significant improvement in amylase and lipase outputs to 1819 U/h and 85.5 U/h, respectively (P < 0.01). These levels were not significantly different from the normal controls. Trypsin output, however, remained significantly impaired at 174.3 U/h (P < 0.01).
  
  
  CONCLUSIONS
  Severe undernutrition is associated with significant impairment of digestive function, with improvement occurring following nutritional support. These changes may affect initial tolerance to enteral feeding, particularly in those patients with co-existent gut disease.
authors.affiliation: Gastrointestinal Clinic, Department of Medicine, University of Cape Town and Groote Schuur Hospital, South Africa. winter@uctgsh2.uct.ac.za
authors.forename: T A
authors.initials: TA
authors.lastname: Winter
authors.forename: E R
authors.initials: ER
authors.lastname: Lemmer
authors.forename: S J
authors.initials: SJ
authors.lastname: O'Keefe
authors.forename: J M
authors.initials: JM
authors.lastname: Ogden
mesh_terms: D002100:Cachexia / Q000503:physiopathology*; D016022:Case-Control Studies; D004063:Digestion; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000503:physiopathology*; D008297:Male; D009748:Nutrition Disorders / Q000503:physiopathology*; D020799:Pancrelipase / Q000378:metabolism; D012720:Severity of Illness Index; D014994:Xylose / Q000652:urine
chemical_list: D020799:Pancrelipase; D014994:Xylose