title: Endogenous amylin and glucagon-like peptide-1 concentrations are not associated with gastric emptying in critical illness.
abstract: BACKGROUND
  In health, the hormones amylin and glucagon-like peptide-1 (GLP-1) slow gastric emptying (GE) and modulate glycaemia. The aims of this study were to determine amylin and GLP-1 concentrations in the critically ill and their relationship with GE, glucose absorption and glycaemia.
  
  
  METHODS
  In fasted critically ill and healthy subjects (n = 26 and 23 respectively), liquid nutrient, containing 100 mg (13) C-sodium octanoate and 3 g 3-O-methlyglucose (3-OMG), was administered via a nasogastric tube. Amylin, GLP-1, glucose and 3-OMG concentrations were measured in blood samples taken during fasting, and 30 min and 60 min after the 'meal'. Breath samples were taken to determine gastric emptying coefficient (GEC). Intolerance to intragastric feeding was defined as a gastric residual volume of ≥ 250 ml and/or vomiting within the 24 h prior to the study.
  
  
  RESULTS
  Although GE was slower (GEC: critically ill 2.8 ± 0.9 vs. health, 3.4 ± 0.2; P = 0.002), fasting blood glucose was higher (7.0 ± 1.9 vs. 5.7 ± 0.2 mmol/l; P = 0.005) and overall glucose absorption was reduced in critically ill patients (3-OMG: 9.4 ± 8.0 vs. 17.7 ± 4.9 mmol/l.60 min; P < 0.001), there were no differences in fasting or postprandial amylin concentrations. Furthermore, although fasting [1.7 (0.4-7.2) vs. 0.7 (0.3-32.0) pmol/l; P = 0.04] and postprandial [3.0 (0.4-8.5) vs. 0.8 (0.4-34.3) pmol/l; P = 0.02] GLP-1 concentrations were increased in the critically ill and were greater in feed intolerant when compared with those tolerating feed [3.7 (0.4-7.2) vs. 1.2 (0.7-4.6) pmol/l; P = 0.02], there were no relationships between GE and fasting amylin or GLP-1 concentrations.
  
  
  CONCLUSIONS
  In the critically ill, fasting GLP-1, but not amylin, concentrations are elevated and associated with feed intolerance. Neither amylin nor GLP-1 appears to substantially influence the rate of GE.
authors.affiliation: Intensive Care Unit, Level 4, Emergency Services Building, Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Summers
authors.forename: A E
authors.initials: AE
authors.lastname: DI Bartolomeo
authors.forename: A V
authors.initials: AV
authors.lastname: Zaknic
authors.forename: M J
authors.initials: MJ
authors.lastname: Chapman
authors.forename: N Q
authors.initials: NQ
authors.lastname: Nguyen
authors.forename: B
authors.initials: B
authors.lastname: Zacharakis
authors.forename: C K
authors.initials: CK
authors.lastname: Rayner
authors.forename: M
authors.initials: M
authors.lastname: Horowitz
authors.forename: A M
authors.initials: AM
authors.lastname: Deane
mesh_terms: D019325:3-O-Methylglucose / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D001944:Breath Tests; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D058228:Islet Amyloid Polypeptide / Q000097:blood*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D058228:Islet Amyloid Polypeptide; D019325:3-O-Methylglucose; D052216:Glucagon-Like Peptide 1; D005947:Glucose