title: Assessment of whole body protein metabolism in critically ill children: can we use the [15N]glycine single oral dose method?
abstract: OBJECTIVE
  Most stable-isotope methods to evaluate whole body protein metabolism in patients are invasive and difficult to use in children. In this study protein metabolism was evaluated with the non-invasive [15N]glycine single oral dose method in critically ill children and the value of the method is discussed.
  
  
  METHODS
  [15N]glycine (100mg) was given orally to children (mean age 5.5 years; range 0.6-15.5 years) with meningococcal septic shock (MSS, n = 8), pneumonia (n = 5), and to healthy, fed and post-absorptive children (n = 10). Urine was collected during 9h, total amount of NH(3), labelled NH(3) and nitrogen were measured, and protein turnover, synthesis and breakdown were calculated using urinary NH(3) as end-product.
  
  
  RESULTS
  Mean protein turnover in children with MSS, pneumonia and fed and post-absorptive healthy children was 0.63+/-0.13, 0.38+/-0.10, 0.28+/-0.03 and 0.28+/-0.02g N/kg/9h, respectively. Mean protein synthesis was 0.55+/-0.12, 0.29+/-0.09, 0.18+/-0.02, 0.20+/-0.02g N/kg/9h, respectively. Mean protein breakdown was 0.56+/-0.14, 0.28+/-0.12, 0.08+/-0.03, 0.28+/-0.02g N/kg/9h, respectively. Protein turnover, synthesis and breakdown were significantly increased in MSS patients compared to fed healthy children (P <0.01) and post-absorptive children (P <0.05). Protein turnover, protein synthesis, protein breakdown were significantly correlated with disease severity and body temperature (P <0.05).
  
  
  CONCLUSIONS
  Results of whole body protein metabolism measured with the [15N]glycine single oral dose method in children with MSS and in healthy children were in line with expectations based on results obtained in earlier reports and with different methods.
authors.affiliation: Department of Paediatrics, University Hospital Maastricht, P Debeyelaan 25, 6202 AZ Maastricht, The Netherlands. d.vanwaardenburg@paed.azm.nl
authors.forename: Dick A
authors.initials: DA
authors.lastname: van Waardenburg
authors.forename: Nicolaas E P
authors.initials: NE
authors.lastname: Deutz
authors.forename: Marije B
authors.initials: MB
authors.lastname: Hoos
authors.forename: Nicolaas J G
authors.initials: NJ
authors.lastname: Jansen
authors.forename: Bernard K
authors.initials: BK
authors.lastname: van Kreel
authors.forename: Gijs D
authors.initials: GD
authors.lastname: Vos
authors.forename: Anton J
authors.initials: AJ
authors.lastname: Wagenmakers
authors.forename: Pierre-Philippe
authors.initials: PP
authors.lastname: Forget
mesh_terms: D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D005260:Female; D005998:Glycine / Q000008:administration & dosage; D006801:Humans; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000008:administration & dosage; D018410:Pneumonia, Bacterial / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D012772:Shock, Septic / Q000378:metabolism / Q000382:microbiology
chemical_list: D009587:Nitrogen Isotopes; D011506:Proteins; D005998:Glycine