title: Short-term protein intake and stimulation of protein synthesis in stunted children with cystic fibrosis.
abstract: BACKGROUND
  Stunted children with cystic fibrosis (CF) have less net protein anabolism than do children without CF, and the result is retarded growth in the CF patients. It is not known whether protein intake above that recommended by the Cystic Fibrosis Foundation would further stimulate whole-body protein synthesis.
  
  
  OBJECTIVE
  We studied the effects of 3 amounts of protein intake on whole-body protein synthesis and breakdown by using isotopic infusion of [1-(13)C]valine and [(15)N(2)]urea in children with stable CF who required tube feeding.
  
  
  METHODS
  In 8 pediatric CF patients, we administered 3 randomly allocated isocaloric diets with normal (NP), intermediate (IP), and high (HP) amounts of protein (1.5, 3, and 5 g . kg(-1) . d(-1), respectively) by continuous drip feeding during a 4-d period at 6-wk intervals. Each patient acted as his or her own control. On the fourth day of feeding, whole-body protein synthesis and breakdown were measured.
  
  
  RESULTS
  Protein synthesis was significantly higher in the HP group (x +/- SEM: 1.78 +/- 0.07 micromol . kg(-1) . min(-1)) than in the IP (1.57 +/- 0.08 micromol . kg(-1) . min(-1); P=0.001) and NP (1.37 +/- 0.07 micromol . kg(-1) . min(-1); P < 0.001) groups. There were no significant differences in protein breakdown. Net retention of nitrogen was significantly higher in the HP group (12.93 +/- 1.42 micromol . kg(-1) . min(-1)) than in the IP (7.61 +/- 1.40 micromol . kg(-1) . min(-1); P=0.01) and HP (2.48 +/- 0.20 micromol . kg(-1) . min(-1); P < 0.001) groups.
  
  
  CONCLUSIONS
  In stunted children with CF requiring tube feeding, the highest stimulation of whole-body protein synthesis was achieved with a short-term dietary protein intake of 5 g . kg(-1) . d(-1).
authors.affiliation: Department of Pediatric Intensive Care, Academic Medical Center, Amsterdam, The Netherlands. v.g.geukers@amc.uva.nl
authors.forename: Vincent G M
authors.initials: VG
authors.lastname: Geukers
authors.forename: Johanna H
authors.initials: JH
authors.lastname: Oudshoorn
authors.forename: Jan A J M
authors.initials: JA
authors.lastname: Taminiau
authors.forename: Cornelis K
authors.initials: CK
authors.lastname: van der Ent
authors.forename: Piet
authors.initials: P
authors.lastname: Schilte
authors.forename: An F C
authors.initials: AF
authors.lastname: Ruiter
authors.forename: Mariëtte T
authors.initials: MT
authors.lastname: Ackermans
authors.forename: Erik
authors.initials: E
authors.lastname: Endert
authors.forename: Cora F
authors.initials: CF
authors.lastname: Jonkers-Schuitema
authors.forename: Hugo S S
authors.initials: HS
authors.lastname: Heymans
authors.forename: Hans P
authors.initials: HP
authors.lastname: Sauerwein
mesh_terms: D001827:Body Height / Q000187:drug effects* / Q000502:physiology; D002247:Carbon Isotopes; D002648:Child; D002657:Child Development; D002664:Child Nutritional Physiological Phenomena; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000378:metabolism* / Q000628:therapy; D004044:Dietary Proteins / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009587:Nitrogen Isotopes; D009751:Nutritional Requirements; D010288:Parenteral Nutrition; D011446:Prospective Studies; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D014508:Urea / Q000378:metabolism; D014633:Valine / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D004044:Dietary Proteins; D009587:Nitrogen Isotopes; D011506:Proteins; D014508:Urea; D014633:Valine