title: High-carbohydrate/low-protein-induced hyperinsulinemia does not improve protein balance in children after cardiac surgery.
abstract: OBJECTIVE
  In pediatric cardiac surgery, fluid-restricted low-protein (LoProt) diets account for cumulative protein deficits with increased morbidity. In this setting, we aimed to inhibit proteolysis by a high-carbohydrate (HiCarb)-intake-induced hyperinsulinemia and improve protein balance.
  
  
  METHODS
  The effect of a HiCarb/LoProt (glucose 10 mg · kg(-1) · min(-1)/protein 0.7 g · kg(-1) · d(-1)) versus a normal-carbohydrate (NormCarb)/LoProt (glucose 7.5 mg · kg(-1) · min(-1)/protein 0.3 g · kg(-1) · d(-1)) enteral diet on whole-body protein breakdown and balance was compared in a prospective, randomized, single-blinded trial in 24 children after cardiac surgery. On the second postoperative day, plasma insulin and amino acid concentrations, protein breakdown (endogenous rate of appearance of valine), protein synthesis (non-oxidative disposal of valine), protein balance, and the rate of appearance of urea were measured by using an isotopic infusion of [1-(13)C]valine and [(15)N(2)]urea.
  
  
  RESULTS
  The HiCarb/LoProt diet led to a serum insulin concentration that was three times higher than the NormCarb/LoProt diet (596 pmol/L, 80-1833, and 198 pmol/L, 76-1292, respectively, P = 0.02), without differences in plasma glucose concentrations. There were no differences in plasma amino acid concentrations, non-oxidative disposal of valine, and endogenous rate of appearance of valine between the groups, with a negative valine balance in the two groups (-0.65 μmol · kg(-1) · min(-1), -1.91 to 0.01, and -0.58 μmol · kg(-1) · min(-1), -2.32 to -0.07, respectively, P = 0.71). The serum cortisol concentration in the HiCarb/LoProt group was lower compared with the NormCarb/LoProt group (204 nmol/L, 50-544, and 532 nmol/L, 108-930, respectively, P = 0.02).
  
  
  CONCLUSIONS
  In children with fluid restriction after cardiac surgery, a HiCarb/LoProt diet compared with a NormCarb/LoProt diet stimulates insulin secretion but does not inhibit proteolysis further and therefore cannot be advocated for this purpose.
authors.affiliation: Pediatric Intensive Care Department, Emma Children's Hospital/Academic Medical Center, Amsterdam, Netherlands. v.g.geukers@amc.uva.nl
authors.forename: Vincent G
authors.initials: VG
authors.lastname: Geukers
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Li
authors.forename: Mariëtte T
authors.initials: MT
authors.lastname: Ackermans
authors.forename: Albert P
authors.initials: AP
authors.lastname: Bos
authors.forename: Liu
authors.initials: L
authors.lastname: Jinfeng
authors.forename: Hans P
authors.initials: HP
authors.lastname: Sauerwein
mesh_terms: D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D018753:Diet, Protein-Restricted; D004040:Dietary Carbohydrates / Q000494:pharmacology* / Q000627:therapeutic use; D004044:Dietary Proteins / Q000097:blood*; D004750:Enteral Nutrition / Q000379:methods; D005260:Female; D005947:Glucose / Q000494:pharmacology / Q000627:therapeutic use; D006330:Heart Defects, Congenital / Q000097:blood / Q000601:surgery*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006946:Hyperinsulinism / Q000097:blood* / Q000209:etiology; D007328:Insulin / Q000097:blood*; D008297:Male; D010084:Oxidation-Reduction; D011183:Postoperative Complications / Q000097:blood / Q000628:therapy; D011446:Prospective Studies; D011488:Protein Deficiency / Q000097:blood* / Q000209:etiology / Q000517:prevention & control; D059748:Proteolysis / Q000187:drug effects; D016037:Single-Blind Method; D014633:Valine / Q000097:blood; D055815:Young Adult
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D007328:Insulin; D014633:Valine; D005947:Glucose; D006854:Hydrocortisone