High-carbohydrate/low-protein–induced hyperinsulinemia does not improve protein balance in children after cardiac surgery

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Vol. 28; no. 6; pp. 644 - 650
• Main Authors: Geukers, Vincent G., M.D, Li, Zhihao, M.D, Ackermans, Mariëtte T., Ph.D, Bos, Albert P., Ph.D, Jinfeng, Liu, Ph.D, Sauerwein, Hans P., Ph.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.2012; Elsevier; Elsevier Limited
• Subjects: Adolescent; Adult; Amino Acids - blood; Biological and medical sciences; Blood Glucose - metabolism; Cardiac surgery; Child; Child, Preschool; Children & youth; Critical illness; Diet; Diet, Protein-Restricted; Dietary Carbohydrates - pharmacology; Dietary Carbohydrates - therapeutic use; Dietary Proteins - blood; Enteral Nutrition - methods; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Glucose - pharmacology; Glucose - therapeutic use; Heart Defects, Congenital - blood; Heart Defects, Congenital - surgery; Humans; Hydrocortisone - blood; Hyperinsulinism - blood; Hyperinsulinism - etiology; Insulin; Insulin - blood; Isotopes; Male; Metabolism; Nutrition; Oxidation-Reduction; Postoperative Complications - blood; Postoperative Complications - therapy; Prospective Studies; Protein; Protein Deficiency - blood; Protein Deficiency - etiology; Protein Deficiency - prevention & control; Proteins; Proteolysis - drug effects; Single-Blind Method; Studies; Valine - blood; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Young Adult; Critical illness; Nutrition; Cardiac surgery; Child; Insulin; Isotopes; Protein; Endocrinopathy; Human; Heart; Hyperinsulinemia; Pancreatic hormone; Feeding; Vertebrata; Mammalia; Low; Surgery; Carbohydrate; Circulatory system; Balance
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2011.09.018

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 N2 ]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). Conclusion 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.