Effect of Orthotopic Liver Transplantation (OLT) on Branched-Chain Amino Acid Requirement

Abstract

Little is known regarding the impact of liver transplantation on amino acid requirements in children. Since plasma levels of the branched-chain amino acids (BCAA) are decreased in the presence of normal levels of the aromatic amino acids after liver transplantation, normalization of hepatic function may not fully correct changes in BCAA metabolism that occur in the pretransplant period. The goal of the present study was to determine total BCAA requirements of children following liver transplantation. The requirement of total BCAA was determined using indicator amino acid oxidation (IAAO) in five clinically stable children (5.7 Ϯ 3.5 y, mean Ϯ SD) 1-8 y post liver transplantation. Children received in random order 6 graded intakes of total BCAA. Individual BCAA in the test diet were provided in the same proportions as present in egg protein to minimize the potential interactive effects of individual BCAA on assessment of requirement. Total BCAA requirement was determined by measuring the oxidation of L-[1-13 C] phenylalanine to 13 CO 2 [F 13 CO 2 in mol/kg/h], after a primed, continuous infusion of the tracer and using a two-phase linear regression crossover regression analysis. The estimated average requirement and the upper limit of the 95% CI for total BCAA in children who have undergone liver transplantation were 172 and 206 mg/kg/d), respectively. Total BCAA requirement in children who have undergone orthotopic liver transplantation (OLT) remain increased in the post-liver transplant period when compared with healthy school aged children, but is decreased when compared with children with mild-moderate chronic cholestatic ( T here is no previous information regarding BCAA requirements in children who have undergone OLT. We have shown previously that total BCAA requirements in children with MCC liver disease are higher than requirements in healthy school-aged children (1,2) This increase in total BCAA requirement was observed in a population of children with a similar body composition, age, growth, and nutritional status as healthy school-aged children studied previously (2). The only major difference was that the children with MCC liver disease had decreased plasma concentrations of the BCAA in the presence of increased requirements for the total BCAA, suggesting that changes in plasma BCAA levels may be reflective of differences in BCAA requirement in this population (1,2). In children, there is little information regarding the impact of OLT on BCAA metabolism. However there is evidence that plasma concentrations of the BCAA remain depressed after OLT, whereas aromatic amino acid concentrations are usually normal, suggesting that BCAA requirements may be increased post-OLT (3-5).There is limited information regarding the potential mechanism responsible for a change in plasma BCAA concentrations after OLT. Normal concentrations of the AAA in the posttransplant period suggest that hepatic metabolism of the AAA have normalized, whereas depressed levels of the BCAA point to the skeletal muscle as the s...

Persistence of Sarcopenia After Pediatric Liver Transplantation Is Associated With Poorer Growth and Recurrent Hospital Admissions

“…However, it is possible that suboptimal energy or protein intake in the immediate post‐LTx period and/or alterations in branched‐chain amino acid (BCAA) metabolism contributing to deficits in protein anabolism may also have contributed to sarcopenia prevalence in these children. We have previously shown that children with cholestatic liver diseases pre‐LTx and post‐LTx have significantly higher BCAA requirements than healthy children which may be due, in part, to increased leucine oxidation in the skeletal muscle . Higher BCAA requirements were noted in children post‐LTx in these studies up to 8 years post‐LTx and, hence, may be a factor .…”

“…We have previously shown that children with cholestatic liver diseases pre‐LTx and post‐LTx have significantly higher BCAA requirements than healthy children which may be due, in part, to increased leucine oxidation in the skeletal muscle . Higher BCAA requirements were noted in children post‐LTx in these studies up to 8 years post‐LTx and, hence, may be a factor . In addition, careful evaluation of overall nutrient support strategies including nutrient and energy deliver pre‐LTx and in the immediate postoperative period are warranted.…”

Role of branched‐chain amino acids in management of cirrhosis and hepatocellular carcinoma

“…The altered amino acid metabolism in patients with cirrhosis improves after liver transplantation, but serum BCAA levels fail to normalize more than 6 months after transplantation 56 . In one study with children, it was shown that the total BCAA requirement in the postoperative period of liver transplantation was higher when compared with healthy school‐aged children but was lower when compared to children with mild to moderate chronic liver disease 57 . This observation posed an important consideration for starting BCAA supplementation in patients undergoing liver transplantation.…”

Effects of ω‐3 Fish Oil Lipid Emulsion Combined With Parenteral Nutrition on Patients Undergoing Liver Transplantation

“…Consequently, 60%–80% of such candidates are glucose intolerant 11 . Branched‐chain amino acids were chosen for this study because they promote protein synthesis in patients with chronic liver disease and avoid the additional metabolic load of the transplanted liver itself, especially in the immediate postoperative period when liver function is abnormal and oral intake is withheld 12 . Medium‐chain triglycerides were included in the regimen to avert glucose intolerance and deposits in the transplanted liver.…”