Mild-to-Moderate Chronic Cholestatic Liver Disease Increases Leucine Oxidation in Children

Abstract

Malnutrition is prevalent in children with chronic cholestatic liver disease. Using the noninvasive indicator amino acid oxidation (IAAO) technique, we recently determined that mild-to-moderate chronic cholestatic (MCC) liver disease increases the need for branched-chain amino acids (BCAA) in children. To examine the underlying mechanisms responsible for this increased need for BCAA in liver disease, we measured L-[1-(13C)]-leucine oxidation in the postabsorptive and fed states in 10 children with MCC liver disease (8.8 +/- 3.5 y) and in 11 healthy children (9.4 +/- 2.2 y). The oxidation of L-[1-(13C)]-leucine to 13CO2 [F13CO2 in micromol/(kg.h)] was determined after a primed, continuous oral administration of the tracer. Total BCAA in diet was provided at 300 mg/(kg.d) to ensure that leucine oxidation was measured when leucine intake was in excess of requirements. In the postabsorptive state, the rate of release of 13CO2 from 13C-leucine oxidation (F13CO2) and whole-body leucine oxidation were significantly higher in children with MCC liver disease (P < 0.05). However, F13CO2 and whole-body leucine oxidation did not differ in the fed state. We conclude that the increased need for dietary BCAA in MCC liver disease is mediated in part by increased leucine oxidation in the postabsorptive state.