Total sulphur amino acid requirement of children with end‐stage renal disease

Abstract

The total sulphur amino acid (TSAA) requirement of children with end-stage renal disease (ESRD) was determined by indicator amino acid oxidation (IAAO) method. Four children (9.8–13.7 yr) with ESRD (glomerular filtration rate = 16–31 ml/min/1.73 m2) randomly received each of six dietary levels of methionine (no cysteine) (0, 5, 10, 15, 25 and 35 mg.kg−1.d−1) as part of an isocaloric and isonitrogenous diet. Breath and urine samples were collected at baseline and during isotopic steady state. TSAA requirement was determined by measuring oxidation of L− [1−13C]-phenylalanine to 13CO2 (F13CO2). Linear regression crossover analysis identified a breakpoint at minimal F13CO2 in response to methionine intakes (Fig. 1). Figure 1. 13C Phenylalanine oxidation (Mean ± SD) in response to methionine intakes (no cysteine) These preliminary data showed that the mean and population-safe (upper limit of 95% CI) TSAA requirements are 12.8 and 19.9 mg methionine kg−1.d−1 respectively. This suggests that TSAA requirements (methionine only) in children with ESRD are similar to those found in healthy children (12.9 and 17.2 mg kg−1.d−1 respectively, unpublished data). Further studies are needed to determine minimum methionine requirements of children with ESRD in the presence of excess dietary cysteine. Figure 1Open in figure viewerPowerPoint (CIHR supported).