Dietary essential amino acids are highly anabolic in pediatric patients with cystic fibrosis

Abstract

Background: Current nutritional approaches have been partially successful in Cystic Fibrosis (CF). Essential amino acids mixtures with high Leucine levels (EAA) have anabolic properties in catabolic conditions, however data in CF are lacking.

Methods: On two days according a randomized crossover design, 15 pediatric CF patients ingested 6.7 g EAA versus mixture of total amino acids as present in whey. Whole body protein and Arginine metabolism (as EAA lack Arginine) were assessed by stable isotope methodology.

Results: Protein synthesis (P<0.05) but not protein breakdown was higher after EAA and 70% higher values for net anabolism (P<0.001)were found both in patients with and without nutritional failure. Arginine turnover was lower (P<0.001) and de novo Arginine synthesis tended lower (P=0.09) after EAA. Nitric oxide synthesis was not different.

Conclusions: CF patients are highly responsive to EAA intake independent of their nutritional status. Addition of Arginine to the EAA mixture may be warranted in CF.

Keywords: Arginine production; BMI; CF; Cystic Fibrosis; DXA; EAA; Essential amino acids; FEV(1); FFM; FM; FVC; NO; NetPS; Nitric oxide synthesis; Nutritional failure; Q Arginine to Citrulline; Q Citrulline to Arginine; Ra; SE; TAA; TTR; WbPB; WbPS; Whole body protein anabolism; balanced mixture of essential and non-essential amino acids; body mass index; cTTR; de novo Arginine production; dual-energy X-ray absorptiometry; essential amino acids; fat mass; fat-free mass; forced expiratory volume in 1s; forced vital capacity; net protein synthesis; nitric oxide; nitric oxide production; rate of appearance; standard error; tracer tracee ratio; tracer–tracee ratios of amino acids corrected for their baseline value; whole body protein breakdown; whole body protein synthesis.