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Administration of Free Amino Acids Improves Exogenous Amino Acid Availability when Compared with Intact Protein in Critically Ill Patients: A Randomized Controlled Study.

Administration of Free Amino Acids Improves Exogenous Amino Acid Availability when Compared with Intact Protein in Critically Ill Patients: A Randomized Controlled Study.

Authors :
van Gassel RJ
Weijzen ME
Kouw IW
Senden JM
Wodzig WK
Olde Damink SW
van de Poll MC
van Loon LJ
Source :
The Journal of nutrition [J Nutr] 2024 Feb; Vol. 154 (2), pp. 554-564. Date of Electronic Publication: 2023 Dec 15.
Publication Year :
2024

Abstract

Background: Protein digestion and amino acid absorption appear compromised in critical illness. The provision of enteral feeds with free amino acids rather than intact protein may improve postprandial amino acid availability.<br />Objective: Our objective was to quantify the uptake of diet-derived phenylalanine after the enteral administration of intact protein compared with an equivalent amount of free amino acids in critically ill patients.<br />Methods: Sixteen patients who were mechanically ventilated in intensive care unit (ICU) at risk of malabsorption received a primed continuous infusion of L-[ring- <superscript>2</superscript> H <subscript>5</subscript> ]-phenylalanine and L-[ring-3,5- <superscript>2</superscript> H <subscript>2</subscript> ]-tyrosine after an overnight fast. Patients were randomly allocated to receive 20 g intrinsically L-[1- <superscript>13</superscript> C]-phenylalanine-labeled milk protein or an equivalent amount of amino acids labeled with free L-[1- <superscript>13</superscript> C]-phenylalanine via a nasogastric tube over a 2-h period. Protein digestion and amino acid absorption kinetics and whole-body protein net balance were assessed throughout a 6-h period.<br />Results: After enteral nutrient infusion, both plasma phenylalanine and leucine concentrations increased (P-time < 0.001), with a more rapid and greater rise after free amino acid compared with intact protein administration (P-time × treatment = 0.003). Diet-derived phenylalanine released into the circulation was 25% greater after free amino acids compared with intact protein administration [68.7% (confidence interval {CI}: 62.3, 75.1%) compared with 43.8% (CI: 32.4, 55.2%), respectively; P < 0.001]. Whole-body protein net balance became positive after nutrient administration (P-time < 0.001) and tended to be more positive after free amino acid in provision (P-time × treatment = 0.07).<br />Conclusions: The administration of free amino acids as opposed to intact protein further increases postprandial plasma amino acid availability in critically ill patients, allowing more diet-derived phenylalanine to become available to peripheral tissues. This trial was registered at clinicaltrials.gov as NCT04791774.<br /> (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Details

Language :
English
ISSN :
1541-6100
Volume :
154
Issue :
2
Database :
MEDLINE
Journal :
The Journal of nutrition
Publication Type :
Academic Journal
Accession number :
38103646
Full Text :
https://doi.org/10.1016/j.tjnut.2023.12.015