title: Enteral Glutamine Administration in Critically Ill Nonseptic Patients Does Not Trigger Arginine Synthesis.
abstract: Glutamine supplementation in specific groups of critically ill patients results in favourable clinical outcome. Enhancement of citrulline and arginine synthesis by glutamine could serve as a potential mechanism. However, while receiving optimal enteral nutrition, uptake and enteral metabolism of glutamine in critically ill patients remain unknown. Therefore we investigated the effect of a therapeutically relevant dose of L-glutamine on synthesis of L-citrulline and subsequent L-arginine in this group. Ten versus ten critically ill patients receiving full enteral nutrition, or isocaloric isonitrogenous enteral nutrition including 0.5 g/kg L-alanyl-L-glutamine, were studied using stable isotopes. A cross-over design using intravenous and enteral tracers enabled splanchnic extraction (SE) calculations. Endogenous rate of appearance and SE of glutamine citrulline and arginine was not different (SE controls versus alanyl-glutamine: glutamine 48 and 48%, citrulline 33 versus 45%, and arginine 45 versus 42%). Turnover from glutamine to citrulline and arginine was not higher in glutamine-administered patients. In critically ill nonseptic patients receiving adequate nutrition and a relevant dose of glutamine there was no extra citrulline or arginine synthesis and glutamine SE was not increased. This suggests that for arginine synthesis enhancement there is no need for an additional dose of glutamine when this population is adequately fed. This trial is registered with NTR2285.
authors.affiliation: Department of Internal Medicine, VU University Medical Center, 1081 HV Amsterdam, Netherlands; Department of Surgery, VU University Medical Center, 1081 HV Amsterdam, Netherlands.
authors.forename: Mechteld A R
authors.initials: MA
authors.lastname: Vermeulen
authors.affiliation: Department of Surgery, VU University Medical Center, 1081 HV Amsterdam, Netherlands.
authors.forename: Saskia J H
authors.initials: SJ
authors.lastname: Brinkmann
authors.affiliation: Department of Surgery, VU University Medical Center, 1081 HV Amsterdam, Netherlands.
authors.forename: Nikki
authors.initials: N
authors.lastname: Buijs
authors.affiliation: Department of Intensive Care Unit, VU University Medical Center, 1081 HV Amsterdam, Netherlands; Intensive Care Unit, Medisch Spectrum Twente, 7511 JX Enschede, Netherlands.
authors.forename: Albertus
authors.initials: A
authors.lastname: Beishuizen
authors.affiliation: Department of Clinical Pharmacology and Pharmacy, VU University Medical Center, 1081 HV Amsterdam, Netherlands.
authors.forename: Pierre M
authors.initials: PM
authors.lastname: Bet
authors.affiliation: Department of Surgery, Medical Center Alkmaar and Trial Center Holland Health, Alkmaar, Netherlands.
authors.forename: Alexander P J
authors.initials: AP
authors.lastname: Houdijk
authors.affiliation: Department of Pediatrics, VU University Medical Center, 1081 HV Amsterdam, Netherlands; Department of Pediatrics, Emma Children's Hospital, AMC, 1105 AZ Amsterdam, Netherlands.
authors.forename: Johannes B
authors.initials: JB
authors.lastname: van Goudoever
authors.affiliation: Department of Surgery, VU University Medical Center, 1081 HV Amsterdam, Netherlands.
authors.forename: Paul A M
authors.initials: PA
authors.lastname: van Leeuwen