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ESPGHAN/ESPEN/ESPR/CSPEN guidelines on pediatric parenteral nutrition: Amino acids. Clin Nutr 2018; 37:2315-2323. [DOI: 10.1016/j.clnu.2018.06.945] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 05/29/2018] [Indexed: 02/02/2023]
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Darmaun D, Lapillonne A, Simeoni U, Picaud JC, Rozé JC, Saliba E, Bocquet A, Chouraqui JP, Dupont C, Feillet F, Frelut ML, Girardet JP, Turck D, Briend A. Parenteral nutrition for preterm infants: Issues and strategy. Arch Pediatr 2018; 25:286-294. [PMID: 29656825 DOI: 10.1016/j.arcped.2018.02.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 01/26/2018] [Accepted: 02/18/2018] [Indexed: 01/13/2023]
Abstract
Due to transient gut immaturity, most very preterm infants receive parenteral nutrition (PN) in the first few weeks of life. Yet providing enough protein and energy to sustain optimal growth in such infants remains a challenge. Extrauterine growth restriction is frequently observed in very preterm infants at the time of discharge from hospital, and has been found to be associated with later impaired neurodevelopment. A few recent randomized trials suggest that intensified PN can improve early growth; whether or not such early PN improves long-term neurological outcome is still unclear. Several other questions regarding what is optimal PN for very preterm infants remain unanswered. Amino acid mixtures designed for infants contain large amounts of branched-chain amino acids and taurine, but there is no consensus on the need for some nonessential amino acids such as glutamine, arginine, and cysteine. Whether excess growth in the first few weeks of life, at a time when very preterm infants receive PN, has an imprinting effect, increasing the risk of metabolic or vascular disease at adulthood continues to be debated. Even though uncertainty remains regarding the long-term effect of early PN, it appears reasonable to propose intensified initial PN. The aim of the current position paper is to review the evidence supporting such a strategy with regards to the early phase of nutrition, which is mainly covered by parenteral nutrition. More randomized trials are, however, needed to further support this type of approach and to demonstrate that this strategy improves short- and long-term outcome.
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Affiliation(s)
- D Darmaun
- Université Nantes-Atlantique, 44300 Nantes, France.
| | | | - U Simeoni
- Université de Lausanne, CHUV, 1011 Lausanne, Suisse
| | - J-C Picaud
- Université Claude-Bernard-Lyon 1, 69008 Lyon, France
| | - J-C Rozé
- Université Nantes-Atlantique, 44300 Nantes, France
| | - E Saliba
- Université François-Rabelais, 37000 Tours, France
| | - A Bocquet
- Université de Franche-Comté, 25000 Besançon, France
| | | | - C Dupont
- Université Paris Descartes, 75006 Paris, France
| | - F Feillet
- Université de Lorraine, 54000 Nancy, France
| | - M-L Frelut
- Université Paris-Sud, CHU de Bicêtre, 94270 Le Kremlin-Bicêtre, France
| | - J-P Girardet
- Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
| | - D Turck
- Université Lille 2, LIRIC-Inserm U995, 59037 Lille, France
| | - A Briend
- Institut de recherche pour le développement, 13572 Marseille, France
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Tan HWS, Sim AYL, Long YC. Glutamine metabolism regulates autophagy-dependent mTORC1 reactivation during amino acid starvation. Nat Commun 2017; 8:338. [PMID: 28835610 PMCID: PMC5569045 DOI: 10.1038/s41467-017-00369-y] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 06/26/2017] [Indexed: 01/08/2023] Open
Abstract
Activation of autophagy and elevation of glutamine synthesis represent key adaptations to maintain amino acid balance during starvation. In this study, we investigate the role of autophagy and glutamine on the regulation of mTORC1, a critical kinase that regulates cell growth and proliferation. We report that supplementation of glutamine alone is sufficient to restore mTORC1 activity during prolonged amino acid starvation. Inhibition of autophagy abolishes the restorative effect of glutamine, suggesting that reactivation of mTORC1 is autophagy-dependent. Inhibition of glutaminolysis or transamination impairs glutamine-mediated mTORC1 reactivation, suggesting glutamine reactivates mTORC1 specifically through its conversion to glutamate and restoration of non-essential amino acid pool. Despite a persistent drop in essential amino acid pool during amino acid starvation, crosstalk between glutamine and autophagy is sufficient to restore insulin sensitivity of mTORC1. Thus, glutamine metabolism and autophagy constitute a specific metabolic program which restores mTORC1 activity during amino acid starvation. mTORC1 is a critical kinase that regulates cell growth and proliferation. Here the authors show that glutamine metabolism is sufficient to restore mTORC1 activity during prolonged amino acid starvation in an autophagy-dependent manner.
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Affiliation(s)
- Hayden Weng Siong Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Arthur Yi Loong Sim
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yun Chau Long
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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Glutamine randomized studies in early life: the unsolved riddle of experimental and clinical studies. Clin Dev Immunol 2012; 2012:749189. [PMID: 23019424 PMCID: PMC3457673 DOI: 10.1155/2012/749189] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 07/25/2012] [Indexed: 11/21/2022]
Abstract
Glutamine may have benefits during immaturity or critical illness in early life but its effects on outcome end hardpoints are controversial. Our aim was to review randomized studies on glutamine supplementation in pups, infants, and children examining whether glutamine affects outcome. Experimental work has proposed various mechanisms of glutamine action but none of the randomized studies in early life showed any effect on mortality and only a few showed some effect on inflammatory response, organ function, and a trend for infection control. Although apparently safe in animal models (pups), premature infants, and critically ill children, glutamine supplementation does not reduce mortality or late onset sepsis, and its routine use cannot be recommended in these sensitive populations. Large prospectively stratified trials are needed to better define the crucial interrelations of “glutamine-heat shock proteins-stress response” in critical illness and to identify the specific subgroups of premature neonates and critically ill infants or children who may have a greater need for glutamine and who may eventually benefit from its supplementation. The methodological problems noted in the reviewed randomized experimental and clinical trials should be seriously considered in any future well-designed large blinded randomized controlled trial involving glutamine supplementation in critical illness.
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Affiliation(s)
- Milan Holecek
- Charles University in Prague, Hradec Kralove, Czech Republic
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Letellier G, Mok E, Alberti C, De Luca A, Gottrand F, Cuisset JM, Denjean A, Darmaun D, Hankard R. Effect of glutamine on glucose metabolism in children with Duchenne muscular dystrophy. Clin Nutr 2012; 32:386-90. [PMID: 23021433 DOI: 10.1016/j.clnu.2012.08.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 08/03/2012] [Accepted: 08/22/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND & AIMS Glutamine is a potent gluconeogenic precursor and stimulates insulin secretion. Glutamine's effect on glucose metabolism in Duchenne muscular dystrophy (DMD) has never been studied. To determine plasma glucose and insulin concentrations measured during and after glutamine administration in DMD boys. We hypothesized that glutamine can modulate whole body glutamine-glucose metabolism in DMD, a genetically determined disease. METHODS As secondary endpoints of a randomized crossover trial in 30 prepubertal DMD boys, we measured fasting blood glucose, insulin and the Homeostasis Model Assessment (HOMA) index after daily oral glutamine (0.5 g kg(-1) d(-1)) for 4 months versus placebo. In a separate time series trial in 6 prepubertal DMD boys, we measured the same endpoints as well as plasma glutamine and whole body glucose turnover (Ra,glc) (primed continuous i.v. infusion of d-[6,6-(2)D]glucose), while participants received acute oral glutamine (0.5 g kg(-1) d(-1)) continuously for 5 h. RESULTS In the randomized trial, baseline measurements of HOMA correlated with age (r = 0,51, p = 0.007) and percent fat estimated by bioelectrical impedance analysis (BIA) (r = 0.39, p = 0.047). After 4 months glutamine supplementation, we observed no treatment or order effect on HOMA or insulin. During acute glutamine for 5 h (time series trial), plasma glutamine doubled and was associated with increased plasma insulin concentration (10.42 ± 2.54 vs 7.32 ± 1.86, p = 0.05) with no effect on plasma glucose, HOMA or Ra,glc. CONCLUSIONS Acute glutamine transiently stimulates insulin secretion in DMD boys, which could be mediated by plasma glutamine concentrations. Fasting insulin concentration and HOMA might provide quantifiable indices of disease progression.
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Affiliation(s)
- Guy Letellier
- INSERM, Centre d'Investigation Clinique 802, Poitiers F-86000, France.
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Abstract
INTRODUCTION Protein intake in fetal life or infancy may play a key role in determining early growth rate, a determinant of later health and disease. Previous work has indicated that hair isotopic composition is influenced by diet and protein intake. METHODS This study analyzes the isotopic composition of hair obtained from 239 mother/newborn pairs randomly selected within a larger cohort enrolled in a study of pre- and postnatal determinants of the child's development and health. The isotopic compositions in nitrogen (δ(15)N) and in carbon (δ(13)C) were determined by isotope ratio mass spectrometry. RESULTS Mother and newborn hair δ(15)N were tightly correlated (Pearson r = 0.88). The mean δ(15)N and δ(13)C values of hair from newborn infants were significantly higher than those for the mothers: 9.7 ± 0.7 vs. 8.8 ± 0.6‰ (P < 0.0001) for δ(15)N and -20.0 ± 0.4 vs. -20.4 ± 0.4‰ (P < 0.0001) for δ(13)C. Maternal hair δ(15)N at parturition was slightly and positively correlated with estimates of protein intake (r = 0.14, P = 0.04). DISCUSSION Hair δ(15)N of the fetus is both highly dependent on and systematically higher than that of the mother. Whether quantitative and qualitative protein intake, disease, or hormonal status alter hair δ(15)N at birth remains to be determined.
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Mok E, Hankard R. Glutamine supplementation in sick children: is it beneficial? J Nutr Metab 2011; 2011:617597. [PMID: 22175008 PMCID: PMC3228321 DOI: 10.1155/2011/617597] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/28/2011] [Indexed: 12/14/2022] Open
Abstract
The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln) supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln.
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Affiliation(s)
- Elise Mok
- INSERM Centre D'Investigation Clinique 802, Centre Hospitalier Universitaire de Poitiers, 86021 Poitiers Cedex, France
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Abstract
Glutamine is a non-essential amino acid that can be synthesized de novo from glutamate. This synthesis can be increased by intravenous infusion of carbon precursors (alpha-ketoglutarate or amino acids) in adults and in infants. The metabolism of glutamine is highly compartmentalized between the splanchnic tissues and the periphery, so that orally administered glutamine is completely metabolized in the splanchnic compartment. Data from studies in adults and children show that plasma levels of glutamine decline during acute stress and illness. Because of its importance in several physiological functions (the demonstrated benefits of supplemental glutamine in adult burns and trauma patients and the inhibitory effect on proteolysis in the skeletal muscle in vitro), it has been suggested that during 'acute stress' the demands of glutamine outweigh its de novo synthesis, resulting in a fall in plasma glutamine levels. As a consequence, glutamine has been considered a 'conditionally essential' amino acid. Because of its instability in solution, glutamine is not routinely added to the parenteral amino acid mixtures. A number of clinical trials of parenteral and enteral supplementation of glutamine have been performed. The outcome measures examined have varied between acute effects and long-term complex clinical events such as mortality and risk of infections. Although acute studies in LBW babies have shown some beneficial effects such as changes in protein metabolism and activation of immune system, these have not been translated into prolonged advantages such as reduction in mortality or in nosocomial infection. The reasons for these differences are discussed.
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Affiliation(s)
- Prabhu S Parimi
- Department of Pediatrics, Case Western Reserve University at MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA.
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Armstrong M, Jonscher K, Reisdorph NA. Analysis of 25 underivatized amino acids in human plasma using ion-pairing reversed-phase liquid chromatography/time-of-flight mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:2717-26. [PMID: 17659659 DOI: 10.1002/rcm.3124] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Amino acids in biological fluids have previously been shown to be detectable using liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) with perfluorinated acids as ion-pairing agents. To date, these studies have used precursor mass, retention time and tandem mass spectrometry (MS/MS) to identify and quantify amino acids. While this is a potentially powerful technique, we sought to adapt the method to time-of-flight (TOF)MS. A new application of a recently described liquid chromatographic separation method was coupled with TOFMS to employ accurate mass for qualitative identification; resulting in additional qualitative data not available with standard single quadrupole data. In the current study, we evaluated 25 physiological amino acids and one dipeptide that are routinely quantified in human plasma. Accuracy and precision of the method was evaluated by spiking human plasma with a mix of the 25 amino acids; in addition, the inclusion of a cation-exchange cleanup step was evaluated. The calibration curves were linear over a range from 1.56 to 400 microM. The dynamic range was found to be within physiological levels for all amino acids analyzed. Accuracy and precision for most of the amino acids was between 80-120% spike recovery and <10% relative standard deviation (RSD). The LC/MS technique described in this study relies on mass accuracy and is suitable for the quantitation of free amino acids in plasma.
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Affiliation(s)
- Michael Armstrong
- Department of Immunology, National Jewish Medical and Research Center, Denver, CO 80206, USA
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Le Bacquer O, Mauras N, Welch S, Haymond M, Darmaun D. Acute depletion of plasma glutamine increases leucine oxidation in prednisone-treated humans. Clin Nutr 2006; 26:231-8. [PMID: 17097772 PMCID: PMC1949027 DOI: 10.1016/j.clnu.2006.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 08/26/2006] [Accepted: 09/27/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND, AIMS & METHODS To determine whether depletion in plasma glutamine worsens the catabolic response to corticosteroids, seven healthy volunteers received oral prednisone for 6 days on two separate occasions, at least 2 weeks apart, and in random order. On the sixth day of each treatment course, they received 5 h intravenous infusions of L-[1-(14)C]-leucine and L-[1-(13)C]-glutamine in the postabsorptive state (1) under baseline conditions (prednisone only day) and (2) after 24h of treatment with phenylbutyrate (prednisone+phenylbutyrate day), a glutamine chelating agent. RESULTS Phenylbutyrate treatment was associated with (1) an approximately 15% decline in plasma glutamine concentration (627+/-39 vs. 530+/-31 micromol l(-1); P<0.05), (2) no change in leucine appearance rate, an index of protein breakdown (124+/-9 vs. 128+/-9 micromol kg(-1) h(-1); NS) nor in non-oxidative leucine disposal, an index of whole body protein synthesis (94+/-9 vs. 91+/-7 micromol kg(-1) h(-1); NS), and (3) a approximately 25% rise in leucine oxidation (30+/-1 vs. 38+/-2 micromol kg(-1) h(-1), P<0.05), despite an approximately 25% decline (P<0.05) in leucine concentration. CONCLUSIONS In a model of mild, stress-induced protein catabolism, depletion of plasma glutamine per se may worsen branched chain amino acid and protein wasting.
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Affiliation(s)
| | - Nelly Mauras
- Division of Endocrinology, Nemours Children’s Clinic, Jacksonville, Florida
| | - Susan Welch
- Division of Endocrinology, Nemours Children’s Clinic, Jacksonville, Florida
| | - Morey Haymond
- USDA Children’s Nutrition Research Center at Baylor College of Medicine, Houston, Texas
| | - Dominique Darmaun
- Division of Endocrinology, Nemours Children’s Clinic, Jacksonville, Florida
- INSERM U.539, Centre de Recherche en Nutrition Humaine, Nantes, France
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Humbert B, Nguyen P, Martin L, Dumon H, Vallette G, Maugère P, Darmaun D. Effect of glutamine on glutathione kinetics in vivo in dogs. J Nutr Biochem 2006; 18:10-6. [PMID: 16563721 DOI: 10.1016/j.jnutbio.2006.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2005] [Revised: 02/05/2006] [Accepted: 02/07/2006] [Indexed: 11/20/2022]
Abstract
To determine whether glutamine affects glutathione (GSH, gamma-glutamyl-cysteinyl-glycine) metabolism, seven healthy beagle dogs received 6-h infusions of [(15)N]glutamate and [(13)C]leucine after a 3-day fast. Isotope infusions were performed during oral feeding with an elemental regimen, supplemented with either l-glutamine or an isonitrogenous amino acid mixture, on two separate days and in randomized order. Timed blood samples were obtained, and a surgical duodenal biopsy was performed after 6 h of isotope infusion. GSH fractional synthesis rate (FSR) was assessed from [(15)N]glutamate incorporation into blood and gut GSH, and duodenal protein synthesis from [(13)C]leucine incorporation into gut protein. Glutamine supplementation failed to alter erythrocyte GSH concentration (2189+/-86 vs. 1994+/-102 micromol L(-1) for glutamine vs. control; ns) or FSR (64+/-17% vs. 74+/-20% day(-1); ns). In the duodenum, glutamine supplementation was associated with a 92% rise in reduced/oxidized GSH ratio (P=.024) and with a 44% decline in GSH FSR (96+/-15% day(-1) vs. 170+/-18% day(-1); P=.005), whereas total GSH concentration remained unchanged (808+/-154 vs. 740+/-127 micromol kg(-1); P=.779). We conclude that, in dogs receiving enteral nutrition after a 3-day fast: (1) glutamine availability does not affect blood GSH, and, (2) in contrast, in the duodenum, the preserved GSH pool, along with a decreased synthesis rate, suggests that glutamine may maintain GSH pool and intestinal redox status by acutely decreasing GSH utilization.
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Affiliation(s)
- Bernard Humbert
- INSERM U.539, Centre de Recherche en Nutrition Humaine, Nantes, 44093 Cedex 1, France
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Alpers DH. Glutamine: do the data support the cause for glutamine supplementation in humans? Gastroenterology 2006; 130:S106-16. [PMID: 16473057 DOI: 10.1053/j.gastro.2005.11.049] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Accepted: 11/14/2005] [Indexed: 12/17/2022]
Abstract
This review examines the preclinical rationale for using glutamine supplements and reviews the prospective randomized trials using glutamine to improve outcomes in patients. A special role for glutamine in gut physiology and in management of a variety of serious illnesses has been suggested, because it is the most abundant extracellular amino acid, and is used at high rates by the gut, liver, central nervous system, and immune cells. A state of relative Gln deficiency has been postulated in humans based on the decrease in plasma Gln in acute critical illness, but the decrease in plasma Gln is not specific for that amino acid, predicts only poorer outcome, and has not been validated to identify a deficiency state. Current evidence does not necessarily predict a special need or role for Gln in critical illness. Clinical efficacy of supplemental Gln has been difficult to demonstrate, possibly related to the lack of a Gln deficiency state, the wide range of end points used that reflect the lack of certainty of the predicted effect of supplementation, the heterogeneous patient populations studied, the lack of stable clinical course during the study, the lack of adequate power, and the relatively short follow-up period. Prospective randomized clinical trials of Gln supplementation were reviewed in patients with short-bowel syndrome, during cancer chemotherapy and in bone marrow transplantation, and in surgical, burn, and intensive care unit patients. No firm recommendation can be made at this time. Future studies should seek to develop a more standard and stable design for intervention in sufficiently powered studies.
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Affiliation(s)
- David H Alpers
- Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
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Darmaun D, Mauras N. Use of Stable Isotopes to Assess Protein and Amino Acid Metabolism in Children and Adolescents: A Brief Review. Horm Res Paediatr 2006; 64 Suppl 3:32-7. [PMID: 16439842 DOI: 10.1159/000089315] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
As protein accretion is a prerequisite for growth, studying the mechanisms by which nutrients and hormones promote protein gain is of the utmost relevance to paediatric endocrinology. Tracers are ideally suited for the assessment of protein and amino acid kinetics in vivo, as they provide an estimate of synthesis and turnover. Current tracer approaches in children and adolescents utilize stable isotopes, 'heavier' forms of elements that have one or several extra neutrons in the nucleus. Such isotopes are already present at low, but significant, levels in all tissues and foodstuffs, are not radioactive and are devoid of any known side-effects when present in small amounts. L-[1-(13)C] labelled leucine, given as a 4- to 6-h intravenous infusion, has become the method of choice to assess whole-body protein kinetics. After infusion, any 13C-leucine that is oxidized appears in the breath as 13CO2, whereas the remainder is incorporated into body proteins through protein synthesis. The isotope enrichments are determined by isotope ratio mass spectrometry and gas chromatography mass spectrometry, and absolute rates of whole-body protein synthesis, oxidation, and breakdown can be extrapolated. This approach has been used extensively to investigate the regulation of protein kinetics by nutrients and by hormones. Attempts have also been made to measure amino acid/protein metabolism in selected body compartments, and to measure the kinetics of specific tissue proteins, for example, muscle, gut, or plasma proteins.
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Parimi PS, Kadrofske MM, Gruca LL, Hanson RW, Kalhan SC. Amino acids, glutamine, and protein metabolism in very low birth weight infants. Pediatr Res 2005; 58:1259-64. [PMID: 16306204 DOI: 10.1203/01.pdr.0000185130.90205.1f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glutamine has been proposed to be conditionally essential for premature infants, and the currently used parenteral nutrient mixtures do not contain glutamine. De novo glutamine synthesis (DGln) is linked to inflow of carbon into and out of the tricarboxylic acid (TCA) cycle. We hypothesized that a higher supply of parenteral amino acids by increasing the influx of amino acid carbon into the TCA cycle will enhance the rate of DGln. Very low birth weight infants were randomized to receive parenteral amino acids either 1.5 g/kg/d for 20 h followed by 3.0 g/kg/d for 5 h (AA1.5) or 3.0 g/kg/d for 20 h followed by 1.5 g/kg/d for 5 h (AA3.0). A third group of babies received amino acids 1.5 g/kg/d for 20 h followed by 3.0 g/kg/d for 20 h (AA-Ext). Glutamine and protein/nitrogen kinetics were examined using [5-(15)N]glutamine, [2H5]phenylalanine, [1-(13)C,15N]leucine, and [15N2]urea tracers. An acute increase in parenteral amino acid infusion for 5 h (AA1.5) resulted in decrease in rate of appearance (Ra) of phenylalanine and urea, but had no effect on glutamine Ra. Infusion of amino acids at 3.0 g/kg/d for 20 h resulted in increase in DGln, leucine transamination, and urea synthesis, but had no effect on Ra phenylalanine (AA-Ext). These data show an acute increase in parenteral amino acid-suppressed proteolysis, however, such an effect was not seen when amino acids were infused for 20 h and resulted in an increase in glutamine synthesis.
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Affiliation(s)
- Prabhu S Parimi
- Department of Pediatrics, Schwartz Center for Metabolism and Nutrition, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, OH 44109, USA.
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Tannus AFS, Junqueira-Franco MM, Suen VMM, Portari GV, Marchini JS. Short time L-glutamine supplementation of malnourished rats. REV NUTR 2005. [DOI: 10.1590/s1415-52732005000600002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJETIVE: Considering that in malnourished patients supplemented with L-glutamine the negativity of the nitrogen balance tends to decrease, the present study aimed to determine whether malnourished Wistar rats supplemented with L-glutamine would show lower urinary nitrogen excretion, a greater deposition of nitrogen content in different tissues, and/or an alteration in the plasma amino acid levels. METHODS: The rats were divided into groups: 1) protein-energy malnutrition, 2) protein malnutrition and 3) normally nourished group. The urinary and tissue nitrogen contents were determined by the Kjeldahl method and plasma amino acids by liquid chromatography. RESULTS: Weight, urinary and tissue nitrogen accumulation were significantly reduced in the group with protein-energy malnutrition, but did not improve with L-glutamine supplementation supplied for a short time. The plasma amino acid concentrations showed no special pattern with L-glutamine supplementation. CONCLUSION: It was concluded that it was not possible to detect any positive effect of L-glutamine supplementation on the tissue and urinary nitrogen metabolism in malnourished rats.
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van den Berg A, van Elburg RM, Teerlink T, Lafeber HN, Twisk JWR, Fetter WPF. A randomized controlled trial of enteral glutamine supplementation in very low birth weight infants: plasma amino acid concentrations. J Pediatr Gastroenterol Nutr 2005; 41:66-71. [PMID: 15990633 DOI: 10.1097/01.mpg.0000167497.55321.65] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVE Glutamine depletion has negative effects on the functional integrity of the gut and leads to immunosuppression. Very low birth weight (VLBW) infants are susceptible to glutamine depletion, as enteral nutrition is limited in the first weeks of life. Enteral glutamine supplementation may have a positive effect on feeding tolerance, infectious morbidity and short-term outcome. The aim of the study was to determine the effect of enteral glutamine supplementation on plasma amino acid concentrations, reflecting one aspect of safety of enteral glutamine supplementation in VLBW infants. METHODS In a double-blind placebo-controlled randomized controlled trial, VLBW infants (gestational age <32 weeks or birth weight <1500 g) received enteral glutamine supplementation (0.3 g/kg per day) or isonitrogenous placebo supplementation (alanine) between day 3 and day 30 of life. Supplementation was added to breast milk or to preterm formula. Plasma amino acid concentrations were measured at four time points: before the start of the study and at days 7, 14 and 30 of life. RESULTS Baseline patient and nutritional characteristics were not different in glutamine (n = 52) and control (n = 50) groups. Plasma concentrations of most essential and non-essential amino acids increased throughout the study period. There was no effect of enteral glutamine supplementation. In particular, the increase of plasma glutamine and glutamate concentrations was not different between the treatment groups (P = 0.49 and P = 0.34 respectively, day 30). CONCLUSIONS Enteral glutamine supplementation in VLBW infants does not alter plasma concentrations of glutamine, glutamate or other amino acids. Enteral supplementation in a dose of 0.3 g/kg per day seems safe in VLBW infants.
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Affiliation(s)
- Anemone van den Berg
- Department of Pediatrics, VU University Medical Center, Amsterdam, the Netherlands.
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Abstract
This is a literature review over a time period of the past 2 years concerning glutamine in clinical nutrition. Emphasis is put upon studies of glutamine in clinical settings, but a brief overview of the large range of literature over the role of glutamine in various experimental settings is also included. The most interesting concept for the past 2 years is the suggestion to use plasma glutamine concentration at admission to the intensive care unit as a prognostic marker and as a possible indicator for indication of glutamine supplementation.
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Affiliation(s)
- Jan Wernerman
- Department of Anesthesiology and Intensive Care, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden.
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