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Rudar M, Suryawan A, Nguyen HV, Chacko SK, Vonderohe C, Stoll B, Burrin DG, Fiorotto ML, Davis TA. Pulsatile Leucine Administration during Continuous Enteral Feeding Enhances Skeletal Muscle Mechanistic Target of Rapamycin Complex 1 Signaling and Protein Synthesis in a Preterm Piglet Model. J Nutr 2024; 154:505-515. [PMID: 38141773 PMCID: PMC10900192 DOI: 10.1016/j.tjnut.2023.12.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/25/2023] Open
Abstract
BACKGROUND Continuous feeding does not elicit an optimal anabolic response in skeletal muscle but is required for some preterm infants. We reported previously that intermittent intravenous pulses of leucine (Leu; 800 μmol Leu·kg-1·h-1 every 4 h) to continuously fed pigs born at term promoted mechanistic target of rapamycin complex 1 (mTORC1) activation and protein synthesis in skeletal muscle. OBJECTIVES The aim was to determine the extent to which intravenous Leu pulses activate mTORC1 and enhance protein synthesis in the skeletal muscle of continuously fed pigs born preterm. METHODS Pigs delivered 10 d preterm was advanced to full oral feeding >4 d and then assigned to 1 of the following 4 treatments for 28 h: 1) ALA (continuous feeding; pulsed with 800 μmol alanine·kg-1·h-1 every 4 h; n = 8); 2) L1× (continuous feeding; pulsed with 800 μmol Leu·kg-1·h-1 every 4 h; n = 7); 3) L2× (continuous feeding; pulsed with 1600 μmol Leu·kg-1·h-1 every 4 h; n = 8); and 4) INT (intermittent feeding every 4 h; supplied with 800 μmol alanine·kg-1 per feeding; n = 7). Muscle protein synthesis rates were determined with L-[2H5-ring]Phenylalanine. The activation of insulin, amino acid, and translation initiation signaling pathways were assessed by Western blot. RESULTS Peak plasma Leu concentrations were 134% and 420% greater in the L2× compared to the L1× and ALA groups, respectively (P < 0.01). Protein synthesis was greater in the L2× than in the ALA and L1× groups in both the longissimus dorsi and gastrocnemius muscles (P < 0.05) but not different from the INT group (P > 0.10). Amino acid signaling upstream and translation initiation signaling downstream of mTORC1 largely corresponded to the differences in protein synthesis. CONCLUSIONS Intravenous Leu pulses potentiate mTORC1 activity and protein synthesis in the skeletal muscles of continuously fed preterm pigs, but the amount required is greater than in pigs born at term.
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Affiliation(s)
- Marko Rudar
- Department of Animal Sciences, Auburn University, Auburn, AL, United States
| | - Agus Suryawan
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Hanh V Nguyen
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Shaji K Chacko
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Caitlin Vonderohe
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Barbara Stoll
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Douglas G Burrin
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Marta L Fiorotto
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
| | - Teresa A Davis
- Department of Pediatrics, USDA/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States.
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Formisano E, Schiavetti I, Gradaschi R, Gardella P, Romeo C, Pisciotta L, Sukkar SG. The Real-Life Use of a Protein-Sparing Modified Fast Diet by Nasogastric Tube (ProMoFasT) in Adults with Obesity: An Open-Label Randomized Controlled Trial. Nutrients 2023; 15:4822. [PMID: 38004217 PMCID: PMC10674249 DOI: 10.3390/nu15224822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Protein-sparing modified fast (PSMF) diet is a very-low-carbohydrate ketogenic diet administered to patients with obesity, which preserves lean mass and suppresses appetite as well as continuous enteral feeding. Thus, we aim to evaluate the effect of the PSMF diet administered continuously by nasogastric tube (NGT) or orally. METHODS Patients with a body mass index (BMI) > 34.9 kg/m2 were randomly assigned to receive a whey protein PSMF formula through NGT (ProMoFasT) or orally. Data were collected at baseline and after 150 days. The endpoints were assessed in the intention-to-treat population. RESULTS We enrolled 20 patients in the ProMoFasT group and 24 in the oral group. No differences in body weight, BMI or waist circumference between the two groups were found after 150 days. At follow-up, FFM (%) and MM (%) results were higher in the ProMoFasT group than the oral group (63.1% vs. 52.9%, p = 0.012 and 45.0% vs. 36.1%, p = 0.009, respectively) and FM (kg) and FM (%) were significantly lower in the ProMoFasT group (36.9 kg vs. 44.0 kg, p = 0.033 and 37.4% vs. 44.9%, p = 0.012, respectively). Insulin levels were lower in the ProMoFasT group than the oral group at follow-up (11.8 mU/L vs. 28.0 mU/L, p = 0.001, respectively). CONCLUSION The ProMoFasT is more effective in improving body composition and glucometabolic markers than the same diet administered orally.
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Affiliation(s)
- Elena Formisano
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy (P.G.)
- Dietetics and Clinical Nutrition Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Irene Schiavetti
- Department of Health Sciences, Section of Biostatistics, University of Genova, 16132 Genova, Italy
| | - Raffaella Gradaschi
- Dietetics and Clinical Nutrition Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Paolo Gardella
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy (P.G.)
| | - Carlotta Romeo
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy (P.G.)
| | - Livia Pisciotta
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy (P.G.)
- Dietetics and Clinical Nutrition Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Samir Giuseppe Sukkar
- Dietetics and Clinical Nutrition Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
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Yavanoglu Atay F, Bozkurt O, Sahin S, Bidev D, Sari FN, Uras N. A Comparison of Slow Infusion Intermittent Feeding versus Gravity Feeding in Preterm Infants: A Randomized Controlled Trial. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1389. [PMID: 37628387 PMCID: PMC10453490 DOI: 10.3390/children10081389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/01/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
BACKGROUND The transition to full enteral feeding is important for ensuring adequate growth in preterm infants. AIMS The aim of this study was to investigate the effects of two different intermittent feeding methods on the transition to full enteral feeding in preterm infants. STUDY DESIGN A prospective, randomized controlled study was conducted in a neonatology and perinatology center. SUBJECTS Preterm infants with a gestational age between 24 + 0/7 and 31 + 6/7 were included in this study. They were divided into two groups: the SIF (slow infusion feeding) group and the IBF (intermittent bolus feeding) group. In the SIF group, feed volumes were administered over one hour using an infusion pump through an orogastric tube, with feeding occurring every three hours. The IBF group received enteral feeding using a gravity-based technique with a syringe through an orogastric tube, completed within 10 to 30 min. OUTCOME MEASURES The primary outcome was the achievement of full enteral feeding and the occurrence of feeding intolerance. RESULTS A total of 103 infants were enrolled in the study (50 in SIF and 53 in IBF). The time to achieve full enteral feeding did not differ significantly between the two groups (p = 0.20). The SIF group had significantly fewer occurrences in which gastric residual volume exceeded 50% (p = 0.01). Moreover, the SIF group had a significantly shorter duration of non-per-oral (NPO) status than the IBF group (p = 0.03). CONCLUSIONS It is our contention that the use of the SIF method as an alternative feeding method is appropriate for infants with feeding intolerance and those at high risk of feeding intolerance.
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Affiliation(s)
- Funda Yavanoglu Atay
- Department of Pediatrics, Division of Neonatology, Umraniye Training and Research Hospital, 34764 Istanbul, Türkiye
| | - Ozlem Bozkurt
- Department of Pediatrics, Division of Neonatology, Faculty of Medicine, Kocaeli University, 41380 Izmit, Türkiye
| | - Suzan Sahin
- Department of Pediatrics, Division of Neonatology, Buca Seyfi Demirsoy Training and Research Hospital, Izmir Democracy University, 35140 Izmir, Türkiye
| | - Duygu Bidev
- Neonatal Care Intensive Unit, Koru Sincan Hospital, 06934 Ankara, Türkiye
| | - Fatma Nur Sari
- Department of Pediatrics, Division of Neonatology, Ankara City Hospital, 06800 Ankara, Türkiye
| | - Nurdan Uras
- Department of Pediatrics, Division of Neonatology, Faculty of Medicine, Istinye University, 34517 Istanbul, Türkiye
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Christiansen LI, Ventura GC, Holmqvist B, Aasmul-Olsen K, Lindholm SEH, Lycas MD, Mori Y, Secher JBM, Burrin DG, Thymann T, Sangild PT, Pankratova S. Insulin-like growth factor 1 supplementation supports motor coordination and affects myelination in preterm pigs. Front Neurosci 2023; 17:1205819. [PMID: 37404461 PMCID: PMC10315495 DOI: 10.3389/fnins.2023.1205819] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/23/2023] [Indexed: 07/06/2023] Open
Abstract
Introduction Preterm infants have increased risk of impaired neurodevelopment to which reduced systemic levels of insulin-like growth factor 1 (IGF-1) in the weeks after birth may play a role. Hence, we hypothesized that postnatal IGF-1 supplementation would improve brain development in preterm pigs, used as a model for preterm infants. Methods Preterm pigs delivered by cesarean section received recombinant human IGF-1/IGF binding protein-3 complex (rhIGF-1/rhIGFBP-3, 2.25 mg/kg/day) or vehicle from birth to postnatal day 19. Motor function and cognition were assessed by monitoring of in-cage and open field activities, balance beam test, gait parameters, novel object recognition and operant conditioning tests. Collected brains were subject to magnetic resonance imaging (MRI), immunohistochemistry, gene expression analyses and protein synthesis measurements. Results The IGF-1 treatment increased cerebellar protein synthesis rates (both in vivo and ex vivo). Performance in the balance beam test was improved by IGF-1 but not in other neurofunctional tests. The treatment decreased total and relative caudate nucleus weights, without any effects to total brain weight or grey/white matter volumes. Supplementation with IGF-1 reduced myelination in caudate nucleus, cerebellum, and white matter regions and decreased hilar synapse formation, without effects to oligodendrocyte maturation or neuron differentiation. Gene expression analyses indicated enhanced maturation of the GABAergic system in the caudate nucleus (decreased NKCC1:KCC2 ratio) with limited effects in cerebellum or hippocampus. Conclusion Supplemental IGF-1 during the first three weeks after preterm birth may support motor function by enhancing GABAergic maturation in the caudate nucleus, despite reduced myelination. Supplemental IGF-1 may support postnatal brain development in preterm infants, but more studies are required to identify optimal treatment regimens for subgroups of very or extremely preterm infants.
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Affiliation(s)
- Line I. Christiansen
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Gemma C. Ventura
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Karoline Aasmul-Olsen
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Sandy E. H. Lindholm
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Matthew D. Lycas
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jan Bojsen-Møller Secher
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Douglas G. Burrin
- United States Department of Agriculture, Agricultural Research Service Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Thomas Thymann
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Per T. Sangild
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Department of Neonatology, Rigshospitalet, Copenhagen, Denmark
- Department of Pediatrics, Odense University Hospital, Odense, Denmark
- Faculty of Theology, University of Copenhagen, Copenhagen, Denmark
| | - Stanislava Pankratova
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animals Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Rudar M, Suryawan A, Nguyen HV, Chacko SK, Vonderohe C, Stoll B, Burrin DG, Fiorotto ML, Davis TA. Regulation of skeletal muscle protein synthesis in the preterm pig by intermittent leucine pulses during continuous parenteral feeding. JPEN J Parenter Enteral Nutr 2023; 47:276-286. [PMID: 36128996 PMCID: PMC10621874 DOI: 10.1002/jpen.2450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/31/2022] [Accepted: 09/15/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Extrauterine growth restriction is a common complication of preterm birth. Leucine (Leu) is an agonist for the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) signaling pathway that regulates translation initiation and protein synthesis in skeletal muscle. Previously, we showed that intermittent intravenous pulses of Leu to neonatal pigs born at term receiving continuous enteral nutrition increases muscle protein synthesis and lean mass accretion. Our objective was to determine the impact of intermittent intravenous pulses of Leu on muscle protein anabolism in preterm neonatal pigs administered continuous parenteral nutrition. METHODS Following preterm delivery (on day 105 of 115 gestation), pigs were fitted with umbilical artery and jugular vein catheters and provided continuous parenteral nutrition. Four days after birth, pigs were assigned to receive intermittent Leu (1600 µmol kg-1 h-1 ; n = 8) or alanine (1600 µmol kg-1 h-1 ; n = 8) parenteral pulses every 4 h for 28 h. Anabolic signaling and fractional protein synthesis were determined in skeletal muscle. RESULTS Leu concentration in the longissimus dorsi and gastrocnemius muscles increased in the leucine (LEU) group compared with the alanine (ALA) group (P < 0.0001). Despite the Leu-induced disruption of the Sestrin2·GATOR2 complex, which inhibits mTORC1 activation, in these muscles (P < 0.01), the abundance of mTOR·RagA and mTOR·RagC was not different. Accordingly, mTORC1-dependent activation of 4EBP1, S6K1, eIF4E·eIF4G, and protein synthesis were not different in any muscle between the LEU and ALA groups. CONCLUSION Intermittent pulses of Leu do not enhance muscle protein anabolism in preterm pigs supplied continuous parenteral nutrition.
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Affiliation(s)
- Marko Rudar
- Department of Animal Sciences, Auburn University, Auburn, Alabama, USA
| | - Agus Suryawan
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Hanh V. Nguyen
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Shaji K. Chacko
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Caitlin Vonderohe
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Barbara Stoll
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Douglas G. Burrin
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Marta L. Fiorotto
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
| | - Teresa A. Davis
- USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA
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Rudar M, Naberhuis JK, Suryawan A, Nguyen HV, Fiorotto ML, Davis TA. Prematurity blunts protein synthesis in skeletal muscle independently of body weight in neonatal pigs. Pediatr Res 2023:10.1038/s41390-022-02456-3. [PMID: 36627358 DOI: 10.1038/s41390-022-02456-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 11/30/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Postnatal growth failure in premature infants is associated with reduced lean mass accretion. Prematurity impairs the feeding-induced stimulation of translation initiation and protein synthesis in the skeletal muscle of neonatal pigs. The objective was to determine whether body weight independently contributes to the blunted postprandial protein synthesis. METHODS Preterm and term pigs that were either fasted or fed were stratified into quartiles according to birth weight to yield preterm and term groups of similar body weight; first and second quartiles of preterm pigs and third and fourth quartiles of term pigs were compared (preterm-fasted, n = 23; preterm-fed, n = 25; term-fasted, n = 21; term-fed, n = 21). Protein synthesis rates and mechanistic target of rapamycin complex 1 (mTORC1) activation in skeletal muscle were determined. RESULTS Relative body weight gain was lower in preterm compared to term pigs. Prematurity attenuated the feeding-induced increase in mTORC1 activation in longissimus dorsi and gastrocnemius muscles (P < 0.05). Protein synthesis in gastrocnemius (P < 0.01), but not in longissimus dorsi muscle, was blunted by preterm birth. CONCLUSION A lower capacity of skeletal muscle to respond adequately to feeding may contribute to reduced body weight gain and lean mass accretion in preterm infants. IMPACT This study has shown that the feeding-induced increase in protein synthesis of skeletal and cardiac muscle is blunted in neonatal pigs born preterm compared to pigs born at term independently of birth weight. These findings support the notion that preterm birth, and not low birth weight, impairs the capacity of skeletal and cardiac muscle to upregulate mechanistic target of rapamycin-dependent anabolic signaling pathways and protein synthesis in response to the postprandial increase in insulin and amino acids. These observations suggest that a blunted anabolic response to feeding contributes to reduced lean mass accretion and altered body composition in preterm infants.
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Affiliation(s)
- Marko Rudar
- Department of Animal Sciences, Auburn University, Auburn, AL, USA
| | - Jane K Naberhuis
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Agus Suryawan
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Hanh V Nguyen
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Marta L Fiorotto
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Teresa A Davis
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
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Holgersen K, Rasmussen MB, Carey G, Burrin DG, Thymann T, Sangild PT. Clinical outcome and gut development after insulin-like growth factor-1 supplementation to preterm pigs. Front Pediatr 2022; 10:868911. [PMID: 35989990 PMCID: PMC9389362 DOI: 10.3389/fped.2022.868911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Elevation of circulating insulin-like growth factor-1 (IGF-1) within normal physiological levels may alleviate several morbidities in preterm infants but safety and efficacy remain unclear. We hypothesized that IGF-1 supplementation during the first 1-2 weeks after preterm birth improves clinical outcomes and gut development, using preterm pigs as a model for infants. METHODS Preterm pigs were given vehicle or recombinant human IGF-1/binding protein-3 (rhIGF-1, 2.25 mg/kg/d) by subcutaneous injections for 8 days (Experiment 1, n = 34), or by systemic infusion for 4 days (Experiment 2, n = 19), before collection of blood and organs for analyses. RESULTS In both experiments, rhIGF-1 treatment increased plasma IGF-1 levels 3-4 fold, reaching the values reported for term suckling piglets. In Experiment 1, rhIGF-1 treatment increased spleen and intestinal weights without affecting clinical outcomes like growth, blood biochemistry (except increased sodium and gamma-glutamyltransferase levels), hematology (e.g., red and white blood cell populations), glucose homeostasis (e.g., basal and glucose-stimulated insulin and glucose levels) or systemic immunity variables (e.g., T cell subsets, neutrophil phagocytosis, LPS stimulation, bacterial translocation to bone marrow). The rhIGF-1 treatment increased gut protein synthesis (+11%, p < 0.05) and reduced the combined incidence of all-cause mortality and severe necrotizing enterocolitis (NEC, p < 0.05), but had limited effects on intestinal morphology, cell proliferation, cell apoptosis, brush-border enzyme activities, permeability and levels of cytokines (IL-1β, IL-6, IL-8). In Experiment 2, rhIGF-1 treated pigs had reduced blood creatine kinase, creatinine, potassium and aspartate aminotransferase levels, with no effects on organ weights (except increased spleen weight), blood chemistry values, clinical variables or NEC. CONCLUSION Physiological elevation of systemic IGF-1 levels for 8 days after preterm birth increased intestinal weight and protein synthesis, spleen weight and potential overall viability of pigs, without any apparent negative effects on recorded clinical parameters. The results add further preclinical support for safety and efficacy of supplemental IGF-1 to hospitalized very preterm infants.
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Affiliation(s)
- Kristine Holgersen
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Martin Bo Rasmussen
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Douglas G Burrin
- Department of Pediatrics, United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, United States
| | - Thomas Thymann
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Per Torp Sangild
- Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.,Department of Neonatology, Rigshospitalet, Copenhagen, Denmark.,Department of Pediatrics, Odense University Hospital, Odense, Denmark
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