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Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [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] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
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Affiliation(s)
- Eszter Szabo
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Balint Nagy
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Andras Czajlik
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Timea Komlodi
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Oliver Ozohanics
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Laszlo Tretter
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Semmelweis University, Budapest, Hungary.
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2
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Price SR, Mitch WE, Garibotto G. Muscle Atrophy in CKD: A Historical Perspective of Advancements in Its Understanding. J Ren Nutr 2023; 33:S88-S92. [PMID: 36183901 DOI: 10.1053/j.jrn.2022.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/21/2022] [Accepted: 09/21/2022] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE This perspective reviews the seminal clinical and experimental observations that led to today's current mechanistic model of muscle protein loss (wasting) in patients with chronic kidney disease (CKD). RESULTS AND CONCLUSION Early International Society of Renal Nutrition and Metabolism (ISRNM) meetings facilitated discussions and hypotheses about the causes of muscle wasting in CKD. It became widely recognized that wasting is common and correlated with increased risks of mortality and morbidity. Although anorexia and dietary restrictions contribute to muscle loss, several features of CKD-associated wasting cannot be explained by malnutrition alone. The protein catabolism-inducing actions of metabolic acidosis, inflammation, insulin resistance, endocrine disorders and uremic toxins were progressively identified. Continued research to understand the interactions of inflammation, anabolic resistance, mitochondrial dysfunction, exercise, and nutrition on muscle protein turnover in patients with CKD will hopefully accelerate discoveries and treatments to ameliorate muscle wasting as well as the progression of CKD.
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Affiliation(s)
- S Russ Price
- Department of Biochemistry & Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina; Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, North Carolina.
| | - William E Mitch
- Nephrology Division, Department of Medicine, Baylor College of Medicine, Houston, Texas
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3
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Gervasini G, Verde Z, González LM, Chicharro C, González-Rodríguez L, Fernández-Araque A, Mota-Zamorano S, Cancho B, Pérez-Hernández A, García-López V, Bandrés F, Robles NR. Prognostic Significance of Amino Acid and Biogenic Amines Profiling in Chronic Kidney Disease. Biomedicines 2023; 11:2775. [PMID: 37893147 PMCID: PMC10604890 DOI: 10.3390/biomedicines11102775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/23/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
There is a pressing need for more precise biomarkers of chronic kidney disease (CKD). Plasma samples from 820 subjects [231 with CKD, 325 with end-stage kidney disease (ESKD) and 264 controls] were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) to determine a metabolic profile of 28 amino acids (AAs) and biogenic amines to test their value as markers of CKD risk and progression. The kynurenine/tryptophan ratio showed the strongest correlation with estimated glomerular filtration rate values (coefficient = -0.731, p < 0.0001). Models created with orthogonal partial least squares-discriminant analysis (OPLS-DA) containing the metabolic signature showed a high goodness of fit and predictability for controls/CKD (R2X:0.73:R2Y:0.92:Q2:0.92, p < 0.0001) and lower values for CKD/ESKD (R2X:0.56:R2Y:0.59:Q2:0.55, p < 0.0001). Based on generated VIP scores, the most relevant markers for segregating samples into control/CKD and CKD/ESKD groups were citrulline (1.63) and tryptophan (1.47), respectively. ROC analysis showed that the addition of the metabolic profile to a model including CKD classic risk factors improved the AUC from 86.7% (83.6-89.9) to 100% (100-100) for CKD risk (p < 0.0001) and from 63.0% (58.2-67.8) to 96.5% (95.3-97.8) for the risk of progression from CKD to ESKD (p < 0.0001). Plasma concentrations of AAs and related amines may be useful as diagnostic biomarkers of kidney disease, both for CKD risk and for progression of CKD patients to ESKD.
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Affiliation(s)
- Guillermo Gervasini
- Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, 06006 Badajoz, Spain; (L.M.G.); (L.G.-R.); (S.M.-Z.); (V.G.-L.)
- Institute of Molecular Pathology Biomarkers, University of Extremadura, 06006 Badajoz, Spain
- RICORS2040 Renal Research Network, 28029 Madrid, Spain;
| | - Zoraida Verde
- Department of Biochemistry, Molecular Biology and Physiology, Universidad de Valladolid, 42005 Soria, Spain;
- GIR—Pharmacogenetics, Cancer Genetics, Genetic Polymorphisms and Pharmacoepidemiology, University of Valladolid, 47005 Valladolid, Spain;
- Research Group Centro de Estudios Gregorio Marañón, Fundación Ortega-Marañón, 28010 Madrid, Spain; (C.C.); (F.B.)
| | - Luz M. González
- Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, 06006 Badajoz, Spain; (L.M.G.); (L.G.-R.); (S.M.-Z.); (V.G.-L.)
| | - Celia Chicharro
- Research Group Centro de Estudios Gregorio Marañón, Fundación Ortega-Marañón, 28010 Madrid, Spain; (C.C.); (F.B.)
- Biopathology-Toxicology Laboratory, Department of Legal Medicine, Psychiatry and Pathology, Faculty of Medicine, University Complutense of Madrid, 28040 Madrid, Spain
| | - Laura González-Rodríguez
- Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, 06006 Badajoz, Spain; (L.M.G.); (L.G.-R.); (S.M.-Z.); (V.G.-L.)
- RICORS2040 Renal Research Network, 28029 Madrid, Spain;
| | - Ana Fernández-Araque
- GIR—Pharmacogenetics, Cancer Genetics, Genetic Polymorphisms and Pharmacoepidemiology, University of Valladolid, 47005 Valladolid, Spain;
- Department of Nursery, University of Valladolid, 42005 Soria, Spain
| | - Sonia Mota-Zamorano
- Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, 06006 Badajoz, Spain; (L.M.G.); (L.G.-R.); (S.M.-Z.); (V.G.-L.)
| | - Bárbara Cancho
- Service of Nephrology, Badajoz University Hospital, 06006 Badajoz, Spain;
| | | | - Virginio García-López
- Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, 06006 Badajoz, Spain; (L.M.G.); (L.G.-R.); (S.M.-Z.); (V.G.-L.)
| | - Fernando Bandrés
- Research Group Centro de Estudios Gregorio Marañón, Fundación Ortega-Marañón, 28010 Madrid, Spain; (C.C.); (F.B.)
- Biopathology-Toxicology Laboratory, Department of Legal Medicine, Psychiatry and Pathology, Faculty of Medicine, University Complutense of Madrid, 28040 Madrid, Spain
| | - Nicolás R. Robles
- RICORS2040 Renal Research Network, 28029 Madrid, Spain;
- Service of Nephrology, Badajoz University Hospital, 06006 Badajoz, Spain;
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Dahabiyeh LA, Nimer RM, Sumaily KM, Alabdaljabar MS, Jacob M, Sabi EM, Hussein MH, Abdel Rahman A. Metabolomics profiling distinctively identified end-stage renal disease patients from chronic kidney disease patients. Sci Rep 2023; 13:6161. [PMID: 37061630 PMCID: PMC10105740 DOI: 10.1038/s41598-023-33377-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 04/12/2023] [Indexed: 04/17/2023] Open
Abstract
Chronic kidney disease (CKD) is a serious public health problem characterized by progressive kidney function loss leading to end-stage renal disease (ESRD) that demands dialysis or kidney transplantation. Early detection can prevent or delay progression to ESRD. The study aimed to gain new insights into the perturbed biochemical reactions and to identify novel distinct biomarkers between ESRD and CKD. Serum samples of 32 patients with ESRD (n = 13) and CKD (n = 19) were analyzed using chemical isotope labeling liquid chromatography-mass spectrometry metabolomics approach. A total of 193 metabolites were significantly altered in ESRD compared to CKD and were mainly involved in aminoacyl-tRNA biosynthesis, branched-chain amino acid (BCAA) biosynthesis, taurine metabolism, and tryptophan metabolism. Three kynurenine derivatives, namely, 2-aminobenzoic acid, xanthurenic acid, and hydroxypicolinic acid were upregulated in ESRD compared to CKD due to the significant decrease in glomerular filtration rate with the progression of CKD to ESRD. N-Hydroxy-isoleucine, 2-aminobenzoic acid, and picolinic acid yielded AUC > 0.99 when analyzed using Receiver Operating Characteristic (ROC) analysis. Our findings suggest that inhibiting the kynurenine pathway might be a promising target to delay CKD progression and that metabolites with high discriminative ability might serve as potential prognostic biomarkers to monitor the progression of CKD to ESRD or used in combination with current markers to indicate the status of kidney damage better.
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Affiliation(s)
- Lina A Dahabiyeh
- Division of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, 11942, Jordan
| | - Refat M Nimer
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Khalid M Sumaily
- Clinical Biochemistry Unit, Pathology Department, College of Medicine, King Saud University, Riyadh, 11461, Saudi Arabia
- Clinical Biochemistry Unit, Laboratory Medicine, King Saud University Medical City, King Saud University, Riyadh, 11461, Saudi Arabia
| | - Mohamad S Alabdaljabar
- Metabolomics Section, Department of Clinical Genomics, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre (KFSHRC), Riyadh, 11211, Saudi Arabia
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, 55902, USA
| | - Minnie Jacob
- Metabolomics Section, Department of Clinical Genomics, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre (KFSHRC), Riyadh, 11211, Saudi Arabia
| | - Essa M Sabi
- Clinical Biochemistry Unit, Pathology Department, College of Medicine, King Saud University, Riyadh, 11461, Saudi Arabia
| | - Maged H Hussein
- Department of Medicine, King Faisal Specialist Hospital and Research Centre (KFSHRC), Riyadh, 11211, Saudi Arabia
| | - Anas Abdel Rahman
- Metabolomics Section, Department of Clinical Genomics, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre (KFSHRC), Riyadh, 11211, Saudi Arabia.
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, 11533, Saudi Arabia.
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5
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Ho JQ, Abramowitz MK. Clinical Consequences of Metabolic Acidosis-Muscle. Adv Chronic Kidney Dis 2022; 29:395-405. [PMID: 36175077 DOI: 10.1053/j.ackd.2022.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 04/10/2022] [Accepted: 04/25/2022] [Indexed: 01/25/2023]
Abstract
Metabolic acidosis is common in people with chronic kidney disease and can contribute to functional decline, morbidity, and mortality. One avenue through which metabolic acidosis can result in these adverse clinical outcomes is by negatively impacting skeletal muscle; this can occur through several pathways. First, metabolic acidosis promotes protein degradation and impairs protein synthesis, which lead to muscle breakdown. Second, metabolic acidosis hinders mitochondrial function, which decreases oxidative phosphorylation and reduces energy production. Third, metabolic acidosis directly limits muscle contraction. The purpose of this review is to examine the specific mechanisms of each pathway through which metabolic acidosis affects muscle, the impact of metabolic acidosis on physical function, and the effect of treating metabolic acidosis on functional outcomes.
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Affiliation(s)
- Jim Q Ho
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Matthew K Abramowitz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY; Fleischer Institute for Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, NY.
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6
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Dimou A, Tsimihodimos V, Bairaktari E. The Critical Role of the Branched Chain Amino Acids (BCAAs) Catabolism-Regulating Enzymes, Branched-Chain Aminotransferase (BCAT) and Branched-Chain α-Keto Acid Dehydrogenase (BCKD), in Human Pathophysiology. Int J Mol Sci 2022; 23:ijms23074022. [PMID: 35409380 PMCID: PMC8999875 DOI: 10.3390/ijms23074022] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 12/26/2022] Open
Abstract
Branched chain amino acids (BCAAs), leucine, isoleucine and valine, are essential amino acids widely studied for their crucial role in the regulation of protein synthesis mainly through the activation of the mTOR signaling pathway and their emerging recognition as players in the regulation of various physiological and metabolic processes, such as glucose homeostasis. BCAA supplementation is primarily used as a beneficial nutritional intervention in chronic liver and kidney disease as well as in muscle wasting disorders. However, downregulated/upregulated plasma BCAAs and their defective catabolism in various tissues, mainly due to altered enzymatic activity of the first two enzymes in their catabolic pathway, BCAA aminotransferase (BCAT) and branched-chain α-keto acid dehydrogenase (BCKD), have been investigated in many nutritional and disease states. The current review focused on the underlying mechanisms of altered BCAA catabolism and its contribution to the pathogenesis of a numerous pathological conditions such as diabetes, heart failure and cancer. In addition, we summarize findings that indicate that the recovery of the dysregulated BCAA catabolism may be associated with an improved outcome and the prevention of serious disease complications.
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Affiliation(s)
- Aikaterini Dimou
- Laboratory of Clinical Chemistry, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
| | - Vasilis Tsimihodimos
- Department of Internal Medicine, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
| | - Eleni Bairaktari
- Laboratory of Clinical Chemistry, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
- Correspondence: ; Tel.: +30-26510-07620
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7
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Mann G, Mora S, Madu G, Adegoke OAJ. Branched-chain Amino Acids: Catabolism in Skeletal Muscle and Implications for Muscle and Whole-body Metabolism. Front Physiol 2021; 12:702826. [PMID: 34354601 PMCID: PMC8329528 DOI: 10.3389/fphys.2021.702826] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
Branched-chain amino acids (BCAAs) are critical for skeletal muscle and whole-body anabolism and energy homeostasis. They also serve as signaling molecules, for example, being able to activate mammalian/mechanistic target of rapamycin complex 1 (mTORC1). This has implication for macronutrient metabolism. However, elevated circulating levels of BCAAs and of their ketoacids as well as impaired catabolism of these amino acids (AAs) are implicated in the development of insulin resistance and its sequelae, including type 2 diabetes, cardiovascular disease, and of some cancers, although other studies indicate supplements of these AAs may help in the management of some chronic diseases. Here, we first reviewed the catabolism of these AAs especially in skeletal muscle as this tissue contributes the most to whole body disposal of the BCAA. We then reviewed emerging mechanisms of control of enzymes involved in regulating BCAA catabolism. Such mechanisms include regulation of their abundance by microRNA and by post translational modifications such as phosphorylation, acetylation, and ubiquitination. We also reviewed implications of impaired metabolism of BCAA for muscle and whole-body metabolism. We comment on outstanding questions in the regulation of catabolism of these AAs, including regulation of the abundance and post-transcriptional/post-translational modification of enzymes that regulate BCAA catabolism, as well the impact of circadian rhythm, age and mTORC1 on these enzymes. Answers to such questions may facilitate emergence of treatment/management options that can help patients suffering from chronic diseases linked to impaired metabolism of the BCAAs.
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Affiliation(s)
| | | | | | - Olasunkanmi A. J. Adegoke
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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8
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Ottka C, Vapalahti K, Määttä A, Huuskonen N, Sarpanen S, Jalkanen L, Lohi H. High serum creatinine concentration is associated with metabolic perturbations in dogs. J Vet Intern Med 2021; 35:405-414. [PMID: 33349961 PMCID: PMC7848334 DOI: 10.1111/jvim.16011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/08/2020] [Accepted: 12/08/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The kidneys have many essential metabolic functions, and metabolic disturbances during decreased renal function have not been studied extensively. OBJECTIVES To identify metabolic changes in blood samples with increased serum creatinine concentration, indicating decreased glomerular filtration. ANIMALS Clinical samples analyzed using a nuclear magnetic resonance (NMR) based metabolomics platform. The case group consisted of 23 samples with serum creatinine concentration >125 μmol/L, and the control group of 873 samples with serum creatinine concentration within the reference interval. METHODS Biomarker association with increased serum creatinine concentration was evaluated utilizing 3 statistical approaches: Wilcoxon rank-sum test, logistic regression analysis (false discovery rate (FDR)-corrected P-values), and random forest classification. Medians of the biomarkers were compared to reference intervals. A heatmap and box plots were used to represent the differences. RESULTS All 3 statistical approaches identified similar analytes associated with increased serum creatinine concentrations. The percentages of citrate, tyrosine, branched-chain amino acids, valine, leucine, albumin, linoleic acid and the ratio of phenylalanine to tyrosine differed significantly using all statistical approaches, acetate differed using the Wilcoxon test and random forest, docosapentaenoic acid percentage only using logistic regression (P < .05), and alanine only using random forest. CONCLUSIONS AND CLINICAL IMPORTANCE We identified several metabolic changes associated with increased serum creatinine concentrations, including prospective diagnostic markers and therapeutic targets. Further research is needed to verify the association of these changes with the clinical state of the dog. The NMR metabolomics test is a promising tool for improving diagnostic testing and management of renal diseases in dogs.
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Affiliation(s)
- Claudia Ottka
- PetMeta Labs LtdHelsinkiFinland
- Department of Veterinary BiosciencesUniversity of HelsinkiHelsinkiFinland
- Department of Medical and Clinical GeneticsUniversity of HelsinkiHelsinkiFinland
- Folkhälsan Research CenterHelsinkiFinland
| | - Katariina Vapalahti
- PetMeta Labs LtdHelsinkiFinland
- Department of Veterinary BiosciencesUniversity of HelsinkiHelsinkiFinland
- Department of Medical and Clinical GeneticsUniversity of HelsinkiHelsinkiFinland
- Folkhälsan Research CenterHelsinkiFinland
| | | | | | | | | | - Hannes Lohi
- PetMeta Labs LtdHelsinkiFinland
- Department of Veterinary BiosciencesUniversity of HelsinkiHelsinkiFinland
- Department of Medical and Clinical GeneticsUniversity of HelsinkiHelsinkiFinland
- Folkhälsan Research CenterHelsinkiFinland
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9
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Feriani M. Bicarbonate-Buffered Capd Solutions: From Clinical Trials to Clinical Practice. Perit Dial Int 2020. [DOI: 10.1177/089686089701702s10] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Mariano Feriani
- Department of Nephrology, St. Bortolo Hospital, Vicenza, Italy
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10
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Park MS, Heimbürger O, Bergström J, Waniewski J, Werynski A, Lindholm B. Peritoneal Transport during Dialysis with Amino Acid-Based Solutions. Perit Dial Int 2020. [DOI: 10.1177/089686089301300404] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective To evaluate the potential clinical role of amino acids as an osmotic agent. Design The peritoneal transport of fluid, amino acids, and other solutes was investigated during a 6–hour single-cycle peritoneal dialysis with PDA 1% versus 1.36% glucose (n=6) or PDA 2.7% versus 3.86% glucose solution (n=9). Patients Fifteen stable nondiabetic continuous ambulatory peritoneal dialysis (CAPD) patients. Results The fractional absorption of the osmotic agents at 6 hours was higher with PDA 2.7% versus glucose 3.86% (p<0.005). The diffusive mass transport coefficient, KeD’ calculated for a period of dialysate isovolemia was higher with PDA 2.7% versus PDA 1% for essential, nonessential (p<0.005), and total (p<0.05) amino acids. The intraperitoneal volume-over-time curves and KqD values for urea, creatinine, glucose, albumin, β2microglobulin, and total protein did not differ between the amino acid solutions and the corresponding glucose solutions. KeD for urea was significantly higher during the dwell with PDA 2.7% versus PDA 1% (p<0.05). Plasma amino acid concentrations increased substantially during the first 1– 2 hours and then decreased gradually. Valine and methionine rose to 792% and 1119% of baseline values, respectively. Conclusions We conclude that the peritoneal transport of fluid and investigated solutes, except amino acids, was not different with the amino acid solutions compared with the corresponding equimolar glucose solutions. However, ultrafiltration tended to be lower with amino acid solutions. Furthermore, the fractional absorption of amino acids and KeD values for amino acids was higher with PDA 2.7% versus PDA 1 %, suggesting an effect of the hypertonic amino acid solution on the peritoneal membrane transport properties. Also, the hypertonic PDA2.7% solution yielded nonphysiologically high plasma levels of several amino acids. We therefore consider this solution not to be safe enough for long term clinical use.”
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Affiliation(s)
- Min Sun Park
- Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
- Hyonam Kidney Laboratory, Soon Chun Hyang University, Seoul, Korea,
| | - Olof Heimbürger
- Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
| | - Jonas Bergström
- Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
| | - Jacek Waniewski
- Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Andrzej Werynski
- Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Bengt Lindholm
- Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
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11
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Lameire N, Faict D. Peritoneal Dialysis Solutions Containing Glycerol and Amino Acids. Perit Dial Int 2020. [DOI: 10.1177/089686089401403s26] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- N. Lameire
- University Hospital, Renal Division, Gent
| | - D. Faict
- Baxter Renal R & D Europe, Nivelles, Belgium
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12
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Wang T, Heimbürger O, Bergström J, Lindholm B. Nutritional Problems in Peritoneal Dialysis: An Overview. Perit Dial Int 2020. [DOI: 10.1177/089686089901902s50] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Tao Wang
- Divisions of Baxter Novum and Renal Medicine, Department of Clinical Science, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
- National Institute of Kidney, Sun Yat-sen University of Medical Sciences, Guangzhou, P. R. China
| | - Olof Heimbürger
- Divisions of Baxter Novum and Renal Medicine, Department of Clinical Science, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
| | - Jonas Bergström
- Divisions of Baxter Novum and Renal Medicine, Department of Clinical Science, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
| | - Bengt Lindholm
- Divisions of Baxter Novum and Renal Medicine, Department of Clinical Science, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
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13
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Feriani M. Adequacy of Acid Base Correction in Continuous Ambulatory Peritoneal Dialysis Patients. Perit Dial Int 2020. [DOI: 10.1177/089686089401403s24] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Mariano Feriani
- Department of Nephrology, St. Bortolo Hospital, Vicenza, Italy
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14
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Hsiung JT, Kleine CE, Naderi N, Park C, Soohoo M, Moradi H, Rhee CM, Obi Y, Kopple JD, Kovesdy CP, Kalantar-Zadeh K, Streja E. Association of Pre-End-Stage Renal Disease Serum Albumin With Post-End-Stage Renal Disease Outcomes Among Patients Transitioning to Dialysis. J Ren Nutr 2019; 29:310-321. [PMID: 30642656 DOI: 10.1053/j.jrn.2018.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/23/2018] [Accepted: 09/24/2018] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Serum albumin is a marker of malnutrition and inflammation and has been demonstrated as a strong predictor of mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. Yet, whether serum albumin levels in late-stage CKD are associated with adverse outcomes after the transition to ESRD is unknown. We hypothesize that lower levels and a decline in serum albumin in late-stage CKD are associated with higher risk of mortality and hospitalization rates 1 year after transition to ESRD. DESIGN AND METHODS This retrospective cohort study included 29,124 US veterans with advanced CKD transitioning to ESRD between 2007 and 2015. We evaluated the association of pre-ESRD (91 days before transition) serum albumin with 12-month post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates as well as the association of 1-year pre-ESRD albumin slope and 12-month post-ESRD mortality using hierarchical multivariable adjustments. RESULTS There was a negative linear association between serum albumin and all-cause mortality, such that risk doubled (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.87, 2.28) for patients with the lowest serum albumin <2.8 g/dL (ref: ≥4.0 g/dL) after full adjustment. A consistent relationship was observed between serum albumin and cardiovascular and infection-related mortality, and hospitalization outcomes. An increase in serum albumin of >0.25 g/dL/year was associated with reduced mortality risk (HR: 0.76, 95% CI: 0.63, 0.91) compared with a slight decline in albumin (ref: >-0.25 to 0 g/dL/year), whereas a decline more than 0.5 g/dL/year was associated with a 55% higher risk in mortality (HR: 1.55, 95% CI: 1.43, 1.68) in fully adjusted models. CONCLUSIONS Lower pre-ESRD serum albumin was associated with higher post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates. Declining serum albumin levels in the pre-ESRD period were also associated with worse 12-month post-ESRD mortality.
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Affiliation(s)
- Jui-Ting Hsiung
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California
| | - Carola-Ellen Kleine
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California
| | - Neda Naderi
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Department of Internal Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Christina Park
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California
| | - Melissa Soohoo
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California
| | - Hamid Moradi
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California
| | - Connie M Rhee
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California
| | - Yoshitsugu Obi
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California
| | - Joel D Kopple
- Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California; UCLA Fielding School of Public Health, Los Angeles, California
| | - Csaba P Kovesdy
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, Tennessee; Nephrology Section, Memphis VA Medical Center, Memphis, Tennessee
| | - Kamyar Kalantar-Zadeh
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California; UCLA Fielding School of Public Health, Los Angeles, California
| | - Elani Streja
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, Department of Medicine, University of California Irvine, School of Medicine, Orange, California; Nephrology Section, Tibor Rubin VA Medical Center, Long Beach, California.
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15
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Zheng CM, Wu CC, Lu CL, Hou YC, Wu MS, Hsu YH, Chen R, Chang TJ, Shyu JF, Lin YF, Lu KC. Hypoalbuminemia differently affects the serum bone turnover markers in hemodialysis patients. Int J Med Sci 2019; 16:1583-1592. [PMID: 31839746 PMCID: PMC6909808 DOI: 10.7150/ijms.39158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/03/2019] [Indexed: 12/20/2022] Open
Abstract
Renal osteodystrophy (ROD) represents bone disorders related to chronic kidney disease (CKD) and several bone biomarkers are used clinically to predict ROD in CKD and hemodialysis (HD) patients. Serum albumin associates with inflammation other than nutritional status in these patients. Chronic inflammation is proved to relate with bone loss, however, the influence of hypoalbuminemia on bone biomarkers is still unclear. In this study, we evaluated the pattern of bone biomarker changes and further studied the influence of hypoalbuminemia on these biomarkers. A total of 300 maintenance HD patients were evaluated and 223 HD patients were included in the study. The patients were grouped according to serum parathyroid hormone (PTH) levels (PTH ≤150 pg/mL, PTH 150-300 pg/mL, PTH 300-600 pg/mL and PTH >600 pg/mL). Bone biomarkers and inflammatory markers were measured and their relation with PTH levels was determined. Significantly increased interleukin-6 (IL-6) and lower albumin levels were noted among PTH>600 pg/mL group. Bone turnover markers were significantly higher in PTH >600 pg/mL group (p< 0.05). Hypoalbuminemia significantly increased the fibroblast growth factor-23 (FGF-23) and procollagen type 1N-terminal propeptide (P1NP) in PTH ≤150 pg/mL, PTH 150-300 pg/mL, PTH 300-600 pg/mL groups, whereas no such relation was noted among PTH> 600 ng/dL group. In conclusion, hypoalbuminemia represents a chronic inflammation which differently relates to bone turnover markers according to serum PTH levels in SHPT patients. Thus, serum albumin measurement should be considered in determining bone disorders among these patients.
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Affiliation(s)
- Cai Mei Zheng
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
| | - Chia Chao Wu
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Chien Lin Lu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Medicine, Fu Jen Catholic University Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan
| | - Yi Chou Hou
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Medicine, Cardinal-Tien Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City 23155, Taiwan
| | - Mai Szu Wu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
| | - Yung Ho Hsu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
| | - Remy Chen
- Chief, Kidney Dialysis Center, Hasuda Hospital, Negane, Hasuda City, Saitama, 3490131, Japan
| | - Tian Jong Chang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan.,Performance Appraisal Section, Secretary Office, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Jia Fwu Shyu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Department of Biology and Anatomy, National Defense Medical Center, Taipei 114, Taiwan
| | - Yuh Feng Lin
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
| | - Kuo Cheng Lu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Division of Nephrology, Department of Medicine, Fu Jen Catholic University Hospital, School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan
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16
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Holeček M. Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements. Nutr Metab (Lond) 2018; 15:33. [PMID: 29755574 PMCID: PMC5934885 DOI: 10.1186/s12986-018-0271-1] [Citation(s) in RCA: 382] [Impact Index Per Article: 63.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/18/2018] [Indexed: 02/07/2023] Open
Abstract
Branched-chain amino acids (BCAAs; valine, leucine, and isoleucine) are essential amino acids with protein anabolic properties, which have been studied in a number of muscle wasting disorders for more than 50 years. However, until today, there is no consensus regarding their therapeutic effectiveness. In the article is demonstrated that the crucial roles in BCAA metabolism play: (i) skeletal muscle as the initial site of BCAA catabolism accompanied with the release of alanine and glutamine to the blood; (ii) activity of branched-chain keto acid dehydrogenase (BCKD); and (iii) amination of branched-chain keto acids (BCKAs) to BCAAs. Enhanced consumption of BCAA for ammonia detoxification to glutamine in muscles is the cause of decreased BCAA levels in liver cirrhosis and urea cycle disorders. Increased BCKD activity is responsible for enhanced oxidation of BCAA in chronic renal failure, trauma, burn, sepsis, cancer, phenylbutyrate-treated subjects, and during exercise. Decreased BCKD activity is the main cause of increased BCAA levels and BCKAs in maple syrup urine disease, and plays a role in increased BCAA levels in diabetes type 2 and obesity. Increased BCAA concentrations during brief starvation and type 1 diabetes are explained by amination of BCKAs in visceral tissues and decreased uptake of BCAA by muscles. The studies indicate beneficial effects of BCAAs and BCKAs in therapy of chronic renal failure. New therapeutic strategies should be developed to enhance effectiveness and avoid adverse effects of BCAA on ammonia production in subjects with liver cirrhosis and urea cycle disorders. Further studies are needed to elucidate the effects of BCAA supplementation in burn, trauma, sepsis, cancer and exercise. Whether increased BCAA levels only markers are or also contribute to insulin resistance should be known before the decision is taken regarding their suitability in obese subjects and patients with type 2 diabetes. It is concluded that alterations in BCAA metabolism have been found common in a number of disease states and careful studies are needed to elucidate their therapeutic effectiveness in most indications.
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Affiliation(s)
- Milan Holeček
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
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17
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Dubé BP, Laveneziana P. Effects of aging and comorbidities on nutritional status and muscle dysfunction in patients with COPD. J Thorac Dis 2018; 10:S1355-S1366. [PMID: 29928518 DOI: 10.21037/jtd.2018.02.20] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a prevalent, complex and debilitating disease which imposes a formidable burden on patients and the healthcare system. The recognition that COPD is a multifaceted disease is not new, and increasing evidence have outlined the importance of its extra-pulmonary manifestations and its relation to other comorbid conditions in the clinical course of the disease and its societal cost. The relationship between aging, COPD and its comorbidities on skeletal muscle function and nutritional status is complex, multidirectional and incompletely understood. Despite this, the current body of knowledge allows the identification of various, seemingly partially independent factors related both to the normal aging process and to the independent deleterious effects of chronic diseases on muscle function and body composition. There is a dire need of studies evaluating the relative contribution of each of these factors, and their potential synergistic effects in patients with COPD and advanced age/comorbid conditions, in order to delineate the best course of therapeutic action in this increasingly prevalent population.
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Affiliation(s)
- Bruno-Pierre Dubé
- Département de Médecine, Service de Pneumologie, Centre Hospitalier de l'Université de Montréal (CHUM) Montréal, Québec, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) - Carrefour de l'Innovation et de l'Évaluation en Santé, Montréal, Québec, Canada
| | - Pierantonio Laveneziana
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée du Département R3S, Paris, France
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18
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Affiliation(s)
- W.E. Bloembergen
- Michigan Kidney Registry, University of Michigan, Ann Arbor
- Department of Internal Medicine, University of Michigan, Ann Arbor
| | - F.K. Port
- Michigan Kidney Registry, University of Michigan, Ann Arbor
- Department of Internal Medicine, University of Michigan, Ann Arbor
- Department of Epidemiology, University of Michigan, Ann Arbor - USA
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19
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Stosovic M, Stanojevic M, Radovic M, Simic-Ogrizovic S, Lezaic V, Naumovic R, Jovanovic D, Ristic G, Djukanovic L, Marinkovic J. Hemodialysis Modality, Percentage of Body Fat, and Patient Survival. Int J Artif Organs 2018; 32:20-30. [DOI: 10.1177/039139880903200103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background A number of studies have reported lower mortality of overweight hemodialysis patients. This post hoc analysis of an observational prospective single-center study was aimed at elucidating whether both being overweight and surviving longer could result from changes in the hemodialysis modality. Methods The study included a cohort of 242 patients who were gradually switched from cuprophane membrane and acetate dialysis to polysulfone (including high-flux) membranes and bicarbonate dialysis. The analysis involved 12 months of baseline data obtained during the first calendar year after the patients entered the study (1994–2001) and repeated measurements for up to 132 months of follow-up (until 2004). Anthropometric measurements were made during the winter season and the percentage of body fat (%fat) was calculated from triceps, biceps, subscapular, and suprailiac skinfolds (K/DOQI guidelines). Kt/V, normalized protein catabolic rate, and cardiovascular comorbidity were also determined and laboratory analyses undertaken. Results Significant correlations were found between %fat and bicarbonate dialysate as well as polysulfone membrane and high-flux membrane. The linear mixed model showed dependence of %fat on polysulfone and high-flux membrane (p<0.01) Multivariate Cox regression (time-dependent covariates) found %fat to be an independent factor for longer survival, in addition to polysulfone and high-flux membranes. Conclusion Changes in hemodialysis modality were followed by both higher body fat percentage and patient survival. The reverse epidemiology of overweight patients might be at least partially the result of the influence of nonnutritional factors, such as a change in hemodialysis modality (introducing biocompatible high-flux and low-flux membranes and bicarbonate dialysis).
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Affiliation(s)
- M. Stosovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - M. Stanojevic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - M. Radovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - S. Simic-Ogrizovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - V. Lezaic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - R. Naumovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - D. Jovanovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - G. Ristic
- Department of Nutrition, School of Medicine, University of Belgrade, Belgrade
| | - L. Djukanovic
- Department of Nephrology, University Clinical Center, School of Medicine, University of Belgrade, Belgrade
| | - J. Marinkovic
- Department of Medical Statistics and Informatics, School of Medicine, University of Belgrade, Belgrade - Serbia
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20
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Bifari F, Nisoli E. Branched-chain amino acids differently modulate catabolic and anabolic states in mammals: a pharmacological point of view. Br J Pharmacol 2017; 174:1366-1377. [PMID: 27638647 PMCID: PMC5429325 DOI: 10.1111/bph.13624] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/28/2016] [Accepted: 08/03/2016] [Indexed: 12/21/2022] Open
Abstract
Substantial evidence has been accumulated suggesting that branched-chain amino acid (BCAA) supplementation or BCAA-rich diets have a positive effect on the regulation of body weight, muscle protein synthesis, glucose homeostasis, the ageing process and extend healthspan. Despite these beneficial effects, epidemiological studies have shown that BCAA plasma concentrations and BCAA metabolism are altered in several metabolic disorders, including type 2 diabetes mellitus and cardiovascular diseases. In this review article, we present an overview of the current literature on the different effects of BCAAs in health and disease. We also highlight the results showing the most promising therapeutic effects of dietary BCAA supplementation and discuss how BCAAs can trigger different and even opposite effects, depending on the catabolic and anabolic states of the organisms. Moreover, we consider the effects of BCAAs when metabolism is abnormal, in the presence of a mixture of different anabolic and catabolic signals. These unique pharmacodynamic properties may partially explain some of the markedly different effects found in BCAA supplementation studies. To predict accurately these effects, the overall catabolic/anabolic status of patients should be carefully considered. In wider terms, a correct modulation of metabolic disorders would make nutraceutical interventions with BCAAs more effective. LINKED ARTICLES This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.
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Affiliation(s)
- Francesco Bifari
- Laboratory of Cell Metabolism and Regenerative Medicine, Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Enzo Nisoli
- Center for Study and Research on Obesity, Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
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21
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Eriguchi R, Obi Y, Rhee CM, Chou JA, Tortorici AR, Mathew AT, Kim T, Soohoo M, Streja E, Kovesdy CP, Kalantar-Zadeh K. Changes in urine volume and serum albumin in incident hemodialysis patients. Hemodial Int 2016; 21:507-518. [PMID: 27885815 DOI: 10.1111/hdi.12517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Hypoalbuminemia is a predictor of poor outcomes in dialysis patients. Among hemodialysis patients, there has not been prior study of whether residual kidney function or decline over time impacts serum albumin levels. We hypothesized that a decline in residual kidney function is associated with an increase in serum albumin levels among incident hemodialysis patients. METHODS In a large national cohort of 38,504 patients who initiated hemodialysis during 1/2007-12/2011, we examined the association of residual kidney function, ascertained by urine volume and renal urea clearance, with changes in serum albumin over five years across strata of baseline residual kidney function, race, and diabetes using case-mix adjusted linear mixed effects models. FINDINGS Serum albumin levels increased over time. At baseline, patients with greater urine volume had higher serum albumin levels: 3.44 ± 0.48, 3.50 ± 0.46, 3.57 ± 0.44, 3.59 ± 0.45, and 3.65 ± 0.46 g/dL for urine volume groups of <300, 300-<600, 600-<900, 900-<1,200, and ≥1,200 mL/day, respectively (Ptrend < 0.001). Over time, urine volume and renal urea clearance declined and serum albumin levels rose, while the baseline differences in serum albumin persisted across groups of urinary volume. In addition, the rate of decline in residual kidney function was not associated with the rate of change in albumin. DISCUSSION Hypoalbuminemia in hemodialysis patients is associated with lower residual kidney function. Among incident hemodialysis patients, there is a gradual rise in serum albumin that is independent of the rate of decline in residual kidney function, suggesting that preservation of residual kidney function does not have a deleterious impact on serum albumin levels.
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Affiliation(s)
- Rieko Eriguchi
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Yoshitsugu Obi
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Connie M Rhee
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Jason A Chou
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Amanda R Tortorici
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Anna T Mathew
- Division of Kidney Diseases and Hypertension, Hofstra Northwell School of Medicine, Great Neck, New York, USA
| | - Taehee Kim
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA.,Division of Nephrology, Inje University, Busan, Korea
| | - Melissa Soohoo
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Elani Streja
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA
| | - Csaba P Kovesdy
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Kamyar Kalantar-Zadeh
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, California, USA.,Long Beach Veterans Affairs Healthcare System, Long Beach, California, USA.,Department Epidemiology, UCLA Fielding School of Public Health, University of California Los Angeles, Los Angeles, California, USA.,Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA
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22
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Body Composition Analysis of Patients on Waiting List for Cadaveric Renal Transplantation: A Comparison of Hemodialysis and Peritoneal Dialysis Patients. Transplant Proc 2013; 45:3489-93. [DOI: 10.1016/j.transproceed.2013.08.097] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
The kidney has an important role in the metabolism of amino acids and control of plasma concentrations. Reabsorption by the tubules recovers about 70g/day of amino acids, derived from both the diet and metabolism in other tissues. Amino acids regulate haemodynamics and proteolysis and maintain integrity of the kidney. Abnormal plasma and muscle amino acid profiles in chronic renal failure (i.e. low essentials and tyrosine with high nonessentials) first indicated malnutrition, which can be partially corrected by supplementation. The loss of effective kidney tissue and uraemia, in addition to nutrition, have been considered in studies of phenylalanine hydroxylation used to investigate low tyrosine. Investigations in normal kidney have shown that glutamine uptake maintains acid-base homeostasis, glycine and citrulline are removed, and serine and arginine are released into the circulation. These metabolic processes are impaired in chronic renal failure. Uraemia affects most tissues and causes malnutrition, whilst acidosis activates catabolism of amino acids and proteins in muscle. Hyperinsulinaemia probably depresses plasma branchedchain amino acids and particularly valine. These abnormalities are less likely to respond to dietary supplementation.
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Bonanni A, Mannucci I, Verzola D, Sofia A, Saffioti S, Gianetta E, Garibotto G. Protein-energy wasting and mortality in chronic kidney disease. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2011; 8:1631-54. [PMID: 21655142 PMCID: PMC3108132 DOI: 10.3390/ijerph8051631] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/29/2011] [Accepted: 05/03/2011] [Indexed: 02/06/2023]
Abstract
Protein-energy wasting (PEW) is common in patients with chronic kidney disease (CKD) and is associated with an increased death risk from cardiovascular diseases. However, while even minor renal dysfunction is an independent predictor of adverse cardiovascular prognosis, PEW becomes clinically manifest at an advanced stage, early before or during the dialytic stage. Mechanisms causing loss of muscle protein and fat are complex and not always associated with anorexia, but are linked to several abnormalities that stimulate protein degradation and/or decrease protein synthesis. In addition, data from experimental CKD indicate that uremia specifically blunts the regenerative potential in skeletal muscle, by acting on muscle stem cells. In this discussion recent findings regarding the mechanisms responsible for malnutrition and the increase in cardiovascular risk in CKD patients are discussed. During the course of CKD, the loss of kidney excretory and metabolic functions proceed together with the activation of pathways of endothelial damage, inflammation, acidosis, alterations in insulin signaling and anorexia which are likely to orchestrate net protein catabolism and the PEW syndrome.
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Affiliation(s)
- Alice Bonanni
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
| | - Irene Mannucci
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
| | - Daniela Verzola
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
| | - Antonella Sofia
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
| | - Stefano Saffioti
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
| | - Ezio Gianetta
- Department of Surgery, Azienda Ospedale Università San Martino, Genoa University, Largo R. Benzi, Genoa, Italy; E-Mail:
| | - Giacomo Garibotto
- Division of Nephrology, Dialysis and Transplantation, Department of Internal Medicine, Azienda Ospedale Università San Martino, Genoa University, Viale Benedetto XV 6, Genoa, Italy; E-Mails: (A.B.); (I.M.); (D.V.); (A.S.); (S.S.)
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Chiu YW, Mehrotra R. What Should Define Optimal Correction of Metabolic Acidosis in Chronic Kidney Disease? Semin Dial 2010; 23:411-4. [DOI: 10.1111/j.1525-139x.2010.00749.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Franch HA, Mitch WE. Navigating Between the Scylla and Charybdis of Prescribing Dietary Protein for Chronic Kidney Diseases. Annu Rev Nutr 2009; 29:341-64. [DOI: 10.1146/annurev-nutr-080508-141051] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Harold A. Franch
- Research Service, Atlanta Veterans Affairs Medical Center, Decatur, Georgia 30033, and Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322;
| | - William E. Mitch
- Division of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030
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Leal VO, Delgado AG, Leite M, Mitch WE, Mafra D. Influence of renal function and diet on acid-base status in chronic kidney disease patients. J Ren Nutr 2009; 19:178-82. [PMID: 19218046 DOI: 10.1053/j.jrn.2008.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE We investigated the influence of potential renal acid load (PRAL) and renal function on the degree of metabolic acidosis in patients with chronic kidney disease (CKD). DESIGN This was a cross-sectional study. SETTING This study was conducted at the Nephrology Outpatient Division of the Hospital Universitário Clementino Fraga Filho (Rio de Janeiro, Brazil). PATIENTS Thirty CKD patients undergoing conservative treatment were divided according to plasma HCO(3)(-) values into acidotic (HCO(3)(-) <or=22 mM, n = 15) and nonacidotic (HCO(3)(-) >22 mM, n = 15). MAIN OUTCOME MEASURE Biochemical, nutritional, and anthropometric parameters and PRAL were measured. RESULTS The mean of plasma HCO(3)(-) values was 17.7 +/- 2.8 mM in the acidotic group, and 25.1 +/- 2.2 mM in the nonacidotic group. There was no significant difference in mean PRAL values between the acidotic (9.8 +/- 6.4 mEq/day) and nonacidotic (12.7 +/- 10.0 mEq/day) groups, but there was a significant correlation between plasma HCO(3)(-) and creatinine clearance (r = 0.78, P < .0001). Based on the receiver operating characteristic curve, the level of creatinine clearance to begin detection of acidosis was 31.8 mL/min, with a sensitivity and specificity of 86.7%. CONCLUSION The acid-base status of this group of CKD patients undergoing conservative treatment was mainly determined by degree of renal insufficiency rather than diet.
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Affiliation(s)
- Viviane O Leal
- Division of Neprology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Chiu YW, Kopple JD, Mehrotra R. Correction of Metabolic Acidosis to Ameliorate Wasting in Chronic Kidney Disease: Goals and Strategies. Semin Nephrol 2009; 29:67-74. [DOI: 10.1016/j.semnephrol.2008.10.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
BACKGROUND Protein restriction has been prescribed for some time for patients with chronic kidney disease (CKD). The effect of a low protein diet on delaying the progression to end-stage kidney disease (ESKD) in children and its impact on growth and nutrition remains unresolved. OBJECTIVES To determine the efficacy of protein restricted diet in delaying the start of maintenance dialysis and maintaining nutrition in children. SEARCH STRATEGY Cochrane Renal group trials register, the Cochrane Central register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles and relevant trials. SELECTION CRITERIA Randomised control trials (RCTs) comparing un-restricted protein diet versus a protein restricted diet (to safe amounts recommended by WHO), with follow-up period of at least six months were included. DATA COLLECTION AND ANALYSIS Two authors independently selected studies. Statistical analysis were performed using the random effects model. For dichotomous outcome results are expressed as relative risk (RR) with 95% confidence intervals (CI). Where continuous scales of measurement are used to assess the effects of treatment, the mean difference (WMD) was used. MAIN RESULTS Two studies (250 children) were identified, 124 received a protein restricted diet and 126 a control diet. No significant differences was found in the number of renal deaths (RR 1.12, 95% CI 0.54 to 2.33), progression of kidney disease (creatinine clearance at two years: WMD 1.47, 95% CI -1.19 to 4.14) or growth (weight - WMD -0.13, 95% CI -1.10 to 0.84; height - WMD -1.99, 95% CI -4.84 to 0.86). AUTHORS' CONCLUSIONS Reducing protein intake does not appear to have significant impact in delaying the progression to ESKD in children.
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Affiliation(s)
- S Chaturvedi
- Royal Children's Hospital, Nephrology, Flemington Road, Parkville, Victoria, Australia, 2051.
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Kamel KS, Sachdeva JS. Does Metabolic Acidosis Have Clinically Important Consequences in Dialysis Patients? Semin Dial 2007. [DOI: 10.1111/j.1525-139x.1998.tb00204.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wang X, Hu J, Price SR. Inhibition of PI3-kinase signaling by glucocorticoids results in increased branched-chain amino acid degradation in renal epithelial cells. Am J Physiol Cell Physiol 2007; 292:C1874-9. [PMID: 17229808 DOI: 10.1152/ajpcell.00617.2006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphatidylinositol 3-kinase(PI3K) is a pivotal enzyme involved in the control of a variety of diverse metabolic functions. Glucocorticoids have been shown to attenuate PI3K signaling in some nonrenal cell types, raising the possibility that some physiological effects of glucocorticoids in renal cells may be achieved by a similar mechanism. Therefore, we tested whether glucocorticoids affect signaling through the insulin receptor substrate (IRS)-1/PI3K/Akt signaling cascade in LLC-PK1-GR101 renal epithelial cells. Treatment of cells with dexamethasone for 24 h: 1) suppressed IRS-1-associated PI3K activity and Akt phosphorylation, 2) increased the level of the PI3K p85 regulatory subunit but not the p110 catalytic subunit, and 3) induced the phosphorylation of IRS-1 on inhibitory Ser307. We have previously reported that glucocorticoids increase branched-chain ketoacid dehydrogenase (BCKD) activity in LLC-PK1-GR101 cells. This response was achieved, in part, by alterations in the transcription of BCKD subunits and BCKD kinase, which inactivates the enzyme complex by phosphorylation. Therefore, we tested whether inhibition of PI3K signaling would mimick glucocorticoids by increasing branched-chain amino acid degradation. Expression of a dominant negative PI3K p85 regulatory subunit (Adp85ΔiSH2) increased BCKD activity, and dexamethasone did not further stimulate enzyme activity. Inhibition of PI3K using LY-294002 increased the transcription of the BCKD E2 subunit but not the E1α subunit or BCKD kinase. Thus, glucocorticoids inhibit signaling through the IRS-1/PI3K/Akt pathway with a consequence of increased branched-chain amino acid catabolism.
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Affiliation(s)
- Xiaonan Wang
- Renal Division, Emory University, Rm. 338, Woodruff Memorial Bldg., 1639 Pierce Dr., Atlanta, GA 30322, USA
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Löfberg E, Gutierrez A, Anderstam B, Wernerman J, Bergström J, Price SR, Mitch WE, Alvestrand A. Effect of bicarbonate on muscle protein in patients receiving hemodialysis. Am J Kidney Dis 2006; 48:419-29. [PMID: 16931215 DOI: 10.1053/j.ajkd.2006.05.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Accepted: 05/03/2006] [Indexed: 11/11/2022]
Abstract
BACKGROUND Metabolic acidosis stimulates whole-body net protein breakdown in healthy adults and patients with kidney failure, but few studies investigated how acidosis affects protein metabolism in individual tissues, such as skeletal muscle. METHODS We evaluated the effect of metabolic acidosis on protein turnover in skeletal muscle, assessed by means of phenylalanine kinetics and free amino acid concentrations in plasma and muscle. Long-term hemodialysis patients (n = 16) were divided into 2 groups in an open crossover study design. In group A, we administered bicarbonate supplements and increased blood standard bicarbonate levels from 17.8 +/- 0.03 to 27.1 +/- 1.2 mEq/L (17.8 +/- 0.03 to 27.1 +/- 1.2 mmol/L). In group B, we decreased bicarbonate supplements, which caused a decrease in standard bicarbonate levels from 26.6 +/- 0.7 to 18.6 +/- 0.3 mEq/L (26.6 +/- 0.7 to 18.6 +/- 0.3 mmol/L). RESULTS Net phenylalanine efflux from leg tissues (muscle) was significantly less when acid-base balance was corrected compared with acidosis (10.8 +/- 1.5 versus 18.6 +/- 3.8 nmol/min/100 g tissue; P = 0.014), as was the rate of phenylalanine appearance (28.3 +/- 3.0 versus 38.4 +/- 5.9 nmol/min/100 g tissue; P = 0.016); the rate of phenylalanine disposal was unchanged. Cortisol and C-reactive protein levels in blood were unchanged after correction of acidosis, as were levels of messenger RNAs encoding components of the ubiquitin-proteasome pathway in muscle biopsy specimens. CONCLUSION Our findings indicate that acidosis increases protein breakdown in skeletal muscle, but additional studies are needed to identify the pathways stimulated to degrade muscle protein in response to acidosis.
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Affiliation(s)
- Erland Löfberg
- Department of Clinical Science, Intervention, and Technology, Division of Renal Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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Wu DY, Shinaberger CS, Regidor DL, McAllister CJ, Kopple JD, Kalantar-Zadeh K. Association between serum bicarbonate and death in hemodialysis patients: is it better to be acidotic or alkalotic? Clin J Am Soc Nephrol 2005; 1:70-8. [PMID: 17699193 DOI: 10.2215/cjn.00010505] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The optimal acid-base status for survival in maintenance hemodialysis (MHD) patients remains controversial. According to recent reports, acidosis is associated with improved survival in MHD patients. It was hypothesized that this inverse association is due to a confounding effect of the malnutrition-inflammation complex syndrome (MICS). Associations between baseline (first 3 mo averaged) predialysis serum bicarbonate (HCO3(-)) and 2-yr mortality were examined in 56,385 MHD patients who were treated in virtually all DaVita dialysis clinics across the United States. The range of HCO3(-) was divided into 12 categories (< 17, > or = 27, and 10 groups in between). Three sets of Cox regression models were evaluated to estimate hazard ratios of all-cause and cardiovascular death in both incident and prevalent patients: (1) Unadjusted, (2) multivariate case mix adjusted (which also included dialysate HCO3(-) and Kt/V), and (3) adjusted for case mix and nine markers of MICS (body mass index; erythropoietin dose; protein intake; serum albumin; creatinine; phosphorus; calcium; ferritin and total iron binding capacity; and blood hemoglobin, WBC, and lymphocytes). There were significant inverse associations between serum HCO3(-) and serum phosphorus and estimated protein intake. The lowest unadjusted mortality was associated with predialysis HCO3(-) in the 17- to 23-mEq/L range, whereas values > or = 23 mEq/L were associated with progressively higher all-cause and cardiovascular death rates. This association, however, reversed after case-mix and MICS multivariate adjustment, so that HCO3(-) values >22 mEq/L had lower death risk. Although previous epidemiologic studies indicated an association between high serum HCO3(-) and increased mortality in MHD patients, this effect seems to be due substantially to the effect of MICS on survival.
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Affiliation(s)
- Dennis Y Wu
- Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 1124 West Carson Street, Torrance, CA 90502-2064, USA
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Kalantar-Zadeh K, Mehrotra R, Fouque D, Kopple JD. Metabolic acidosis and malnutrition-inflammation complex syndrome in chronic renal failure. Semin Dial 2005; 17:455-65. [PMID: 15660576 DOI: 10.1111/j.0894-0959.2004.17606.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metabolic acidosis, a common condition in patients with renal failure, may be linked to protein-energy malnutrition (PEM) and inflammation, together also known as malnutrition-inflammation complex syndrome (MICS). Methods of serum bicarbonate measurement may misrepresent the true bicarbonate level, since the total serum carbon dioxide measurement usually overestimates the serum bicarbonate concentration. Moreover, the air transportation of blood samples to distant laboratories may lead to erroneous readings. In patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD), a significant number of endocrine, musculoskeletal, and metabolic abnormalities are believed to result from acidemia. Metabolic acidosis may be related to PEM and MICS due to an increased protein catabolism, decreased protein synthesis, endocrine abnormalities including insulin resistance, decreased serum leptin level, and inflammation among individuals with renal failure. Evidence suggests that the catabolic effects of metabolic acidosis may result from an increased activity of the adenosine triphosphate (ATP)-dependent ubiquitin-proteasome and branched-chain keto acid dehydrogenase. In contrast to the metabolic studies, many epidemiologic studies in maintenance dialysis patients have indicated a paradoxically inverse association between mildly decreased serum bicarbonate and improved markers of protein-energy nutritional state. Hence metabolic acidosis may be considered as yet another element of the reverse epidemiology in ESRD patients. Interventional studies have yielded inconsistent results in CKD and ESRD patients, although in peritoneal dialysis patients, mitigating acidemia appears to more consistently improve nutritional status and reduce hospitalizations. Large-scale, prospective randomized interventional studies are needed to ascertain the potential benefits of correcting acidemia in malnourished and/or inflamed CKD and maintenance hemodialysis patients. Until then, all attempts should be made to adhere to the National Kidney Foundation Kidney Disease and Dialysis Outcome Quality Initiative guidelines to maintain a serum bicarbonate level in ESRD patients of at least 22 mEq/L.
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Affiliation(s)
- Kamyar Kalantar-Zadeh
- Division of Nephrology and Hypertension, Harbor-UCLA Medical Center, 1124 West Carson Street, Torrance, CA 90502, USA.
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Ahuja TS, Mitch WE. The evidence against malnutrition as a prominent problem for chronic dialysis patients. Semin Dial 2005; 17:427-31. [PMID: 15660572 DOI: 10.1111/j.0894-0959.2004.17602.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A large number of dialysis patients have been classified as being malnourished because of anthropometric measurements and laboratory values that are similar to those in patients with protein-energy malnutrition. Malnutrition implies that abnormalities can be reversed with better nutrition. However, this approach of providing more nutrients in the diet has been unsuccessful in reversing these changes, suggesting that a diagnosis of malnutrition is generally a misdiagnosis for dialysis patients In this review we discuss mechanisms that cause a loss of protein stores, muscle mass, albumin, and other plasma proteins in dialysis patients. We also review the shortcomings of techniques that are used to measure the nutritional status of these patients.
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Affiliation(s)
- Tejinder S Ahuja
- Department of Medicine, Division of Nephrology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0562, USA.
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Prakash S, Pande DP, Sharma S, Sharma D, Bal CS, Kulkarni H. Randomized, double-blind, placebo-controlled trial to evaluate efficacy of ketodiet in predialytic chronic renal failure. J Ren Nutr 2005; 14:89-96. [PMID: 15060873 DOI: 10.1053/j.jrn.2004.01.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE To assess whether a ketodiet, a combination of ketoanalogs of essential amino acids (KAs) and a very low-protein diet, retards progression of chronic renal failure and maintains nutritional status. DESIGN A prospective, randomized, double-blind, placebo-controlled trial. SETTING Nephrology outpatient department in Northern Railways Central Hospital, New Delhi, India. PATIENTS Thirty-four patients in predialytic stages of chronic renal failure (CRF), randomized to 2 comparable groups in terms of age, sex distribution, blood pressure control, etiology, use of angiotensin converting enzyme inhibitors, serum creatinine, glomerular filtration rate (GFR), and body mass index (BMI). INTERVENTION Subjects randomly received either 0.6 g/kg/d protein plus placebo (n = 16) or 0.3 g/kg/d protein plus tablets of KAs (Ketosteril; Fresenius Kabi, Germany) (n = 18) for 9 months. A dietician administered the diet as well as the KAs or the placebo to the patients. OUTCOME MEASURES Changes in GFR and renal and nutritional parameters were measured. RESULTS Mean (+/- SD) GFR measured by the 99mTc-DTPA (99 m technetium diethylenetri-aminepenta-aceticacid) plasma sample method was unchanged in the ketodiet group: 28.1 +/- 8.8 (before) and 27.6 +/- 10.1 mL/min/1.73 m2 (after the study) (P =.72). However, it significantly decreased from 28.6 +/- 17.6 to 22.5 +/- 15.9 mL/min/1.73 m2 in the placebo group (P =.015). Serum creatinine before and after the study in the ketodiet group was 2.26 +/- 1.03 mg/dL and 2.07 +/- 0.8 mg/dL (P =.90) and in the placebo group was 2.37 +/- 0.85 and 3.52 +/- 2.9 mg/dL (P =.066), respectively. In both groups the mean BMI did not change from 25.4 +/- 4.2 to 24.5 +/- 4.2 kg/m2 (P =.46) for ketodiet and from 25.0 +/- 6.8 to 23.9 +/- 4.1 kg/m2 (P =.39) for the placebo group. Serum total proteins decreased significantly (P =.038) in the placebo group, and serum albumin showed a trend (P =.061) toward reduction, whereas both of these parameters were maintained in the ketodiet group. CONCLUSION Over a 9-month period, very low-protein diet supplemented with ketoanalogs helped CRF patients to preserve GFR and maintain BMI. KAs were safe and efficacious in retarding the progression of renal failure and preserving the nutritional status of CRF patients.
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Affiliation(s)
- Sunil Prakash
- Division, Northern Railway Central Hospital, New Delhi, India.
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Abstract
PURPOSE OF REVIEW Abnormalities of acid-base balance accompany many pathological conditions. Acidosis is associated with several diseases such as chronic renal failure, diabetic ketosis, severe trauma and sepsis, and chronic obstructive respiratory disease, which are often associated with muscle wasting. There is evidence that acidosis can induce muscle protein catabolism and it could therefore be an important factor contributing to loss of muscle protein in these conditions. This review aims at outlining the effects of acid-base balance abnormalities on muscle protein metabolism, and will in particular summarize and evaluate the most recent studies on the impact of pH on control of muscle protein metabolism. RECENT FINDINGS Acidosis has been shown to promote muscle protein catabolism by stimulating protein degradation and amino acid oxidation. This effect is achieved through up-regulation of the ubiquitin-proteasome pathway - one of the major enzyme systems for protein degradation. Recent studies in animals and humans have also shown that acidosis inhibits muscle protein synthesis. Little is known about the mechanisms by which acidosis depresses protein synthesis, or of the impact of alkalosis on protein metabolism. SUMMARY Increasing evidence suggests that acidosis promotes muscle protein wasting by both increasing protein degradation and inhibiting protein synthesis. Correction of acidosis may therefore help to preserve muscle mass and improve the health of patients with pathological conditions associated with acidosis.
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Affiliation(s)
- Giuseppe Caso
- Department of Surgery, State University of New York, Stony Brook, New York, USA.
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Weinstein J, Schreiber M, Kamel KS. Opinion: What Unique Acid-Base Considerations Exist in Dialysis Patients? Semin Dial 2004. [DOI: 10.1111/j.0894-0959.2004.17343.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
In stable adults or patients with kidney disease, the daily turnover of cellular proteins is very large, amounting to the quantity of protein in 1 to 1.5 kg of muscle. Consequently, even a small but persistent increase in protein degradation or decrease in protein synthesis leads to a substantial loss of muscle mass. In chronic kidney disease, the pathway that degrades muscle protein is the ubiquitin-proteasome system. We tested whether either of two complications of chronic kidney disease, metabolic acidosis or insulin resistance accelerates the loss of muscle protein. Metabolic acidosis activates the ubiquitin-proteasome system and this can explain an large number of clinical conditions in which metabolic acidosis also causes loss of muscle protein. Insulin deficiency as a model of insulin resistance also activates the ubiquitin-proteasome system. Both complications also activate caspase-3 and we found that this protease performs a critical initial step in breaking down the complex structure of muscle to provide actin, myosin and fragments of these proteins as substrates for the ubiquitin-proteasome system. Defects in insulin signalling processes can activate both caspase-3 and the ubiquitin-proteasome system to degrade muscle protein. Understanding mechanisms that activate protein breakdown will lead to therapies that successfully prevent the loss of muscle mass in patients with kidney disease.
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Affiliation(s)
- William E Mitch
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
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Abstract
Metabolic acidosis in maintenance dialysis patients: Clinical considerations. Metabolic acidosis is a common consequence of advanced chronic renal failure (CRF) and maintenance dialysis (MD) therapies are not infrequently unable to completely correct the base deficit. In MD patients, severe metabolic acidosis is associated with an increased relative risk for death. The chronic metabolic acidosis of the severity commonly encountered in patients with advanced CRF has two well-recognized major systemic consequences. First, metabolic acidosis induces net negative nitrogen and total body protein balance, which improves upon bicarbonate supplementation. The data suggest that metabolic acidosis is both catabolic and antianabolic. Emerging data also indicate that metabolic acidosis may be one of the triggers for chronic inflammation, which may in turn promote protein catabolism among MD patients. In contrast to these findings, metabolic acidosis may be associated with a decrease in hyperleptinemia associated with CRF. Several studies have shown that correction of metabolic acidosis among MD patients is associated with modest improvements in the nutritional status. Second, metabolic acidosis has several effects on bone, causing physicochemical dissolution of bone and cell-mediated bone resorption (inhibition of osteoblast and stimulation of osteoclast function). Metabolic acidosis is probably also associated with worsening of secondary hyperparathyroidism. Data on the effect of correction of metabolic acidosis on renal osteodystrophy, however, are limited. Preliminary evidence suggest that metabolic acidosis may play a role in beta2-microglobulin accumulation, as well as the hypertriglyceridemia seen in renal failure. Given the body of evidence pointing to the several systemic consequences of metabolic acidosis, a more aggressive approach to the correction of metabolic acidosis is proposed.
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Affiliation(s)
- Rajnish Mehrotra
- Division of Nephrology and Hypertension and Research and Education Institute at Harbor-UCLA Medical Center, Torrance, California, USA
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Cupisti A, D'Alessandro C, Morelli E, Rizza GM, Galetta F, Franzoni F, Barsotti G. Nutritional status and dietary manipulation in predialysis chronic renal failure patients. J Ren Nutr 2004; 14:127-33. [PMID: 15232790 DOI: 10.1053/j.jrn.2004.04.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE A properly implemented dietary treatment for patients with chronic renal failure (CRF) can correct several metabolic and endocrine disturbances and delay initiation of dialysis, but concerns exist about the risk of malnutrition and protein depletion. The goal of this study is to evaluate nutritional status and its relation to the dietary treatment in patients with advanced CRF. DESIGN Cross-sectional survey. SETTING Predialysis outpatient clinic. PATIENTS Seventy patients (43 males, 27 females, 50 +/- 12 years) with severe CRF (glomerular filtration rate [GFR] <15 mL/min) being treated with a low-protein (0.6 g/kg/day) diet (LPD) or a very-low-protein (0.3 g/kg/day) diet supplemented with essential amino acids and ketoacids (KAD). Fifty-two healthy subjects with comparable age and sex served as controls. MAIN OUTCOME MEASURES In all patients and controls, we performed biochemistry, anthropometry, bioelectrical impedance vector analysis (BIVA), and subjective global assessment (SGA), and the patients' outcomes were also assessed. RESULTS Values of anthropometry and BIVA were similar in patients and controls. SGA scores showed a normal nutritional status (SGA-0) in 50 patients (71.4%) and mild to moderate SGA abnormalities (SGA-1) in 20 patients (28.6%); none had severe malnutrition. The SGA-1 patients differed from the SGA-0 patients by having higher serum urea, lower bicarbonate, and lower renal function (87% of SGA-1 patients had GFR <10 mL/min.). At the same GFR values (6.6 +/- 2.3 versus 6.6 +/- 2.3 mL/min) SGA-1 patients had lower bicarbonate (21.9 +/- 4.3 versus 25.3 +/- 2.7 mM, P <.01) and higher serum urea (115 +/- 29 versus 82 +/- 38 mg/dL, P =.01) and protein intake than SGA-0 patients; SGA-1 score was more prevalent with LPD compared with KAD treatment (45% versus 27%, P <.05). BIVA and anthropometry, serum levels of albumin, prealbumin, insulin-like growth factor-1, hematocrit, and lymphocyte count did not differ between SGA-1 and SGA-0 patients, but the number entering dialysis was higher in the group scoring as SGA-1 compared with SGA-0 (82% versus 47%, P <.05). CONCLUSIONS With a planned dietary regimen, severe or overt malnutrition does not occur in predialysis CRF without other serious illnesses. However, some mild to moderate SGA abnormalities were detected in association with a more severe renal insufficiency, a lower serum bicarbonate, a higher serum urea and dietary protein levels and were predictive of poor renal outcome. This study emphasizes the role of proper dietary implementation, correction of metabolic acidosis, and clinical monitoring including SGA in the predialysis conservative care of CRF patients.
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Affiliation(s)
- Adamasco Cupisti
- Department of Internal Medicine, Section of Nephrology, University of Pisa, Pisa, Italy.
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Caso G, Garlick BA, Casella GA, Sasvary D, Garlick PJ. Acute metabolic acidosis inhibits muscle protein synthesis in rats. Am J Physiol Endocrinol Metab 2004; 287:E90-6. [PMID: 14982751 DOI: 10.1152/ajpendo.00387.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, we investigated the effect of acute metabolic acidosis on tissue protein synthesis. Groups of rats were made acidotic with intragastric administration of NH(4)Cl (20 mmol/kg body wt every 12 h for 24 h) or given equimolar amounts of NaCl (controls). Protein synthesis in skeletal muscle and a variety of different tissues, including lymphocytes, was measured after 24 h by injection of l-[(2)H(5)]phenylalanine (150 micromol/100 g body wt, 40 moles percent). Results show that acute acidosis inhibits protein synthesis in skeletal muscle (-29% in gastrocnemius, -23% in plantaris, and -17% in soleus muscles, P < 0.01) but does not affect protein synthesis in heart, liver, gut, kidney, and spleen. Protein synthesis in lymphocytes is also reduced by acidosis (-8%, P < 0.05). In a separate experiment, protein synthesis was also measured in acidotic and control rats by a constant infusion of l-[(2)H(5)]phenylalanine (1 micromol.100 g body wt(-1).h(-1)). The results confirm the earlier findings showing an inhibition of protein synthesis in gastrocnemius (-28%, P < 0.01) and plantaris (-19%, P < 0.01) muscles but no effect on heart and liver by acidosis. Similar results were also observed using a different model of acute metabolic acidosis, in which rats were given a cation exchange resin in the H(+) (acidotic) or the Na(+) (controls) form. In conclusion, this study demonstrates that acute metabolic acidosis for 24 h depresses protein synthesis in skeletal muscle and lymphocytes but does not alter protein synthesis in visceral tissues. Inhibition of muscle protein synthesis might be another mechanism contributing to the loss of muscle tissue observed in acidosis.
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Affiliation(s)
- Giuseppe Caso
- Dept. of Surgery, HSC T19-048, State Univ. of New York at Stony Brook, Stony Brook, NY 11794-8191, USA.
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Feriani M, Passlick-Deetjen J, Jaeckle-Meyer I, La Greca G. Individualized bicarbonate concentrations in the peritoneal dialysis fluid to optimize acid-base status in CAPD patients. Nephrol Dial Transplant 2004; 19:195-202. [PMID: 14671057 DOI: 10.1093/ndt/gfg472] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A large percentage of peritoneal dialysis (PD) patients being treated with standard lactate-containing solutions tend to have serum bicarbonate concentrations below or above the normal range. The inter-patient variability of serum bicarbonate is a result of many influences and it may be appropriate to adjust the bicarbonate concentration in the peritoneal dialysis fluid (PDF) to the current serum bicarbonate in the individual patient. METHODS Two concentrations of bicarbonate in PDF were compared in this study (34 and 39 mmol/l). Eligible patients underwent a pre-study phase of 12 weeks to determine serum bicarbonate every six weeks. Sixty-one patients entered the stratification phase. Acidotic patients (serum venous bicarbonate <25.3 mmol/l) were allocated to the high bicarbonate solution, patients in the normal serum bicarbonate range or alkalotic patients (serum venous bicarbonate >25.3 mmol/l) to the low bicarbonate solution. Patients were followed up for 24 weeks, in which study visits were performed every 6 weeks to assess acid-base status, peritoneal and renal function, and to calculate protein nitrogen appearance rate (PNA). RESULTS Patients with acidosis at baseline had higher body weight, body surface area, blood urea nitrogen, serum creatinine and PNA than patients with bicarbonate within the normal range or with alkalosis. They significantly improved their serum bicarbonate (23.45 +/- 2.5 vs 25.7 +/- 2.8 mmol/l, baseline vs week 24; P < 0.01), whereas patients treated with the low bicarbonate PDF maintained their serum venous bicarbonate over the 24 week study period (27.77 +/- 2.9 vs 27.06 +/- 2.1 mmol/l, baseline vs week 24; P = NS). Analysing both study groups together, at baseline, 66% of the patients presented with mild to moderate acidosis, this figure at the end of the study was 23.4%. PNA did not change in the two groups; however, in the subgroup of patients (N = 23) in whom the 39 mmol/l PDF was effective in correcting metabolic acidosis, a decrease in PNA was observed. CONCLUSIONS The study demonstrated that the individualized application of low and high bicarbonate PD PDFs allows one to achieve normal acid-base status in a large percentage of CAPD patients with potential benefits to nutritional status.
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Kaysen GA, Greene T, Daugirdas JT, Kimmel PL, Schulman GW, Toto RD, Levin NW, Yan G. Longitudinal and cross-sectional effects of C-reactive protein, equilibrated normalized protein catabolic rate, and serum bicarbonate on creatinine and albumin levels in dialysis patients. Am J Kidney Dis 2003; 42:1200-11. [PMID: 14655192 DOI: 10.1053/j.ajkd.2003.08.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Loss of muscle mass and hypoalbuminemia each may result in part from either malnutrition, inflammation, or a combination of both. Short-term acidosis increases muscle protein catabolism and inhibits albumin synthesis. METHODS We analyzed albumin and creatinine levels as outcome variables and their association with C-reactive protein (CRP) level, equilibrated normalized protein catabolic rate (enPCR), and serum bicarbonate level as independent variables from laboratory data obtained from patients in the Hemodialysis Study. Analyses controlled for race, sex, age, body mass index, and randomized treatment group. RESULTS Albumin level correlated with both enPCR and CRP level, but not serum bicarbonate level, in both cross-sectional and longitudinal analyses. Effects of CRP level and enPCR were not linear. Albumin level correlated positively with enPCR for an enPCR less than 1.0 g/kg/d, but not for a greater enPCR, and correlated inversely with CRP level for a CRP level greater than 13 mg/L. Similarly, creatinine level correlated with both enPCR and CRP level. As in the case of albumin level, effects were not linear. Creatinine level correlated positively with enPCR for values less than 1.0 g/kg/d, but not for greater enPCR values. In contrast to albumin level, creatinine level correlated negatively with serum bicarbonate level, even when adjusted for enPCR. CONCLUSION Albumin and creatinine levels are independently associated with nutrition (enPCR) and inflammation (CRP level). The cross-sectional relationship with enPCR is apparent only at values less than 1.0 g/kg/d. CRP level is associated with reduced albumin and creatinine values when increased to values greater than 5.6 mg/dL. CRP may be increased to levels associated with increased cardiovascular risk with little or no effect on either serum albumin or creatinine level. Thus, a normal albumin level does not exclude elevated CRP levels.
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Affiliation(s)
- George A Kaysen
- Veterans Affairs Northern California Health Care System, Mather, USA.
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Wang X, Price SR. Differential regulation of branched-chain alpha-ketoacid dehydrogenase kinase expression by glucocorticoids and acidification in LLC-PK1-GR101 cells. Am J Physiol Renal Physiol 2003; 286:F504-8. [PMID: 14612386 DOI: 10.1152/ajprenal.00296.2003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acidosis and glucocorticoids (GC) are two catabolic signals associated with chronic renal disease. Previously, we reported that these signals stimulate branched-chain amino acid (BCAA) oxidation in renal tubule cells by increasing both the amount and activation state of branched-chain alpha-ketoacid dehydrogenase (BCKD). Activation of the BCKD complex could result from decreased expression of BCKD kinase, which inhibits BCKD by phosphorylating its E1 alpha subunit. To investigate this possibility, we examined how dexamethasone and acidification (pH 7.0) influence BCKD kinase expression in LLC-PK(1)-GR101 cells. Dexamethasone, a synthetic GC, decreased BCKD kinase protein by 65% (P < 0.05 vs. control), whereas a low pH (i.e., pH 7.0) decreased the amount of kinase by 71% (P < 0.05 vs. control). Either GC or acidification reduced BCKD kinase mRNA by 46% (P < 0.05 vs. control), but the two signals together did not reduce kinase mRNA more than either signal alone. To examine the mechanism(s) leading to lower kinase mRNA, kinase transcription was evaluated by transiently transfecting LLC-PK(1)-GR101 cells with BCKD kinase promoter-luciferase mini-genes containing approximately 3.5 kb of proximal rat kinase promoter. GC, but not acidification, decreased luciferase activity 42% (P < 0.05 vs. control). Nuclear run-on assays confirmed that GC decrease kinase mRNA by attenuating its transcription. Thus two catabolic signals associated with renal failure, GC and acidification, reduce BCKD kinase expression by different mechanisms. These responses lead to an increase in the activation state of BCKD and a resulting acceleration of BCAA degradation.
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Affiliation(s)
- Xiaonan Wang
- Renal Division, Rm. 338 Woodruff Memorial Bldg., 1639 Pierce Drive, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Abstract
Serum albumin, transferrin, and prealbumin levels decrease as glomerular filtration rate (GFR) declines, even prior to the start of dialysis. The levels of these serum proteins are also associated with creatinine levels and lean body mass. Lean body mass also decreases with advancing renal failure. While all of these measures are regarded as reflections of nutritional status, each are strongly associated with any of several indicators of inflammation: positive acute-phase proteins or the cytokines that regulate their synthesis rate, in both longitudinal and cross-sectional studies. Inflammation in turn is associated with comorbid conditions, cardiovascular disease, chronic infections, age, and vascular access type. Additionally, dialysis patients are subjected to oxidative stress and exposure of blood to foreign antigens in the dialysis process that also potentially contribute to inflammation. In otherwise healthy individuals reduced protein and calorie intake does not cause hypoalbuminemia since albumin fractional catabolic rate (FCR) and resting energy expenditure (REE) normally decrease in response. The simultaneous occurrence of decreased protein intake and inflammation prevent these homeostatic compensations to reduced nitrogen and energy intake from occurring, resulting in decreasing albumin, transferrin, and prealbumin levels and loss of muscle mass. Nutritional intake may also be challenged as a result of renal failure associated with anorexia, gastroparesis, and socioeconomic factors, which may all cause nutritional intake to be sufficiently marginal so that the combined effects of inflammation and decrease protein intake are expressed as decreased visceral and somatic protein stores.
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Affiliation(s)
- George A Kaysen
- Department of Medicine, Division of Nephrology, University of California-Davis, Davis, Califonia 95616, USA.
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Mitch WE. Malnutrition: a frequent misdiagnosis for hemodialysis patients. J Clin Invest 2002; 110:437-9. [PMID: 12189236 PMCID: PMC150424 DOI: 10.1172/jci16494] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- William E Mitch
- Nephrology Division, Department of Medicine, University of Texas, Galveston, Galveston, Texas 77555, USA.
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