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Abstract
Chronic kidney disease (CKD) has become a global health burden and is associated with increased morbidity and mortality. In particular, wasting is highly prevalent in later stages of the illness with muscle loss being a common problem. The aetiology and progression of this wasting is complex and multiple states have been identified linked to wasting in CKD. These include: ‘malnutrition’, ‘disease-related malnutrition’, ‘protein-energy wasting’, ‘cachexia’, ‘sarcopenia’, ‘frailty’ and ‘muscle wasting’. The purpose of this paper is to review these terms in the context of CKD. Common features include weight loss, loss of muscle mass and muscle function principally driven by CKD disease specific factors and inflammatory mediators. Disease-related malnutrition would appear to be a more appropriate term for CKD than malnutrition as it take in to consideration disease specific factors such as inflammation for example. Frailty is commonly associated with age-related decline in physiological function. Development of novel screening tools measuring across multiple domains of nutritional status, muscle and physical function may be useful in CKD. Research into potential treatments are currently underway with focus on multi-modal therapies including nutrition, resistance training and anabolic drugs such as myostatin blockade and selective androgen receptor modulators. A better understanding of different states and terms may help guide assessment and treatment opportunities for patients.
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Quiñones H, Hamdi T, Sakhaee K, Pasch A, Moe OW, Pak CYC. Control of metabolic predisposition to cardiovascular complications of chronic kidney disease by effervescent calcium magnesium citrate: a feasibility study. J Nephrol 2018; 32:93-100. [PMID: 30465137 PMCID: PMC6373382 DOI: 10.1007/s40620-018-0559-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/16/2018] [Indexed: 12/19/2022]
Abstract
Aims Cardiovascular (CV) complications are common in chronic kidney disease (CKD). Numerous metabolic disturbances including hyperphosphatemia, high circulating calciprotein particles (CPP), hyperparathyroidism, metabolic acidosis, and magnesium deficiency are associated with, and likely pathogenic for CV complications in CKD. The goal of this feasibility study was to determine whether effervescent calcium magnesium citrate (EffCaMgCit) ameliorates the aforementioned pathogenic intermediates. Methods Nine patients with Stage 3 and nine patients with Stage 5D CKD underwent a randomized crossover study, where they took EffCaMgCit three times daily for 7 days in one phase, and a conventional phosphorus binder calcium acetate (CaAc) three times daily for 7 days in the other phase. Two-hour postprandial blood samples were obtained on the day before and on the 7th day of treatment. Results In Stage 5D CKD, EffCaMgCit significantly increased T50 (half time for conversion of primary to secondary CPP) from baseline by 63% (P = 0.013), coincident with statistically non-significant declines in serum phosphorus by 25% and in saturation of octacalcium phosphate by 35%; CaAc did not change T50. In Stage 3 CKD, neither EffCaMgCit nor CaAc altered T50. With EffCaMgCit, a significant increase in plasma citrate was accompanied by statistically non-significant increase in serum Mg and phosphate. CaAc was without effect in any of these parameters in Stage 3 CKD. In both Stages 3 and 5D, both drugs significantly reduced serum parathyroid hormone. Only EffCaMgCit significantly increased serum bicarbonate by 3 mM (P = 0.015) in Stage 5D. Conclusions In Stage 5D, EffCaMgCit inhibited formation of CPP, suppressed PTH, and conferred magnesium and alkali loads. These effects were unique, since they were not observed with CaAc. In Stage 3 CKD, neither of the regimens have any effect. These metabolic changes suggest that EffCaMgCit might be useful in protecting against cardiovascular complications of CKD by ameliorating pathobiologic intermediates.
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Affiliation(s)
- Henry Quiñones
- Divisions of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Tamim Hamdi
- Divisions of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Khashayar Sakhaee
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Divisions of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Mineral Metabolism, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | - Orson W Moe
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Divisions of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Internal Medicine, Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Charles Y C Pak
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
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Ahmed AR, Lappin D. Oral alkali therapy and the management of metabolic acidosis of chronic kidney disease: A narrative literature review. World J Nephrol 2018; 7:117-122. [PMID: 30324086 PMCID: PMC6181870 DOI: 10.5527/wjn.v7.i6.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/05/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023] Open
Abstract
Chronic metabolic acidosis is a common complication seen in advanced chronic kidney disease (CKD). There is currently no consensus on its management in the Republic of Ireland. Recent trials have suggested that appropriate active management of metabolic acidosis through oral alkali therapy and modified diet can have a deterring impact on CKD progression. The potential benefits of treatment include preservation of bone health and improvement in muscle function; however, present data is limited. This review highlights the current evidence, available primarily from randomised control trials (RCTs) over the last decade, in managing the metabolic acidosis of CKD and outlines ongoing RCTs that are promising. An economic perspective is also briefly discussed to support decision-making.
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Affiliation(s)
- Adeel Rafi Ahmed
- Department of Nephrology, University Hospital Galway, Galway H91YR1, Ireland
| | - David Lappin
- Department of Nephrology, University Hospital Galway, Galway H91YR1, Ireland
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Retarding progression of chronic kidney disease: use of modalities that counter acid retention. Curr Opin Nephrol Hypertens 2018; 27:94-101. [PMID: 29140821 DOI: 10.1097/mnh.0000000000000386] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Acid retention because of chronic kidney disease (CKD) increases tissue acidity and accelerates progression of CKD, whereas reduction in acid retention slows progression of CKD. Herein, we describe the mechanisms through which increased tissue acidity worsens CKD, modalities for countering acid retention and their impact on progression of CKD, and current recommendations for therapy. RECENT FINDINGS Studies in animals and humans show that increased tissue acidity raises the renal levels of endothelin, angiotensin II, aldosterone, and ammoniagenesis, thereby worsening renal fibrosis and causing progression of CKD. Measures that counter acid retention, such as providing alkali or modifying the quantity or type of dietary protein, reduce the levels of endothelin, angiotensin II, aldosterone, and ammoniagenesis, slowing progression of CKD. Alkali can be provided as NaHCO3, sodium citrate, or base in fruits and vegetables. A serum [HCO3] of 24-26 mEq/l is targeted, because higher values can be associated with adverse consequences. SUMMARY Insights into the mechanisms through which increased tissue acidity mediates progression of CKD and the beneficial impact of ameliorating positive acid balance underlie our recommendation for modalities that counter acid retention in CKD.
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Scialla JJ, Brown L, Gurley S, Corcoran DL, Bain JR, Muehlbauer MJ, O’Neal SK, M. O’Connell T, Wolf M, Melamed ML, Hostetter TH, Abramowitz MK. Metabolic Changes with Base-Loading in CKD. Clin J Am Soc Nephrol 2018; 13:1244-1246. [PMID: 29934431 PMCID: PMC6086694 DOI: 10.2215/cjn.01830218] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | | | - David L. Corcoran
- Department of Medicine
- Duke Center for Genomic and Computational Biology, and
| | - James R. Bain
- Department of Medicine
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| | - Michael J. Muehlbauer
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| | - Sara K. O’Neal
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| | - Thomas M. O’Connell
- Department of Medicine
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Myles Wolf
- Department of Medicine
- Duke Clinical Research Institute
| | - Michal L. Melamed
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York; and
| | - Thomas H. Hostetter
- Department of Medicine, University Hospitals Cleveland Medical Center, Case Western Reserve School of Medicine, Cleveland, Ohio
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St-Jules DE, Goldfarb DS, Popp CJ, Pompeii ML, Liebman SE. Managing protein-energy wasting in hemodialysis patients: A comparison of animal- and plant-based protein foods. Semin Dial 2018; 32:41-46. [DOI: 10.1111/sdi.12737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- David E. St-Jules
- Division of Health and Behavior, Department of Population Health; New York University School of Medicine; New York NY USA
| | - David S. Goldfarb
- Division of Nephrology, Department of Medicine; New York University School of Medicine; New York NY USA
| | - Collin J. Popp
- Division of Health and Behavior, Department of Population Health; New York University School of Medicine; New York NY USA
| | - Mary Lou Pompeii
- Division of Health and Behavior, Department of Population Health; New York University School of Medicine; New York NY USA
| | - Scott E. Liebman
- Division of Nephrology, Department of Medicine; University of Rochester School of Medicine; Rochester NY USA
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Biolo G, Di Girolamo FG, Heer M, Sturma M, Mazzucco S, Agostini F, Situlin R, Vinci P, Giordano M, Buehlmeier J, Frings-Meuthen P, Mearelli F, Fiotti N. Alkalinization with potassium bicarbonate improves glutathione status and protein kinetics in young volunteers during 21-day bed rest. Clin Nutr 2018; 38:652-659. [PMID: 29739680 DOI: 10.1016/j.clnu.2018.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 12/22/2017] [Accepted: 04/06/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND & AIMS Physical inactivity is associated with lean body mass wasting, oxidative stress and pro-inflammatory changes of cell membrane lipids. Alkalinization may potentially counteract these alterations. We evaluated the effects of potassium bicarbonate supplementation on protein kinetics, glutathione status and pro- and anti-inflammatory polyunsaturated fatty acids (PUFA) in erythrocyte membranes in humans, during experimental bed rest. METHODS Healthy, young, male volunteers were investigated at the end of two 21-day bed rest periods, one with, and the other without, daily potassium bicarbonate supplementation (90 mmol × d-1), according to a cross-over design. Oxidative stress in erythrocytes was evaluated by determining the ratio between reduced (GSH) and oxidized glutathione (GSSG). Glutathione turnover and phenylalanine kinetics, a marker of whole body protein metabolism, were determined by stable isotope infusions. Erythrocyte membranes PUFA composition was analyzed by gas-chromatography. RESULTS At the end of the two study periods, urinary pH was 10 ± 3% greater in subjects receiving potassium bicarbonate supplementation (7.23 ± 0.15 vs. 6.68 ± 0.11, p < 0.001). Alkalinization increased total glutathione concentrations by 5 ± 2% (p < 0.05) and decreased its rate of clearance by 38 ± 13% (p < 0.05), without significantly changing GSH-to-GSSG ratio. After alkalinization, net protein balance in the postabsorptive state improved significantly by 17 ± 5% (p < 0.05) as well as the sum of n-3 PUFA and the n-3-to-n-6 PUFA ratio in erythrocyte membranes (p < 0.05). CONCLUSIONS Alkalinization during long-term inactivity is associated with improved glutathione status, anti-inflammatory lipid pattern in cell membranes and reduction in protein catabolism at whole body level. This study suggests that, in clinical conditions characterized by inactivity, oxidative stress and inflammation, alkalinization could be a useful adjuvant therapeutic strategy.
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Affiliation(s)
- Gianni Biolo
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy.
| | | | - Martina Heer
- Department of Nutrition and Food Science, Nutrition Physiology, University of Bonn, Bonn, Germany
| | - Mariella Sturma
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Sara Mazzucco
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Francesco Agostini
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Roberta Situlin
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Pierandrea Vinci
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Mauro Giordano
- Department of Medical, Surgical, Neurological, Metabolic and Geriatrics Sciences, Second University of Naples, Naples, Italy
| | - Judith Buehlmeier
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Köln, Germany
| | | | - Filippo Mearelli
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Nicola Fiotti
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
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Dietary Treatment of Metabolic Acidosis in Chronic Kidney Disease. Nutrients 2018; 10:nu10040512. [PMID: 29677110 PMCID: PMC5946297 DOI: 10.3390/nu10040512] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 01/19/2023] Open
Abstract
Chronic kidney disease and reduced glomerular filtration rate are risk factors for the development of chronic metabolic acidosis. The prevention or correction of chronic metabolic acidosis has been found to slow progression of chronic kidney disease. Dietary composition can strongly affect acid–base balance. Major determinants of net endogenous acid production are the generation of large amounts of hydrogen ions, mostly by animal-derived protein, which is counterbalanced by the metabolism of base-producing foods like fruits and vegetables. Alkali therapy of chronic metabolic acidosis can be achieved by providing an alkali-rich diet or oral administration of alkali salts. The primary goal of dietary treatment should be to increase the proportion of fruits and vegetables and to reduce the daily protein intake to 0.8–1.0 g per kg body weight. Diet modifications should begin early, i.e., even in patients with moderate kidney impairment, because usual dietary habits of many developed societies contribute an increased proportion of acid equivalents due to the high intake of protein from animal sources.
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Nixon AC, Bampouras TM, Pendleton N, Woywodt A, Mitra S, Dhaygude A. Frailty and chronic kidney disease: current evidence and continuing uncertainties. Clin Kidney J 2018; 11:236-245. [PMID: 29644065 PMCID: PMC5888002 DOI: 10.1093/ckj/sfx134] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/16/2017] [Indexed: 12/12/2022] Open
Abstract
Frailty, the state of increased vulnerability to physical stressors as a result of progressive and sustained degeneration in multiple physiological systems, is common in those with chronic kidney disease (CKD). In fact, the prevalence of frailty in the older adult population is reported to be 11%, whereas the prevalence of frailty has been reported to be greater than 60% in dialysis-dependent CKD patients. Frailty is independently linked with adverse clinical outcomes in all stages of CKD and has been repeatedly shown to be associated with an increased risk of mortality and hospitalization. In recent years there have been efforts to create an operationalized definition of frailty to aid its diagnosis and to categorize its severity. Two principal concepts are described, namely the Fried Phenotype Model of Physical Frailty and the Cumulative Deficit Model of Frailty. There is no agreement on which frailty assessment approach is superior, therefore, for the time being, emphasis should be placed on any efforts to identify frailty. Recognizing frailty should prompt a holistic assessment of the patient to address risk factors that may exacerbate its progression and to ensure that the patient has appropriate psychological and social support. Adequate nutritional intake is essential and individualized exercise programmes should be offered. The acknowledgement of frailty should prompt discussions that explore the future care wishes of these vulnerable patients. With further study, nephrologists may be able to use frailty assessments to inform discussions with patients about the initiation of renal replacement therapy.
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Affiliation(s)
- Andrew C Nixon
- Department of Renal Medicine, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, UK
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | | | - Neil Pendleton
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK
| | - Alexander Woywodt
- Department of Renal Medicine, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, UK
| | - Sandip Mitra
- Manchester Academy of Health Sciences Centre and NIHR Devices for Dignity, Health Technology Cooperative, Manchester, UK
| | - Ajay Dhaygude
- Department of Renal Medicine, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, UK
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Bushinsky DA, Hostetter T, Klaerner G, Stasiv Y, Lockey C, McNulty S, Lee A, Parsell D, Mathur V, Li E, Buysse J, Alpern R. Randomized, Controlled Trial of TRC101 to Increase Serum Bicarbonate in Patients with CKD. Clin J Am Soc Nephrol 2018; 13:26-35. [PMID: 29102959 PMCID: PMC5753317 DOI: 10.2215/cjn.07300717] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/10/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Metabolic acidosis is common in patients with CKD and has significant adverse effects on kidney, muscle, and bone. We tested the efficacy and safety of TRC101, a novel, sodium-free, nonabsorbed hydrochloric acid binder, to increase serum bicarbonate in patients with CKD and metabolic acidosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS One hundred thirty-five patients were enrolled in this randomized, double-blind, placebo-controlled, multicenter, in-unit study (designated the TRCA-101 Study). Patients had a mean baseline eGFR of 35 ml/min per 1.73 m2, a mean baseline serum bicarbonate of 17.7 mEq/L, and comorbidities, including hypertension (93%), diabetes (70%), and heart failure (21%). Patients ate a controlled diet and were treated for 14 days with placebo or one of four TRC101 dosing regimens (1.5, 3, or 4.5 g twice daily or 6 g once daily). After treatment, patients were discharged and followed for 7-14 days. RESULTS All TRC101 treatment groups had a mean within-group increase in serum bicarbonate of ≥1.3 mEq/L (P<0.001) within 72 hours of the first dose and a mean increase in serum bicarbonate of 3.2-3.9 mEq/L (P<0.001) at the end of treatment compared with placebo, in which serum bicarbonate did not change. In the combined TRC101 treatment group, serum bicarbonate was normalized (22-29 mEq/L) at the end of treatment in 35% of patients and increased by ≥4 mEq/L in 39% of patients. After discontinuation of TRC101, serum bicarbonate decreased nearly to baseline levels within 2 weeks. All adverse events were mild or moderate, with gastrointestinal events most common. All patients completed the study. CONCLUSIONS TRC101 safely and significantly increased the level of serum bicarbonate in patients with metabolic acidosis and CKD.
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Affiliation(s)
- David A. Bushinsky
- Department of Medicine, University of Rochester School of Medicine, Rochester, New York
| | - Thomas Hostetter
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | | | - Yuri Stasiv
- Tricida Inc., South San Francisco, California
| | | | | | - Angela Lee
- Tricida Inc., South San Francisco, California
| | | | | | | | | | - Robert Alpern
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
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Affiliation(s)
- Denver Brown
- Departments of Pediatrics and Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York
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Abstract
Metabolic acidosis is not uncommon in CKD and is linked with bone demineralization, muscle catabolism, and higher risks of CKD progression and mortality. Clinical practice guidelines recommend maintaining serum total CO2 at ≥22 mEq/L to help prevent these complications. Although a definitive trial testing whether correcting metabolic acidosis improves clinical outcomes has not been conducted, results from small, single-center studies support this notion. Furthermore, biologic plausibility supports the notion that a subset of patients with CKD have acid-mediated organ injury despite having a normal serum total CO2 and might benefit from oral alkali before overt acidosis develops. Identifying these individuals with subclinical metabolic acidosis is challenging, but recent results suggest that urinary acid excretion measurements may be helpful. The dose of alkali to provide in this setting is unknown as well. The review discusses these topics and the prevalence and risk factors of metabolic acidosis, mechanisms of acid-mediated organ injury, results from interventional studies, and potential harms of alkali therapy in CKD.
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Affiliation(s)
- Kalani L Raphael
- Veterans Affairs Salt Lake City Health Care System and Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
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Peritoneal dialysis: The unique features by compartmental delivery of renal replacement therapy. Med Hypotheses 2017; 108:128-132. [PMID: 29055386 DOI: 10.1016/j.mehy.2017.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/06/2017] [Indexed: 11/23/2022]
Abstract
Despite decades of research, the clinical efficacy of peritoneal dialysis (PD) remains enigmatic. We may wonder why the modality fail in some patients but perhaps the more proper question would be, why it works in so many? We know that the contribution of residual renal function (RRF), more so than in hemodialysis, is critically important to the well-being of many of the patients. Unique features of the modality include the relatively low volume of dialysate fluid needed to provide effective uremic control and the disproportionate tendency for both hypokalemia and hypoalbuminemia, when compared to hemodialysis. It is currently believed that most uremic toxins are generated on the interface of human and bacterial structures in the gastrointestinal tract, the intestinal biota. PD offers disproportionate removal of these toxins upon "first-pass", i.e., via PD fluid exchanges before reaching the systemic circulation beyond the gastrointestinal compartment. Studies examining the net removal gradient of protein-bound uremic toxins during PD are scarce, whereas RRF receives considerably more attention without effective interventions being developed to preserve it. We propose an alternative view on PD, emphasizing the modality's compartmental nature, both for its benefits and the limitations.
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Goraya N, Wesson DE. Management of the Metabolic Acidosis of Chronic Kidney Disease. Adv Chronic Kidney Dis 2017; 24:298-304. [PMID: 29031356 DOI: 10.1053/j.ackd.2017.06.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/27/2017] [Indexed: 01/31/2023]
Abstract
Subjects with CKD and reduced glomerular filtration rate are at risk for chronic metabolic acidosis, and CKD is its most common cause. Untreated metabolic acidosis, even in its mildest forms, is associated with increased mortality and morbidity and should therefore be treated. If reduced glomerular filtration rate or the tubule abnormality causing chronic metabolic acidosis cannot be corrected, it is typically treated with dietary acid (H+) reduction using Na+-based alkali, usually NaHCO3. Dietary H+ reduction can also be accomplished with the addition of base-producing foods such as fruits and vegetables and limiting intake of H+-producing foods like animal-sourced protein. The optimal dose of Na+-based alkali that prevents the untoward effects of metabolic acidosis while minimizing adverse effects and the appropriate combination of this traditional therapy with dietary strategies remain to be determined by ongoing studies. Recent emerging evidence supports a phenomenon of H+ retention, which precedes the development of metabolic acidosis by plasma acid-base parameters, but further studies will be needed to determine how best to identify patients with this phenomenon and whether they too should be treated with dietary H+ reduction.
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Zha Y, Qian Q. Protein Nutrition and Malnutrition in CKD and ESRD. Nutrients 2017; 9:nu9030208. [PMID: 28264439 PMCID: PMC5372871 DOI: 10.3390/nu9030208] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/23/2017] [Indexed: 01/28/2023] Open
Abstract
Elevated protein catabolism and protein malnutrition are common in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The underlying etiology includes, but is not limited to, metabolic acidosis intestinal dysbiosis; systemic inflammation with activation of complements, endothelin-1 and renin-angiotensin-aldosterone (RAAS) axis; anabolic hormone resistance; energy expenditure elevation; and uremic toxin accumulation. All of these derangements can further worsen kidney function, leading to poor patient outcomes. Many of these CKD-related derangements can be prevented and substantially reversed, representing an area of great potential to improve CKD and ESRD care. This review integrates known information and recent advances in the area of protein nutrition and malnutrition in CKD and ESRD. Management recommendations are summarized. Thorough understanding the pathogenesis and etiology of protein malnutrition in CKD and ESRD patients will undoubtedly facilitate the design and development of more effective strategies to optimize protein nutrition and improve outcomes.
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Affiliation(s)
- Yan Zha
- Department of Nephrology, Guizhou Provincial People's Hospital, Guizhou 550002, China.
| | - Qi Qian
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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Dhondup T, Qian Q. Electrolyte and Acid-Base Disorders in Chronic Kidney Disease and End-Stage Kidney Failure. Blood Purif 2017; 43:179-188. [PMID: 28114143 DOI: 10.1159/000452725] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The kidneys play a pivotal role in the regulation of electrolyte and acid-base balance. With progressive loss of kidney function, derangements in electrolytes and acid-base inevitably occur and contribute to poor patient outcomes. As chronic kidney disease (CKD) has become a worldwide epidemic, medical providers are increasingly confronted with such problems. Adequate diagnosis and treatment will minimize complications and can potentially be lifesaving. In this review, we discuss the current understanding of the disease process, clinical presentation, diagnosis and treatment strategies, integrating up-to-date knowledge in the field. Although electrolyte and acid-base derangements are significant causes of morbidity and mortality in CKD and end-stage renal disease patients, they can be effectively managed through a timely institution of combined preventive measures and pharmacological therapy. Exciting advances and several upcoming outcome trials will provide further information to guide treatment and improve patient outcomes.
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Affiliation(s)
- Tsering Dhondup
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, College of Medicine, Rochester, MN, USA
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Glaser J, Lemery J, Rajagopalan B, Diaz HF, García-Trabanino R, Taduri G, Madero M, Amarasinghe M, Abraham G, Anutrakulchai S, Jha V, Stenvinkel P, Roncal-Jimenez C, Lanaspa MA, Correa-Rotter R, Sheikh-Hamad D, Burdmann EA, Andres-Hernando A, Milagres T, Weiss I, Kanbay M, Wesseling C, Sánchez-Lozada LG, Johnson RJ. Climate Change and the Emergent Epidemic of CKD from Heat Stress in Rural Communities: The Case for Heat Stress Nephropathy. Clin J Am Soc Nephrol 2016; 11:1472-1483. [PMID: 27151892 PMCID: PMC4974898 DOI: 10.2215/cjn.13841215] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Climate change has led to significant rise of 0.8°C-0.9°C in global mean temperature over the last century and has been linked with significant increases in the frequency and severity of heat waves (extreme heat events). Climate change has also been increasingly connected to detrimental human health. One of the consequences of climate-related extreme heat exposure is dehydration and volume loss, leading to acute mortality from exacerbations of pre-existing chronic disease, as well as from outright heat exhaustion and heat stroke. Recent studies have also shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN. Epidemics of CKD consistent with heat stress nephropathy are now occurring across the world. Here, we describe this disease, discuss the locations where it appears to be manifesting, link it with increasing temperatures, and discuss ongoing attempts to prevent the disease. Heat stress nephropathy may represent one of the first epidemics due to global warming. Government, industry, and health policy makers in the impacted regions should place greater emphasis on occupational and community interventions.
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Affiliation(s)
- Jason Glaser
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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Chen W, Melamed ML, Hostetter TH, Bauer C, Raff AC, Almudevar AL, Lalonde A, Messing S, Abramowitz MK. Effect of oral sodium bicarbonate on fibroblast growth factor-23 in patients with chronic kidney disease: a pilot study. BMC Nephrol 2016; 17:114. [PMID: 27495287 PMCID: PMC4974735 DOI: 10.1186/s12882-016-0331-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/02/2016] [Indexed: 12/16/2022] Open
Abstract
Background The regulation of fibroblast growth factor-23 (FGF23) secretion in patients with chronic kidney disease (CKD) is incompletely understood. An in vitro study showed that metabolic acidosis increased FGF23 in mouse bone. The objective of this study is to evaluate the effect of oral sodium bicarbonate on circulating FGF23 levels in patients with CKD. Methods This was a single-blind pilot study. Twenty adults with estimated glomerular filtration rate between 15–45 mL/min/1.73 m2 and serum bicarbonate between 20–24 mEq/L were treated with placebo for 2 weeks, followed by increasing doses of oral sodium bicarbonate (0.3, 0.6 and 1.0 mEq/kg/day) in 2 week intervals for a total of 6 weeks. C-terminal FGF23 levels were measured at the initial visit, after 2 weeks of placebo and after 6 weeks of bicarbonate therapy. Wilcoxon matched-pairs signed-rank test was used to compare FGF23 before and after sodium bicarbonate. Results After 6 weeks of oral sodium bicarbonate, the median FGF23 increased significantly from 150.9 RU/mL (IQR 107.7–267.43) to 191.4 RU/mL (IQR 132.6–316.9) (p = 0.048) and this persisted after excluding participants who received activated vitamin D. Conclusions FGF23 increased after short-term oral sodium bicarbonate therapy in patients with CKD and mild metabolic acidosis. It is unclear whether this was due to the alkalinizing effect of sodium bicarbonate or other factors. Trial registration The study was registered at ClinicalTrials.gov (NCT00888290) on April 23, 2009.
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Affiliation(s)
- Wei Chen
- Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 675, Rochester, NY, 14642, USA.
| | - Michal L Melamed
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Thomas H Hostetter
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Carolyn Bauer
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Amanda C Raff
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Anthony L Almudevar
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Amy Lalonde
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Susan Messing
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Matthew K Abramowitz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
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Misra M. Pro: Higher serum bicarbonate in dialysis patients is protective: Table 1. Nephrol Dial Transplant 2016; 31:1220-4. [DOI: 10.1093/ndt/gfw259] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/11/2015] [Indexed: 01/11/2023] Open
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Melamed ML, Buttar RS, Coco M. CKD-Mineral Bone Disorder in Stage 4 and 5 CKD: What We Know Today? Adv Chronic Kidney Dis 2016; 23:262-9. [PMID: 27324680 PMCID: PMC5034723 DOI: 10.1053/j.ackd.2016.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 01/20/2016] [Accepted: 03/29/2016] [Indexed: 11/11/2022]
Abstract
Patients with CKD stages 4 and 5 experience biochemical derangements associated with CKD-mineral bone disorder. Some of the key abnormalities are hyperparathyroidism, hyperphosphatemia, hypocalcemia, and metabolic acidosis. We review the available treatments for these conditions and the evidence behind the treatments. We conclude that there is greater evidence for treating hyperphosphatemia than hyperparathyroidism. Treatment of metabolic acidosis in small clinical trials appears to be safe. We caution the reader about side effects associated with some of these treatments that differ in patients with CKD Stages 4 and 5 compared with patients on dialysis. The use of cinacalcet has been associated with hyperphosphatemia in patients with functioning kidneys. Activated vitamin D therapy has been associated with elevated creatinine levels, which may or may not be a reflection of true decrement in kidney function. Finally, the use of non-calcium-containing phosphate binders may be associated with improved clinical outcomes in patients; however, many more clinical trials are needed in this important area of medicine.
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Affiliation(s)
- Michal L Melamed
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY.
| | - Rupinder Singh Buttar
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY
| | - Maria Coco
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY
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Packham DK, Kosiborod M. Pharmacodynamics and pharmacokinetics of sodium zirconium cyclosilicate [ZS-9] in the treatment of hyperkalemia. Expert Opin Drug Metab Toxicol 2016; 12:567-73. [PMID: 26998854 DOI: 10.1517/17425255.2016.1164691] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Hyperkalemia is a common electrolyte disorder that arises from dysfunctional homeostatic mechanisms or as a consequence of decreased renal function. Sodium zirconium cyclosilicate (ZS-9) is a potential new therapy for hyperkalemia in both acute and chronic settings. AREAS COVERED Here we discuss mechanisms of potassium homeostasis and preclinical and clinical studies that present pharmacokinetics/pharmacodynamics, efficacy and safety profiles of ZS-9. EXPERT OPINION ZS-9 has a unique mechanism of action consisting of thermodynamically favorable sequestration of potassium ions, enabling rapid trapping and removal of excess potassium. The potassium lowering action of ZS-9 is predictable and rapid, leading to significant reduction of serum potassium within 1 hour of administration by irreversibly eliminating excess potassium rather than acting via intracellular translocation. Its safety profile, including gastrointestinal events, has been generally similar to that of placebo, with the exception of infrequent but manageable events of peripheral edema and transient hypokalemia. ZS-9 has demonstrated potential for enabling renin-angiotensin-aldosterone system inhibitors in mid-term studies, with long-term studies ongoing.
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Affiliation(s)
- David K Packham
- a Melbourne Renal Research Group and Departments of Medicine , University of Melbourne and Nephrology, Royal Melbourne Hospital , Melbourne , VIC , Australia
| | - Mikhail Kosiborod
- b Saint Luke's Mid America Heart Institute , University of Missouri , Kansas City , MO , USA
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Kraut JA, Madias NE. Metabolic Acidosis of CKD: An Update. Am J Kidney Dis 2015; 67:307-17. [PMID: 26477665 DOI: 10.1053/j.ajkd.2015.08.028] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 08/01/2015] [Indexed: 01/02/2023]
Abstract
The kidney has the principal role in the maintenance of acid-base balance. Therefore, a decrease in renal ammonium excretion and a positive acid balance often leading to a reduction in serum bicarbonate concentration are observed in the course of chronic kidney disease (CKD). The decrease in serum bicarbonate concentration is usually absent until glomerular filtration rate decreases to <20 to 25mL/min/1.73 m(2), although it can develop with lesser degrees of decreased kidney function. Non-anion gap acidosis, high-anion gap acidosis, or both can be found at all stages of CKD. The acidosis can be associated with muscle wasting, bone disease, hypoalbuminemia, inflammation, progression of CKD, and increased mortality. Administration of base may decrease muscle wasting, improve bone disease, and slow the progression of CKD. Base is suggested when serum bicarbonate concentration is <22 mEq/L, but the target serum bicarbonate concentration is unclear. Evidence that increments in serum bicarbonate concentration > 24 mEq/L might be associated with worsening of cardiovascular disease adds complexity to treatment decisions. Further study of the mechanisms through which metabolic acidosis contributes to the progression of CKD, as well as the pathways involved in mediating the benefits and complications of base therapy, is warranted.
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Affiliation(s)
- Jeffrey A Kraut
- Medical and Research Services, VHAGLA Healthcare System, UCLA Membrane Biology Laboratory, Los Angeles, CA; Division of Nephrology, VHAGLA Healthcare System and David Geffen School of Medicine, Los Angeles, CA.
| | - Nicolaos E Madias
- Department of Medicine, Division of Nephrology, St. Elizabeth's Medical Center, Boston, MA; Department of Medicine, Tufts University School of Medicine, Boston, MA.
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Roncal-Jimenez C, García-Trabanino R, Barregard L, Lanaspa MA, Wesseling C, Harra T, Aragón A, Grases F, Jarquin ER, González MA, Weiss I, Glaser J, Sánchez-Lozada LG, Johnson RJ. Heat Stress Nephropathy From Exercise-Induced Uric Acid Crystalluria: A Perspective on Mesoamerican Nephropathy. Am J Kidney Dis 2015; 67:20-30. [PMID: 26455995 DOI: 10.1053/j.ajkd.2015.08.021] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 08/07/2015] [Indexed: 11/11/2022]
Abstract
Mesoamerican nephropathy (MeN), an epidemic in Central America, is a chronic kidney disease of unknown cause. In this article, we argue that MeN may be a uric acid disorder. Individuals at risk for developing the disease are primarily male workers exposed to heat stress and physical exertion that predisposes to recurrent water and volume depletion, often accompanied by urinary concentration and acidification. Uric acid is generated during heat stress, in part consequent to nucleotide release from muscles. We hypothesize that working in the sugarcane fields may result in cyclic uricosuria in which uric acid concentrations exceed solubility, leading to the formation of dihydrate urate crystals and local injury. Consistent with this hypothesis, we present pilot data documenting the common presence of urate crystals in the urine of sugarcane workers from El Salvador. High end-of-workday urinary uric acid concentrations were common in a pilot study, particularly if urine pH was corrected to 7. Hyperuricemia may induce glomerular hypertension, whereas the increased urinary uric acid may directly injure renal tubules. Thus, MeN may result from exercise and heat stress associated with dehydration-induced hyperuricemia and uricosuria. Increased hydration with water and salt, urinary alkalinization, reduction in sugary beverage intake, and inhibitors of uric acid synthesis should be tested for disease prevention.
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Affiliation(s)
| | - Ramón García-Trabanino
- Scientific Board, Department of Investigation, Hospital Nacional Rosales, San Salvador, El Salvador
| | - Lars Barregard
- Occupational and Environmental Medicine, Sahlgrenska University Hospital and University of Gothenburg, Gothenburg, Sweden
| | - Miguel A Lanaspa
- Division of Kidney Diseases and Hypertension, University of Colorado, Denver, CO
| | - Catharina Wesseling
- Unit of Occupational Medicine, Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden
| | - Tamara Harra
- Division of Kidney Diseases and Hypertension, University of Colorado, Denver, CO
| | - Aurora Aragón
- Research Center on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), León, Nicaragua
| | - Felix Grases
- University of Balearic Islands, Palma de Mallorca, Spain
| | - Emmanuel R Jarquin
- Agencia para el Desarrollo y la Salud Agropecuaria, San Salvador, El Salvador
| | - Marvin A González
- Research Center on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), León, Nicaragua; Department of Non-communicable Disease Epidemiology of London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ilana Weiss
- La Isla Foundation, San Salvador, El Salvador
| | | | - Laura G Sánchez-Lozada
- Laboratory of Renal Physiopathology and Nephrology Department, INC Ignacio Chavez, Mexico City, Mexico
| | - Richard J Johnson
- Division of Kidney Diseases and Hypertension, University of Colorado, Denver, CO; Division of Nephrology, Eastern Colorado Health Care System, Department of Veteran Affairs, Denver, CO.
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Weiner ID, Mitch WE, Sands JM. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion. Clin J Am Soc Nephrol 2015; 10:1444-58. [PMID: 25078422 PMCID: PMC4527031 DOI: 10.2215/cjn.10311013] [Citation(s) in RCA: 237] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.
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Affiliation(s)
- I David Weiner
- Nephrology and Hypertension Section, North Florida/South Georgia Veterans Health System, Gainesville, Florida; Division of Nephrology, Hypertension, and Transplantation, University of Florida College of Medicine, Gainesville, Florida;
| | - William E Mitch
- Nephrology Division, Baylor College of Medicine, Houston, Texas; and
| | - Jeff M Sands
- Nephrology Division, Emory University School of Medicine, Atlanta, Georgia
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Pratten J, Wiecek J, Mordan N, Lomax A, Patel N, Spratt D, Middleton AM. Physical disruption of oral biofilms by sodium bicarbonate: an in vitro study. Int J Dent Hyg 2015. [PMID: 26198308 DOI: 10.1111/idh.12162] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Sodium bicarbonate has been shown clinically to be efficacious at removing dental plaque; however, its effect of mechanism against biofilms has not been evaluated in vitro. Here, we used a well-established in vitro plaque biofilm model to investigate the disruption of dental plaque biofilms. METHODS Biofilms were grown in a constant depth film fermentor for up to 14 days. The fermentor was inoculated with pooled human saliva and growth maintained with artificial saliva. After various time points, replicate biofilms were removed and subjected to treatment at varying concentrations of sodium bicarbonate. Disruption of the plaque was assessed by viable counts and microscopy. RESULTS The viable count results showed that younger biofilms were less susceptible to the action of sodium bicarbonate; however, biofilms of 7 days and older were increasingly susceptible to the material with the oldest biofilms being the most susceptible. Sixty-seven percentage of sodium bicarbonate slurry was able to reduce the number of organisms present by approx. 3 log10 . These quantitative data were corroborated qualitatively with both confocal and electron microscopy, which both showed substantial qualitative removal of mature biofilms. CONCLUSIONS The results from this study have shown that sodium bicarbonate is able to disrupt mature dental plaque grown in vitro and that its reported efficacy in maintaining oral hygiene may be related to this key factor.
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Affiliation(s)
- J Pratten
- GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, UK
| | - J Wiecek
- UCL Eastman Dental Institute, London, UK
| | - N Mordan
- UCL Eastman Dental Institute, London, UK
| | - A Lomax
- GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, UK
| | - N Patel
- GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, UK
| | - D Spratt
- UCL Eastman Dental Institute, London, UK
| | - A M Middleton
- GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, UK
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de-Brito Ashurst I, O'Lone E, Kaushik T, McCafferty K, Yaqoob MM. Acidosis: progression of chronic kidney disease and quality of life. Pediatr Nephrol 2015; 30:873-9. [PMID: 25085611 DOI: 10.1007/s00467-014-2873-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 05/23/2014] [Accepted: 05/30/2014] [Indexed: 11/25/2022]
Abstract
Metabolic acidosis (MA) is relatively common in patients with chronic kidney disease (CKD) particularly in stages 4 and 5. It is assumed to play a contributory role in the development of several complications including bone disease, skeletal muscle wasting, altered protein synthesis, and degradation. Recent evidence also suggests that even mild acidosis might play a role in progressive glomerular filtration rate loss. Experimental and clinical studies suggest that correction of acidosis by alkali therapy attenuates these complications and improves quality of life. Despite several recent small and single-center studies supporting this notion, more robust evidence is required with regard to the long-term benefits of alkali therapy, type of alkali supplements, and the optimal level of serum bicarbonate.
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Affiliation(s)
- Ione de-Brito Ashurst
- Department of Renal Medicine and Transplantation, Barts Health NHS Trust, Cardiovascular Biological Research Unit and William Harvey Research Institute, London, UK
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Abstract
Metabolic acidosis was one of the earliest complications to be recognized and explained pathologically in patients with CKD. Despite the accumulated evidence of deleterious effects of acidosis, treatment of acidosis has been tested very little, especially with respect to standard clinical outcomes. On the basis of fundamental research and small alkali supplementation trials, correcting metabolic acidosis has a strikingly broad array of potential benefits. This review summarizes the published evidence on the association between serum bicarbonate and clinical outcomes. We discuss the role of alkali supplementation in CKD as it relates to retarding kidney disease progression, improving metabolic and musculoskeletal complications.
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Affiliation(s)
- Mirela Dobre
- Division of Nephrology and Hypertension, Case Western Reserve University, University Hospital Case Medical Center, Cleveland, Ohio
| | - Mahboob Rahman
- Division of Nephrology and Hypertension, Case Western Reserve University, University Hospital Case Medical Center, Cleveland, Ohio
| | - Thomas H Hostetter
- Division of Nephrology and Hypertension, Case Western Reserve University, University Hospital Case Medical Center, Cleveland, Ohio
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Ori Y, Zingerman B, Bergman M, Bessler H, Salman H. The effect of sodium bicarbonate on cytokine secretion in CKD patients with metabolic acidosis. Biomed Pharmacother 2015; 71:98-101. [PMID: 25960222 DOI: 10.1016/j.biopha.2015.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/12/2015] [Indexed: 10/23/2022] Open
Abstract
The incidence of acidosis increases with the progression of chronic kidney disease (CKD). Correction of acidosis by sodium bicarbonate may slow CKD deterioration. Inflammation, which is common in CKD, may be related to acidosis. Whether the slower rate of GFR decline following the correction of acidosis is related to changes in inflammatory markers is unknown. The current study examined whether correcting CKD-acidosis affected inflammatory cytokines secretion. Thirteen patients with CKD 4-5 and acidosis were tested for cytokines secretion from peripheral-blood mononuclear cells at baseline and after one month of oral sodium bicarbonate. Following treatment with sodium bicarbonate there was no change in weight, blood pressure, serum creatinine, albumin, sodium, calcium, phosphate, PTH, hemoglobin and CRP. Serum urea decreased (134±10-116±8 mg/dl, P=0.002), potassium decreased (5.1±0.4-4.8±0.1 mequiv./l, P=0.064), pH increased (7.29±0.01-7.33±0.01, P=0.008), and serum bicarbonate increased (18.6±0.4 mequiv./l to 21.3±0.3 mequiv./l, P=0.001). The secretion of the anti-inflammatory cytokine IL-10 decreased (2.75±0.25 ng/ml to 2.29±0.21 ng/ml, P=0.041). There was no significant change in the secretion of the other pro-inflammatory and anti-inflammatory cytokines, including IL-1β, IL-2, IL-6, TNFα, IFNγ, IL-1ra. Thus, correcting acidosis in CKD with bicarbonate decreases IL-10 secretion. Its significance needs to be further investigated.
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Affiliation(s)
- Yaacov Ori
- Department of Nephrology and Hypertension, Rabin Medical Center-Hasharon Hospital, Petah-Tiqva, Israel; Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel.
| | - Boris Zingerman
- Department of Nephrology and Hypertension, Rabin Medical Center-Hasharon Hospital, Petah-Tiqva, Israel; Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel
| | - Michael Bergman
- Department of Nephrology and Hypertension, Rabin Medical Center-Hasharon Hospital, Petah-Tiqva, Israel; Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel
| | - Hanna Bessler
- Laboratory for Immunology and Hematology Research, Rabin Medical Center-Hasharon Hospital, Petah-Tiqva, Israel; Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel
| | - Hertzel Salman
- Department of Internal Medicine C, Rabin Medical Center-Hasharon Hospital, Petah-Tiqva, Israel; Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Israel
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Olek RA, Luszczyk M, Kujach S, Ziemann E, Pieszko M, Pischel I, Laskowski R. Single pyruvate intake induces blood alkalization and modification of resting metabolism in humans. Nutrition 2015; 31:466-74. [PMID: 25701336 DOI: 10.1016/j.nut.2014.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/18/2014] [Accepted: 09/26/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Three separate studies were performed with the aim to 1) determine the effect of a single sodium pyruvate intake on the blood acid-base status in males and females; 2) compare the effect of sodium and calcium pyruvate salts and establish their role in the lipolysis rate; and 3) quantify the effect of single pyruvate intake on the resting energy metabolism. METHODS In all, 48 individuals completed three separate studies. In all the studies, participants consumed a single dose of pyruvate 0.1 g/kg 60 min before commencing the measurements. The whole blood pH, bicarbonate concentration, base excess or plasma glycerol, free fatty acids, glucose concentrations, or resting energy expenditure and calculated respiratory exchange ratio were determined. The analysis of variance for repeated measurements was performed to examine the interaction between treatment and time. RESULTS The single dose of sodium pyruvate induced blood alkalization, which was more marked in the male than in the female participants. Following the ingestion of sodium or calcium pyruvate, the blood acid-base parameters were higher than in the placebo trial. Furthermore, 3-h postingestion glycerol was lower in both pyruvate trials than in placebo. Resting energy expenditure did not differ between the trials; however, carbohydrate oxidation was increased after sodium pyruvate ingestion. CONCLUSION Pyruvate intake induced mild alkalization in a sex-dependent fashion. Moreover, it accelerated carbohydrate metabolism and delayed the rate of glycerol appearance in the blood, but had no effect on the resting energy expenditure. Furthermore, sodium salt seems to have had a greater effect on the blood buffering level than calcium salt.
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Affiliation(s)
- Robert A Olek
- Department of Biochemistry, University of Physical Education and Sport, Gdansk, Poland.
| | - Marcin Luszczyk
- Department of Physiology, University of Physical Education and Sport, Gdansk, Poland
| | - Sylwester Kujach
- Department of Physiology, University of Physical Education and Sport, Gdansk, Poland
| | - Ewa Ziemann
- Department of Physiology, University of Physical Education and Sport, Gdansk, Poland
| | - Magdalena Pieszko
- Department of Clinical Nutrition, Medical University of Gdansk, Gdansk, Poland
| | - Ivo Pischel
- Centre for Pharmacognosy and Phytotherapy, UCL School of Pharmacy, University of London, London, United Kingdom; Phytolab GmbH & Co. KG, Vestenbergsgreuth, Germany
| | - Radoslaw Laskowski
- Department of Physiology, University of Physical Education and Sport, Gdansk, Poland
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A phase 2 study on the treatment of hyperkalemia in patients with chronic kidney disease suggests that the selective potassium trap, ZS-9, is safe and efficient. Kidney Int 2015; 88:404-11. [PMID: 25651363 PMCID: PMC4526769 DOI: 10.1038/ki.2014.382] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/17/2014] [Accepted: 10/01/2014] [Indexed: 01/04/2023]
Abstract
Hyperkalemia contributes to significant mortality and limits the use of cardioprotective and renoprotective renin-angiotensin-aldosterone blockers. Current therapies are poorly tolerated and not always effective. Here we conducted a phase 2 randomized, double-blind, placebo-controlled dose-escalation study to assess safety and efficacy of ZS-9. This oral selective cation exchanger that preferentially entraps potassium in the gastrointestinal tract was given to patients with stable Stage 3 chronic kidney disease and hyperkalemia (5.0 to 6.0 mEq/l) during a 2-day period. Of 90 eligible patients with mean baseline serum potassium of 5.1 mEq/l, 30 were randomized to placebo, 12-0.3 g, 24-3 g, or 24 to 10 g of ZS-9 three times daily for 2 days with regular meals. None withdrew and ZS-9 dose-dependently reduced serum potassium. The primary efficacy end point (rate of serum potassium decline in the first 48 h) was met with significance in the 3- and 10-g cohorts. From baseline, mean serum potassium was significantly decreased by 0.92±0.52 mEq/l at 38 h. Urinary potassium excretion significantly decreased with 10-g ZS-9 as compared to placebo at day 2 (+15.8 +/- 21.8 vs. +8.9 +/- 22.9 mEq per 24h) from placebo at day 2. In this short-term study, no serious adverse events were reported; only mild constipation in the 3-g dose group was possibly related to treatment. Thus, ZS-9 was well-tolerated in patients with stable chronic kidney disease and hyperkalemia leading to a rapid, sustained reduction in serum potassium.
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82
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Jeong J, Kwon SK, Kim HY. Effect of bicarbonate supplementation on renal function and nutritional indices in predialysis advanced chronic kidney disease. Electrolyte Blood Press 2014; 12:80-7. [PMID: 25606047 PMCID: PMC4297707 DOI: 10.5049/ebp.2014.12.2.80] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 12/19/2014] [Indexed: 02/06/2023] Open
Abstract
Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR <15mL/min per 1.73m2) and 40 patients with stage 4 CKD (eGFR 15 to 30mL/min per 1.73m2) who had a total CO2 less than 22mEq/L were assigned into the bicarbonate treatment group or control group for 12 months. In stage 4 CKD, there were significant differences in the changes of eGFR during the study between the treatment group and the control group (-2.30±4.49 versus -6.58±6.32mL/min/1.73m2, p<0.05). However, in stage 5 CKD, there were no significant differences in the change of eGFR during the study between the two groups (-2.10±2.06 versus -3.23±1.95mL/min/1.73 m2).There were no significant differences in the changes of nutritional indices such as albumin, prealbumin, transferrin, total lymphocyte count (TLC), and Ondodera's prognostic nutritional index (OPNI) during the study between the two groups. In stage 5 CKD, there were significant differences in the changes of TLC and OPNI between the two groups. In conclusion, our results demonstrate that bicarbonate supplementation slows the rate of decline of renal function in stage 4 CKD and improves nutritional indices in stage 5 CKD. Alkali therapy in advanced CKD may have beneficial effect on renal function and malnutrition.
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Affiliation(s)
- Jiwon Jeong
- Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Soon Kil Kwon
- Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Hye-Young Kim
- Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
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Yenchek R, Ix JH, Rifkin DE, Shlipak MG, Sarnak MJ, Garcia M, Patel KV, Satterfield S, Harris TB, Newman AB, Fried LF. Association of serum bicarbonate with incident functional limitation in older adults. Clin J Am Soc Nephrol 2014; 9:2111-6. [PMID: 25381341 DOI: 10.2215/cjn.05480614] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Cross-sectional studies have found that low serum bicarbonate is associated with slower gait speed. Whether bicarbonate levels independently predict the development of functional limitation has not been previously studied. Whether bicarbonate was associated with incident persistent lower extremity functional limitation and whether the relationship differed in individuals with and without CKD were assessed in participants in the Health, Aging, and Body Composition study, a prospective study of well functioning older individuals DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Functional limitation was defined as difficulty in walking 0.25 miles or up 10 stairs on two consecutive reports 6 months apart in the same activity (stairs or walking). Kidney function was measured using eGFR by the Chronic Kidney Disease Epidemiology Collaboration creatinine equation, and CKD was defined as an eGFR<60 ml/min per 1.73 m(2). Serum bicarbonate was measured using arterialized venous blood gas. Cox proportional hazards analysis was used to assess the association of bicarbonate (<23, 23-25.9, and ≥26 mEq/L) with functional limitation. Mixed model linear regression was performed to assess the association of serum bicarbonate on change in gait speed over time. RESULTS Of 1544 participants, 412 participants developed incident persistent functional limitation events over a median 4.4 years (interquartile range, 3.1 to 4.5). Compared with ≥26 mEq/L, lower serum bicarbonate was associated with functional limitation. After adjustment for demographics, CKD, diabetes, body mass index, smoking, diuretic use, and gait speed, lower serum bicarbonate was significantly associated with functional limitation (hazard ratio, 1.35; 95% confidence interval, 1.08 to 1.68 and hazard ratio, 1.58; 95% confidence interval, 1.12 to 2.22 for bicarbonate levels from 23 to 25.9 and <23, respectively). There was not a significant interaction of bicarbonate with CKD. In addition, bicarbonate was not significantly associated with change in gait speed. CONCLUSIONS Lower serum bicarbonate was associated with greater risk of incident, persistent functional limitation. This association was present in individuals with and without CKD.
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Affiliation(s)
- Robert Yenchek
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Joachim H Ix
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Dena E Rifkin
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michael G Shlipak
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Mark J Sarnak
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Melissa Garcia
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Kushang V Patel
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Suzanne Satterfield
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Tamara B Harris
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Anne B Newman
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Linda F Fried
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
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Affiliation(s)
- Matthew K Abramowitz
- Department of Medicine, Division of Nephrology andDepartment of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
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85
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Kato A, Kido R, Onishi Y, Kurita N, Fukagawa M, Akizawa T, Fukuhara S. Association of serum bicarbonate with bone fractures in hemodialysis patients: the mineral and bone disorder outcomes study for Japanese CKD stage 5D patients (MBD-5D). Nephron Clin Pract 2014; 128:79-87. [PMID: 25378374 DOI: 10.1159/000365089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 06/04/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Bone fracture is often complicated in hemodialysis (HD) patients. Metabolic acidosis is related to bone disease and muscle wasting, but it is not known whether acid-base disturbance is associated with the risk of bone fractures. The aim of this study was to clarify the association of serum bicarbonate level with bone fracture in HD patients. METHODS Using a subcohort of the Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D), 890 prevalent HD patients (age: 62 years old, male: 62.8%, duration of dialysis: 8.3 years) with secondary hyperparathyroidism were studied. After measuring predialysis serum bicarbonate at a 2-day interdialytic interval, we prospectively followed them every 3 months, and examined the occurrence of any type of bone fracture or hospitalization due to fracture over a 3-year observation period. RESULTS Seventy-four bone fractures and 47 hospitalizations due to fracture were observed during the follow-up period. HD patients with serum bicarbonate <20 mmol/l had a 1.93 (95% CI 1.01-3.71)-fold higher risk for all-cause fractures than those with serum bicarbonate of 20.0-21.9 mmol/l. A higher bicarbonate level (≥22 mmol/l) was also related to an increased risk of bone fracture. A restricted cubic regression spline disclosed that the higher or the lower than 21.0 mmol/l of serum bicarbonate, the greater the risk for bone fracture. CONCLUSION Both a lower level and a higher level of predialysis bicarbonate concentration were associated with risk of bone fracture in HD patients with secondary hyperparathyroidism.
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Affiliation(s)
- Akihiko Kato
- Blood Purification Unit, Hamamatsu University Hospital, Hamamatsu, Japan
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Hung CC, Yang ML, Lin MY, Lin HYH, Lim LM, Kuo HT, Hwang SJ, Tsai JC, Chen HC. Dipyridamole treatment is associated with improved renal outcome and patient survival in advanced chronic kidney disease. Kaohsiung J Med Sci 2014; 30:599-607. [PMID: 25476097 DOI: 10.1016/j.kjms.2014.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 01/29/2023] Open
Abstract
Dipyridamole has been shown to decrease proteinuria and improve renal function progression especially in early chronic kidney disease (CKD) patients with glomerulonephropathy. A combination therapy of dipyridamole with aspirin could prevent second strokes in the general population. Whether these effects of dipyridamole are also true in advanced CKD patients and whether dipyridamole could improve renal outcomes or patient survival is unknown. We retrospectively analyzed an observational cohort of 3074 participants with CKD stage 3-5 from southern Taiwan, of whom 871 (28.3%) had received dipyridamole treatment ≥50 mg/d for ≥3 months and more than half of the observation period. The mean age was 63.6 ± 13.4 years and the mean estimated glomerular filtration rate (eGFR) was 25.5 mL/min/1.73 m(2). After inverse probability of treatment weighted adjustment by propensity score, there were no differences between the dipyridamole-treated and untreated groups. Dipyridamole treatment was associated with decreased odds for rapid eGFR decline [odds ratio, 0.755; 95% confidence interval (CI), 0.595-0.958; p = 0.007] and progression of urine protein-to-creatinine ratio (odds ratio, 0.655; 95% CI, 0.517-0.832; p = 0.002). In survival analysis, the dipyridamole-treated group was also associated with a decreased risk for end-stage renal disease (hazard ratio, 0.847; 95% CI, 0.733-0.980; p = 0.011) and all-cause mortality (hazard ratio, 0.765; 95% CI, 0.606-0.971; p = 0.001) but not for cardiovascular events. Our findings demonstrate that dipyridamole treatment is significantly associated with better renal outcomes and patient survival in patients with CKD stage 3-5. Further investigations are warranted to confirm these independent positive effects.
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Affiliation(s)
- Chi-Chih Hung
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Mei-Li Yang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Ming-Yen Lin
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hugo You-Hsien Lin
- Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Lee-Moay Lim
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Hung-Tien Kuo
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shang-Jyh Hwang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jer-Chia Tsai
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Hung-Chun Chen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Namba T, Takabatake Y, Kimura T, Takahashi A, Yamamoto T, Matsuda J, Kitamura H, Niimura F, Matsusaka T, Iwatani H, Matsui I, Kaimori J, Kioka H, Isaka Y, Rakugi H. Autophagic clearance of mitochondria in the kidney copes with metabolic acidosis. J Am Soc Nephrol 2014; 25:2254-66. [PMID: 24700866 DOI: 10.1681/asn.2013090986] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Metabolic acidosis, a common complication of CKD, causes mitochondrial stress by undefined mechanisms. Selective autophagy of impaired mitochondria, called mitophagy, contributes toward maintaining cellular homeostasis in various settings. We hypothesized that mitophagy is involved in proximal tubular cell adaptations to chronic metabolic acidosis. In transgenic mice expressing green fluorescent protein-tagged microtubule-associated protein 1 light chain 3 (GFP-LC3), NH4Cl loading increased the number of GFP puncta exclusively in the proximal tubule. In vitro, culture in acidic medium produced similar results in proximal tubular cell lines stably expressing GFP-LC3 and facilitated the degradation of SQSTM1/p62 in wild-type cells, indicating enhanced autophagic flux. Upon acid loading, proximal tubule-specific autophagy-deficient (Atg5-deficient) mice displayed significantly reduced ammonium production and severe metabolic acidosis compared with wild-type mice. In vitro and in vivo, acid loading caused Atg5-deficient proximal tubular cells to exhibit reduced mitochondrial respiratory chain activity, reduced mitochondrial membrane potential, and fragmented morphology with marked swelling in mitochondria. GFP-LC3-tagged autophagosomes colocalized with ubiquitinated mitochondria in proximal tubular cells cultured in acidic medium, suggesting that metabolic acidosis induces mitophagy. Furthermore, restoration of Atg5-intact nuclei in Atg5-deficient proximal tubular cells increased mitochondrial membrane potential and ammoniagenesis. In conclusion, metabolic acidosis induces autophagy in proximal tubular cells, which is indispensable for maintaining proper mitochondrial functions including ammoniagenesis, and thus for adapted urinary acid excretion. Our results provide a rationale for the beneficial effect of alkali supplementation in CKD, a condition in which autophagy may be reduced, and suggest a new therapeutic option for acidosis by modulating autophagy.
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Affiliation(s)
- Tomoko Namba
- Departments of Geriatric Medicine and Nephrology (B6)
| | | | - Tomonori Kimura
- Departments of Geriatric Medicine and Nephrology (B6), Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico; and
| | | | | | - Jun Matsuda
- Departments of Geriatric Medicine and Nephrology (B6)
| | | | | | - Taiji Matsusaka
- Institute of Medical Science and Department of Internal Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | | | - Isao Matsui
- Departments of Geriatric Medicine and Nephrology (B6)
| | | | - Hidetaka Kioka
- Medical Biochemistry, and Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | | | - Hiromi Rakugi
- Departments of Geriatric Medicine and Nephrology (B6)
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Cernaro V, Trifirò G, Lorenzano G, Lucisano S, Buemi M, Santoro D. New therapeutic strategies under development to halt the progression of renal failure. Expert Opin Investig Drugs 2014; 23:693-709. [DOI: 10.1517/13543784.2014.899352] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Chen JLT, Kalantar-Zadeh K. Is an increased serum bicarbonate concentration during hemodialysis associated with an increased risk of death? Semin Dial 2014; 27:259-62. [PMID: 24621002 DOI: 10.1111/sdi.12231] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Joline L T Chen
- Division of Nephrology and Hypertension, Harold Simmons Center for Kidney Disease Research and Epidemiology, University of California Irvine, Orange, California; Long Beach Veterans Affairs Healthcare System, Long Beach, California
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Łoniewski I, Wesson DE. Bicarbonate therapy for prevention of chronic kidney disease progression. Kidney Int 2013; 85:529-35. [PMID: 24107852 DOI: 10.1038/ki.2013.401] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/23/2013] [Accepted: 08/01/2013] [Indexed: 11/10/2022]
Abstract
Kidney injury in chronic kidney disease (CKD) is likely multifactorial, but recent data support that a component is mediated by mechanisms used by the kidney to increase acidification in response to an acid challenge to systemic acid-base status. If so, systemic alkalization might attenuate this acid-induced component of kidney injury. An acid challenge to systemic acid-base status increases nephron acidification through increased production of endothelin, aldosterone, and angiotensin II, each of which can contribute to kidney inflammation and fibrosis that characterizes CKD. Systemic alkalization that ameliorates an acid challenge might attenuate the contributions of angiotensin II, endothelin, and aldosterone to kidney injury. Some small clinical studies support the efficacy of alkalization in attenuating kidney injury and slowing glomerular filtration rate decline in CKD. This review focuses on the potential that orally administered NaHCO₃ prevents CKD progression and additionally addresses its mechanism of action, side effects, possible complications, dosage, interaction, galenic form description, and contraindications. Current National Kidney Foundation guidelines recommend oral alkali, including NaHCO₃(-), in CKD patients with serum HCO₃(-) <22 mmol/l. Although oral alkali can be provided by other medications and by base-inducing dietary constituents, oral NaHCO₃ will be the focus of this review because of its relative safety and apparent efficacy, and its comparatively low cost.
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Affiliation(s)
- Igor Łoniewski
- Sanum Polska Sp. z o.o. ul. Kurza Stopka 5/c, Szczecin, Poland
| | - Donald E Wesson
- 1] Department of Internal Medicine, Scott and White Healthcare, Temple, Texas, USA [2] Texas A&M Health Sciences Center College of Medicine, Temple, Texas, USA
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Workeneh B, Bajaj M. The regulation of muscle protein turnover in diabetes. Int J Biochem Cell Biol 2013; 45:2239-44. [DOI: 10.1016/j.biocel.2013.06.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 06/28/2013] [Accepted: 06/29/2013] [Indexed: 12/25/2022]
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Chen W, Abramowitz MK. Treatment of metabolic acidosis in patients with CKD. Am J Kidney Dis 2013; 63:311-7. [PMID: 23932089 DOI: 10.1053/j.ajkd.2013.06.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/19/2013] [Indexed: 01/02/2023]
Abstract
Metabolic acidosis is a common complication of chronic kidney disease and is believed to contribute to a number of sequelae, including bone disease, altered protein metabolism, skeletal muscle wasting, and progressive glomerular filtration rate loss. Small trials in animal models and humans suggest a role for alkali therapy to lessen these complications. Recent studies support this notion, although more definitive evidence is needed on the long-term benefits of alkali therapy and the optimal serum bicarbonate level. The role of dietary modification also should be given greater consideration. In addition, potential adverse effects of alkali treatment must be taken into consideration, including sodium retention and the theoretical concern of promoting vascular calcification. This teaching case summarizes the rationale for and benefits and complications of base therapy in patients with chronic kidney disease.
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Affiliation(s)
- Wei Chen
- Division of Nephrology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Matthew K Abramowitz
- Division of Nephrology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY; Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY.
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