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Stevens PE, Ahmed SB, Carrero JJ, Foster B, Francis A, Hall RK, Herrington WG, Hill G, Inker LA, Kazancıoğlu R, Lamb E, Lin P, Madero M, McIntyre N, Morrow K, Roberts G, Sabanayagam D, Schaeffner E, Shlipak M, Shroff R, Tangri N, Thanachayanont T, Ulasi I, Wong G, Yang CW, Zhang L, Levin A. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024; 105:S117-S314. [PMID: 38490803 DOI: 10.1016/j.kint.2023.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 03/17/2024]
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2
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Stewart GW. Pyroglutamate acidosis 2023. A review of 100 cases. Clin Med (Lond) 2024; 24:100030. [PMID: 38431210 PMCID: PMC11091441 DOI: 10.1016/j.clinme.2024.100030] [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: 03/05/2024]
Abstract
This review concerns the rare, acquired, usually iatrogenic, high-anion-gap metabolic acidosis, pyroglutamic acidosis. Pyroglutamate is a derivative of the amino acid glutamate, and is an intermediate in the 'glutathione cycle', by which glutathione is continuously synthesized and broken down. The vast majority of pyroglutamic acidosis cases occur in patients on regular, therapeutic doses of paracetamol. In about a third of cases, flucloxacillin is co-prescribed. In addition, the patients are almost always seriously unwell in other ways, typically with under-nourishment of some form. Paracetamol, with underlying disorders, conspires to divert the glutathione cycle, leading to the overproduction of pyroglutamate. Hypokalaemia is seen in about a third of cases. Once the diagnosis is suspected, it is simple to stop the paracetamol and change the antibiotic (if flucloxacillin is present), pending biochemistry. N-acetyl-cysteine can be given, but while the biochemical justification is compelling, the clinical evidence base is anecdotal.
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Affiliation(s)
- Gordon W Stewart
- Emeritus Professor of Experimental Medicine, UCL, Division of Medicine, University College London, London WC1E 6JJ, UK.
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3
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Piner A, Spangler R. Disorders of Potassium. Emerg Med Clin North Am 2023; 41:711-728. [PMID: 37758419 DOI: 10.1016/j.emc.2023.07.005] [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: 10/03/2023]
Abstract
Abnormalities in serum potassium are commonly encountered in patients presenting to the emergency department. A variety of acute and chronic causes can lead to life-threatening illness in both hyperkalemia and hypokalemia. Here we summarize the relevant causes, risks, and treatment options for these frequently encountered disorders.
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Affiliation(s)
- Andrew Piner
- Department of Emergency Medicine, University of Maryland Medical Center, 110 South Paca Street, 6th floor, Suite 200, Baltimore, MD 21201, USA
| | - Ryan Spangler
- Department of Emergency Medicine, University of Maryland Medical Center, 110 South Paca Street, 6th floor, Suite 200, Baltimore, MD 21201, USA.
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4
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Wouda RD, Gritter M, Karsten M, Michels EH, Nieuweboer TM, Danser AJ, de Borst MH, Hoorn EJ, Rotmans JI, Vogt L. Kaliuresis and Intracellular Uptake of Potassium with Potassium Citrate and Potassium Chloride Supplements: A Randomized Controlled Trial. Clin J Am Soc Nephrol 2023; 18:1260-1271. [PMID: 37382933 PMCID: PMC10578626 DOI: 10.2215/cjn.0000000000000228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND A potassium replete diet is associated with lower cardiovascular risk but may increase the risk of hyperkalemia, particularly in people using renin-angiotensin-aldosterone system inhibitors. We investigated whether intracellular uptake and potassium excretion after an acute oral potassium load depend on the accompanying anion and/or aldosterone and whether this results in altered plasma potassium change. METHODS In this placebo-controlled interventional cross-over trial including 18 healthy individuals, we studied the acute effects of one oral load of potassium citrate (40 mmol), potassium chloride (40 mmol), and placebo in random order after overnight fasting. Supplements were administered after a 6-week period with and without lisinopril pretreatment. Linear mixed effect models were used to compare blood and urine values before and after supplementation and between the interventions. Univariable linear regression was used to determine the association between baseline variables and change in blood and urine values after supplementation. RESULTS During the 4-hour follow-up, the rise in plasma potassium was similar for all interventions. After potassium citrate, both red blood cell potassium-as measure of the intracellular potassium-and transtubular potassium gradient (TTKG)-reflecting potassium secretory capacity-were higher than after potassium chloride or potassium citrate with lisinopril pretreatment. Baseline aldosterone was significantly associated with TTKG after potassium citrate, but not after potassium chloride or potassium citrate with lisinopril pretreatment. The observed TTKG change after potassium citrate was significantly associated with urine pH change during this intervention ( R =0.60, P < 0.001). CONCLUSIONS With similar plasma potassium increase, red blood cell potassium uptake and kaliuresis were higher after an acute load of potassium citrate as compared with potassium chloride alone or pretreatment with lisinopril. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER Potassium supplementation in patients with chronic kidney disease and healthy subjects: effects on potassium and sodium balance, NL7618.
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Affiliation(s)
- Rosa D. Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Martin Gritter
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Micky Karsten
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Erik H.A. Michels
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Tamar M. Nieuweboer
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - A.H. Jan Danser
- Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martin H. de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I. Rotmans
- Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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5
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Al-Qusairi L, Ferdaus MZ, Pham TD, Li D, Grimm PR, Zapf AM, Abood DC, Tahaei E, Delpire E, Wall SM, Welling PA. Dietary anions control potassium excretion: it is more than a poorly absorbable anion effect. Am J Physiol Renal Physiol 2023; 325:F377-F393. [PMID: 37498547 PMCID: PMC10639028 DOI: 10.1152/ajprenal.00193.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 07/28/2023] Open
Abstract
The urinary potassium (K+) excretion machinery is upregulated with increasing dietary K+, but the role of accompanying dietary anions remains inadequately characterized. Poorly absorbable anions, including [Formula: see text], are thought to increase K+ secretion through a transepithelial voltage effect. Here, we tested if they also influence the K+ secretion machinery. Wild-type mice, aldosterone synthase (AS) knockout (KO) mice, or pendrin KO mice were randomized to control, high-KCl, or high-KHCO3 diets. The K+ secretory capacity was assessed in balance experiments. Protein abundance, modification, and localization of K+-secretory transporters were evaluated by Western blot analysis and confocal microscopy. Feeding the high-KHCO3 diet increased urinary K+ excretion and the transtubular K+ gradient significantly more than the high-KCl diet, coincident with more pronounced upregulation of epithelial Na+ channels (ENaC) and renal outer medullary K+ (ROMK) channels and apical localization in the distal nephron. Experiments in AS KO mice revealed that the enhanced effects of [Formula: see text] were aldosterone independent. The high-KHCO3 diet also uniquely increased the large-conductance Ca2+-activated K+ (BK) channel β4-subunit, stabilizing BKα on the apical membrane, the Cl-/[Formula: see text] exchanger, pendrin, and the apical KCl cotransporter (KCC3a), all of which are expressed specifically in pendrin-positive intercalated cells. Experiments in pendrin KO mice revealed that pendrin was required to increase K+ excretion with the high-KHCO3 diet. In summary, [Formula: see text] stimulates K+ excretion beyond a poorly absorbable anion effect, upregulating ENaC and ROMK in principal cells and BK, pendrin, and KCC3a in pendrin-positive intercalated cells. The adaptive mechanism prevents hyperkalemia and alkalosis with the consumption of alkaline ash-rich diets but may drive K+ wasting and hypokalemia in alkalosis.NEW & NOTEWORTHY Dietary anions profoundly impact K+ homeostasis. Here, we found that a K+-rich diet, containing [Formula: see text] as the counteranion, enhances the electrogenic K+ excretory machinery, epithelial Na+ channels, and renal outer medullary K+ channels, much more than a high-KCl diet. It also uniquely induces KCC3a and pendrin, in B-intercalated cells, providing an electroneutral KHCO3 secretion pathway. These findings reveal new K+ balance mechanisms that drive adaption to alkaline and K+-rich foods, which should guide new treatment strategies for K+ disorders.
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Affiliation(s)
- Lama Al-Qusairi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Mohammed Z Ferdaus
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Truyen D Pham
- Department of Medicine Nephrology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Dimin Li
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - P Richard Grimm
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Ava M Zapf
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Delaney C Abood
- Department of Medicine Nephrology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Ebrahim Tahaei
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Susan M Wall
- Department of Medicine Nephrology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Paul A Welling
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
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6
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Su G, Qin X, Yang C, Sabatino A, Kelly JT, Avesani CM, Carrero JJ. Fiber intake and health in people with chronic kidney disease. Clin Kidney J 2022; 15:213-225. [PMID: 35145637 PMCID: PMC8825222 DOI: 10.1093/ckj/sfab169] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence suggests that diet, particularly one that is rich in dietary fiber, may prevent the progression of chronic kidney disease (CKD) and its associated complications in people with established CKD. This narrative review summarizes the current evidence and discusses the opportunities for increasing fiber intake in people with CKD to improve health and reduce disease complications. A higher consumption of fiber exerts multiple health benefits, such as increasing stool output, promoting the growth of beneficial microbiota, improving the gut barrier and decreasing inflammation, as well decreasing uremic toxin production. Despite this, the majority of people with CKD consume less than the recommended dietary fiber intake, which may be due in part to the competing dietary potassium concern. Based on existing evidence, we see benefits from adopting a higher intake of fiber-rich food, and recommend cooperation with the dietitian to ensure an adequate diet plan. We also identify knowledge gaps for future research and suggest means to improve patient adherence to a high-fiber diet.
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Affiliation(s)
- Guobin Su
- National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Clinical Research Center for Kidney Disease, Department of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital, The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Global Public Health, Health Systems and Policy, Karolinska Institutet, Stockholm, Sweden
| | - Xindong Qin
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital, The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Changyuan Yang
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital, The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Alice Sabatino
- Department of Nephrology, Parma University Hospital, Parma, Italy
| | - Jaimon T Kelly
- Centre for Online Health, The University of Queensland, Brisbane, Australia.,Centre for Health Services Research, The University of Queensland, Brisbane, Australia
| | - Carla Maria Avesani
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.,Medical Unit Clinical Nutrition, Karolinska University Hospital, Stockholm, Sweden
| | - Juan Jesus Carrero
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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7
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González-Ortiz A, Xu H, Ramos-Acevedo S, Avesani CM, Lindholm B, Correa-Rotter R, Espinosa-Cuevas Á, Carrero JJ. Nutritional status, hyperkalaemia and attainment of energy/protein intake targets in haemodialysis patients following plant-based diets: a longitudinal cohort study. Nephrol Dial Transplant 2021; 36:681-688. [PMID: 33020805 PMCID: PMC8008364 DOI: 10.1093/ndt/gfaa194] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/24/2020] [Indexed: 02/06/2023] Open
Abstract
Background Patients undergoing haemodialysis (HD) are often discouraged from eating fruits and vegetables because of fears of hyperkalaemia and undernutrition, yet evidence to support these claims is scarce. We here explore the association between adherence to a healthy plant-based diet with serum potassium, surrogates of nutritional status and attainment of energy/protein intake targets in HD patients. Methods We performed an observational single-centre study of stable patients undergoing HD with repeated dietary assessment every 3 months. Patients were provided with personalized nutritional counselling according to current guidelines. The diet was evaluated by 3-day food records and characterized by a healthy plant-based diet score (HPDS), which scores positively the intake of plant foods and negatively animal foods and sugar. The malnutrition inflammation score (MIS) and serum potassium were also assessed at each visit. We used mixed-effects models to evaluate the association of the HPDS with markers of nutritional status, serum potassium levels and attainment of energy/protein intake targets. Results After applying inclusion and exclusion criteria, a total of 150 patients contributing to 470 trimestral observations were included. Their mean age was 42 years [standard deviation (SD) 18] and 59% were women. In multivariable models, a higher HPDS was not associated with serum potassium levels or odds of hyperkalaemia {potassium >5.5 mEq/L; odds ratio [OR] 1.00 [95% confidence interval (CI) 0.94–1.07] per HPDS unit higher}. Patients with a higher HPDS did not differ in terms of energy intake [OR for consuming <30 kcal/kg day 1.05 (95% CI 0.97–1.13)] but were at risk of low protein intake [OR for consuming <1.1 g of protein/kg/day 1.11 (95% CI 1.04–1.19)]. A higher HPDS was associated with a lower MIS, indicating better nutritional status. Conclusions In patients undergoing HD, adherence to a healthy plant-based diet was not associated with serum potassium, hyperkalaemia or differences in energy intake. Although these patients were less likely to reach daily protein intake targets, they appeared to associate with better nutritional status over time.
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Affiliation(s)
- Ailema González-Ortiz
- Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Hong Xu
- Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden
| | - Samuel Ramos-Acevedo
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Carla M Avesani
- Department of Clinical Science, Intervention and Technology, Division of Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
| | - Bengt Lindholm
- Department of Clinical Science, Intervention and Technology, Division of Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
| | - Ricardo Correa-Rotter
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Ángeles Espinosa-Cuevas
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Juan Jesús Carrero
- Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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8
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Saglimbene VM, Su G, Wong G, Natale P, Ruospo M, Palmer SC, Craig JC, Carrero JJ, Strippoli GFM. Dietary intake in adults on hemodialysis compared with guideline recommendations. J Nephrol 2021; 34:1999-2007. [PMID: 33591554 PMCID: PMC8610942 DOI: 10.1007/s40620-020-00962-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 12/29/2020] [Indexed: 11/25/2022]
Abstract
Background Clinical practice guidelines of dietary management are designed to promote a balanced diet and maintain health in patients undergoing haemodialysis but they may not reflect patients’ preferences.
We aimed to investigate the consistency between the dietary intake of patients on maintenance haemodialysis and guideline recommendations. Methods Cross-sectional analysis of the DIET-HD study, which included 6,906 adults undergoing haemodialysis in 10 European countries. Dietary intake was determined using the Global Allergy and Asthma European Network (GA2LEN) Food Frequency Questionnaire (FFQ), and compared with the European Best Practice Guidelines. Consistency with guidelines was defined as achieving the minimum daily recommended intake for energy (≥ 30 kcal/kg) and protein (≥ 1.1 g/kg), and not exceeding the maximum recommended daily intake for phosphate (≤ 1000 mg), potassium (≤ 2730 mg), sodium (≤ 2300 mg) and calcium (≤ 800 mg). Results Overall, patients’ dietary intakes of phosphate and potassium were infrequently consistent with guidelines (consistent in 25% and 25% of patients, respectively). Almost half of the patients reported that energy (45%) and calcium intake (53%) was consistent with the guidelines, while the recommended intake of sodium and protein was consistent in 85% and 67% of patients, respectively. Results were similar across all participating countries. Intake was consistent with all six guideline recommendations in only 1% of patients. Conclusion Patients on maintenance haemodialysis usually have a dietary intake which is inconsistent with current recommendations, especially for phosphate and potassium. Supplementary Information The online version contains supplementary material available at 10.1007/s40620-020-00962-3.
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Affiliation(s)
- Valeria M Saglimbene
- Faculty of Medicine and Health, Sydney School of Public Health, University of Sydney, Sydney, Australia
- Department of Emergency and Organ Transplantation, University of Bari, Piazza Giulio Cesare, 70124, Bari, Italy
| | - Guobin Su
- National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Department of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou City, Guangdong Province, China
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou City, Guangdong Province, China
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Germaine Wong
- Faculty of Medicine and Health, Sydney School of Public Health, University of Sydney, Sydney, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, Australia
| | - Patrizia Natale
- Faculty of Medicine and Health, Sydney School of Public Health, University of Sydney, Sydney, Australia
- Department of Emergency and Organ Transplantation, University of Bari, Piazza Giulio Cesare, 70124, Bari, Italy
| | - Marinella Ruospo
- Department of Emergency and Organ Transplantation, University of Bari, Piazza Giulio Cesare, 70124, Bari, Italy
| | - Suetonia C Palmer
- Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Jonathan C Craig
- College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Juan J Carrero
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Giovanni F M Strippoli
- Faculty of Medicine and Health, Sydney School of Public Health, University of Sydney, Sydney, Australia.
- Department of Emergency and Organ Transplantation, University of Bari, Piazza Giulio Cesare, 70124, Bari, Italy.
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9
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Kamel KS, Halperin ML. Use of Urine Electrolytes and Urine Osmolality in the Clinical Diagnosis of Fluid, Electrolytes, and Acid-Base Disorders. Kidney Int Rep 2021; 6:1211-1224. [PMID: 34013099 PMCID: PMC8116912 DOI: 10.1016/j.ekir.2021.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 02/01/2021] [Indexed: 01/16/2023] Open
Abstract
We discuss the use of urine electrolytes and urine osmolality in the clinical diagnosis of patients with fluid, electrolytes, and acid-base disorders, emphasizing their physiological basis, their utility, and the caveats and limitations in their use. While our focus is on information obtained from measurements in the urine, clinical diagnosis in these patients must integrate information obtained from the history, the physical examination, and other laboratory data.
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Affiliation(s)
- Kamel S. Kamel
- Renal Division, St. Michael’s Hospital and The University of Toronto, Toronto, Ontario, Canada
- Keenan Research Center in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Correspondence: Kamel S. Kamel, University of Toronto, Division of Nephrology, St. Michael’s Hospital, Toronto, Ontario, M5B 1W8, Canada.
| | - Mitchell L. Halperin
- Renal Division, St. Michael’s Hospital and The University of Toronto, Toronto, Ontario, Canada
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10
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11
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Hughes C, Koppanarayana S, Watson M, Nipah R, Laing I. Hypokalemia: A Curious Case in a Young Woman. J Appl Lab Med 2020; 5:802-807. [DOI: 10.1093/jalm/jfaa046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/14/2020] [Indexed: 11/12/2022]
Affiliation(s)
- Chris Hughes
- Department of Clinical Biochemistry, Lancashire Teaching Hospitals NHS Foundation Trust, Lancashire, UK
| | - Shashithej Koppanarayana
- Department of Diabetes and Endocrinology, Lancashire Teaching Hospitals NHS Foundation Trust, Lancashire, UK
| | - Michael Watson
- Medical & Dental Bank, Lancashire Teaching Hospitals NHS Foundation Trust, Lancashire, UK
| | - Robert Nipah
- Department of Renal Medicine, Lancashire Teaching Hospitals NHS Foundation Trust, Lancashire, UK
| | - Ian Laing
- Department of Clinical Biochemistry, Lancashire Teaching Hospitals NHS Foundation Trust, Lancashire, UK
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12
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Carrero JJ, González-Ortiz A, Avesani CM, Bakker SJL, Bellizzi V, Chauveau P, Clase CM, Cupisti A, Espinosa-Cuevas A, Molina P, Moreau K, Piccoli GB, Post A, Sezer S, Fouque D. Plant-based diets to manage the risks and complications of chronic kidney disease. Nat Rev Nephrol 2020; 16:525-542. [PMID: 32528189 DOI: 10.1038/s41581-020-0297-2] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2020] [Indexed: 02/07/2023]
Abstract
Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling, these restrictions can result in a low intake of fruits and vegetables and a lack of diversity in the diet. Plant nutrients and plant-based diets could have beneficial effects in patients with CKD: increased fibre intake shifts the gut microbiota towards reduced production of uraemic toxins; plant fats, particularly olive oil, have anti-atherogenic effects; plant anions might mitigate metabolic acidosis and slow CKD progression; and as plant phosphorus has a lower bioavailability than animal phosphorus, plant-based diets might enable better control of hyperphosphataemia. Current evidence suggests that promoting the adoption of plant-based diets has few risks but potential benefits for the primary prevention of CKD, as well as for delaying progression in patients with CKD G3-5. These diets might also help to manage and prevent some of the symptoms and metabolic complications of CKD. We suggest that restriction of plant foods as a strategy to prevent hyperkalaemia or undernutrition should be individualized to avoid depriving patients with CKD of these potential beneficial effects of plant-based diets. However, research is needed to address knowledge gaps, particularly regarding the relevance and extent of diet-induced hyperkalaemia in patients undergoing dialysis.
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Affiliation(s)
- Juan J Carrero
- Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
| | - Ailema González-Ortiz
- Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Nephrology and Mineral Metabolism Department, Instituto Nacional de Ciencias Médicas y Nutrición Salvador, Zubirán, Mexico
| | - Carla M Avesani
- Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Stephan J L Bakker
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Vincenzo Bellizzi
- Nephrology Unit, University Hospital "San Giovanni di Dio e Ruggi d'Aragona", Salerno, Italy
| | - Philippe Chauveau
- Service de Néphrologie Transplantation Dialyse, Centre Hospitalier Universitaire de Bordeaux et Aurad-Aquitaine, Bordeaux, France
| | - Catherine M Clase
- Departments of Medicine and Health Evidence and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Adamasco Cupisti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Angeles Espinosa-Cuevas
- Nephrology and Mineral Metabolism Department, Instituto Nacional de Ciencias Médicas y Nutrición Salvador, Zubirán, Mexico
| | - Pablo Molina
- Department of Nephrology, Hospital Universitari Dr Peset, Universitat de València, València, Spain
| | - Karine Moreau
- Renal transplant unit, Pellegrin Hospital, Bordeaux, France
| | - Giorgina B Piccoli
- Department of Clinical and Biological Sciences, University of Torino, Torino, Italy.,Nephrologie, Centre Hospitalier Le Mans, Le Mans, France
| | - Adrian Post
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Siren Sezer
- Department of Nephrology, Baskent University School of Medicine, Ankara, Turkey
| | - Denis Fouque
- Department of Nephrology, Université de Lyon, Carmen, Hospital Lyon-Sud, Lyon, France
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Ameliorating Chronic Kidney Disease Using a Whole Food Plant-Based Diet. Nutrients 2020; 12:nu12041007. [PMID: 32268544 PMCID: PMC7230354 DOI: 10.3390/nu12041007] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 12/18/2022] Open
Abstract
Novel approaches to ameliorating chronic kidney disease (CKD) are warranted as most patients are undiagnosed until they begin displaying symptoms of kidney failure. There is increasing evidence that a whole food plant-based (WFPB) diet may offer benefits that slow the progression of CKD, decrease the incidence cardiovascular disease, decrease rates of diabetes and obesity, and reduce inflammation and cholesterol, which in turn can delay kidney failure and the initiation of dialysis. While animal-based protein ingestion promotes an acidic environment, inflammation and renal hyperfiltration, study authors report plant-based protein can be alkaline-producing and anti-inflammatory and can contain renoprotective properties. Although there may be benefits to adopting a WFPB diet, macronutrient and micronutrient content should be carefully considered and adjusted to avoid malnutrition in CKD patients. Further research needs to be done in order to establish the biological plausibility and feasibility of a WFPB in individuals with diagnosed CKD.
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Barbance O, De Bels D, Honoré PM, Bargalzan D, Tolwani A, Ismaili K, Biarent D, Redant S. Potassium disorders in pediatric emergency department: Clinical spectrum and management. Arch Pediatr 2020; 27:146-151. [PMID: 31955956 DOI: 10.1016/j.arcped.2019.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 06/18/2019] [Accepted: 12/30/2019] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Potassium abnormalities are frequent in intensive care but their incidence in the emergency department is unknown. AIM We describe the spectrum of potassium abnormalities in our tertiary-level pediatric emergency department. METHODS Retrospective case-control study of all the patients admitted to a single-center tertiary emergency department over a 2.5-year period. We compared patients with hypokalemia (<3.0mEq/L) and patients with hyperkalemia (>6.0mEq/L) against a normal randomized population recruited on a 3:1 ratio with potassium levels between 3.5 and 5mEq/L. RESULTS Between January 1, 2013 and August 31, 2016 we admitted 108,209 patients to our emergency department. A total of 9342 blood samples were tested and the following potassium measurements were found: 60 cases of hypokalemia (2.8±0.2mEq/L) and 55 cases of hyperkalemia (6.4±0.6mEq/L). In total, 200 patients with normokalemia were recruited (4.1±0.3mEq/L). The main causes of the disorders were non-specific: lower respiratory tract infection (23%) and fracture (15%) for hypokalemia, lower respiratory tract (21.8%) and ear-nose-throat infections (20.0%) for hyperkalemia. Patients with hyperkalemia had an elevated creatinine level (0.72±1.6 vs. 0.40±0.16mg/dL, P<0.0001) with lower bicarbonate (19.4±3.8 vs. 21.8±2.8mmol/L, P=0.0001) and higher phosphorus levels (1.95±0.6 vs. 1.42±0.27mg/dL, P=0.0001). Patients with hypokalemia had an elevated creatinine level (0.66±0.71 vs. 0.40±0.16mg/dL, P<0.0001) and a lower phosphorus level (1.12±0.31 vs. 1.42±0.27mg/dL, P=0.0001). We did not observe significant differences in pH, PCO2, base excess and lactate, or in the mean duration of hospitalization in general wards and pediatric intensive care units according to the PIM and PRISM scores. DISCUSSION Dyskalemia is rare in emergency department patients: 0.64% for hypokalemia and 0.58% for hyperkalemia. This condition could be explained by a degree of renal failure due to transient volume disturbance. The main mechanism is dehydration due to digestive losses, polypnea in young patients, and poor intake. In the case of hypokalemia, poor intake and digestive losses could be the main explanation. These disorders resolve easily with feeding or perfusion and do not impair development. CONCLUSION Dyskalemia is rare in emergency department patients and is easily resolved with feeding or perfusion. A plausible etiological mechanism is a transient volume disturbance. Dyskalemia is not predictive of poor development in the emergency pediatric population.
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Affiliation(s)
- O Barbance
- Emergency Department, Hospital Universitaire des Enfants Reine Fabiola (HUDERF), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - D De Bels
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - P M Honoré
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - D Bargalzan
- Clinical Biology, CHU de Brugmann-Brugmann University Hospital, place Van Gehuchtenplein, 4, 1020 Brussels, Belgium
| | - A Tolwani
- Division of Nephrology, University of Alabama at Birmingham School of Medicine, Birmingham. AL, USA
| | - K Ismaili
- Department of Nephrology, Hospital Universitaire des Enfants Reine Fabiola (HUDERF), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - D Biarent
- Emergency Department, Hospital Universitaire des Enfants Reine Fabiola (HUDERF), Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - S Redant
- Emergency Department, Hospital Universitaire des Enfants Reine Fabiola (HUDERF), Université Libre de Bruxelles (ULB), Bruxelles, Belgium; Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles (ULB), Bruxelles, Belgium.
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15
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16
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Palmer BF, Clegg DJ. The Use of Selected Urine Chemistries in the Diagnosis of Kidney Disorders. Clin J Am Soc Nephrol 2019; 14:306-316. [PMID: 30626576 PMCID: PMC6390907 DOI: 10.2215/cjn.10330818] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Urinary chemistries vary widely in both health and disease and are affected by diet, volume status, medications, and disease states. When properly examined, these tests provide important insight into the mechanism and therapy of various clinical disorders that are first detected by abnormalities in plasma chemistries. These tests cannot be interpreted in isolation, but instead require knowledge of key clinical information, such as medications, physical examination, and plasma chemistries, to include kidney function. When used appropriately and with knowledge of limitations, urine chemistries can provide important insight into the pathophysiology and treatment of a wide variety of disorders.
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Affiliation(s)
- Biff F Palmer
- Division of Nephrology, Department of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Deborah Joy Clegg
- Department of Internal Medicine, University of California, Los Angeles School of Medicine, Los Angeles, California
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17
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Lien YHH. Urine Tests for Chronic Hypokalemia: When in Doubt, Check Urine-Sodium-to-Chloride Ratio. Am J Med 2017; 130:761-762. [PMID: 28359722 DOI: 10.1016/j.amjmed.2017.02.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 02/27/2017] [Indexed: 10/19/2022]
Affiliation(s)
- Yeong-Hau H Lien
- Department of Medicine, College of Medicine, University of Arizona, Tucson; Arizona Kidney Disease and Hypertension Center, Tucson
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18
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Dormohammadi Toosi T, Naderi N, Movassaghi S, Seradj MH, Khalvat A, Shahbazi F. Secondary Sjogren's syndrome presenting with hypokalemic periodic paralysis. Oxf Med Case Reports 2015; 2014:135-7. [PMID: 25988057 PMCID: PMC4369992 DOI: 10.1093/omcr/omu052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 09/25/2014] [Accepted: 10/13/2014] [Indexed: 11/13/2022] Open
Abstract
Renal tubular acidosis (RTA) may develop in a large population of patients with Sjogren's syndrome (SS), but most of the subjects are asymptomatic. Here, we report a patient with known rheumatoid arthritis and symptoms of xerostomia, xerophthalmia and periodic paralysis. SS should be considered as a cause of RTA. The treatment of the underlying disorder may ameliorate the symptoms.
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Affiliation(s)
- Taraneh Dormohammadi Toosi
- Department of Rheumatology , Vali-asr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences , Tehran , Iran
| | - Neda Naderi
- Department of Internal Medicine , Imam Khomeini Hospital Complex, Tehran University of Medical Sciences , Tehran , Iran
| | - Shafieh Movassaghi
- Department of Rheumatology , Vali-asr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences , Tehran , Iran
| | | | - Ali Khalvat
- Department of Rheumatology , Vali-asr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences , Tehran , Iran
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Kamel KS, Schreiber M, Halperin ML. Integration of the response to a dietary potassium load: a paleolithic perspective. Nephrol Dial Transplant 2014; 29:982-9. [PMID: 24789504 DOI: 10.1093/ndt/gft499] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our purpose is to integrate new insights in potassium (K(+)) physiology to understand K(+) homeostasis and illustrate some of their clinical implications. Since control mechanisms that are essential for survival were likely developed in Paleolithic times, we think the physiology of K(+) homeostasis can be better revealed when viewed from what was required to avoid threats and achieve balance in Paleolithic times. Three issues will be highlighted. First, we shall consider the integrative physiology of the gastrointestinal tract and the role of lactic acid released from enterocytes following absorption of sugars (fruit and berries) to cause a shift of this K(+) load into the liver. Second, we shall discuss the integrative physiology of WNK kinases and modulation of delivery of bicarbonate to the distal nephron to switch the aldosterone response from sodium chloride retention to K(+) secretion when faced with a K(+) load. Third, we shall emphasize the role of intra-renal recycling of urea in achieving K(+) homeostasis when the diet contains protein and K(+).
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Affiliation(s)
- Kamel S Kamel
- Renal Division, St Michael's Hospital and University of Toronto, Toronto, ON, Canada
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21
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Affiliation(s)
- John K. Healy
- From the Princess Alexandra Hospital Brisbane, Brisbane, Queensland, Australia; and Renal Unit, Royal Brisbane Hospital, Brisbane, Queensland, Australia
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22
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23
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Goraya N, Simoni J, Jo CH, Wesson DE. A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate. Clin J Am Soc Nephrol 2013; 8:371-81. [PMID: 23393104 DOI: 10.2215/cjn.02430312] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND OBJECTIVES Current guidelines recommend Na(+)-based alkali for CKD with metabolic acidosis and plasma total CO2 (PTCO2) < 22 mM. Because diets in industrialized societies are typically acid-producing, we compared base-producing fruits and vegetables with oral NaHCO3 (HCO3) regarding the primary outcome of follow-up estimated GFR (eGFR) and secondary outcomes of improved metabolic acidosis and reduced urine indices of kidney injury. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Individuals with stage 4 (eGFR, 15-29 ml/min per 1.73 m(2)) CKD due to hypertensive nephropathy, had a PTCO2 level < 22 mM, and were receiving angiotensin-converting enzyme inhibition were randomly assigned to 1 year of daily oral NaHCO3 at 1.0 mEq/kg per day (n=35) or fruits and vegetables dosed to reduce dietary acid by half (n=36). RESULTS Plasma cystatin C-calculated eGFR did not differ at baseline and 1 year between groups. One-year PTCO2 was higher than baseline in the HCO3 group (21.2±1.3 versus 19.5±1.5 mM; P<0.01) and the fruits and vegetables group (19.9±1.7 versus 19.3±1.9 mM; P<0.01), consistent with improved metabolic acidosis, and was higher in the HCO3 than the fruits and vegetable group (P<0.001). One-year urine indices of kidney injury were lower than baseline in both groups. Plasma [K(+)] did not increase in either group. CONCLUSIONS One year of fruits and vegetables or NaHCO3 in individuals with stage 4 CKD yielded eGFR that was not different, was associated with higher-than-baseline PTCO2, and was associated with lower-than-baseline urine indices of kidney injury. The data indicate that fruits and vegetables improve metabolic acidosis and reduce kidney injury in stage 4 CKD without producing hyperkalemia.
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Affiliation(s)
- Nimrit Goraya
- Department of Internal Medicine, Texas A&M College of Medicine, Temple, Texas 76508, USA
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Cornelius RJ, Wen D, Hatcher LI, Sansom SC. Bicarbonate promotes BK-α/β4-mediated K excretion in the renal distal nephron. Am J Physiol Renal Physiol 2012; 303:F1563-71. [PMID: 22993067 DOI: 10.1152/ajprenal.00490.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Ca-activated K channels (BK), which are stimulated by high distal nephron flow, are utilized during high-K conditions to remove excess K. Because BK predominantly reside with BK-β4 in acid/base-transporting intercalated cells (IC), we determined whether BK-β4 knockout mice (β4KO) exhibit deficient K excretion when consuming a high-K alkaline diet (HK-alk) vs. high-K chloride diet (HK-Cl). When wild type (WT) were placed on HK-alk, but not HK-Cl, renal BK-β4 expression increased (Western blot). When WT and β4KO were placed on HK-Cl, plasma K concentration ([K]) was elevated compared with control K diets; however, K excretion was not different between WT and β4KO. When HK-alk was consumed, the plasma [K] was lower and K clearance was greater in WT compared with β4KO. The urine was alkaline in mice on HK-alk; however, urinary pH was not different between WT and β4KO. Immunohistochemical analysis of pendrin and V-ATPase revealed the same increases in β-IC, comparing WT and β4KO on HK-alk. We found an amiloride-sensitive reduction in Na excretion in β4KO, compared with WT, on HK-alk, indicating enhanced Na reabsorption as a compensatory mechanism to secrete K. Treating mice with an alkaline, Na-deficient, high-K diet (LNaHK) to minimize Na reabsorption exaggerated the defective K handling of β4KO. When WT on LNaHK were given NH(4)Cl in the drinking water, K excretion was reduced to the magnitude of β4KO on LNaHK. These results show that WT, but not β4KO, efficiently excretes K on HK-alk but not on HK-Cl and suggest that BK-α/β4-mediated K secretion is promoted by bicarbonaturia.
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Affiliation(s)
- Ryan J Cornelius
- Dept. of Cellular and Integrative Physiology, Nebraska Medical Center, Omaha, NE 68198-5850, USA
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25
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Kamel KS, Schreiber M. Asking the question again: are cation exchange resins effective for the treatment of hyperkalemia? Nephrol Dial Transplant 2012; 27:4294-7. [DOI: 10.1093/ndt/gfs293] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cheema-Dhadli S, Chong CK, Kamel K, Halperin M. An Acute Infusion of Lactic Acid Lowers the Concentration of Potassium in Arterial Plasma by Inducing a Shift of Potassium into Cells of the Liver in Fed Rats. ACTA ACUST UNITED AC 2012; 120:p7-15. [DOI: 10.1159/000336321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Kamel KS, Halperin ML. Intrarenal urea recycling leads to a higher rate of renal excretion of potassium: an hypothesis with clinical implications. Curr Opin Nephrol Hypertens 2011; 20:547-54. [PMID: 21788894 DOI: 10.1097/mnh.0b013e328349b8f9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW This review aims to illustrate why urea recycling may play an important role in potassium (K⁺) excretion and to emphasize its potential clinical implications. RECENT FINDINGS A quantitative analysis of the process of intrarenal urea recycling reveals that the amount of urea delivered to the distal convoluted tubule is about two-fold larger than the quantity of urea excreted in the urine. As the number of osmoles delivered to the late cortical distal nephron (CCD) determines its flow rate when aquaporin 2 water channels have been inserted in the luminal membrane of principal cells, urea recycling may play an important role in regulating the rate of excretion of K⁺ when the distal delivery of electrolytes is not very high. SUMMARY Urea recycling aids the excretion of K⁺; this is especially important in patients with disorders or those who are taking drugs that lead to a less lumen-negative voltage in the CCD. As a large quantity of urea is reabsorbed daily in the inner medullary collecting duct, the assumption made in the calculation of the transtubular K concentration gradient that there is no appreciable reabsorption of osmoles downstream CCD is not valid.
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Affiliation(s)
- Kamel S Kamel
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Division of Nephrology, University of Toronto, Toronto, Ontario, Canada
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28
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Goraya N, Simoni J, Jo C, Wesson DE. Dietary acid reduction with fruits and vegetables or bicarbonate attenuates kidney injury in patients with a moderately reduced glomerular filtration rate due to hypertensive nephropathy. Kidney Int 2011; 81:86-93. [PMID: 21881553 DOI: 10.1038/ki.2011.313] [Citation(s) in RCA: 229] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The neutralization of dietary acid with sodium bicarbonate decreases kidney injury and slows the decline of the glomerular filtration rate (GFR) in animals and patients with chronic kidney disease. The sodium intake, however, could be problematic in patients with reduced GFR. As alkali-induced dietary protein decreased kidney injury in animals, we compared the efficacy of alkali-inducing fruits and vegetables with oral sodium bicarbonate to diminish kidney injury in patients with hypertensive nephropathy at stage 1 or 2 estimated GFR. All patients were evaluated 30 days after no intervention; daily oral sodium bicarbonate; or fruits and vegetables in amounts calculated to reduce dietary acid by half. All patients had 6 months of antihypertensive control by angiotensin-converting enzyme inhibition before and during these studies, and otherwise ate ad lib. Indices of kidney injury were not changed in the stage 1 group. By contrast, each treatment of stage 2 patients decreased urinary albumin, N-acetyl β-D-glucosaminidase, and transforming growth factor β from the controls to a similar extent. Thus, a reduction in dietary acid decreased kidney injury in patients with moderately reduced eGFR due to hypertensive nephropathy and that with fruits and vegetables was comparable to sodium bicarbonate. Fruits and vegetables appear to be an effective kidney protective adjunct to blood pressure reduction and angiotensin-converting enzyme inhibition in hypertensive and possibly other nephropathies.
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Affiliation(s)
- Nimrit Goraya
- Department of Internal Medicine, Texas A&M College of Medicine, Temple, Texas 76508, USA
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29
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Rachoin JS, Cerceo EA. Four nephrology myths debunked. J Hosp Med 2011; 6:E1-5. [PMID: 21661096 DOI: 10.1002/jhm.703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 02/25/2010] [Accepted: 03/02/2010] [Indexed: 11/08/2022]
Abstract
There are many controversial topics relating to renal disease in hospitalized patients. The aim of this review is to shed light on some important and often debated issues. Hypothyroidism, unlike myxedema, is not a cause of hyponatremia (although it can be sometimes seen in conjunction with the latter) and additional investigations should be done to determine its etiology. Sodium bicarbonate is effective for treatment of hyperkalemia primarily by enhancing renal potassium elimination rather than by translocating potassium into cells. Acetaminophen can be a cause of metabolic acidosis by causing 5-oxoprolinuria. Furosemide (and sulfa containing diuretics) can safely be used in patients with an allergy to sulfa-containing antibiotics (SCA).
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Affiliation(s)
- Jean-Sebastien Rachoin
- Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Cooper University Hospital, Camden, New Jersey, USA.
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Shingarev R, Allon M. A physiologic-based approach to the treatment of acute hyperkalemia. Am J Kidney Dis 2010; 56:578-84. [PMID: 20570423 DOI: 10.1053/j.ajkd.2010.03.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 03/04/2010] [Indexed: 11/11/2022]
Abstract
Hyperkalemia is a common and potentially lethal disorder. Given its variable presentation, clinicians should have a high index of suspicion, especially in patients with chronic kidney disease. The present case highlights key physiologic mechanisms in the development of hyperkalemia and provides an outline for emergent treatment. In this context, we discuss specific mechanisms of action of available treatments of hyperkalemia.
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Affiliation(s)
- Roman Shingarev
- Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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31
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Wynn E, Krieg MA, Aeschlimann JM, Burckhardt P. Alkaline mineral water lowers bone resorption even in calcium sufficiency: alkaline mineral water and bone metabolism. Bone 2009; 44:120-4. [PMID: 18926940 DOI: 10.1016/j.bone.2008.09.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 08/22/2008] [Accepted: 09/10/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Dietary acid charge enhances bone loss. Bicarbonate or alkali diet decreases bone resorption in humans. We compared the effect of an alkaline mineral water, rich in bicarbonate, with that of an acid one, rich in calcium only, on bone markers, in young women with a normal calcium intake. METHODS This study compared water A (per litre: 520 mg Ca, 291 mg HCO(3)(-), 1160 mg SO(4)(-), Potential Renal Acid load (PRAL) +9.2 mEq) with water B (per litre: 547 mg Ca, 2172 mg HCO(3)(-), 9 mg SO(4)(-), PRAL -11.2 mEq). 30 female dieticians aged 26.3 yrs (SD 7.3) were randomized into two groups, followed an identical weighed, balanced diet (965 mg Ca) and drank 1.5 l/d of the assigned water. Changes in blood and urine electrolytes, C-telopeptides (CTX), urinary pH and bicarbonate, and serum PTH were measured after 2 and 4 weeks. RESULTS The two groups were not different at baseline, and showed a similar increase in urinary calcium excretion. Urinary pH and bicarbonate excretion increased with water B, but not with water A. PTH (p=0.022) and S-CTX (p=0.023) decreased with water B but not with water A. CONCLUSION In calcium sufficiency, the acid calcium-rich water had no effect on bone resorption, while the alkaline water rich in bicarbonate led to a significant decrease of PTH and of S-CTX.
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Affiliation(s)
- Emma Wynn
- Centre of Bone Diseases, Lausanne University Hospital, Lausanne, Switzerland.
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33
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Halperin ML, Cheema Dhadli S, Kamel KS. Physiology of acid-base balance: links with kidney stone prevention. Semin Nephrol 2007; 26:441-6. [PMID: 17275581 DOI: 10.1016/j.semnephrol.2006.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two processes permit the urine pH and the medullary interstitial pH to remain in an "ideal range" to minimize the risk of forming kidney stones. First, a medullary shunt for NH(3) maintains the urine pH near 6.0 to minimize uric acid precipitation when distal H(+) secretion is high. Second, excreting dietary alkali excreting alkali as a family of organic anions--including citrate--rather than as bicarbonate maintains the urine pH near 6.0 while urinary citrate chelates ionized calcium, which minimizes CaHPO(4) precipitation. In patients with idiopathic hypercalciuria and recurrent calcium oxalate stones, the initial nidus is a calcium phosphate precipitate on the basolateral membrane of the thin limb of the loop of Henle (Randall's plaque). Formation of this precipitate requires medullary alkalinization; K(+) -depletion and augmented medullary H(+)/K(+) -ATPase may be predisposing factors.
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Affiliation(s)
- Mitchell L Halperin
- Renal Division, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
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34
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Halperin ML, Cheema-Dhadli S, Lin SH, Kamel KS. Control of potassium excretion: a Paleolithic perspective. Curr Opin Nephrol Hypertens 2006; 15:430-6. [PMID: 16775458 DOI: 10.1097/01.mnh.0000232884.73518.9c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Regulation of potassium (K) excretion was examined in an experimental setting that reflects the dietary conditions for humans in Paleolithic times (high, episodic intake of K with organic anions; low intake of NaCl), because this is when major control mechanisms were likely to have developed. RECENT FINDINGS The major control of K secretion in this setting is to regulate the number of luminal K channels in the cortical collecting duct. Following a KCl load, the K concentration in the medullary interstitial compartment rose; the likely source of this medullary K was its absorption by the H/K-ATPase in the inner medullary collecting duct. As a result of the higher medullary K concentration, the absorption of Na and Cl was inhibited in the loop of Henle, and this led to an increased distal delivery of a sufficient quantity of Na to raise K excretion markedly, while avoiding a large natriuresis. In addition, because K in the diet was accompanied by 'future' bicarbonate, a role for bicarbonate in the control of K secretion via 'selecting' whether aldosterone would be a NaCl-conserving or a kaliuretic hormone is discussed. SUMMARY This way of examining the control of K excretion provides new insights into clinical disorders with an abnormal plasma K concentration secondary to altered K excretion, and also into the pathophysiology of calcium-containing kidney stones.
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Affiliation(s)
- Mitchell L Halperin
- Renal Division, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
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35
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Odvina CV, Mason RP, Pak CYC. Prevention of thiazide-induced hypokalemia without magnesium depletion by potassium-magnesium-citrate. Am J Ther 2006; 13:101-8. [PMID: 16645424 DOI: 10.1097/01.mjt.0000149922.16098.c0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Thiazide can cause magnesium depletion, which may exaggerate renal potassium wasting and hypokalemia. The purpose of this double-blind, randomized trial was to compare the metabolic effects of potassium-magnesium-citrate (K-Mg-citrate) and potassium chloride (KCl) during long-term treatment with thiazide. Twenty-two normal volunteers received hydrochlorothiazide 50 mg/d. Ten subjects concurrently took K-Mg-citrate (42 mEq K/d and 21 mEq Mg/d), and 12 subjects were given KCl 42 mEq/d. Serum potassium concentration remained unchanged during K-Mg-citrate supplementation, with a change from baseline of 21.7% over 6 months, compared with 26.4% with KCl supplementation. Serum electrolytes were normal and not significantly different between K-Mg-citrate and KCl. During K-Mg-citrate treatment, serum magnesium increased significantly by about 10%, associated with an adequate increase in urinary magnesium and a nonsignificant increase in monocyte and free muscle magnesium. Serum magnesium was unchanged, and monocyte and free muscle magnesium showed a nonsignificant decline during KCl supplementation. K-Mg-citrate provided an alkali load, increasing urinary pH, and reducing urinary undissociated uric acid. It also increased urinary citrate and tended to lower the saturation of calcium oxalate. KCl supplementation lacked these actions. K-Mg-citrate prevents thiazide-induced hypokalemia without provoking metabolic alkalosis. It seems to prevent magnesium depletion. By providing an alkali load, it retards the propensity for the crystallization of uric acid and probably of calcium oxalate. Though not conclusive, KCl supplementation may be less effective than K-Mg-citrate in maintaining normokalemia because of a subtle magnesium wasting. Moreover, KCl is devoid of protective action toward crystallization of stone-forming salts.
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Affiliation(s)
- Clarita V Odvina
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-8885, USA.
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Cheema-Dhadli S, Lin SH, Keong-Chong C, Kamel KS, Halperin ML. Requirements for a high rate of potassium excretion in rats consuming a low electrolyte diet. J Physiol 2006; 572:493-501. [PMID: 16455691 PMCID: PMC1779674 DOI: 10.1113/jphysiol.2005.101576] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Control mechanisms for potassium (K(+)) excretion in humans developed in Palaeolithic times when diets were sodium poor and episodically K(+) rich. Nevertheless, our understanding of the regulation of K(+) excretion comes from experiments in rats with large sodium and K(+) intakes. Our objective was to identify how K(+) excretion was regulated when rats consumed a low NaCl diet to reflect Palaeolithic conditions. Rats that were given mineralocorticoids plus either NaCl, mannitol, or NaHCO(3) had a small kaliuresis. In contrast, KCl load induced a large kaliuresis and a near-maximal luminal [K(+)] in the terminal cortical collecting duct ([K(+)](CCD)). The time course of events was important. The rise in the [K(+)](CCD) was prompt, but the initial kaliuresis was only modest. Over the next 4 h, kaliuresis increased markedly due solely to a higher calculated distal flow rate, which appeared to be due to diminished reabsorption of NaCl in the loop of Henle; of note, the measured papillary [K(+)] rose. In summary, the increase in the [K(+)](CCD) in rats given KCl is likely to be due to an increase in the number of luminal K(+) channels rather than to mechanisms that are known to induce a lumen-negative voltage in cortical distal nephron segments. The higher distal flow rate might be due to a higher interstitial [K(+)], which inhibited NaCl reabsorption in the loop of Henle. Thus, to understand which of the potential control mechanisms are operating, one must look very closely at the conditions imposed by the experimental setting.
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Groeneveld JHM, Sijpkens YWJ, Lin SH, Davids MR, Halperin ML. An approach to the patient with severe hypokalaemia: the potassium quiz. QJM 2005; 98:305-16. [PMID: 15760922 DOI: 10.1093/qjmed/hci046] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The objective of this teaching session with Professor McCance is to develop an approach to the management of patients with a very low plasma potassium (K(+)) concentration (P(K)). The session begins with a quiz based on six recent medical consultations for a P(K) < 2 mmol/l. Professor McCance outlined how he would proceed with his diagnosis and therapy, using the synopsis that described each patient. This approach was then applied to a new patient, a 69-year-old woman who had a large volume of dependent oedema and developed a severe degree of weakness and hypokalaemia during more aggressive diuretic therapy that included a K(+)-sparing diuretic. The initial challenge for Professor McCance was to deduce why the K(+)-sparing diuretic was not effective in this patient. He also needed to explain why the P(K) was so low on admission.
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Affiliation(s)
- J H M Groeneveld
- Department of Nephrology, Leiden University Medical Center, The Netherlands
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Bailey MA, Giebisch G, Abbiati T, Aronson PS, Gawenis LR, Shull GE, Wang T. NHE2-mediated bicarbonate reabsorption in the distal tubule of NHE3 null mice. J Physiol 2004; 561:765-75. [PMID: 15604231 PMCID: PMC1665379 DOI: 10.1113/jphysiol.2004.074716] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Accepted: 10/06/2004] [Indexed: 12/16/2022] Open
Abstract
NHE3(-/-) mice display a profound defect in proximal tubule bicarbonate reabsorption but are only mildly acidotic owing to reduced glomerular filtration rate and enhanced H(+) secretion in distal nephron segments. In vivo microperfusion of rat distal tubules suggests that a significant fraction of bicarbonate reabsorption in this nephron segment is mediated by NHE2. Two approaches were used to evaluate the role of distal tubule NHE2 in compensating for the proximal defect of H(+) secretion in NHE3(-/-) mice. First, renal clearance experiments were used to assess the impact of HOE694, an inhibitor with significant affinity for NHE2, on excretion of bicarbonate in NHE3(-/-) and NHE2(-/-) mice. Second, in vivo micropuncture and microperfusion were employed to measure the concentration of bicarbonate in early distal tubule fluid and to measure distal bicarbonate reabsorption during a constant bicarbonate load. Our data show that HOE694 had no effect on urinary bicarbonate excretion in NHE3(+/+) mice, whereas bicarbonate excretion was higher in NHE3(-/-) mice receiving HOE694. HOE694 induced a significant increase in bicarbonate excretion in mice given an acute bicarbonate load, but there was no effect during metabolic acidosis. Bicarbonate excretion was not affected by HOE694 in bicarbonate-loaded NHE2(-/-) mice. In vivo micropuncture revealed that early distal bicarbonate concentration was elevated in both bicarbonate-loaded and NHE3(-/-) mice. Further, microperfusion experiments showed that HOE694-sensitive bicarbonate reabsorption capacity was higher in acidotic and NHE3 null animals. We conclude that NHE2 contributes importantly to acidification in the distal tubule, and that it plays a major role in limiting urinary bicarbonate losses in states in which a high luminal bicarbonate load is presented to the distal tubule, such as in NHE3 null mice.
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Affiliation(s)
- Matthew A Bailey
- Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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Luthra M, Davids MR, Shafiee MA, Halperin ML. Anorexia nervosa and chronic renal insufficiency: a prescription for disaster. QJM 2004; 97:167-78. [PMID: 14976274 DOI: 10.1093/qjmed/hch031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Our imaginary consultant, Professor McCance, is asked to explain the basis for four major acute electrolyte abnormalities in a young woman with long-standing anorexia nervosa. She has a severe degree of hypokalaemia (2.0 mmol/l) with renal potassium wasting, a contracted extracellular fluid volume with renal NaCl wasting, hyponatraemia (118 mmol/l) while excreting hypoosmolar urine, and metabolic acidosis with a normal plasma anion gap (pH 7.20, bicarbonate 9 mmol/l). McCance begins his discussion by considering the basis for hypokalaemia, as this electrolyte disorder is potentially life-threatening. Its pathophysiology is linked to the other major findings, using principles of integrative physiology together with a deductive and quantitative analysis. Nevertheless, to reach his final diagnosis, he requires information about newer molecular discoveries. Not only is he able to suggest a likely diagnosis, but he also devises a novel long-term plan for therapy.
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Affiliation(s)
- M Luthra
- Division of Nephrology, St Michael's Hospital, University of Toronto, Toronto, Canada
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40
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Weinstein JJ. Bulimia nervosa. N Engl J Med 2003; 349:2363-4; author reply 2363-4. [PMID: 14668468 DOI: 10.1056/nejm200312113492420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Lin SH, Hsu YJ, Chiu JS, Chu SJ, Davids MR, Halperin ML. Osmotic demyelination syndrome: a potentially avoidable disaster. QJM 2003; 96:935-47. [PMID: 14631061 DOI: 10.1093/qjmed/hcg159] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Osmotic demyelination of the brain (ODS) is a dreaded complication that typically occurs several days after aggressive therapy for chronic hyponatraemia, but is eminently avoidable. In this teaching exercise, Professor McCance, an imaginary consultant, is asked to explain how he would have treated a 28-year-old female who had hyperkalaemia, hypoglycaemia, hypotension and hyponatraemia (118 mM) to prevent the development of ODS. He begins with a review of the physiology, including his own landmark work on chronic hyponatraemia associated with a contracted extracellular fluid volume. Adding quantitative analysis, the cause of the excessive rise in plasma sodium concentration is revealed, and a better plan for therapy is proposed.
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Affiliation(s)
- S-H Lin
- Departments of Medicine and Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC
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Amorim JBO, Bailey MA, Musa-Aziz R, Giebisch G, Malnic G. Role of luminal anion and pH in distal tubule potassium secretion. Am J Physiol Renal Physiol 2003; 284:F381-8. [PMID: 12529275 DOI: 10.1152/ajprenal.00236.2002] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Potassium secretory flux (J(K)) by the distal nephron is regulated by systemic and luminal factors. In the present investigation, J(K) was measured with a double-barreled K(+) electrode during paired microperfusion of superficial segments of the rat distal nephron. We used control solutions (100 mM NaCl, pH 7.0) and experimental solutions in which Cl(-) had been replaced with a less permeant anion and/or pH had been increased to 8.0. J(K) increased when Cl(-) was replaced by either acetate ( approximately 37%), sulfate ( approximately 32%), or bicarbonate ( approximately 62%), and also when the pH of the control perfusate was increased ( approximately 26%). The majority (80%) of acetate-stimulated J(K) was Ba(2+) sensitive, but furosemide (1 mM) further reduced secretion ( approximately 10% of total), suggesting that K(+)-Cl(-) cotransport was operative. Progressive reduction in luminal Cl(-) concentration from 100 to 20 to 2 mM caused increments in J(K) that were abolished by inhibitors of K(+)-Cl(-) cortransport, i.e., furosemide and [(dihydroindenyl)oxy]alkanoic acid. Increasing the pH of the luminal perfusion fluid also increased J(K) even in the presence of Ba(2+), suggesting that this effect cannot be accounted for only by K(+) channel modulation of K(+) secretion in the distal nephron of the rat. Collectively, these data suggest a role for K(+)-Cl(-) cotransport in distal nephron K(+) secretion.
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Affiliation(s)
- J B O Amorim
- Basic Science Department, Faculdade de Odontologia de São José dos Campos, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-900 São Paulo, Brazil
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Odvina CV, Preminger GM, Lindberg JS, Moe OW, Pak CYC. Long-term combined treatment with thiazide and potassium citrate in nephrolithiasis does not lead to hypokalemia or hypochloremic metabolic alkalosis. Kidney Int 2003; 63:240-7. [PMID: 12472789 DOI: 10.1046/j.1523-1755.2003.00719.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Potassium citrate is commonly used in combination with a thiazide diuretic in the medical management of recurrent hypercalciuric nephrolithiasis. However, concerns have been raised that administration of this nonchloride potassium alkali with a kaliuretic and natriuretic agent such as thiazide may not be efficacious in correcting or preventing hypokalemia, and may produce hypochloremic metabolic alkalosis. This retrospective analysis was conducted to determine if these two potential complications are encountered in patients on long-term potassium citrate and thiazide therapy. METHODS Data were collected on 95 patients who had been on combination therapy for at least 4 months from the stone clinics of the University of Texas Southwestern Medical Center, Duke University Medical Center, and Ochsner Clinic. RESULTS Mean serum potassium concentration remained within normal limits without a significant decrease during combined therapy. Serum chloride was significantly lower from pretreatment but by only 1 mEq/L and remained within normal limits throughout treatment. There was a small increase in serum bicarbonate concentration compared to the baseline level of less than 1 mEq/L at 8 to 12 and 18 to 24 months, but not at other treatment periods. CONCLUSION Co-administration of potassium citrate did not induce hypokalemia or hypochloremic metabolic alkalosis in our thiazide-treated patient population.
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Affiliation(s)
- Clarita V Odvina
- Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, and Department of Veterans Affairs Medical Center, Dallas, Texas 75390-8885, USA.
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Cheema-Dhadli S, Lin SH, Halperin ML. Mechanisms used to dispose of progressively increasing alkali load in rats. Am J Physiol Renal Physiol 2002; 282:F1049-55. [PMID: 11997321 DOI: 10.1152/ajprenal.00006.2001] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our objective was to describe the process of alkali disposal in rats. Balance studies were performed while incremental loads of alkali were given to rats fed a low-alkali diet or their usual alkaline ash diet. Control groups received equimolar NaCl or KCl. Virtually all of the alkali was eliminated within 24 h when the dose exceeded 750 micromol. The most sensitive response to alkali input was a decline in the excretion of NH(4)(+). The next level of response was to increase the excretion of unmeasured anions; this rise was quantitatively the most important process in eliminating alkali. The maximum excretion of citrate was approximately 70% of its filtered load. An even higher alkali load augmented the excretion of 2-oxoglutarate to >400% of its filtered load. Only with the largest alkali load did bicarbonaturia become quantitatively important. We conclude that renal mechanisms eliminate alkali while minimizing bicarbonaturia. This provides a way of limiting changes in urine pH without sacrificing acid-base balance, a process that might lessen the risk of kidney stone formation.
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Affiliation(s)
- Surinder Cheema-Dhadli
- Renal Division, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada M5B 1A6
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Halperin ML, Kamel KS. Dynamic interactions between integrative physiology and molecular medicine: The key to understand the mechanism of action of aldo sterone in the kidney. Can J Physiol Pharmacol 2000. [DOI: 10.1139/y00-039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our objective is to illustrate how an approach that integrates new insights from molecular biology and traditional physiology can lead to the development of new concepts. This dynamic interaction is illustrated by examining the steps taken to improve our understanding of the renal actions of aldosterone. We began by defining the big picture of what aldosterone does in the kidney. This led to the conclusion that aldosterone must at times become a sodium chloride-retaining hormone, while at other times it must function primarily or exclusively as a kaliuretic hormone. The second step was to define the major molecular actions of this hormone. Acting on the principal cells in the cortical collecting duct (CCD), aldosterone leads to the insertion of active epithelial sodium ion channels (ENaC) in their luminal membranes. This active ENaC, however, does not distinguish between the two major renal actions of aldosterone. Accordingly, we returned to integrative physiology and examined a possible role of renal and non-renal events. We implicated the potential importance of the delivery of bicarbonate ions to the CCD to determine which effect of aldosterone will become manifest. This, however, required that we reconsider some of the traditional views in interpretation of acid-base balance. At the clinical level, this global view can help us understand why, for example, a low dietary intake of potassium salts might predispose a person to an elevated blood pressure. Using a similar approach, it is possible to understand how the risk of the formation of kidney stones can be minimized.Key words: acid-base, hypertension, integrative physiology, kidney stones, potassium, sodium.
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Wuermser LA, Reilly C, Poindexter JR, Sakhaee K, Pak CY. Potassium-magnesium citrate versus potassium chloride in thiazide-induced hypokalemia. Kidney Int 2000; 57:607-12. [PMID: 10652038 DOI: 10.1046/j.1523-1755.2000.00881.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The purpose of this study was to compare the value of potassium-magnesium citrate (KMgCit) with potassium chloride in overcoming thiazide-induced hypokalemia. METHODS Sixty normal subjects first took hydrochlorothiazide (HCTZ; 50 mg/day). After three weeks of treatment (or earlier if hypokalemia developed), they were randomized to take KMgCit (42 mEq K, 21 mEq Mg, and 63 mEq citrate/day) or potassium chloride (42 mEq/day) for three weeks while continuing on HCTZ. RESULTS KMgCit significantly increased the serum potassium concentration from 3.42 +/- 0.30 mEq/L on HCTZ alone to about 3.8 mEq/L (P < 0.001). Potassium chloride produced a similar increase in serum potassium concentration from 3.45 +/- 0.44 mEq/L to about 3.8 mEq/L (P < 0. 001). KMgCit significantly increased the serum magnesium concentration by 0.11 to 0.12 mEq/L (P < 0.01), whereas potassium chloride produced a marginal decline or no significant change. KMgCit was less effective than potassium chloride in correcting HCTZ-induced hypochloridemia and hyperbicarbonatemia. KMgCit, but not potassium chloride, significantly increased urinary pH (by about 0.6 unit), citrate (by about 260 mg/day), and urinary magnesium. CONCLUSIONS KMgCit is equally effective as potassium chloride in correcting thiazide-induced hypokalemia. In addition, KMgCit, but not potassium chloride, produces a small but significant increase in serum magnesium concentration by delivering a magnesium load, and it confers alkalinizing and citraturic actions.
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Affiliation(s)
- L A Wuermser
- Center for Mineral Metabolism and Clinical Research, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8885, USA.
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Abstract
In a logical, stepwise approach to patients presenting with hypokalaemia or hyperkalaemia the clinician must first recognise circumstances in which the dyskalaemia represents a clinical emergency because therapy then takes precedence over diagnosis. If a dyskalaemia has been present for a long time, there is an abnormal renal handling of K+. The next step to analyse is the rate of excretion of K+ and, if necessary, its two components (urine flow rate and K+ concentration in the cortical collecting duct [CCD]) analysed independently. If the K+ concentration in the CCD is not in the expected range, its basis should be defined at the ion-channel level in the CCD from clinical information that can be used to deduce the relative rates of reabsorption of Na+ and Cl- in the CCD. This analysis provides the basis for diagnosis and may indicate where non-emergency therapy should then be directed.
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Affiliation(s)
- M L Halperin
- Division of Nephrology, St Michael's Hospital, University of Toronto, Ontario, Canada.
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Kamel SK, Lin SH, Cheema-Dhadli S, Marliss EB, Halperin ML. Prolonged total fasting: a feast for the integrative physiologist. Kidney Int 1998; 53:531-9. [PMID: 9507196 DOI: 10.1046/j.1523-1755.1998.00803.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- S K Kamel
- Division of Nephrology, St, Michael's Hospital, University of Toronto, Canada
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Lin SH, Cheema-Dhadli S, Gowrishankar M, Marliss EB, Kamel KS, Halperin ML. Control of excretion of potassium: lessons from studies during prolonged total fasting in human subjects. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:F796-800. [PMID: 9374844 DOI: 10.1152/ajprenal.1997.273.5.f796] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A deficit of K+ of close to 300 mmol develops in the first 2 wk of fasting, but little further excretion of K+ occurs, despite high levels of aldosterone and the delivery of ketoacid anions that are not reabsorbed in the distal nephron. Our purpose was to evaluate how aldosterone could have primarily NaCl-retaining, rather than kaliuretic, properties in this setting. To evaluate the role of distal delivery of Na+, four fasted subjects received an acute infusion of NaCl to induce a natriuresis. To assess the role of distal delivery of HCO3-, five fasted subjects were given an infusion containing NaHCO3. The natriuresis induced by an infusion of NaCl caused only a small rise in the rate of excretion of K+ (0.8 +/- 0.1 to 1.9 +/- 0.3 mmol/h); in contrast, when HCO3- replaced Cl- in the infusate, K+ excretion rose to 8.3 +/- 2.2 mmol/h, despite little excretion of HCO3- (urine, pH 5.8) and similar rates of excretion of Na+. The transtubular K+ concentration gradient was 19 +/- 3 with HCO3- and 6 +/- 2 with NaCl. We conclude that the infusion of NaHCO3 led to an increase in K+ excretion, likely reflecting an increased rate of distal K+ secretion. With a low distal delivery of HCO3-, aldosterone acts as a NaCl-retaining, rather than a kaliuretic, hormone.
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Affiliation(s)
- S H Lin
- Renal Division, National Defense Medical Center, Taipei, Taiwan, Republic of China
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Kamel KS, Quaggin S, Scheich A, Halperin ML. Disorders of potassium homeostasis: an approach based on pathophysiology. Am J Kidney Dis 1994; 24:597-613. [PMID: 7942818 DOI: 10.1016/s0272-6386(12)80220-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Disorders of potassium (K+) homeostasis are frequently encountered in clinical medicine and may have serious sequelae, particularly cardiac arrhythmias. Since long-term K+ balance depends on regulation of renal excretion of K+, the focus of this paper is to provide a novel way to analyze the K+ excretory process at the bedside in a noninvasive fashion. A fundamental aim was to incorporate recent new advances in K+ physiology to the clinical analysis of K+ disorders. In so doing, we have tried to replace eponyms and largely descriptive terms with more specific, but hypothetical pathophysiologic diagnoses. The approach we used focuses on an assessment of the components of K+ excretion in vivo. If the rate of excretion of K+ differs from the "expected" value for the stimulus of hypokalemia or hyperkalemia, one should determine whether the fault is with the flow rate and/or the [K+] in the terminal cortical collecting duct. The former is influenced primarily by the rate of excretion of osmoles when antidiuretic hormone acts, whereas the [K+] in the cortical collecting duct is determined by factors that modulate rate of electrogenic reabsorption of Na+ in that segment and its conductance for K+. By examining the extracellular fluid (ECF) volume status, the plasma renin activity, and the renal response to the induction of ECF volume contraction, we attempted to deduce whether the change in electrogenic reabsorption of Na+ was due to an altered Na+ transport or apparent permeability to chloride in the cortical collecting duct. We believe that an approach which draws heavily on pathophysiology can be of practical use at the bedside and, in addition, indicate areas in which more research could be fruitful. To illustrate these points, two clinical cases with hypokalemia and two with hyperkalemia were analyzed. Nevertheless, it is important to emphasize that the approach provided is speculative.
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Affiliation(s)
- K S Kamel
- Renal Division, St Michael's Hospital, University of Toronto, Canada
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