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Sprick JD, Jeong J, Sabino-Carvalho JL, Li S, Park J. Neurocirculatory regulation and adaptations to exercise in chronic kidney disease. Am J Physiol Heart Circ Physiol 2023; 324:H843-H855. [PMID: 37000610 PMCID: PMC10191135 DOI: 10.1152/ajpheart.00115.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 04/01/2023]
Abstract
Chronic kidney disease (CKD) is characterized by pronounced exercise intolerance and exaggerated blood pressure reactivity during exercise. Classic mechanisms of exercise intolerance in CKD have been extensively described previously and include uremic myopathy, chronic inflammation, malnutrition, and anemia. We contend that these classic mechanisms only partially explain the exercise intolerance experienced in CKD and that alterations in cardiovascular and autonomic regulation also play a key contributing role. The purpose of this review is to examine the physiological factors that contribute to neurocirculatory dysregulation during exercise and discuss the adaptations that result from regular exercise training in CKD. Key neurocirculatory mechanisms contributing to exercise intolerance in CKD include augmentation of the exercise pressor reflex, aberrations in neurocirculatory control, and increased neurovascular transduction. In addition, we highlight how some contributing factors may be improved through exercise training, with a specific focus on the sympathetic nervous system. Important areas for future work include understanding how the exercise prescription may best be optimized in CKD and how the beneficial effects of exercise training may extend to the brain.
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Affiliation(s)
- Justin D Sprick
- Department of Kinesiology, Health Promotion and Recreation, University of North Texas, Denton, Texas, United States
| | - Jinhee Jeong
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Jeann L Sabino-Carvalho
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Sabrina Li
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Jeanie Park
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
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2
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Lee DY, Kim JY, Ahn E, Hyeon JS, Kim GH, Park KJ, Jung Y, Lee YJ, Son MK, Kim SW, Han SY, Kim JH, Roh GS, Cha DR, Hwang GS, Kim WH. Associations between local acidosis induced by renal LDHA and renal fibrosis and mitochondrial abnormalities in patients with diabetic kidney disease. Transl Res 2022; 249:88-109. [PMID: 35788054 DOI: 10.1016/j.trsl.2022.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/23/2022] [Accepted: 06/22/2022] [Indexed: 10/31/2022]
Abstract
During the progression of diabetic kidney disease (DKD), renal lactate metabolism is rewired. The relationship between alterations in renal lactate metabolism and renal fibrosis in patients with diabetes has only been partially established due to a lack of biopsy tissues from patients with DKD and the intricate mechanism of lactate homeostasis. The role of lactate dehydrogenase A (LDHA)-mediated lactate generation in renal fibrosis and dysfunction in human and animal models of DKD was explored in this study. Measures of lactate metabolism (urinary lactate levels and LDHA expression) and measures of DKD progression (estimated glomerular filtration rate and Wilms' tumor-1 expression) were strongly negatively correlated in patients with DKD. Experiments with streptozotocin-induced DKD rat models and the rat renal mesangial cell model confirmed our findings. We found that the pathogenesis of DKD is linked to hypoxia-mediated lactic acidosis, which leads to fibrosis and mitochondrial abnormalities. The pathogenic characteristics of DKD were significantly reduced when aerobic glycolysis or LDHA expression was inhibited. Further studies will aim to investigate whether local acidosis caused by renal LDHA might be exploited as a therapeutic target in patients with DKD.
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Affiliation(s)
- Dae-Yeon Lee
- Division of Cardiovascular Disease Research, Korea National Institute of Health, Cheongju, Republic of Korea; Department of Anatomy and Convergence Medical Science, Bio Anti-aging Medical Research Center, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Republic of Korea
| | - Ji-Yeon Kim
- Division of Cardiovascular Disease Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Eunyong Ahn
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
| | - Jin Seong Hyeon
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
| | - Gyu-Hee Kim
- Division of Metabolic Disease Research, Department for Chronic Disease Convergence Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Keon-Jae Park
- Division of Metabolic Disease Research, Department for Chronic Disease Convergence Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Youngae Jung
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
| | - Yoo-Jeong Lee
- Division of Metabolic Disease Research, Department for Chronic Disease Convergence Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Mi Kyoung Son
- Division of Cardiovascular Disease Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Seung Woo Kim
- Division of Cardiovascular Disease Research, Korea National Institute of Health, Cheongju, Republic of Korea
| | - Sang Youb Han
- Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - Jae-Hong Kim
- Division of Life Sciences, College of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Bio Anti-aging Medical Research Center, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Republic of Korea
| | - Dae Ryong Cha
- Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
| | - Geum-Sook Hwang
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea.
| | - Won-Ho Kim
- Division of Cardiovascular Disease Research, Korea National Institute of Health, Cheongju, Republic of Korea.
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3
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Ho JQ, Verghese J, Abramowitz MK. Serum bicarbonate levels and gait abnormalities in older adults: a cross-sectional study. Sci Rep 2022; 12:9171. [PMID: 35654910 PMCID: PMC9163170 DOI: 10.1038/s41598-022-12907-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 05/18/2022] [Indexed: 11/17/2022] Open
Abstract
Metabolic acidosis is associated with impaired physical function in patients with chronic kidney disease (CKD) and older adults. However, whether acidosis is associated with gait abnormalities has received little attention. In a cohort of 323 community-dwelling adults ≥ 65 years old who underwent quantitative gait analysis, we examined associations of serum bicarbonate with eight individual gait variables. After multivariable adjustment, participants in the lowest bicarbonate tertile (< 25 mEq/L) had 8.6 cm/s slower speed (95% confidence interval [CI] 3.2–13.9), 7.9 cm shorter stride length (95% CI 3.5–12.2), and 0.03 s longer double support time (95% CI 0.002–0.1) compared with those in the middle tertile (25–27 mEq/L). Furthermore, lower bicarbonate levels were associated with more severe gait abnormalities in a graded manner. After further adjustment for possible mediating factors, associations were attenuated but remained significant. Among participants with CKD, associations were of similar or greater magnitude compared with those without CKD. Factor analysis was performed to synthesize the individual gait variables into unifying domains: among the pace, rhythm, and variability domains, lower serum bicarbonate was associated with worse performance in pace. In sum, lower serum bicarbonate was independently associated with worse performance on several quantitative measures of gait among older adults.
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Affiliation(s)
- Jim Q Ho
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ullmann 615, Bronx, NY, 10461, USA
| | - Joe Verghese
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ullmann 615, Bronx, NY, 10461, USA.,Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA.,Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Matthew K Abramowitz
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Ullmann 615, Bronx, NY, 10461, USA. .,Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, USA. .,Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY, USA. .,Fleischer Institute for Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, NY, USA.
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4
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Bollenbecker S, Czaya B, Gutiérrez OM, Krick S. Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases. Am J Physiol Lung Cell Mol Physiol 2022; 322:L625-L640. [PMID: 35272496 DOI: 10.1152/ajplung.00152.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 03/01/2022] [Accepted: 03/08/2022] [Indexed: 11/22/2022] Open
Abstract
Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.
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Affiliation(s)
- Seth Bollenbecker
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian Czaya
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Orlando M Gutiérrez
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Stefanie Krick
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, Alabama
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5
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Gone AR, Chen W. Veverimer for treatment of chronic metabolic acidosis in patients with chronic kidney disease. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1539. [PMID: 33313284 PMCID: PMC7729350 DOI: 10.21037/atm-20-3320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anirudh R Gone
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Wei Chen
- Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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6
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Copur S, Sag AA, Afsar B, Rossignol P, Covic A, Kanbay M. Complications of metabolic acidosis and alkalinizing therapy in chronic kidney disease patients: a clinician-directed organ-specific primer. Int Urol Nephrol 2020; 52:2311-2320. [PMID: 32661618 DOI: 10.1007/s11255-020-02563-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/29/2020] [Indexed: 01/09/2023]
Abstract
Chronic kidney disease is prevalent, affecting more than one in ten adults. In this population, metabolic acidosis is considered a key underlying pathophysiological feature, tying together bone mineral disorders, sarcopenia, insulin resistance, vascular calcification, pro-inflammatory and pro-thrombotic states. This review aims to address the paucity of literature on alkalinizing agents, a promising treatment option that has known adverse effects.
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Affiliation(s)
- Sidar Copur
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Alan A Sag
- Division of Vascular and Interventional Radiology, Department of Radiology, Duke University Medical Center, Durham, USA
| | - Baris Afsar
- Division of Nephrology, Department of Internal Medicine, Suleyman Demirel University School of Medicine, Isparta, Turkey
| | - Patrick Rossignol
- Université de Lorraine, INSERM CIC-P 1433, CHRU de Nancy, INSERM U1116, FCRIN INI-CRCT (Cardiovascular and Renal Clinical Trialists), Nancy, France
| | - Adrian Covic
- Department of Nephrology, Grigore T. Popa' University of Medicine, Iasi, Romania
| | - Mehmet Kanbay
- Department of Medicine, Division of Nephrology, Koc University School of Medicine, 34010, Istanbul, Turkey.
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7
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Advances in management of chronic metabolic acidosis in chronic kidney disease. Curr Opin Nephrol Hypertens 2020; 28:409-416. [PMID: 31232712 DOI: 10.1097/mnh.0000000000000524] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW Chronic metabolic acidosis is a common complication of chronic kidney disease (CKD) and is associated with adverse consequences, such as CKD progression and muscle wasting. We review the findings from recent clinical trials that have examined the effects of sodium bicarbonate therapy and veverimer in patients with CKD and chronic metabolic acidosis. RECENT FINDINGS There are four recent clinical trials on chronic metabolic acidosis of CKD. In a pilot, cross-over study, 6 weeks of sodium bicarbonate therapy improved vascular endothelial function, measured by brachial artery flow-mediated dilation. In a single-center, randomized, open-label study, 6 months of sodium bicarbonate therapy increased muscle mass and lean body mass, and preserved kidney function. The other two clinical trials (phase 1/2 and phase 3 studies) examined the effects of veverimer, which is a hydrochloric acid binder. The phase 3 study showed that 12-weeks of veverimer increased serum bicarbonate levels and might improve physical function. The effects of veverimer on CKD progression, physical function and cardiovascular endpoints as well as its long-term safety are yet to be determined. SUMMARY Recent studies suggest that sodium bicarbonate therapy may improve vascular endothelial function and muscle mass, and preserve renal function. Veverimer increases serum bicarbonate level and could be a potential new therapeutic option for treating chronic metabolic acidosis.
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8
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Sahu KK, Mishra AK, Lal A, Javadi H. Calciphylaxis: Continues to surprise. Nephrology (Carlton) 2019; 25:360-361. [PMID: 31486258 DOI: 10.1111/nep.13643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Kamal Kant Sahu
- Department of Internal MedicineSaint Vincent Hospital Worcester Massachusetts USA
| | - Ajay Kumar Mishra
- Department of Internal MedicineSaint Vincent Hospital Worcester Massachusetts USA
| | - Amos Lal
- Department of Internal MedicineSaint Vincent Hospital Worcester Massachusetts USA
| | - Houman Javadi
- Department of Internal MedicineSaint Vincent Hospital Worcester Massachusetts USA
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9
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Oliveira EA, Zheng R, Carter CE, Mak RH. Cachexia/Protein energy wasting syndrome in CKD: Causation and treatment. Semin Dial 2019; 32:493-499. [PMID: 31286575 DOI: 10.1111/sdi.12832] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cachexia is a multifactorial syndrome defined by significant body weight loss, fat and muscle mass reduction, and increased protein catabolism. Protein energy wasting (PEW) is characterized as a syndrome of adverse changes in nutrition and body composition being highly prevalent in patients with CKD, especially in those undergoing dialysis, and it is associated with high morbidity and mortality in this population. Multiple mechanisms are involved in the genesis of these adverse nutritional changes in CKD patients. There is no obvious distinction between PEW and cachexia from a pathophysiologic standpoint and should be considered as part of the spectrum of the same nutritional disorder in CKD with similar management approaches for prevention and treatment based on current understanding. A plethora of factors can affect the nutritional status of CKD patients requiring a combination of therapeutic approaches to prevent or reverse protein and energy depletion. At present, there is no effective pharmacologic intervention that prevents or attenuates muscle atrophy in catabolic conditions like CKD. Prevention and treatment of uremic muscle wasting involve optimal nutritional support, correction of acidosis, and physical exercise. There has been emerging consistent evidence that active treatment, perhaps by combining nutritional interventions and resistance exercise, may be able to improve but not totally reverse or prevent the supervening muscle wasting and weakness. Active research into more direct pharmacological treatment based on basic mechanistic research is much needed for this unmet medical need in patients with CKD.
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Affiliation(s)
- Eduardo A Oliveira
- Division of Pediatric Nephrology, Rady Children's Hospital San Diego, University of California San Diego, California.,Pediatric Nephrourology Division, Department of Pediatrics, School of Medicine, Federal University of Minas Gerais (UFMG), Minas Gerais, Brazil
| | - Ronghao Zheng
- Department of Pediatric Nephrology, Rheumatology and Immunology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Caitlin E Carter
- Division of Pediatric Nephrology, Rady Children's Hospital San Diego, University of California San Diego, California
| | - Robert H Mak
- Division of Pediatric Nephrology, Rady Children's Hospital San Diego, University of California San Diego, California
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10
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Goutham KTC, Harichandrakumar KT, Dhanin P, Priyamvada PS, Haridasan S, Parameswaran S. Persistent Metabolic Acidosis on Regular Hemodialysis or Peritoneal Dialysis. Indian J Nephrol 2019; 29:84-89. [PMID: 30983747 PMCID: PMC6440337 DOI: 10.4103/ijn.ijn_309_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Metabolic acidosis is known to have adverse consequences in patients with chronic kidney disease (CKD) including protein-energy wasting, inflammation, bone disease, and disturbance in endocrine function. Unlike in the management of patients with predialysis CKD, bicarbonate levels were not being routinely monitored in dialysis patients at our center. The KDOQI guidelines recommend serum bicarbonate levels ≥22 mEq/L in patients on dialysis. We measured the predialysis serum bicarbonate levels in 100 adult patients on regular hemodialysis (HD) and 41 adult patients on peritoneal dialysis (PD). We also studied the extent of rise in serum bicarbonate levels from predialysis levels after HD in our patients. Predialysis serum bicarbonate level was <22 mEq/L in 73% of patients on HD and 12% of patients on PD. The serum bicarbonate levels remained <22 mEq/L at the end of HD in 41% of patients on HD. Thirty-nine percent of patients were on a HD schedule of thrice a week, and 93% of PD patients performed three PD exchanges a day. The dialysate bicarbonate level was 34 mEq/L. There was a significant increase in serum bicarbonate levels with HD, but the mean postdialysis bicarbonate level was 23.45 mEq/L. A very high proportion of our patients on HD continued to have uncorrected metabolic acidosis, with metabolic acidosis persisting in the immediate postdialysis period in a significant number of patients. Predialysis serum bicarbonate level needs to be monitored in patients on HD. There is an urgent need to modify HD prescription to ensure better correction of metabolic acidosis in our HD population. Compared to HD, the proportion of patients having persistent metabolic acidosis is significantly lower in PD.
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Affiliation(s)
| | | | - P Dhanin
- Department of Nephrology, JIPMER, Puducherry, India
| | | | - S Haridasan
- Department of Nephrology, JIPMER, Puducherry, India
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11
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Bushinsky DA. Tolerance to Sodium in Patients With CKD-Induced Metabolic Acidosis: Does the Accompanying Anion Matter? Am J Kidney Dis 2018; 73:858-865. [PMID: 30518477 DOI: 10.1053/j.ajkd.2018.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 09/07/2018] [Indexed: 11/11/2022]
Abstract
Patients with chronic kidney disease (CKD) continue to produce endogenous acids but have a reduction in net acid excretion, resulting in a primary decrease in serum bicarbonate concentration, which is termed chronic metabolic acidosis. Recent prospective studies, along with retrospective cohort analyses, demonstrate a higher risk for CKD progression with untreated metabolic acidosis. To normalize serum bicarbonate levels, acidemic patients are often treated with sodium bicarbonate (NaHCO3) or sodium citrate, which have been shown to slow the progression of CKD. However, studies using this approach have routinely excluded patients with common sodium-sensitive comorbid conditions, such as poorly controlled hypertension, congestive heart failure, volume overload, or edema. This article examines the effect of the anion that accompanies sodium delivered with these therapies. Do the negative effects on blood pressure (BP) and sodium retention, as measured by an increase in edema, weight gain, and congestive heart failure, observed with oral administration of sodium chloride (NaCl) differ when a similar amount of sodium is given with bicarbonate or citrate in this patient population? A review of the literature suggests that NaHCO3 does not increase BP or sodium retention when administered to patients with CKD during a concurrent severe NaCl dietary restriction (∼10 mEq/d). However, this degree of NaCl restriction is feasible only under strict control in clinical research environments. In contrast, when NaHCO3 is given to patients without severe dietary NaCl restriction, there is an increase in BP and sodium retention. Thus, unless patients with CKD can tolerate a diet virtually devoid of NaCl, additional sodium, regardless of the accompanying anion, appears to increase BP and sodium retention.
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Affiliation(s)
- David A Bushinsky
- University of Rochester School of Medicine and Dentistry, Rochester, NY.
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12
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Ahmed AR, Lappin D. Oral alkali therapy and the management of metabolic acidosis of chronic kidney disease: A narrative literature review. World J Nephrol 2018; 7:117-122. [PMID: 30324086 PMCID: PMC6181870 DOI: 10.5527/wjn.v7.i6.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/05/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023] Open
Abstract
Chronic metabolic acidosis is a common complication seen in advanced chronic kidney disease (CKD). There is currently no consensus on its management in the Republic of Ireland. Recent trials have suggested that appropriate active management of metabolic acidosis through oral alkali therapy and modified diet can have a deterring impact on CKD progression. The potential benefits of treatment include preservation of bone health and improvement in muscle function; however, present data is limited. This review highlights the current evidence, available primarily from randomised control trials (RCTs) over the last decade, in managing the metabolic acidosis of CKD and outlines ongoing RCTs that are promising. An economic perspective is also briefly discussed to support decision-making.
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Affiliation(s)
- Adeel Rafi Ahmed
- Department of Nephrology, University Hospital Galway, Galway H91YR1, Ireland
| | - David Lappin
- Department of Nephrology, University Hospital Galway, Galway H91YR1, Ireland
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13
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Chen W, Newman AB, Fried LF, Rifkin DE, Shlipak MG, Sarnak MJ, Katz R, Madero M, Raphael KL, Bushinsky DA, Ix JH. Relationship of acid-base status with arterial stiffness in community-living elders: the Health ABC Study. Nephrol Dial Transplant 2018; 33:1572-1579. [PMID: 29177410 DOI: 10.1093/ndt/gfx292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/09/2017] [Indexed: 11/13/2022] Open
Abstract
Background Animal studies suggest that acidosis protects against arterial calcification, which contributes to arterial stiffness. The goal of this study was to investigate the associations of serum bicarbonate and pH with arterial stiffness in community-living older adults. Methods We performed cross-sectional analyses among 1698 well-functioning participants 70-79 years of age. Bicarbonate and pH were measured by arterialized venous blood gas at the point of care. Bicarbonate was categorized into low (<23 mEq/L), normal (23-27.9) and high (≥28). Arterialized venous pH (AVpH) was categorized into tertiles: ≤7.40, >7.40-7.42 and >7.42. Arterial stiffness was evaluated by pulse wave velocity (PWV) and high ankle-brachial index (ABI; >1.3/incompressible). We used linear and logistic regression to evaluate the association of bicarbonate and AVpH with PWV and high ABI, respectively. Results The mean age was 76 years and 15% had an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. The mean bicarbonate was 25.2 ± 2.1 mEq/L and the mean AVpH was 7.41 ± 0.03. Compared with participants in the normal bicarbonate category, those in the low bicarbonate group had 8.8% higher PWV (P = 0.006) and 1.87 greater odds of high ABI (P = 0.04). However, the associations were not significant after adjusting for eGFR (P = 0.24 and 0.43, respectively). There was no difference in PWV or high ABI across AVpH tertiles. Results were similar in those with and without chronic kidney disease and after excluding participants on diuretics. Conclusions We did not observe an independent association of bicarbonate or AVpH with arterial stiffness measured by high PWV or ABI in community-living older individuals. Future studies evaluating patients with a greater severity of chronic kidney disease and with more extreme alterations in acid-base status are warranted.
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Affiliation(s)
- Wei Chen
- Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - Anne B Newman
- Center for Aging and Population Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Linda F Fried
- Renal Section, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
| | - Dena E Rifkin
- Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Michael G Shlipak
- General Internal Medicine Section, VA Medical Center, University of California, San Francisco, CA, USA
| | - Mark J Sarnak
- Department of Nephrology, Tufts Medical Center, Boston, MA, USA
| | - Ronit Katz
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | | | | | - David A Bushinsky
- Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY, USA
| | - Joachim H Ix
- Department of Medicine, University of California San Diego, San Diego, CA, USA.,Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
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14
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Kasai T, Washida N, Muraoka H, Fujii K, Uchiyama K, Shinozuka K, Morimoto K, Tokuyama H, Wakino S, Itoh H. Penile calciphylaxis in a patient on combined peritoneal dialysis and hemodialysis. CEN Case Rep 2018; 7:204-207. [PMID: 29594982 DOI: 10.1007/s13730-018-0327-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 03/25/2018] [Indexed: 02/06/2023] Open
Abstract
Calciphylaxis presents with painful purpura and intractable skin ulcers on the trunk and particularly the distal extremities, and it mainly occurs in patients on chronic dialysis. A 66-year-old man with renal failure due to diabetic nephropathy was on peritoneal dialysis alone for 1 year, followed by peritoneal dialysis combined with hemodialysis for 3 years. He developed calciphylaxis of the penis, which was diagnosed from the skin biopsy findings and clinical observation. To treat this condition, PD was stopped and HD was performed three times a week. In addition, warfarin therapy was discontinued and infusion of sodium thiosulfate was performed. The penile ulcers decreased in size and pain was markedly improved, so the patient was discharged from hospital. Following discharge, PD was resumed after changing the peritoneal dialysis fluid to bicarbonate-buffered dialysate. The penile ulcers eventually resolved completely. There have been very few reports about calciphylaxis in patients on combined dialysis modalities. In our patient, penile calciphylaxis progressed when lactate-buffered peritoneal dialysis fluid was used and resolved after switching to bicarbonate-buffered fluid together with cessation of warfarin therapy and infusion of sodium thiosulfate.
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Affiliation(s)
- Takahiro Kasai
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Naoki Washida
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
- Department of Nephrology, International University of Health and Welfare Hospital, Nasushiobara, Tochigi, Japan.
| | - Hirokazu Muraoka
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kentarou Fujii
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kiyotaka Uchiyama
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Keisuke Shinozuka
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kohkichi Morimoto
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hirobumi Tokuyama
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shu Wakino
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hiroshi Itoh
- Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
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15
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Bushinsky DA, Hostetter T, Klaerner G, Stasiv Y, Lockey C, McNulty S, Lee A, Parsell D, Mathur V, Li E, Buysse J, Alpern R. Randomized, Controlled Trial of TRC101 to Increase Serum Bicarbonate in Patients with CKD. Clin J Am Soc Nephrol 2018; 13:26-35. [PMID: 29102959 PMCID: PMC5753317 DOI: 10.2215/cjn.07300717] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/10/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Metabolic acidosis is common in patients with CKD and has significant adverse effects on kidney, muscle, and bone. We tested the efficacy and safety of TRC101, a novel, sodium-free, nonabsorbed hydrochloric acid binder, to increase serum bicarbonate in patients with CKD and metabolic acidosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS One hundred thirty-five patients were enrolled in this randomized, double-blind, placebo-controlled, multicenter, in-unit study (designated the TRCA-101 Study). Patients had a mean baseline eGFR of 35 ml/min per 1.73 m2, a mean baseline serum bicarbonate of 17.7 mEq/L, and comorbidities, including hypertension (93%), diabetes (70%), and heart failure (21%). Patients ate a controlled diet and were treated for 14 days with placebo or one of four TRC101 dosing regimens (1.5, 3, or 4.5 g twice daily or 6 g once daily). After treatment, patients were discharged and followed for 7-14 days. RESULTS All TRC101 treatment groups had a mean within-group increase in serum bicarbonate of ≥1.3 mEq/L (P<0.001) within 72 hours of the first dose and a mean increase in serum bicarbonate of 3.2-3.9 mEq/L (P<0.001) at the end of treatment compared with placebo, in which serum bicarbonate did not change. In the combined TRC101 treatment group, serum bicarbonate was normalized (22-29 mEq/L) at the end of treatment in 35% of patients and increased by ≥4 mEq/L in 39% of patients. After discontinuation of TRC101, serum bicarbonate decreased nearly to baseline levels within 2 weeks. All adverse events were mild or moderate, with gastrointestinal events most common. All patients completed the study. CONCLUSIONS TRC101 safely and significantly increased the level of serum bicarbonate in patients with metabolic acidosis and CKD.
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Affiliation(s)
- David A. Bushinsky
- Department of Medicine, University of Rochester School of Medicine, Rochester, New York
| | - Thomas Hostetter
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | | | - Yuri Stasiv
- Tricida Inc., South San Francisco, California
| | | | | | - Angela Lee
- Tricida Inc., South San Francisco, California
| | | | | | | | | | - Robert Alpern
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
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17
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Sheikh IA, Malik A, AlBasri SFM, Beg MA. In silico identification of genes involved in chronic metabolic acidosis. Life Sci 2018; 192:246-252. [PMID: 29138116 DOI: 10.1016/j.lfs.2017.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/10/2017] [Indexed: 10/18/2022]
Abstract
AIMS Chronic metabolic acidosis (CMA) refers to increased plasma acidity due to disturbed acid-base equilibrium in human body. CMA leads to many dysfunctions including disorders of intestinal metabolism and barrier functions. The human body responds to these intestinal dysfunctions by creating a compensatory mechanism at genomic level in intestinal epithelial cells. This study was to identify the molecular pathways involved in metabolic dysfunction and compensatory adaptations in intestinal epithelium during CMA. MAIN METHODS In silico approaches were utilized to characterize a set of 88 differentially expressed genes (DEGs) from intestinal cells of rat CMA model. Interaction networks were constructed for DEGs by GeneMANIA and hub genes as well as enriched clusters in the network were screened using GLay. Gene Ontology (GO) was used for enriching functions in each cluster. KEY FINDINGS Four gene hubs, i.e., trefoil factor 1, 5-hydroxytryptamine (serotonin) receptor 5a, solute carrier family 6 (neurotransmitter transporter), member 11, and glutamate receptor, ionotropic, n-methyl d-aspartate 2b, exhibiting the highest node degree were predicted. Six biologically related gene clusters were also predicted. Functional enrichment of GO terms predicted neurological processes such as neurological system process regulation and nerve impulse transmission which are related to negative and positive regulation of digestive system processes., intestinal motility and absorption and maintenance of gastrointestinal epithelium. SIGNIFICANCE The study predicted several important genomic pathways that potentially play significant roles in metabolic disruptions or compensatory adaptations of intestinal epithelium induced by CMA. The results provide a further insight into underlying molecular mechanisms associated with CMA.
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Affiliation(s)
- Ishfaq A Sheikh
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Adeel Malik
- Perdana University Centre for Bioinformatics, MARDI Complex, Jalan MAEPS Perdana, 43400 Serdang, Selangor, Malaysia
| | - Sameera F M AlBasri
- Department of Obstetrics and Gynecology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohd A Beg
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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18
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Chang KY, Kim HW, Kim WJ, Kim YK, Kim SH, Song HC, Kim YO, Jin DC, Choi EJ, Yang CW, Kim YL, Kim NH, Kang SW, Kim YS, Kim YS. The impact of high serum bicarbonate levels on mortality in hemodialysis patients. Korean J Intern Med 2017; 32:109-116. [PMID: 27044857 PMCID: PMC5214722 DOI: 10.3904/kjim.2015.168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/31/2015] [Accepted: 08/04/2015] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIMS The optimal serum bicarbonate level is controversial for patients who are undergoing hemodialysis (HD). In this study, we analyzed the impact of serum bicarbonate levels on mortality among HD patients. METHODS Prevalent HD patients were selected from the Clinical Research Center registry for End Stage Renal Disease cohort in Korea. Patients were categorized into quartiles according to their total carbon dioxide (tCO2) levels: quartile 1, a tCO2 of < 19.4 mEq/L; quartile 2, a tCO2 of 19.4 to 21.5 mEq/L; quartile 3, a tCO2 of 21.6 to 23.9 mEq/L; and quartile 4, a tCO2 of ≥ 24 mEq/L. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) and confidence interval (CI) for mortality. RESULTS We included 1,159 prevalent HD patients, with a median follow-up period of 37 months. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher in patients from quartile 4, compared to those from the other quartiles (p = 0.009, log-rank test). The multivariate Cox proportional hazard model revealed that patients from quartile 4 had significantly higher risk of mortality than those from quartile 1, 2 and 3, after adjusting for the clinical variables in model 1 (HR, 1.99; 95% CI, 1.15 to 3.45; p = 0.01) and model 2 (HR, 1.82; 95% CI, 1.03 to 3.22; p = 0.04). CONCLUSIONS Our data indicate that high serum bicarbonate levels (a tCO2 of ≥ 24 mEq/L) were associated with increased mortality among prevalent HD patients. Further effort might be necessary in finding the cause and correcting metabolic alkalosis in the chronic HD patients with high serum bicarbonate levels.
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Affiliation(s)
- Kyung Yoon Chang
- Department of Internal Medicine, College of Medicine, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Hyung Wook Kim
- Department of Internal Medicine, College of Medicine, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Woo Jeong Kim
- Department of Internal Medicine, College of Medicine, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Yong Kyun Kim
- College of Medicine, Bucheon St. Mary’s Hospital, The Catholic University of Korea, Bucheon, Korea
| | - Su-Hyun Kim
- Chung-Ang University College of Medicine, Seoul, Korea
| | - Ho Chul Song
- College of Medicine, Bucheon St. Mary’s Hospital, The Catholic University of Korea, Bucheon, Korea
| | - Young Ok Kim
- College of Medicine, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, Uijeongbu, Korea
| | - Dong Chan Jin
- Department of Internal Medicine, College of Medicine, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Euy Jin Choi
- College of Medicine, Bucheon St. Mary’s Hospital, The Catholic University of Korea, Bucheon, Korea
| | - Chul Woo Yang
- College of Medicine, Seoul St. Mary’s Hospital, The Catholic University of Korea, Seoul, Korea
| | - Yong-Lim Kim
- Kyungpook National University School of Medicine, Daegu, Korea
| | - Nam-Ho Kim
- Chonnam National University Medical School, Gwangju, Korea
| | | | - Yon-Su Kim
- Seoul National University College of Medicine, Seoul, Korea
| | - Young Soo Kim
- College of Medicine, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, Uijeongbu, Korea
- Correspondence to Young Soo Kim, M.D. Division of Nephrology, Department of Internal Medicine, College of Medicine, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 11765, Korea Tel: +82-31-820-3039 Fax: +82-31-847-2719 E-mail:
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19
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Chen W, Melamed ML, Hostetter TH, Bauer C, Raff AC, Almudevar AL, Lalonde A, Messing S, Abramowitz MK. Effect of oral sodium bicarbonate on fibroblast growth factor-23 in patients with chronic kidney disease: a pilot study. BMC Nephrol 2016; 17:114. [PMID: 27495287 PMCID: PMC4974735 DOI: 10.1186/s12882-016-0331-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/02/2016] [Indexed: 12/16/2022] Open
Abstract
Background The regulation of fibroblast growth factor-23 (FGF23) secretion in patients with chronic kidney disease (CKD) is incompletely understood. An in vitro study showed that metabolic acidosis increased FGF23 in mouse bone. The objective of this study is to evaluate the effect of oral sodium bicarbonate on circulating FGF23 levels in patients with CKD. Methods This was a single-blind pilot study. Twenty adults with estimated glomerular filtration rate between 15–45 mL/min/1.73 m2 and serum bicarbonate between 20–24 mEq/L were treated with placebo for 2 weeks, followed by increasing doses of oral sodium bicarbonate (0.3, 0.6 and 1.0 mEq/kg/day) in 2 week intervals for a total of 6 weeks. C-terminal FGF23 levels were measured at the initial visit, after 2 weeks of placebo and after 6 weeks of bicarbonate therapy. Wilcoxon matched-pairs signed-rank test was used to compare FGF23 before and after sodium bicarbonate. Results After 6 weeks of oral sodium bicarbonate, the median FGF23 increased significantly from 150.9 RU/mL (IQR 107.7–267.43) to 191.4 RU/mL (IQR 132.6–316.9) (p = 0.048) and this persisted after excluding participants who received activated vitamin D. Conclusions FGF23 increased after short-term oral sodium bicarbonate therapy in patients with CKD and mild metabolic acidosis. It is unclear whether this was due to the alkalinizing effect of sodium bicarbonate or other factors. Trial registration The study was registered at ClinicalTrials.gov (NCT00888290) on April 23, 2009.
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Affiliation(s)
- Wei Chen
- Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 675, Rochester, NY, 14642, USA.
| | - Michal L Melamed
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Thomas H Hostetter
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Carolyn Bauer
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Amanda C Raff
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Anthony L Almudevar
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Amy Lalonde
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Susan Messing
- Department of Biostatistics & Computation Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Matthew K Abramowitz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
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High (≥6.5) Spontaneous and Persistent Urinary pH Is Protective of Renal Function at Baseline and during Disease Course in Idiopathic Membranous Nephropathy. Int J Nephrol 2015; 2015:730234. [PMID: 26294975 PMCID: PMC4534628 DOI: 10.1155/2015/730234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/30/2015] [Accepted: 07/14/2015] [Indexed: 12/04/2022] Open
Abstract
Metabolic acidosis correction in advanced renal failure slows renal function decline attributed to tubulointerstitial damage (TID) reduction. No study evaluated if spontaneous baseline high urinary pH (UpH) is renoprotective in patients with normal renal function and without metabolic acidosis. The study tested this hypothesis in idiopathic membranous nephropathy (IMN). Eighty-five patients (follow-up 81 ± 54 months) measured UpH, serum creatinine, eGFR, protein/creatinine ratio, fractional excretion of albumin, IgG, α1-microglobulin, and urinary N-acetyl-β-D-glucosaminidase (β-NAG)/creatinine ratio. Twenty-eight patients (33%) had UpH ≥ 6.5 and 57 (67%) pH < 6.5; high versus low UpH patients had significantly lower values of the tubulointerstitial damage (TID) markers FE α1m and β-NAG and significantly better baseline renal function. These differences persisted over time in a subset of 38 patients with 5 measurements along 53 ± 26 months. In 29 patients with nephrotic syndrome (NS) treated with supportive therapy (follow-up: 80 ± 52 months) renal function was stable in 10 high and significantly worse in 19 low UpH patients. Steroids + cyclophosphamide treatment in 35 NS patients masks the renoprotection of high UpH. Conclusions. In IMN high and persistent UpH is associated with reduction of the proteinuric markers of tubulointerstitial damage and baseline better renal function in all patients and in NS patients treated only with supportive therapy during disease course. The factors associated with high pH-dependent renoprotection were lower values of TID markers, eGFR ≥ 60 mL/min, BP < 140/90 mmHg, and age < 55 years.
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21
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Lee HW, Osis G, Handlogten ME, Guo H, Verlander JW, Weiner ID. Effect of dietary protein restriction on renal ammonia metabolism. Am J Physiol Renal Physiol 2015; 308:F1463-73. [PMID: 25925252 DOI: 10.1152/ajprenal.00077.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022] Open
Abstract
Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during protein restriction. Ammonia is the primary component of net acid excretion, and inappropriate ammonia excretion can lead to negative nitrogen balance. Accordingly, we examined ammonia excretion in response to protein restriction and then we determined the molecular mechanism of the changes observed. Wild-type C57Bl/6 mice fed a 20% protein diet and then changed to 6% protein developed an 85% reduction in ammonia excretion within 2 days, which persisted during a 10-day study. The expression of multiple proteins involved in renal ammonia metabolism was altered, including the ammonia-generating enzymes phosphate-dependent glutaminase (PDG) and phosphoenolpyruvate carboxykinase (PEPCK) and the ammonia-metabolizing enzyme glutamine synthetase. Rhbg, an ammonia transporter, increased in expression in the inner stripe of outer medullary collecting duct intercalated cell (OMCDis-IC). However, collecting duct-specific Rhbg deletion did not alter the response to protein restriction. Rhcg deletion did not alter ammonia excretion in response to dietary protein restriction. These results indicate 1) dietary protein restriction decreases renal ammonia excretion through coordinated regulation of multiple components of ammonia metabolism; 2) increased Rhbg expression in the OMCDis-IC may indicate a biological role in addition to ammonia transport; and 3) Rhcg expression is not necessary to decrease ammonia excretion during dietary protein restriction.
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Affiliation(s)
- Hyun-Wook Lee
- Division of Nephrology, Hypertension and Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Gunars Osis
- Division of Nephrology, Hypertension and Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Mary E Handlogten
- Division of Nephrology, Hypertension and Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Hui Guo
- Division of Nephrology, Second Hospital of Shanxi Medical University, Yaiyuan, Shanxi, Peoples Republic of China; and
| | - Jill W Verlander
- Division of Nephrology, Hypertension and Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - I David Weiner
- Division of Nephrology, Hypertension and Transplantation, University of Florida College of Medicine, Gainesville, Florida, Nephrology and Hypertension Section, Medical Service, North Florida/South Georgia Veterans Health System, Gainesville, Florida
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Leibrock CB, Alesutan I, Voelkl J, Pakladok T, Michael D, Schleicher E, Kamyabi-Moghaddam Z, Quintanilla-Martinez L, Kuro-o M, Lang F. NH4Cl Treatment Prevents Tissue Calcification in Klotho Deficiency. J Am Soc Nephrol 2015; 26:2423-33. [PMID: 25644113 DOI: 10.1681/asn.2014030230] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 11/30/2014] [Indexed: 11/03/2022] Open
Abstract
Klotho, a cofactor in suppressing 1,25(OH)2D3 formation, is a powerful regulator of mineral metabolism. Klotho-hypomorphic mice (kl/kl) exhibit excessive plasma 1,25(OH)2D3, Ca(2+), and phosphate concentrations, severe tissue calcification, volume depletion with hyperaldosteronism, and early death. Calcification is paralleled by overexpression of osteoinductive transcription factor Runx2/Cbfa1, Alpl, and senescence-associated molecules Tgfb1, Pai-1, p21, and Glb1. Here, we show that NH4Cl treatment in drinking water (0.28 M) prevented soft tissue and vascular calcification and increased the life span of kl/kl mice >12-fold in males and >4-fold in females without significantly affecting extracellular pH or plasma concentrations of 1,25(OH)2D3, Ca(2+), and phosphate. NH4Cl treatment significantly decreased plasma aldosterone and antidiuretic hormone concentrations and reversed the increase of Runx2/Cbfa1, Alpl, Tgfb1, Pai-1, p21, and Glb1 expression in aorta of kl/kl mice. Similarly, in primary human aortic smooth muscle cells (HAoSMCs), NH4Cl treatment reduced phosphate-induced mRNA expression of RUNX2/CBFA1, ALPL, and senescence-associated molecules. In both kl/kl mice and phosphate-treated HAoSMCs, levels of osmosensitive transcription factor NFAT5 and NFAT5-downstream mediator SOX9 were higher than in controls and decreased after NH4Cl treatment. Overexpression of NFAT5 in HAoSMCs mimicked the effect of phosphate and abrogated the effect of NH4Cl on SOX9, RUNX2/CBFA1, and ALPL mRNA expression. TGFB1 treatment of HAoSMCs upregulated NFAT5 expression and prevented the decrease of phosphate-induced NFAT5 expression after NH4Cl treatment. In conclusion, NH4Cl treatment prevents tissue calcification, reduces vascular senescence, and extends survival of klotho-hypomorphic mice. The effects of NH4Cl on vascular osteoinduction involve decrease of TGFB1 and inhibition of NFAT5-dependent osteochondrogenic signaling.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Makoto Kuro-o
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas
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Affiliation(s)
- Matthew K Abramowitz
- Department of Medicine, Division of Nephrology andDepartment of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
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