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Chrysant SG. The Interaction of Kidneys and Gut in Development of Salt-Sensitive Hypertension. Cardiol Rev 2024; 32:356-361. [PMID: 37273192 DOI: 10.1097/crd.0000000000000518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The incidence of salt-sensitive hypertension is quite common and varies between 30-60% in hypertensive patients. Regarding the causal role of high salt intake in the development of salt-sensitive hypertension, recent evidence has demonstrated that the gut through its microbiota plays a significant role in its genesis. Besides the gut, the kidneys also play important role in salt-sensitive hypertension and there is clinical and experimental evidence of an interrelationship between the gut and the kidneys in the development of salt-sensitive hypertension through the so-called "gastro-renal axis." The gut besides being an absorptive organ, it is also a hormonal secretory organ involving the secretion of gastrin, dopamine, norepinephrine, angiotensin, and aldosterone which through their action with the kidneys are involved in the development of salt-sensitive hypertension. In addition, the kidneys exert a protective role against the development of hypertension through the secretion of prostaglandins and their vasodilatory action. To assess the current evidence on the role of high salt intake and the interplay of the gut and kidneys in its development, a Medline search of the English literature was contacted between 2012 and 2022, and 46 pertinent papers were selected. These papers together with collateral literature will be discussed in this review.
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Affiliation(s)
- Steven G Chrysant
- From the University of Oklahoma Health Sciences Center, Oklahoma City, OK
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Wang M, Xiao J, Du Q, Zhang W, Zhang J, Yan Z, Luo J, Yu C, Ye Z, Chen J. Phosphorus balance calculator: an individualized tool for treatment of hyperphosphatemia in hemodialysis patients. Nephrol Dial Transplant 2024; 39:1159-1170. [PMID: 38037501 DOI: 10.1093/ndt/gfad256] [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: 07/29/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Lack of evaluations of the dietary phosphorus and dialysis phosphorus removal in daily clinical practice are common obstacles to assessing phosphorus balance and controlling phosphorus in hemodialysis patients. We aimed to investigate whether individualized therapy using a phosphorus balance calculator improves phosphorus control. METHODS A randomized, open-label, multicenter, 4-week clinical trial was conducted. A total of 119 maintenance hemodialysis patients aged 18-85 years old and with serum phosphorus level >1.45 mmol/L from three university teaching hospitals in Shanghai were enrolled. Patients were randomized in a 1:1 ratio to individualized therapy (n = 60) or conventional therapy (n = 59). The primary outcome was the serum phosphorus concentration after 4-week treatment. Secondary outcomes included the serum calcium and parathyroid hormone (PTH) concentrations, changes in serum phosphorus, calcium and PTH concentrations, and the proportion of patients achieving target ranges of serum phosphorus, calcium and PTH after 4-week treatment. RESULTS Among 119 randomized participants [mean age 62 years; 68 male (57%)], 116 completed the trial. Using the phosphorus balance calculator, the individualized group achieved a better phosphorus balance state and significantly reduced serum phosphorus (1.62 ± 0.45 mmol/L versus 1.85 ± 0.45 mmol/L, P = .006), increased the proportions of patients achieving target serum phosphorus range (41% versus 18%, P = .006) and had greater adjusted mean difference in change in serum phosphorus over the 4 weeks (-0.47 versus -0.23 mmol/L, P = .010) when compared with conventional therapy. No significant changes were observed in serum calcium and PTH levels, the proportion of patients achieving target serum calcium or PTH levels, or the adjusted mean difference of serum calcium and PTH levels over the treatment period. CONCLUSION Phosphorus balance calculator was proved to improve serum phosphorus control in patients undergoing maintenance hemodialysis, offering a new tool for managing hyperphosphatemia.
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Affiliation(s)
- Mengjing Wang
- Nephrology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Xiao
- Nephrology, Huadong Hospital, Fudan University, Shanghai, China
| | - Qiuna Du
- Nephrology, Tongji Hospital, Tongji University, Shanghai, China
| | - Weichen Zhang
- Nephrology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiaying Zhang
- Division of Nutrition, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhenwen Yan
- Nephrology, Huadong Hospital, Fudan University, Shanghai, China
| | - Jianfeng Luo
- Department of Biostatistics, School of Public Health, Fudan University, Shanghai, China
| | - Chen Yu
- Nephrology, Tongji Hospital, Tongji University, Shanghai, China
| | - Zhibin Ye
- Nephrology, Huadong Hospital, Fudan University, Shanghai, China
| | - Jing Chen
- Nephrology, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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Magagnoli L, Ciceri P, Cozzolino M. Secondary hyperparathyroidism in chronic kidney disease: pathophysiology, Current treatments and investigational drugs. Expert Opin Investig Drugs 2024. [PMID: 38881200 DOI: 10.1080/13543784.2024.2369307] [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: 02/14/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
INTRODUCTION Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). It begins as an adaptive increase in parathyroid hormone levels to prevent calcium and phosphate derangements. Over time, this condition becomes maladaptive and is associated with increased morbidity and mortality. Current therapies encompass phosphate-lowering strategies, vitamin D analogues, calcimimetics and parathyroidectomy. These approaches harbor inherent limitations, stimulating interest in the development of new drugs for SHPT to overcome these limitations and improve survival and quality of life among CKD patients. AREAS COVERED This review delves into the main pathophysiological mechanisms involved in SHPT, alongside the treatment options that are currently available and under active investigation. Data presented herein stem from a comprehensive search conducted across PubMed, Web of Science, ClinicalTrials.gov and International Clinical Trials Registry Platform (ICTRP) spanning from 2000 onwards. EXPERT OPINION The advancements in investigational drugs for SHPT hold significant promise for enhancing treatment efficacy while minimizing side effects associated with conventional therapies. Although several challenges still hinder their adoption in clinical practice, ongoing research will likely continue to expand the available therapeutic options, refine treatment strategies, and tailor them to individual patient profiles.
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Affiliation(s)
- Lorenza Magagnoli
- Department of Health Sciences, University of Milan, IT, Milano, Italy
| | - Paola Ciceri
- Laboratory of Experimental Nephrology, Department of Health Sciences, University of Milan, IT, Milano, Italy
| | - Mario Cozzolino
- Department of Health Sciences, University of Milan, IT, Milano, Italy
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Cernaro V, Longhitano E, Casuscelli C, Peritore L, Santoro D. Hyperphosphatemia in Chronic Kidney Disease: The Search for New Treatment Paradigms and the Role of Tenapanor. Int J Nephrol Renovasc Dis 2024; 17:151-161. [PMID: 38831770 PMCID: PMC11144652 DOI: 10.2147/ijnrd.s385826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 05/14/2024] [Indexed: 06/05/2024] Open
Abstract
Hyperphosphataemia represents a significant challenge in the management of chronic kidney disease, exerting a pronounced influence on the pathogenesis of cardiovascular complications and mineral bone disorders. Traditional approaches to address hyperphosphataemia involve implementing dietary phosphate restrictions, administering phosphate binders, and, in cases of end-stage renal disease, resorting to dialysis. Unfortunately, these interventions frequently prove inadequate in maintaining phosphate levels within recommended ranges. Additionally, commonly employed pharmacological agents are not immune to eliciting adverse events, thereby limiting their prescription and therapeutic adherence. There is a growing focus on exploring novel therapeutic strategies in this context. The current discussion centres on tenapanor, a pharmacological agent predominantly acting as a selective inhibitor of sodium/hydrogen exchanger isoform 3 (NHE3). Its mechanism of action involves modulating tight junctions, resulting in reduced sodium absorption and intestinal paracellular permeability to phosphate. Furthermore, tenapanor downregulates sodium-dependent phosphate 2b transport protein (NaPi2b) expression, thereby impeding active transcellular phosphate transport. Clinical trials have elucidated the efficacy and safety profile of tenapanor. This evidence hints at a potential paradigm shift in the management of hyperphosphataemia. However, the burgeoning optimism surrounding tenapanor warrants tempered enthusiasm, as further research remains indispensable. The imperative lies in meticulously delineating its efficacy and safety contours within the crucible of clinical practice. In this review, we synthesize the intricate interplay between hyperphosphataemia and Chronic Kidney Disease-Mineral Bone Disorder, and we discuss the existing pharmacological interventions for hyperphosphataemia and explore emerging treatment paradigms that offer novel perspectives in managing elevated phosphate levels in CKD patients.
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Affiliation(s)
- Valeria Cernaro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Elisa Longhitano
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Chiara Casuscelli
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Luigi Peritore
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Domenico Santoro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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Li J, Zhang W, Wang X, Sun N, Li L, Chang W. Peritoneal Phosphate Clearance: Determinants and Association With Mortality. Semin Dial 2024; 37:259-268. [PMID: 38506151 DOI: 10.1111/sdi.13205] [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: 01/21/2023] [Revised: 01/14/2024] [Accepted: 02/18/2024] [Indexed: 03/21/2024]
Abstract
BACKGROUND Dialytic phosphate removal is a cornerstone of the management of hyperphosphatemia in peritoneal dialysis (PD) patients, but the influencing factors on peritoneal phosphate clearance (PPC) are incompletely understood. Our objective was to explore clinically relevant factors associated with PPC in patients with different PD modality and peritoneal transport status and the association of PPC with mortality. METHODS This is a cross-sectional and prospective observational study. Four hundred eighty-five PD patients were enrolled and divided into 2 groups according to PPC. All-cause mortality was evaluated after followed-up for at least 3 months. RESULTS High PPC group showed lower mortality compared with Low PPC group by Kaplan-Meier analysis and log-rank test. Both multivariate linear regression and multivariate logistic regression revealed that high transport status, total effluent dialysate volume per day, continuous ambulatory PD (CAPD), and protein in total effluent dialysate volume appeared to be positively correlated with PPC; body mass index (BMI) and the normalized protein equivalent of total nitrogen appearance (nPNA) were negatively correlated with PPC. Besides PD modality and membrane transport status, total effluent dialysate volume showed a strong relationship with PPC, but the correlation differed among PD modalities. CONCLUSIONS Higher PPC was associated with lower all-cause mortality risk in PD patients. Higher PPC correlated with CAPD modality, fast transport status, higher effluent dialysate volume and protein content, and with lower BMI and nPNA.
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Affiliation(s)
- Jinping Li
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
| | - Wenyu Zhang
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
| | - Xichao Wang
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
| | - Na Sun
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
| | - Lei Li
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
| | - Wenxiu Chang
- Department of Nephrology, Tianjin First Central Hospital, Tianjin, China
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Sprague SM, Weiner DE, Tietjen DP, Pergola PE, Fishbane S, Block GA, Silva AL, Fadem SZ, Lynn RI, Fadda G, Pagliaro L, Zhao S, Edelstein S, Spiegel DM, Rosenbaum DP. Tenapanor as Therapy for Hyperphosphatemia in Maintenance Dialysis Patients: Results from the OPTIMIZE Study. KIDNEY360 2024; 5:732-742. [PMID: 38323855 PMCID: PMC11146652 DOI: 10.34067/kid.0000000000000387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
Key Points Tenapanor, a first-in-class local inhibitor of sodium/hydrogen exchanger isoform 3, acts as a phosphate absorption inhibitor by decreasing paracellular phosphate absorption. Tenapanor alone or with phosphate binders achieved P ≤ 5.5 mg/dl over 10 weeks in 34%–38% of patients taking phosphate binders at baseline. Tenapanor can help adults with CKD on maintenance dialysis achieve normal serum phosphate concentrations. Background OPTIMIZE was a randomized, open-label study evaluating different tenapanor initiation methods. OPTIMIZE evaluated tenapanor alone and in combination with phosphate binders (PBs) to achieve target serum phosphate (P) ≤5.5 mg/dl. Methods Patients with inadequately controlled P receiving maintenance dialysis from 42 US locations who were taking PBs with baseline P > 5.5 mg/dl and ≤ 10.0 mg/dl, or were PB-naive with baseline P > 4.5 mg/dl and ≤ 10.0 mg/dl, were included in OPTIMIZE. Participants taking PBs at baseline were randomized to switch from PBs to tenapanor (Straight Switch ; n =151) or reduce PB dosage by ≥50% and add tenapanor (Binder Reduction ; n =152); PB-naive patients started tenapanor alone (Binder-Naive ; n =30). Participants received tenapanor 30 mg twice a day for 10 weeks (part A), followed by an elective, 16-week open-label extension (part B). Outcomes included changes from baseline in P, intact fibroblast growth factor 23, parathyroid hormone, serum calcium, and medication burden; patient-reported outcomes; and safety. Results By part A end point, 34.4% (Straight Switch ), 38.2% (Binder Reduction ), and 63.3% (Binder-Naive ) of patients achieved P ≤ 5.5 mg/dl. Mean P reduction and median pill burden reduction from baseline to part A end point were 0.91±1.7 mg/dl and 4 pills/d for the Straight Switch and 0.99±1.8 mg/dl and 1 pill/d for the Binder Reduction group. The mean P reduction for Binder-Naive patients was 0.87±1.5 mg/dl. Among Straight Switch and Binder Reduction patients who completed patient experience questionnaires, 205 of 243 (84.4%) reported an improved phosphate management routine. Diarrhea was the most common adverse event (133 of 333 [39.9%]). Conclusions Tenapanor as monotherapy or in combination with PBs effectively lowered P toward the target range in patients who were PB-naive or who were not at goal despite PB use. Clinical Trial registration number NCT04549597 .
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Affiliation(s)
- Stuart M. Sprague
- NorthShore University Health System, Evanston, Illinois
- University of Chicago Pritzker School of Medicine, Chicago, Illinois
| | | | | | | | - Steven Fishbane
- Zucker School of Medicine at Hofstra & Northwell Health, Great Neck, New York
| | | | | | - Stephen Z. Fadem
- Kidney Associates, PLLC and Baylor College of Medicine, Houston, Texas
| | | | - George Fadda
- Balboa Nephrology Medical Group, La Mesa, California
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Dominguez Rieg JA, Rieg T. New functions and roles of the Na +-H +-exchanger NHE3. Pflugers Arch 2024; 476:505-516. [PMID: 38448727 DOI: 10.1007/s00424-024-02938-9] [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: 02/05/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it contributes to hydrogen secretion and sodium (re)absorption. The roles of this transporter have been studied by the use of the respective knockout mice and by using pharmacological inhibitors. Whole-body NHE3 knockout mice suffer from a high mortality rate (with only ∼30% of mice surviving into adulthood), and based on the expression of NHE3 in both intestine and kidney, some conclusions that were originally derived were based on this rather complex phenotype. In the last decade, more refined models have been developed that added temporal and spatial control of NHE3 expression. For example, novel mouse models have been developed with a knockout of NHE3 in intestinal epithelial cells, tubule/collecting duct of the kidney, proximal tubule of the kidney, and thick ascending limb of the kidney. These refined models have significantly contributed to our understanding of the role of NHE3 in a tissue/cell type-specific manner. In addition, tenapanor was developed, which is a non-absorbable, intestine-specific NHE3 inhibitor. In rat and human studies, tenapanor lowered intestinal Pi uptake and was effective in lowering plasma Pi levels in patients on hemodialysis. Of note, diarrhea is seen as a side effect of tenapanor (with its indication for the treatment of constipation) and in intestine-specific NHE3 knockout mice; however, effects on plasma Pi were not supported by this mouse model which showed enhanced and not reduced intestinal Pi uptake. Further studies indicated that the gut microbiome in mice lacking intestinal NHE3 resembles an intestinal environment favoring the competitive advantage of inflammophilic over anti-inflammatory species, something similar seen in patients with inflammatory bowel disease. This review will highlight recent developments and summarize newly gained insight from these refined models.
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Affiliation(s)
- Jessica A Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
- James A. Haley Veterans' Hospital, Tampa, FL, 33612, USA
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
- James A. Haley Veterans' Hospital, Tampa, FL, 33612, USA.
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA.
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Wagner CA, Rubio Aliaga I, Egli-Spichtig D. Is fibroblast growth factor 23 the main culprit for cardiovascular disease in chronic kidney disease? Am J Physiol Renal Physiol 2024; 326:F561-F562. [PMID: 38205545 DOI: 10.1152/ajprenal.00379.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024] Open
Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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Vachey C, Candellier A, Toutain S, Mac-Way F. The Bone-Vascular Axis in Chronic Kidney Disease: From Pathophysiology to Treatment. Curr Osteoporos Rep 2024; 22:69-79. [PMID: 38195897 DOI: 10.1007/s11914-023-00858-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/26/2023] [Indexed: 01/11/2024]
Abstract
PURPOSE OF REVIEW This review aims to describe the pathogenic factors involved in bone-vessel anomalies in CKD which are the object of numerous experimental and clinical research. RECENT FINDINGS Knowledge on the pathophysiological mechanisms involved in the regulation of vascular calcification and mineral-bone disorders is evolving. Specific bone turnover anomalies influence the vascular health while recent studies demonstrate that factors released by the calcified vessels also contribute to bone deterioration in CKD. Current therapies used to control mineral dysregulations will impact both the vessels and bone metabolism. Available anti-osteoporotic treatments used in non-CKD population may negatively or positively affect vascular health in the context of CKD. It is essential to study the bone effects of the new therapeutic options that are currently under investigation to reduce vascular calcification. Our paper highlights the complexity of the bone-vascular axis and discusses how current therapies may affect both organs in CKD.
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Affiliation(s)
- Clément Vachey
- CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Faculty and Department of Medicine, Université Laval, 10 McMahon, Quebec City, Quebec, G1R 2J6, Canada
| | - Alexandre Candellier
- CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Faculty and Department of Medicine, Université Laval, 10 McMahon, Quebec City, Quebec, G1R 2J6, Canada
| | - Soline Toutain
- CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Faculty and Department of Medicine, Université Laval, 10 McMahon, Quebec City, Quebec, G1R 2J6, Canada
| | - Fabrice Mac-Way
- CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Faculty and Department of Medicine, Université Laval, 10 McMahon, Quebec City, Quebec, G1R 2J6, Canada.
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Wang X, Yu X, Gavardinas K, Dey A, Zhang HY, Porter G, Porras L, Yu L, Guo H, Reidy CA, Haas JV, Xu Y, Kowala MC, Jadhav PK, Wetterau JR. Effect of an NHE3 inhibitor in combination with an NPT2b inhibitor on gastrointestinal phosphate absorption in Rodent models. PLoS One 2024; 19:e0292091. [PMID: 38277356 PMCID: PMC10817170 DOI: 10.1371/journal.pone.0292091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 09/12/2023] [Indexed: 01/28/2024] Open
Abstract
Many of the pathological consequences of chronic kidney disease can be attributed to an elevation in serum phosphate levels. Current therapies focused on decreasing intestinal phosphate absorption to treat hyperphosphatemia are inadequate. The most effective therapeutic strategy may be to target multiple absorptive pathways. In this study, the ability of a novel inhibitor of the intestinal sodium hydrogen exchanger 3 (NHE3), LY3304000, which inhibits paracellular, diffusional uptake of phosphate, to work in combination with an inhibitor of the active transporter, sodium dependent phosphate cotransporter 2b (NPT2b), LY3358966, was explored. LY3304000 modestly inhibited the acute uptake of phosphate into plasma of rats, while surprisingly, it doubled the rate of phosphate uptake in mice, an animal model dominated by NPT2b mediated acute phosphate uptake. In rats, LY3004000 and LY3358966 work in concert to inhibit acute phosphate uptake. On top of LY3358966, LY3304000 further decreased the acute uptake of phosphate into plasma. Studies measuring the recovery of radiolabeled phosphate in the intestine demonstrated LY3304000 and LY3358966 synergistically inhibited the absorption of phosphate in rats. We hypothesize the synergism is because the NHE3 inhibitor, LY3304000, has two opposing effects on intestinal phosphate absorption in rats, first it decreases diffusion mediated paracellular phosphate absorption, while second, it simultaneously increases phosphate absorption through the NPT2b pathway. NHE3 inhibition decreases proton export from enterocytes and raises the cell surface pH. In vitro, NPT2b mediated phosphate transport is increased at higher pHs. The increased NPT2b mediated transport induced by NHE3 inhibition is masked in rats which have relatively low levels of NPT2b mediated phosphate transport, by the more robust inhibition of diffusion mediated phosphate absorption. Thus, the inhibition of NPT2b mediated phosphate transport in rats in the presence of NHE3 inhibition has an effect that exceeds its effect in the absence of NHE3 inhibition, leading to the observed synergism on phosphate absorption between NPT2b and NHE3 inhibition.
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Affiliation(s)
- Xiaojun Wang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Xiaohong Yu
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Kostas Gavardinas
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Asim Dey
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Hong Y. Zhang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Gina Porter
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Leah Porras
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Lan Yu
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Haihong Guo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Charles A. Reidy
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Joseph V. Haas
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Yanping Xu
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Mark C. Kowala
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Prabhakar K. Jadhav
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - John R. Wetterau
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, United States of America
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Gan L, Xing L, Xu Y, Zhou L, Jiang H, Sun X, Guan T, Luo P, Wang J, Sun F, Guo Z, Guo M, Gao J, Wei G, Zhong W, Zhou Y, Zuo L. Tenapanor in Chinese ESRD patients with hyperphosphatemia on haemodialysis: a randomised, phase 3 trial. Clin Kidney J 2024; 17:sfad216. [PMID: 38186905 PMCID: PMC10768776 DOI: 10.1093/ckj/sfad216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Indexed: 01/09/2024] Open
Abstract
Background The efficacy and safety of tenapanor has not been confirmed in Chinese end-stage renal disease (ESRD) patients with hyperphosphatemia on haemodialysis (HD). Methods This was a randomised, double blind, phase 3 trial conducted at 26 dialysis facilities in China (https://www.chictr.org.cn/index.aspx; CTR20202588). After a 3-week washout, adults with ESRD on HD with hyperphosphatemia were randomised (1:1) using an interactive web response system to oral tenapanor 30 mg twice a day or placebo for 4 weeks. The primary endpoint was the change in mean serum phosphorous level from baseline to the endpoint visit (day 29 or last serum phosphorus measurement). Efficacy was analysed in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of the study drug. Results Between 5 March 2021 and 8 June 2022, 77 patients received tenapanor and 73 received placebo. Tenapanor treatment (n = 75) resulted in a significantly greater least squares (LS) mean reduction in serum phosphate at the endpoint visit versus placebo (n = 72): LS mean difference -1.17 mg/dl (95% CI -1.694 to -0.654, P < .001). More patients receiving tenapanor achieved a serum phosphorous level <5.5 mg/dl at the endpoint visit (44.6% versus 10.1%). The most common treatment-related adverse event was diarrhoea [tenapanor 28.6% (22/77), placebo 2.7% (2/73)], which was mostly mild and led to treatment discontinuation in two patients receiving tenapanor. Conclusions Tenapanor significantly reduced the serum phosphorous level versus placebo in Chinese ESRD patients on HD and was generally well tolerated.
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Affiliation(s)
- Liangying Gan
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Li Xing
- Hemodialysis Room, People's Hospital of Zhengzhou, Zhengzhou, China
| | - Yan Xu
- Department of Nephrology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Linghui Zhou
- Department of Nephrology, First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Hong Jiang
- Division of Nephrology, Department of Internal Medicine, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Xiuli Sun
- Department of Nephrology, Baotou Central Hospital, Baotou, China
| | - Tianjun Guan
- Department of Nephrology, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Ping Luo
- Department of Nephrology, Second Hospital of Jilin University, Changchun, China
| | - Junxia Wang
- Blood Purifying Center, First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Fuyun Sun
- Department of Nephrology, Cangzhou Center Hospital, Cangzhou, China
| | - Zhiyong Guo
- Department of Nephrology, Shanghai Changhai Hospital, Shanghai, China
| | - Minghao Guo
- Department of Nephrology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Ju Gao
- Panjin Liaohe Oilfield Baoshihua Hospital, Panjin, China
| | - Gang Wei
- R&D Center, Fosun Pharma, Shanghai, China
| | - Wen Zhong
- R&D Center, Fosun Pharma, Shanghai, China
| | | | - Li Zuo
- Department of Nephrology, Peking University People's Hospital, Beijing, China
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Edmonston D, Grabner A, Wolf M. FGF23 and klotho at the intersection of kidney and cardiovascular disease. Nat Rev Cardiol 2024; 21:11-24. [PMID: 37443358 DOI: 10.1038/s41569-023-00903-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/15/2023]
Abstract
Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD). As CKD progresses, CKD-specific risk factors, such as disordered mineral homeostasis, amplify traditional cardiovascular risk factors. Fibroblast growth factor 23 (FGF23) regulates mineral homeostasis by activating complexes of FGF receptors and transmembrane klotho co-receptors. A soluble form of klotho also acts as a 'portable' FGF23 co-receptor in tissues that do not express klotho. In progressive CKD, rising circulating FGF23 levels in combination with decreasing kidney expression of klotho results in klotho-independent effects of FGF23 on the heart that promote left ventricular hypertrophy, heart failure, atrial fibrillation and death. Emerging data suggest that soluble klotho might mitigate some of these effects via several candidate mechanisms. More research is needed to investigate FGF23 excess and klotho deficiency in specific cardiovascular complications of CKD, but the pathophysiological primacy of FGF23 excess versus klotho deficiency might never be precisely resolved, given the entangled feedback loops that they share. Therefore, randomized trials should prioritize clinical practicality over scientific certainty by targeting disordered mineral homeostasis holistically in an effort to improve cardiovascular outcomes in patients with CKD.
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Affiliation(s)
- Daniel Edmonston
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA
| | - Alexander Grabner
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA.
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA.
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Silva AL, Chertow GM, Hernandez GT, Lynn RI, Tietjen DP, Rosenbaum DP, Yang Y, Edelstein S. Tenapanor Improves Long-Term Control of Hyperphosphatemia in Patients Receiving Maintenance Dialysis: the NORMALIZE Study. KIDNEY360 2023; 4:1580-1589. [PMID: 37853560 PMCID: PMC10695649 DOI: 10.34067/kid.0000000000000280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Key Points Tenapanor is a first-in-class, minimally systemic sodium–hydrogen exchanger 3 inhibitor with a mechanism of action distinct from phosphate binders. Tenapanor alone or with phosphate binders led to 35%–49% of patients achieving serum phosphate ≤4.5 mg/dl over an 18-month period versus 22% at baseline. Tenapanor alone or with phosphate binders may help adults with CKD on maintenance dialysis achieve normal serum phosphate concentrations. Background Most patients with ESKD and hyperphosphatemia have difficulty controlling serum phosphate (sP) concentrations despite maintenance dialysis, dietary restriction, and phosphate binder treatment. NORMALIZE evaluated the efficacy and safety of tenapanor 30 mg twice daily alone or in combination with phosphate binders to achieve sP within the adult population reference range (2.5–4.5 mg/dl). Methods Patients who completed the Phase 3 PHREEDOM study could enroll in NORMALIZE. Patients enrolled in NORMALIZE who had received tenapanor during the PHREEDOM study (n =111) added sevelamer carbonate if sP was >4.5 mg/dl. Patients who had received sevelamer carbonate during the PHREEDOM study (n =61) added tenapanor and decreased sevelamer carbonate if sP was ≤4.5 mg/dl, per protocol titration schedule. Patients were followed in NORMALIZE for up to 18 months. We assessed efficacy in the full analysis set, defined as patients who received ≥1 dose of study drug and had ≥1 post-treatment sP measurement (n =171). We assessed safety in all patients who received ≥1 dose of study drug (n =172). Results At the end point visit, 57 of 171 patients (33%) in the full analysis set achieved sP between 2.5 and 4.5 mg/dl. Eight of 23 patients (35%) who were on tenapanor alone at the end point visit achieved sP between 2.5 and 4.5 mg/dl. The mean reduction from PHREEDOM baseline to end of NORMALIZE in sP was 2.0 mg/dl. Serum intact fibroblast growth factor-23 was significantly reduced; serum intact parathyroid hormone was significantly reduced among patients with intact parathyroid hormone ≥300 pg/ml at PHREEDOM baseline. The most commonly reported treatment-emergent adverse event was diarrhea in 38 of 172 patients (22%), which led to tenapanor discontinuation in four patients (2%). Conclusions Tenapanor alone or in combination with phosphate binders helped adult patients on maintenance dialysis achieve normal sP concentrations. Safety was consistent with previous studies of tenapanor. Clinical trial registry name and registration number A Long-Term Study to Evaluate the Ability of Tenapanor Alone or in Combination With Sevelamer to Treat to Goal Serum Phosphorus in Patients With ESKD on Dialysis (NORMALIZE), NCT03988920 .
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Affiliation(s)
| | - Glenn M. Chertow
- Departments of Medicine and Epidemiology and Population Health, Stanford University School of Medicine, Stanford, California
| | | | | | | | | | - Yang Yang
- Ardelyx, Inc., Waltham, Massachusetts
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Wish JB. Tenapanor as Add-on Treatment for Hyperphosphatemia in Dialysis Patients: Enough Bang for the Buck? Kidney Int Rep 2023; 8:2194-2197. [PMID: 38025212 PMCID: PMC10658425 DOI: 10.1016/j.ekir.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023] Open
Affiliation(s)
- Jay B. Wish
- Division of Nephrology, Indiana University School of Medicine, IU Health University Hospital, Indianapolis, Indiana, USA
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15
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Kalantar-Zadeh K, Forfang D, Bakris G, Martin KJ, Moe SM, Sprague SM. Managing Phosphate Burden in Patients Receiving Dialysis: Beyond Phosphate Binders and Diet. KIDNEY360 2023; 4:1650-1656. [PMID: 37870525 PMCID: PMC10695651 DOI: 10.34067/kid.0000000000000262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/07/2023] [Indexed: 10/24/2023]
Abstract
Most patients receiving dialysis rely on dietary restriction and phosphate binders to minimize the risk of hyperphosphatemia, which is associated with increased mortality. However, dietary restriction is difficult because of hidden phosphate additives in processed foods and medications. Restriction of dietary phosphate sources such as protein may increase the risk of malnutrition. Phosphate binders, the only pharmacologic option for phosphate management since aluminum salts were introduced several decades ago, are often insufficient for binding the 1400-2500 mg of phosphate potentially consumed daily. Over the last decade, serum phosphate levels in the United States have risen, and >69% of patients receiving dialysis exhibited a most recent phosphate level >4.5 mg/dl (above the normal range), indicating an urgent need for new, more effective therapies to manage phosphate burden. Novel, nonbinder therapies such as transcellular and paracellular phosphate absorption inhibitors may be used for phosphate management, and future studies should examine whether they allow fewer dietary restrictions for patients receiving dialysis, potentially improving patient quality of life and nutritional status. It is imperative that we collaborate to move beyond the restrictive approaches available today and provide patients and clinicians with an array of strategies so that they may choose the most appropriate patient-centered therapy.
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Affiliation(s)
- Kamyar Kalantar-Zadeh
- Division of Nephrology, Hypertension and Kidney Transplantation, University of California Irvine, Irvine, California
| | - Derek Forfang
- The Co-Chair of the National Forum of ESRD Network's Kidney Patient Advisory Council (KPAC), Henrico, Virginia
- National Kidney Foundation, Public Policy Committee, New York, New York
| | - George Bakris
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Kevin J. Martin
- Department of Internal Medicine, Division of Nephrology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Sharon M. Moe
- Division of Nephrology and Hypertension, Indiana University School of Medicine, Indianapolis, Indiana
| | - Stuart M. Sprague
- Division of Nephrology and Hypertension, NorthShore University Health System-University of Chicago Pritzker School of Medicine, Evanston, Illinois
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16
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Nitta K, Itoyama S, Ikejiri K, Kinoshita J, Nakanishi K, Fukagawa M, Akizawa T. Randomized Study of Tenapanor Added to Phosphate Binders for Patients With Refractory Hyperphosphatemia. Kidney Int Rep 2023; 8:2243-2253. [PMID: 38025211 PMCID: PMC10658421 DOI: 10.1016/j.ekir.2023.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/26/2023] [Accepted: 08/07/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Serum phosphorus management is important for patients with chronic kidney disease on dialysis to reduce the risk of hyperparathyroidism and ectopic vascular calcification. Phosphate binders (PBs) control serum phosphorus levels; however, some patients do not achieve adequate control with existing PBs. The similar mechanisms of action of each PB may limit their ability to lower serum phosphorus levels. Therefore, drugs with novel mechanisms of action that can be added to existing PBs to further lower serum phosphorus levels are desired. Tenapanor, a novel selective inhibitor of intestinal sodium/hydrogen exchanger 3 transporters, decreases passive phosphate absorption in the intestine, thereby decreasing serum phosphorus levels. Methods This study evaluated the efficacy and safety of tenapanor treatment with up-titration when added to PBs among Japanese hemodialysis patients with hyperphosphatemia poorly controlled by PBs alone. In total, 169 patients taking PBs whose serum phosphorus level was ≥6.1 and <10.0 mg/dl initiated the 8-week treatment (placebo + PB, n = 85; tenapanor + PB, n = 84). Results The least squares mean change from baseline to week 8 in serum phosphorus level was -0.24 and -2.00 mg/dl in the placebo and tenapanor groups, respectively, with a statistically significant difference between groups (-1.76 mg/dl; P < 0.0001). Diarrhea as a treatment-emergent adverse event (TEAE) occurred in 14.1% and 63.1% of patients in the placebo and tenapanor groups, respectively. All diarrhea events were mild or moderate. Conclusion Tenapanor added to PBs improved serum phosphorus levels that could not previously be controlled by PBs alone, and no new safety concerns were raised.
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Affiliation(s)
- Kosaku Nitta
- Department of Nephrology, Tokyo Women’s Medical University, Tokyo, Japan
| | - Saki Itoyama
- Research and Development Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Kazuaki Ikejiri
- Research and Development Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Jun Kinoshita
- Research and Development Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Kaoru Nakanishi
- Research and Development Division, Kyowa Kirin Co., Ltd., Tokyo, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology, and Metabolism, Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan
| | - Tadao Akizawa
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
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Dąbek B, Dybiec J, Frąk W, Fularski P, Lisińska W, Radzioch E, Młynarska E, Rysz J, Franczyk B. Novel Therapeutic Approaches in the Management of Chronic Kidney Disease. Biomedicines 2023; 11:2746. [PMID: 37893119 PMCID: PMC10604464 DOI: 10.3390/biomedicines11102746] [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: 08/31/2023] [Revised: 10/02/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023] Open
Abstract
Chronic kidney disease (CKD) is a progressive and incurable disease that impairs kidney function. Its prevalence is estimated to affect up to 800 million individuals within the general population, and patients with diabetes and hypertension are particularly at risk. This disorder disrupts the physiological mechanisms of the body, including water and electrolyte balance, blood pressure regulation, the excretion of toxins, and vitamin D metabolism. Consequently, patients are exposed to risks such as hyperkalemia, hyperphosphatemia, metabolic acidosis, and blood pressure abnormalities. These risks can be reduced by implementing appropriate diagnostic methods, followed by non-pharmacological (such as physical activity, dietary, and lifestyle adjustment) and pharmacological strategies after diagnosis. Selecting the appropriate diet and suitable pharmacological treatment is imperative in maintaining kidney function as long as possible. Drugs such as finerenone, canakinumab, and pentoxifylline hold promise for improved outcomes among CKD patients. When these interventions prove insufficient, renal replacement therapy becomes essential. This is particularly critical in preserving residual renal function while awaiting renal transplantation or for patients deemed ineligible for such a procedure. The aim of this study is to present the current state of knowledge and recent advances, providing novel insights into the treatment of chronic kidney disease.
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Affiliation(s)
- Bartłomiej Dąbek
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Jill Dybiec
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Weronika Frąk
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Piotr Fularski
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Wiktoria Lisińska
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Ewa Radzioch
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Ewelina Młynarska
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Beata Franczyk
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
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18
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Luo H, Feng J, Zhang Y, Wang J, Xue G, Huang X, You S, Dong H, Li L, Li J, Xiao H, Ai X, Li X, Huang B. Efficacy and safety of tenapanor in hemodialysis patients with hyperphosphatemia: A systematic review and meta-analysis of randomized placebo-controlled trials. Ther Apher Dial 2023; 27:839-847. [PMID: 37349983 DOI: 10.1111/1744-9987.14028] [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: 04/26/2023] [Revised: 05/30/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND The effects of tenapanor in reducing serum phosphorus in hemodialysis patients with hyperphosphatemia are uncertain and no relevant meta-analysis has been conducted. We performed a meta-analysis of randomized placebo-controlled trials to evaluate the efficacy and safety of tenapanor. METHODS All randomized controlled trials of tenapanor were searched up to 1 August 2022. The primary endpoint was the change in serum phosphorus level from baseline with tenapanor and placebo. Data on drug-related adverse events (AEs), gastrointestinal AEs and diarrhea were collected to determine the safety of tenapanor. RESULTS There were 533 patients throughout five trials that were eligible. Tenapanor significantly lowered blood phosphorus level by 1.79 mg/dl in the mean difference than the placebo. Diarrhea, gastrointestinal AEs, and drug-related AEs were more severe than placebo. CONCLUSIONS This meta-analysis showed that although drug side effects were common, tenapanor significantly reduced serum phosphorus level in hemodialysis patients.
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Affiliation(s)
- Houli Luo
- Department of Radiology, Cheng du First People's Hospital, Chengdu, Sichuan, China
| | - Jian Feng
- Department of Critical Care Medicine, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Yanbiao Zhang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Jie Wang
- Department of Critical Care Medicine, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Gang Xue
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xi Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Shuang You
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Hongfei Dong
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Lingfan Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Juncheng Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Hualin Xiao
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xiang Ai
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xianhui Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Bo Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
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Magagnoli L, Cozzolino M, Galassi A. The open system of FGF-23 at the crossroad between additional P-lowering therapy, anemia and inflammation: how to deal with the intact and the C-terminal assays? Clin Kidney J 2023; 16:1543-1549. [PMID: 37779858 PMCID: PMC10539210 DOI: 10.1093/ckj/sfad144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Indexed: 10/03/2023] Open
Abstract
Fibroblast growth factor 23 (FGF-23) has been associated with increased cardiovascular risk and poor survival in dialysis patients. It is well established that FGF-23 synthesis is directly induced by positive phosphate (P) balance. On the other hand, P-lowering treatments such as nutritional P restriction, P binders and dialysis are capable of reducing FGF-23 levels. However, there are many uncertainties regarding the possibility of adopting FGF-23 to guide the clinical decision-making process in the context of chronic kidney disease-mineral bone disorder (CKD-MBD). Furthermore, the best assay to adopt for measurement of FGF-23 levels (namely the intact vs the C-terminal one) remains to be determined, especially in conditions capable of altering the synthesis as well as the cleavage of the intact and biologically active molecule, as occurs in the presence of CKD and its complications. This Editorial discusses the main insights provided by the post hoc analysis of the NOPHOS trial, with particular attention given to evidence-based peculiarities of the intact and the C-terminal assays available for measuring FGF-23 levels, especially in patients receiving additive P-lowering therapy in the presence of inflammation, anemia and iron deficiency.
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Affiliation(s)
- Lorenza Magagnoli
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
| | - Mario Cozzolino
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
| | - Andrea Galassi
- University of Milan, Department of Health Sciences, Milano, Italy
- ASST Santi Paolo e Carlo, Renal Division, Milano, Italy
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Pantazi AC, Kassim MAK, Nori W, Tuta LA, Mihai CM, Chisnoiu T, Balasa AL, Mihai L, Lupu A, Frecus CE, Lupu VV, Chirila SI, Badescu AG, Hangan LT, Cambrea SC. Clinical Perspectives of Gut Microbiota in Patients with Chronic Kidney Disease and End-Stage Kidney Disease: Where Do We Stand? Biomedicines 2023; 11:2480. [PMID: 37760920 PMCID: PMC10525496 DOI: 10.3390/biomedicines11092480] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/26/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The gut microbiota (GM) plays a vital role in human health, with increasing evidence linking its imbalance to chronic kidney disease and end-stage kidney disease. Although the exact methods underlying kidney-GM crosstalk are not fully understood, interventions targeting GM were made and lay in three aspects: diagnostic, predictive, and therapeutic interventions. While these interventions show promising results in reducing uremic toxins and inflammation, challenges remain in the form of patient-specific GM variability, potential side effects, and safety concerns. Our understanding of GMs role in kidney disease is still evolving, necessitating further research to elucidate the causal relationship and mechanistic interactions. Personalized interventions focusing on specific GM signatures could enhance patient outcomes. However, comprehensive clinical trials are needed to validate these approaches' safety, efficacy, and feasibility.
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Affiliation(s)
| | | | - Wassan Nori
- College of Medicine, Mustansiriyah University, Baghdad 10052, Iraq;
| | - Liliana Ana Tuta
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Cristina Maria Mihai
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Tatiana Chisnoiu
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Adriana Luminita Balasa
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Larisia Mihai
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Ancuta Lupu
- Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| | - Corina Elena Frecus
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
- Clinical Emergency Hospital of Constanta, 900591 Constanta, Romania
| | - Vasile Valeriu Lupu
- Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| | - Sergiu Ioachim Chirila
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
| | | | - Laurentiu-Tony Hangan
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
| | - Simona Claudia Cambrea
- Faculty of Medicine, “Ovidius” University of Constanta, 900470 Constanta, Romania (L.A.T.)
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Cernaro V, Longhitano E, Calabrese V, Casuscelli C, Di Carlo S, Spinella C, Gembillo G, Santoro D. Progress in pharmacotherapy for the treatment of hyperphosphatemia in renal failure. Expert Opin Pharmacother 2023; 24:1737-1746. [PMID: 37527180 DOI: 10.1080/14656566.2023.2243817] [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: 03/11/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/03/2023]
Abstract
INTRODUCTION Among the clinical and metabolic complications of progressive chronic kidney disease (CKD), CKD-mineral bone disorder (CKD-MBD) significantly contributes to morbidity and mortality. While overt and persistent hyperphosphatemia is typical of advanced CKD and requires treatment, other abnormalities of calcium/phosphate metabolism begin to occur since the early stages of the disease. AREAS COVERED We searched on the PubMed database, without restrictions for language or time range, for randomized clinical trials and meta-analyses investigating phosphate-lowering therapies. The various phosphate binders show different safety profiles and diverse effects on calcium/phosphate metabolism and vascular calcification. The in-depth knowledge of the characteristics of these drugs is crucial to ensure adequate treatment to CKD patients. EXPERT OPINION A proper control of serum phosphate can be achieved using phosphate binders. These medications may induce side effects. Moreover, data on their impact on clinical outcomes are partly controversial or scarce, especially for the new generation drugs. Hyperphosphatemia favors cardiovascular disease and increases the risk for CKD progression. These effects are partially mediated by fibroblast growth factor 23 (FGF23), a phosphaturic hormone that raises to maintain normal serum phosphate. Since there are no data supporting the use of phosphate-lowering agents when phosphataemia is normal, a key role is played by reducing dietary phosphate intake with the aim to control serum phosphate and the compensatory FGF23 and parathyroid hormone (PTH) increase.
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Affiliation(s)
- Valeria Cernaro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Elisa Longhitano
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Vincenzo Calabrese
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Chiara Casuscelli
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Silvia Di Carlo
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Claudia Spinella
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Guido Gembillo
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Domenico Santoro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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Luo H, Feng J, Xue G, Zhang Y, Li Y, Huang X, Chen X, You S, Dong H, Li L, Li J, Xiao H, Ai X, Li X, Huang B. Comparative Efficacy and Acceptability of 12 Phosphorus-Lowering Drugs in Adults with Hyperphosphatemia and Chronic Kidney Disease: A Systematic Review and Network Meta-Analysis. Blood Purif 2023; 52:609-620. [PMID: 37591223 DOI: 10.1159/000531577] [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: 11/20/2022] [Accepted: 06/09/2023] [Indexed: 08/19/2023]
Abstract
BACKGROUND Hyperphosphatemia is associated with cardiovascular morbidity and mortality in adults with chronic kidney disease (CKD). Drug therapy has an irreplaceable role in the management of hyperphosphatemia. OBJECTIVES We aimed to compare and rank phosphorus-lowering drugs, including phosphate binder and nonphosphate binder, in hyperphosphatemia adults with CKD. METHODS We did a systematic review and frequentist random-effect network meta-analysis. We searched in PubMed, Cochrane Library, Web of Science, and Embase from inception to February 1, 2023, for randomized controlled trials of 12 phosphorus-lowering drugs in adults with hyperphosphatemia and CKD. Primary outcomes were efficacy (changes in serum phosphorus) and acceptability (treatment withdrawals due to any cause). We ranked each drug according to the value of surface under the cumulative ranking curve. We applied the Confidence in Network Meta-Analysis frameworks to rate the certainty of evidence. This study was registered with PROSPERO, number CRD42022322270. RESULTS We identified 2,174 citations, and of these, we included 94 trials comprising 14,459 participants and comparing 13 drugs or placebo. In terms of efficacy, except for niacinamide, all drugs lowered the level of serum phosphorus compared with placebo, with mean difference ranging between -1.61 (95% credible interval [CrI], -2.60 to -0.62) mg/dL for magnesium carbonate and -0.85 (-1.66 to -0.05) mg/dL for bixalomer. Only ferric citrate with odds ratios 0.56 (95% CrI: 0.36-0.89) was significantly associated with fewer dropouts for acceptability. Of the 94 trials, 43 (46%), 7 (7%), and 44 (47%) trials were rated as high, moderate, and low risk of bias, respectively, the certainty of the evidence was moderate to very low. CONCLUSIONS Magnesium carbonate has the best phosphorus-lowering effect in hyperphosphatemia adults with CKD; considering efficacy and acceptability, ferric citrate shows evidence to be the most appropriate drug with or without dialysis.
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Affiliation(s)
- Houli Luo
- Department of Radiology, Chengdu First People's Hospital, Chengdu, China
| | - Jian Feng
- Department of Critical Care Medicine, The General Hospital of Western Theater Command, Chengdu, China
| | - Gang Xue
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Yanbiao Zhang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Yunming Li
- Department of Information, The General Hospital of Western Theater Command, Chengdu, China
| | - Xi Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Xin Chen
- Department of Neurosurgery, The General Hospital of Western Theater Command, Chengdu, China
| | - Shuang You
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Hongfei Dong
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Lingfan Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Juncheng Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Hualin Xiao
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Xiang Ai
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Xianhui Li
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
| | - Bo Huang
- Department of Burn and Plastic, The General Hospital of Western Theater Command, Chengdu, China
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Sprague SM, Reddy G, Jermasek D, Gupta P. High Phosphate-Binding Capacity of Oxylanthanum Carbonate with a Low Medication Volume: Comparison with Commercially Available Phosphate Binders. Am J Nephrol 2023; 54:219-223. [PMID: 37231835 PMCID: PMC10614253 DOI: 10.1159/000530989] [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: 02/18/2023] [Accepted: 04/26/2023] [Indexed: 05/27/2023]
Abstract
BACKGROUND A key focus for chronic kidney disease management is phosphate control, but currently available binders have suboptimal phosphate-binding capacity, and their characteristics result in low adherence and poor phosphate regulation. Oxylanthanum carbonate, a novel compound that uses proprietary nanoparticle technology to deliver lanthanum, has the potential to combine high phosphate-binding capacity with good intake convenience, thus improving adherence and patient quality of life. The goal of this study was to assess the volume of oxylanthanum Carbonate required to bind 1 g of phosphate and compare it with other currently available phosphate binders to determine which binder allows for the highest normalized potency with the lowest daily medication volume. METHODS Six phosphate binders were assessed: ferric citrate, calcium acetate, lanthanum carbonate, sevelamer carbonate, sucroferric oxyhydroxide, and oxylanthanum carbonate. Table volume measurements were taken using fluid displacement in corn oil or water. Mean daily dose volume to bind 1 g of phosphate was calculated as volume per tablet multiplied by the mean number of tablets taken per day. Volume to bind 1 g of phosphate was calculated by dividing the volume per tablet by its in vivo binding capacity. RESULTS Oxylanthanum carbonate had the lowest mean volume, daily phosphate binder dose volume, and equivalent phosphate-binding dose volume (volume to bind 1 g of phosphate for each binder). CONCLUSIONS Oxylanthanum carbonate has the lowest daily phosphate binder dose volume and the smallest volume required to bind 1 g of phosphate compared to all other commercially available phosphate binders. A randomized trial that compares gastrointestinal tolerability across binders would be warranted to demonstrate acceptability and adherence in the target population.
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Affiliation(s)
- Stuart M. Sprague
- Division of Nephrology and Hypertension, NorthShore University Health System, Evanston, IL, USA
| | - Guru Reddy
- Preclinical Research and Development, Unicycive Therapeutics, Inc., Los Altos, CA, USA
| | - Douglas Jermasek
- Corporate Strategy, Unicycive Therapeutics, Inc., Los Altos, CA, USA
| | - Pramod Gupta
- Pharmaceutical and Business Operations, Unicycive Therapeutics, Inc., Los Altos, CA, USA
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Anand A, Aoyagi H. Understudied Hyperphosphatemia (Chronic Kidney Disease) Treatment Targets and New Biological Approaches. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59050959. [PMID: 37241191 DOI: 10.3390/medicina59050959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/19/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023]
Abstract
Hyperphosphatemia is a secondary disorder of chronic kidney disease that causes vascular calcifications and bone-mineral disorders. As per the US Centers for Disease Control and Prevention, renal damage requires first-priority medical attention for patients with COVID-19; according to a Johns Hopkins Medicine report, SARS-CoV-2 can cause renal damage. Therefore, addressing the research inputs required to manage hyperphosphatemia is currently in great demand. This review highlights research inputs, such as defects in the diagnosis of hyperphosphatemia, flaws in understanding the mechanisms associated with understudied tertiary toxicities, less cited adverse effects of phosphate binders that question their use in the market, socioeconomic challenges of renal treatment and public awareness regarding the management of a phosphate-controlled diet, novel biological approaches (synbiotics) to prevent hyperphosphatemia as safer strategies with potential additional health benefits, and future functional food formulations to enhance the quality of life. We have not only introduced our contributions to emphasise the hidden aspects and research gaps in comprehending hyperphosphatemia but also suggested new research areas to strengthen approaches to prevent hyperphosphatemia in the near future.
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Affiliation(s)
- Ajeeta Anand
- Institute of Life Sciences and Bioengineering, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Hideki Aoyagi
- Institute of Life Sciences and Bioengineering, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
- Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
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Williams MJ, White SC, Joseph Z, Hruska KA. Updates in the chronic kidney disease-mineral bone disorder show the role of osteocytic proteins, a potential mechanism of the bone-Vascular paradox, a therapeutic target, and a biomarker. Front Physiol 2023; 14:1120308. [PMID: 36776982 PMCID: PMC9909112 DOI: 10.3389/fphys.2023.1120308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/17/2023] [Indexed: 01/27/2023] Open
Abstract
The chronic kidney disease-mineral bone disorder (CKD-MBD) is a complex multi-component syndrome occurring during kidney disease and its progression. Here, we update progress in the components of the syndrome, and synthesize recent investigations, which suggest a potential mechanism of the bone-vascular paradox. The discovery that calcified arteries in chronic kidney disease inhibit bone remodeling lead to the identification of factors produced by the vasculature that inhibit the skeleton, thus providing a potential explanation for the bone-vascular paradox. Among the factors produced by calcifying arteries, sclerostin secretion is especially enlightening. Sclerostin is a potent inhibitor of bone remodeling and an osteocyte specific protein. Its production by the vasculature in chronic kidney disease identifies the key role of vascular cell osteoblastic/osteocytic transdifferentiation in vascular calcification and renal osteodystrophy. Subsequent studies showing that inhibition of sclerostin activity by a monoclonal antibody improved bone remodeling as expected, but stimulated vascular calcification, demonstrate that vascular sclerostin functions to brake the Wnt stimulation of the calcification milieu. Thus, the target of therapy in the chronic kidney disease-mineral bone disorder is not inhibition of sclerostin function, which would intensify vascular calcification. Rather, decreasing sclerostin production by decreasing the vascular osteoblastic/osteocytic transdifferentiation is the goal. This might decrease vascular calcification, decrease vascular stiffness, decrease cardiac hypertrophy, decrease sclerostin production, reduce serum sclerostin and improve skeletal remodeling. Thus, the therapeutic target of the chronic kidney disease-mineral bone disorder may be vascular osteoblastic transdifferentiation, and sclerostin levels may be a useful biomarker for the diagnosis of the chronic kidney disease-mineral bone disorder and the progress of its therapy.
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Affiliation(s)
- Matthew J. Williams
- Division of Pediatric Nephrology, Department of Pediatrics, Washington University, Saint Louis, MO, United States,*Correspondence: Keith A. Hruska, ; Matthew J. Williams,
| | - Sarah C. White
- Division of Pediatric Nephrology, Department of Pediatrics, Washington University, Saint Louis, MO, United States
| | - Zachary Joseph
- Division of Pediatric Nephrology, Department of Pediatrics, Washington University, Saint Louis, MO, United States
| | - Keith A. Hruska
- Division of Pediatric Nephrology, Department of Pediatrics, Washington University, Saint Louis, MO, United States,Departments of Medicine and Cell Biology, Washington University, Saint Louis, MO, United States,*Correspondence: Keith A. Hruska, ; Matthew J. Williams,
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Sodium phosphate cotransporter 2a inhibitors: potential therapeutic uses. Curr Opin Nephrol Hypertens 2022; 31:486-492. [PMID: 35894284 PMCID: PMC9387751 DOI: 10.1097/mnh.0000000000000828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW Targeting sodium phosphate cotransporter 2a (Npt2a) offers a novel strategy for treating hyperphosphatemia in chronic kidney disease (CKD). Here we review recent studies on the efficacy of Npt2a inhibition, its plasma phosphate (Pi)-lowering effects, as well as potential "off-target" beneficial effects on cardiovascular consequences. RECENT FINDINGS Two novel Npt2a-selective inhibitors (PF-06869206 and BAY-767) have been developed. Pharmacological Npt2a inhibition shows a significant phosphaturic effect and consequently lowers plasma Pi and parathyroid hormone (PTH) levels regardless of CKD. However, plasma fibroblast growth factor 23 (FGF23), a master regulator of Pi homeostasis, shows inconsistent responses between these two inhibitors (no effect by PF-06869206 vs. reduction by BAY-767). In addition to the effects on Pi homeostasis, Npt2a inhibition also enhances urinary excretions of Na+, Cl-, and Ca2+, which is recapitulated in animal models with reduced kidney function. The effect of Npt2a inhibition by BAY-767 on vascular calcification has been studied, with positive results showing that oral treatment with BAY-767 (10 mg kg-1) attenuated the increases in plasma Pi and Ca2+ content in the aorta under the setting of vascular calcification induced by a pan-FGF receptor inhibitor. Together, Npt2a inhibition offers a promising therapeutic approach for treating hyperphosphatemia and reducing cardiovascular complications in CKD. SUMMARY Npt2a inhibition significantly increases urinary Pi excretion and lowers plasma Pi and PTH levels; moreover, it exerts pleiotropic "off-target" effects, providing a novel treatment for hyperphosphatemia and exhibiting beneficial potential for cardiovascular complications in CKD.
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Phosphate Frustration: Treatment Options to Complement Current Therapies. Int J Nephrol 2022; 2022:9457440. [PMID: 36045900 PMCID: PMC9424003 DOI: 10.1155/2022/9457440] [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: 05/26/2022] [Accepted: 07/16/2022] [Indexed: 11/18/2022] Open
Abstract
Hyperphosphatemia eventually develops in almost all patients with advanced chronic kidney disease and is associated with negative clinical outcomes. Thus, guidelines recommend targeting treatment to normal phosphate levels in patients with chronic kidney disease. Despite low phosphorus diets, clearance by dialysis, and phosphate binder use, many patients with chronic kidney disease on dialysis are unable to consistently achieve and maintain serum phosphate concentrations <5.5 mg/dL. A chart audit of patients on dialysis receiving phosphate binders showed that 74 to 86% were unable to consistently achieve serum phosphate ≤5.5 mg/dL over 6 months. Furthermore, although there is evidence that serum phosphate concentrations <4.5 mg/dL are associated with improved survival and cardiovascular outcomes, real-world phosphate control data suggest achieving and maintaining this goal for most patients would be extremely challenging, if not near impossible, using current therapies. As phosphate binders can only remove approximately 300 mg of the 2,500 mg or more daily dietary phosphate intake, therapeutic innovations are necessary to improve phosphate management. We present treatment options to complement current therapies including tenapanor, a novel sodium/hydrogen exchanger isoform 3 inhibitor that blocks the dominant paracellular phosphate absorption pathway and has been shown to reduce phosphate levels in several clinical trials.
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Abstract
Phosphate homeostasis is dependent on the interaction and coordination of four main organ systems: thyroid/parathyroids, gastrointestinal tract, bone and kidneys, and three key hormonal regulators, 1,25-hydroxyvitamin D3, parathyroid hormone and FGF23 with its co- factor klotho. Phosphorus is a critical nutritional element for normal cellular function, but in excess can be toxic to tissues, particularly the vasculature. As phosphate, it also has an important interaction and inter-dependence with calcium and calcium homeostasis sharing some of the same controlling hormones, although this is not covered in our article. We have chosen to provide a current overview of phosphate homeostasis only, focusing on the role of two major organ systems, the gastrointestinal tract and kidneys, and their contribution to the control of phosphate balance. We describe in some detail the mechanisms of intestinal and renal phosphate transport, and compare and contrast their regulation. We also consider a significant example of phosphate imbalance, with phosphate retention, which is chronic kidney disease; why consequent hyperphosphatemia is important, and some of the newer means of managing it.
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Affiliation(s)
- Joanne Marks
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Robert J Unwin
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom; Department of Renal Medicine, University College London, London, United Kingdom.
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Duque EJ, Elias RM, Moysés RMA. Phosphate balance during dialysis and after kidney transplantation in patients with chronic kidney disease. Curr Opin Nephrol Hypertens 2022; 31:326-331. [PMID: 35703226 DOI: 10.1097/mnh.0000000000000802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW In patients with chronic kidney disease (CKD), hyperphosphatemia is associated with several adverse outcomes, including bone fragility and progression of kidney and cardiovascular disease. However, there is a knowledge gap regarding phosphate balance in CKD. This review explores its current state, depending on the stage of CKD, dialysis modalities, and the influence of kidney transplantation. RECENT FINDINGS Adequate phosphate control is one of the goals of treatment for CKD-mineral and bone disorder. However, ongoing studies are challenging the benefits of phosphate-lowering treatment. Nevertheless, the current therapy is based on dietary restriction, phosphate binders, and optimal removal by dialysis. In the face of limited adherence, due to the high pill burden, adjuvant options are under investigation. The recent discovery that intestinal absorption of phosphate is mostly paracellular when the intraluminal concentration is adequate might help explain why phosphate is still well absorbed in CKD, despite the lower levels of calcitriol. SUMMARY Future studies could confirm the benefits of phosphate control. Greater understanding of the complex distribution of phosphate among the body compartments will help us define a better therapeutic strategy in patients with CKD.
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Affiliation(s)
- Eduardo J Duque
- Laboratorio de Fisiopatologia Renal LIM16, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo
| | - Rosilene M Elias
- Laboratorio de Fisiopatologia Renal LIM16, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo
- Postgraduate Program in Medicine, Nove de Julho University, São Paulo, SP, Brazil
| | - Rosa M A Moysés
- Laboratorio de Fisiopatologia Renal LIM16, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo
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Yamada S, Tsuruya K, Kitazono T, Nakano T. Emerging cross-talks between chronic kidney disease-mineral and bone disorder (CKD-MBD) and malnutrition-inflammation complex syndrome (MICS) in patients receiving dialysis. Clin Exp Nephrol 2022; 26:613-629. [PMID: 35353283 PMCID: PMC9203392 DOI: 10.1007/s10157-022-02216-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/22/2022] [Indexed: 12/14/2022]
Abstract
Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a systemic disorder that affects multiple organs and systems and increases the risk of morbidity and mortality in patients with CKD, especially those receiving dialysis therapy. CKD–MBD is highly prevalent in CKD patients, and its treatment is gaining attention from healthcare providers who manage these patients. Additional important pathologies often observed in CKD patients are chronic inflammation and malnutrition/protein-energy wasting (PEW). These two pathologies coexist to form a vicious cycle that accelerates the progression of various other pathologies in CKD patients. This concept is integrated into the term “malnutrition–inflammation–atherosclerosis syndrome” or “malnutrition–inflammation complex syndrome (MICS)”. Recent basic and clinical studies have shown that CKD–MBD directly induces inflammation as well as malnutrition/PEW. Indeed, higher circulating levels of inorganic phosphate, fibroblast growth factor 23, parathyroid hormone, and calciprotein particles, as markers for critical components and effectors of CKD–MBD, were shown to directly induce inflammatory responses, thereby leading to malnutrition/PEW, cardiovascular diseases, and clinically relevant complications. In this short review, we discuss the close interplay between CKD–MBD and MICS and emphasize the significance of simultaneous control of these two seemingly distinct pathologies in patients with CKD, especially those receiving dialysis therapy, for better management of the CKD/hemodialysis population.
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Affiliation(s)
- Shunsuke Yamada
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 8128582, Japan.
| | | | - Takanari Kitazono
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 8128582, Japan
| | - Toshiaki Nakano
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 8128582, Japan
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Ogata H, Takeshima A, Ito H. An update on phosphate binders for the treatment of hyperphosphatemia in chronic kidney disease patients on dialysis: a review of safety profiles. Expert Opin Drug Saf 2022; 21:947-955. [PMID: 35180026 DOI: 10.1080/14740338.2022.2044472] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Hyperphosphatemia is an inevitable complication for patients undergoing dialysis, as is the resulting need for treatment with phosphate binders. Currently, various phosphate binders are clinically available. In addition to their phosphate-lowering activity, individual phosphate binders have differing safety profiles and off-target actions. AREAS COVERED This paper reviews the safety of phosphate binders and issues to be resolved. EXPERT OPINION Calcium-based phosphate binders are well tolerated but may increase calcium overload risk. Sevelamer reduces serum cholesterol levels and exerts anti-inflammatory effects. Compared to sevelamer, bixalomer is associated with fewer gastrointestinal symptoms. Aluminum-containing binders, lanthanum carbonate, and sucroferric oxyhydroxide exhibit strong phosphate-lowering activity. Although ferric citrate reduces erythropoiesis-stimulating agents and intravenous iron doses, its use requires monitoring of iron metabolic markers to avoid overload. Occasionally, combined use of multiple phosphate binders can offer the advantages of each phosphate binder while minimizing their drawbacks; thus, this may be desirable according to individual patients' conditions and comorbidities. However, increased pill burden and nonadherence to phosphate binders emerge as new problems. We expect that novel therapeutic strategies will be developed to resolve these issues.
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Affiliation(s)
- Hiroaki Ogata
- Division of Nephrology, Department of Internal Medicine, Showa University, Northern Yokohama Hospital, Chigasaki-chuo 35-1, Tsuzuki, Yokohama 2248503, JAPAN
| | - Akiko Takeshima
- Division of Nephrology, Department of Internal Medicine, Showa University, Northern Yokohama Hospital, Chigasaki-chuo 35-1, Tsuzuki, Yokohama 2248503, JAPAN
| | - Hidetoshi Ito
- Division of Nephrology, Department of Internal Medicine, Showa University, Northern Yokohama Hospital, Chigasaki-chuo 35-1, Tsuzuki, Yokohama 2248503, JAPAN
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Xue J, Thomas L, Murali SK, Levi M, Fenton RA, Dominguez Rieg JA, Rieg T. Enhanced phosphate absorption in intestinal epithelial cell-specific NHE3 knockout mice. Acta Physiol (Oxf) 2022; 234:e13756. [PMID: 34978760 PMCID: PMC9286053 DOI: 10.1111/apha.13756] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/16/2021] [Accepted: 01/01/2022] [Indexed: 12/11/2022]
Abstract
Aims The kidneys play a major role in maintaining Pi homeostasis. Patients in later stages of CKD develop hyperphosphatemia. One novel treatment option is tenapanor, an intestinal‐specific NHE3 inhibitor. To gain mechanistic insight into the role of intestinal NHE3 in Pi homeostasis, we studied tamoxifen‐inducible intestinal epithelial cell‐specific NHE3 knockout (NHE3IEC‐KO) mice. Methods Mice underwent dietary Pi challenges, and hormones as well as urinary/plasma Pi were determined. Intestinal 33P uptake studies were conducted in vivo to compare the effects of tenapanor and NHE3IEC‐KO. Ex vivo Pi transport was measured in everted gut sacs and brush border membrane vesicles. Intestinal and renal protein expression of Pi transporters were determined. Results On the control diet, NHE3IEC‐KO mice had similar Pi homeostasis, but a ~25% reduction in FGF23 compared with control mice. Everted gut sacs and brush border membrane vesicles showed enhanced Pi uptake associated with increased Npt2b expression in NHE3IEC‐KO mice. Acute oral Pi loading resulted in higher plasma Pi in NHE3IEC‐KO mice. Tenapanor inhibited intestinal 33P uptake acutely but then led to hyper‐absorption at later time points compared to vehicle. In response to high dietary Pi, plasma Pi and FGF23 increased to higher levels in NHE3IEC‐KO mice which was associated with greater Npt2b expression. Reduced renal Npt2c and a trend for reduced Npt2a expression were unable to correct for higher plasma Pi. Conclusion Intestinal NHE3 has a significant contribution to Pi homeostasis. In contrast to effects described for tenapanor on Pi homeostasis, NHE3IEC‐KO mice show enhanced, rather than reduced, intestinal Pi uptake.
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Affiliation(s)
- Jianxiang Xue
- Department of Molecular Pharmacology and Physiology Morsani College of Medicine University of South Florida Tampa Florida USA
| | - Linto Thomas
- Department of Molecular Pharmacology and Physiology Morsani College of Medicine University of South Florida Tampa Florida USA
| | | | - Moshe Levi
- Department of Biochemistry and Molecular & Cellular Biology Georgetown University Washington District of Columbia USA
| | | | - Jessica A. Dominguez Rieg
- Department of Molecular Pharmacology and Physiology Morsani College of Medicine University of South Florida Tampa Florida USA
- James A. Haley Veterans' Hospital Tampa Florida USA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology Morsani College of Medicine University of South Florida Tampa Florida USA
- James A. Haley Veterans' Hospital Tampa Florida USA
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Doshi SM, Wish JB. Past, Present, and Future of Phosphate Management. Kidney Int Rep 2022; 7:688-698. [PMID: 35497793 PMCID: PMC9039476 DOI: 10.1016/j.ekir.2022.01.1055] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/12/2022] [Accepted: 01/17/2022] [Indexed: 11/20/2022] Open
Abstract
Cardiovascular (CV) disease (CVD) accounts for >50% of deaths with known causes in patients on dialysis. Elevated serum phosphorus levels are an important nontraditional risk factor for bone mineral disease and CVD in patients with chronic kidney disease (CKD). Given that phosphorus concentrations drive other disorders associated with increased CV risk (e.g., endothelial dysfunction, vascular calcification, fibroblast growth factor-23, parathyroid hormone), phosphate is a logical target to improve CV health. Phosphate binders are the only pharmacologic treatment approved for hyperphosphatemia. Although their safety has improved since inception, the mechanism of action leads to characteristics that make ingestion difficult and unpleasant; large pill size, objectionable taste, and multiple pills required for each meal and snack make phosphate binders a burden. Side effects, especially those affecting the gastrointestinal (GI) system, are common with binders, often leading to treatment discontinuation. The presence of “hidden” phosphates in processed foods and certain medications makes phosphate management even more challenging. Owing to these significant issues, most patients on dialysis are not consistently achieving and maintaining target phosphorus concentrations of <5.5 mg/dl, let alone more normal levels of <4.5 mg/dl, indicating novel approaches to improve phosphate management and CV health are needed. Several new nonbinder therapies that target intestinal phosphate absorption pathways have been developed. These include EOS789, which acts on the transcellular pathway, and tenapanor, which targets the dominant paracellular pathway. As observational evidence has established a strong association between phosphorus concentration and clinical outcomes, such as mortality, phosphate is an important target for improving the health of patients with CKD and end-stage kidney disease (ESKD).
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Kovesdy CP, Adebiyi A, Rosenbaum D, Jacobs JW, Quarles LD. Novel Treatments from Inhibition of the Intestinal Sodium-Hydrogen Exchanger 3. Int J Nephrol Renovasc Dis 2021; 14:411-420. [PMID: 34880650 PMCID: PMC8646223 DOI: 10.2147/ijnrd.s334024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/11/2021] [Indexed: 12/31/2022] Open
Abstract
Plasma membrane sodium–hydrogen exchangers (NHE) transport Na+ into cells in exchange for H+. While there are nine isoforms of NHE in humans, this review focuses on the NHE3 isoform, which is abundantly expressed in the gastrointestinal tract, where it plays a key role in acid–base balance and water homeostasis. NHE3 inhibition in the small intestine results in luminal sodium and water retention, leading to a general decrease in paracellular water flux and diffusional driving force, reduced intestinal sodium absorption, and increased stool sodium excretion. The resulting softer and more frequent stools are the rationale for the development of tenapanor as a novel, first-in-class NHE3 inhibitor to treat irritable bowel syndrome with constipation. NHE3 also has additional therapeutic implications in nephrology. Inhibition of intestinal NHE3 also lowers blood pressure by reducing intestinal sodium absorption. Perhaps, the most novel effect is its ability to decrease intestinal phosphate absorption by inhibiting the paracellular phosphate absorption pathway. Therefore, selective pharmacological inhibition of NHE3 could be a potential therapeutic strategy to treat not only heart failure and hypertension but also hyperphosphatemia. This review presents an overview of the molecular and physiological functions of NHE3 and discusses how these functions translate to potential clinical applications in nephrology.
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Affiliation(s)
- Csaba P Kovesdy
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | | | | | - L Darryl Quarles
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN, USA
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Fishbane SN, Nigwekar S. Phosphate Absorption and Hyperphosphatemia Management in Kidney Disease: A Physiology-Based Review. Kidney Med 2021; 3:1057-1064. [PMID: 34939015 PMCID: PMC8664730 DOI: 10.1016/j.xkme.2021.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Phosphate absorption occurs in the gastrointestinal tract through paracellular absorption and transcellular transport. The paracellular pathway does not saturate and has a significantly higher absorption capacity than does the transcellular pathway. Evidence indicates that this pathway is the primary mechanism of intestinal phosphate absorption, particularly with Western diets containing high amounts of phosphorus. Elevated serum phosphorus concentrations are associated with cardiovascular morbidity and mortality but serum phosphorus concentrations > 5.5 mg/dL are highly prevalent despite best efforts with dietary phosphate restriction, dialysis, and the use of phosphate binders. The efficacy of phosphate binders may be inherently limited because the mechanism of action does not target any phosphate absorption pathway. Thus, therapeutic innovations are needed to address the limitations of phosphate binders. Novel therapies leveraging new mechanistic understandings of phosphate absorption and the primacy of the paracellular pathway may improve phosphate control. Phosphate absorption inhibitors that target the pathway are a novel therapeutic class. Tenapanor is an investigational first-in-class nonbinder phosphate absorption inhibitor that inhibits the sodium-hydrogen exchanger isoform 3 to reduce paracellular permeability specific to phosphate. Phosphate absorption inhibitors may represent a new mechanistic approach to phosphate management with the potential to improve clinical outcomes.
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Affiliation(s)
- Steven N. Fishbane
- Department of Medicine, Zucker School of Medicine at Hofstra, Hempstead, Great Neck, NY
- Northwell, Great Neck, NY
| | - Sagar Nigwekar
- Department of Medicine, Harvard Medical School, Boston, MA
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Block GA, Bleyer AJ, Silva AL, Weiner DE, Lynn RI, Yang Y, Rosenbaum DP, Chertow GM. Safety and Efficacy of Tenapanor for Long-term Serum Phosphate Control in Maintenance Dialysis: A 52-Week Randomized Phase 3 Trial (PHREEDOM). KIDNEY360 2021; 2:1600-1610. [PMID: 35372979 PMCID: PMC8785778 DOI: 10.34067/kid.0002002021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022]
Abstract
Background Treating hyperphosphatemia is a tenet of dialysis care. This trial assessed the safety and efficacy of tenapanor for the management of hyperphosphatemia. Methods In this 52-week phase 3 study (NCT03427125), participants receiving maintenance dialysis with both hyperphosphatemia (serum phosphate 6.0-10.0 mg/dl) and a 1.5 mg/dl increase after phosphate binder washout were randomized (3:1) to tenapanor 30 mg twice daily for 26 weeks (randomized treatment period) or sevelamer carbonate (52-week safety control). Participants completing 26 weeks of treatment with tenapanor were rerandomized (1:1) to tenapanor or placebo for 12 weeks (randomized withdrawal period), and were eligible to enter the 14-week safety extension period. With input from the US Food and Drug Administration, the primary efficacy end point was the difference in the change in serum phosphate from the end of the randomized treatment period to the end of the randomized withdrawal period, among participants who achieved ≥1.2 mg/dl decrease in serum phosphate during the randomized treatment period (efficacy analysis set). Efficacy was also evaluated in the intention-to-treat (ITT) analysis set. Results Of 564 eligible participants randomized to receive tenapanor (n=423) or sevelamer carbonate (n=141) during the randomized treatment period, 255 (60%) in the tenapanor group subsequently were rerandomized to tenapanor (n=128) or placebo (n=127) during the randomized withdrawal period. In the efficacy analysis set (n=131), the difference in estimated mean change in serum phosphate level between tenapanor and placebo from the beginning to the end of the randomized withdrawal period was -1.4 mg/dl (P<0.0001); in the ITT analysis set (n=243), the estimated mean difference was -0.7 mg/dl (P=0.002). Loosened stools were the most frequently reported adverse event (53% during the randomized treatment period). Serious adverse events were reported more frequently for participants treated with sevelamer carbonate (16%-23% across the three study periods) compared with tenapanor (11%-17%). Conclusions Tenapanor reduced serum phosphate concentrations and maintained control of serum phosphate in participants receiving maintenance dialysis, with an acceptable safety and tolerability profile.
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Affiliation(s)
- Geoffrey A Block
- Clinical Research and Medical Affairs, US Renal Care, Inc., Plano, Texas
| | - Anthony J Bleyer
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Arnold L Silva
- Boise Kidney and Hypertension Institute, Meridian, Idaho
| | - Daniel E Weiner
- Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
| | - Robert I Lynn
- Department of Medicine, Albert Einstein College of Medicine, New York, New York.,Kidney Medical Associates, New York, New York
| | - Yang Yang
- Biometrics, Ardelyx, Inc., Fremont, California
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Phosphate and fibroblast growth factor 23 in diabetes. Clin Sci (Lond) 2021; 135:1669-1687. [PMID: 34283205 PMCID: PMC8302806 DOI: 10.1042/cs20201290] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 12/11/2022]
Abstract
Diabetes is associated with a strongly elevated risk of cardiovascular disease, which is even more pronounced in patients with diabetic nephropathy. Currently available guideline-based efforts to correct traditional risk factors are only partly able to attenuate this risk, underlining the urge to identify novel treatment targets. Emerging data point towards a role for disturbances in phosphate metabolism in diabetes. In this review, we discuss the role of phosphate and the phosphate-regulating hormone fibroblast growth factor 23 (FGF23) in diabetes. We address deregulations of phosphate metabolism in patients with diabetes, including diabetic ketoacidosis. Moreover, we discuss potential adverse consequences of these deregulations, including the role of deregulated phosphate and glucose as drivers of vascular calcification propensity. Finally, we highlight potential treatment options to correct abnormalities in phosphate and FGF23. While further studies are needed to more precisely assess their clinical impact, deregulations in phosphate and FGF23 are promising potential target in diabetes and diabetic nephropathy.
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Pergola PE, Rosenbaum DP, Yang Y, Chertow GM. Authors' Reply. J Am Soc Nephrol 2021; 32:1824-1825. [PMID: 36630522 PMCID: PMC8425642 DOI: 10.1681/asn.2021050606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
| | | | | | - Glenn M. Chertow
- Department of Medicine/Nephrology, Stanford University School of Medicine, Stanford, California
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Editorial: A humble way forward amid hype and hope. Curr Opin Nephrol Hypertens 2021; 30:385-386. [PMID: 34027901 DOI: 10.1097/mnh.0000000000000720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kulkarni M. Utility of Phosphate Binder Equivalent Dose Concept. J Am Soc Nephrol 2021; 32:1824. [PMID: 36630521 PMCID: PMC8425652 DOI: 10.1681/asn.2021040440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Manjunath Kulkarni
- Department of Nephrology, Father Muller Medical College, Mangalore, Karnataka, India
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Sprague SM, Martin KJ, Coyne DW. Phosphate Balance and CKD-Mineral Bone Disease. Kidney Int Rep 2021; 6:2049-2058. [PMID: 34386654 PMCID: PMC8343779 DOI: 10.1016/j.ekir.2021.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/10/2021] [Indexed: 12/29/2022] Open
Abstract
Chronic kidney disease–mineral bone disorder (CKD-MBD) is a common comorbidity in patients with CKD. Characterized by laboratory abnormalities, bone abnormality, and vascular calcification, CKD-MBD encompasses a group of mineral and hormone disturbances that are strongly associated with increased cardiovascular (CV) morbidity and mortality. Abnormal serum phosphate concentrations are an independent risk factor for CV morbidity and mortality, and overall mortality. Phosphate retention plays a central role in initiating and driving many other disturbances in CKD-MBD (e.g., increased parathyroid hormone and fibroblast growth factor 23 concentrations, hypocalcemia, low vitamin D) that are also linked to increased CV risk. Thus, effective phosphate control is a logical therapeutic target for CKD-MBD treatment. Current phosphate management strategies (dietary restrictions, dialysis, phosphate binders) are insufficient to consistently achieve and maintain target phosphate concentrations in patients on dialysis. Phosphate binders reduce available phosphate for intestinal absorption but do not impair the dominant phosphate absorption pathway. Novel therapies that consider new mechanistic understandings of intestinal phosphate absorption are needed. One such therapy is tenapanor, a targeted sodium-hydrogen exchanger isoform 3 inhibitor that has been shown to reduce serum phosphate concentrations in multiple clinical trials. Tenapanor has a novel mechanism of action that reduces intestinal phosphate absorption in the primary paracellular phosphate absorption pathway.
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Affiliation(s)
- Stuart M Sprague
- Division of Nephrology and Hypertension, NorthShore University Health System, Evanston, IL, USA
| | | | - Daniel W Coyne
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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