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Murashima M, Fujii N, Goto S, Hasegawa T, Abe M, Hanafusa N, Fukagawa M, Hamano T. Associations of calcium, phosphate and intact parathyroid hormone levels with mortality, residual kidney function and technical failure among patients on peritoneal dialysis. Clin Kidney J 2023; 16:1957-1964. [PMID: 37915934 PMCID: PMC10616493 DOI: 10.1093/ckj/sfad223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Indexed: 11/03/2023] Open
Abstract
Background Associations of calcium, phosphate and intact parathyroid hormone (iPTH) levels with outcomes may be different between patients on peritoneal dialysis (PD) and hemodialysis (HD). The aim of the study is to evaluate these associations among PD patients. Methods In this prospective cohort study on the Japan Renal Data Registry, adults on PD at the end of 2009 were included. The observation period was until the end of 2018 and the data were censored at the time of transplantation or transition to HD. Exposures were time-averaged or time-dependent albumin-corrected calcium (cCa), phosphate and iPTH levels. Outcomes were all-cause and cardiovascular mortality, transition to HD and urine output. Data were analyzed using Cox regression models or linear mixed-effects models and the results were shown as cubic spline curves. Results Among 7393 patients, 590 deaths and 211 cardiovascular deaths were observed during a median follow-up of 3.0 years. Higher cCa and phosphate levels were associated with higher mortality. Lower cCa levels were associated with a faster decline, whereas lower phosphate was associated with a slower decline in urine output. Lower phosphate and iPTH levels were associated with a lower incidence of transition to HD. Conclusions Among PD patients, the observed associations of cCa, phosphate and iPTH with mortality, residual kidney function and technical failure suggest that avoiding high cCa, phosphate and iPTH levels might improve outcomes.
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Affiliation(s)
- Miho Murashima
- Department of Nephrology, Nagoya City University, Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Naohiko Fujii
- Department of Nephrology, Hyogo Prefectural Nishinomiya Hospital, Nishinomiya, Hyogo, Japan
| | - Shunsuke Goto
- Division of Nephrology and Kidney Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
- Committee of Renal Data Registry of the Japanese Society for Dialysis Therapy, Tokyo, Japan
| | - Takeshi Hasegawa
- Committee of Renal Data Registry of the Japanese Society for Dialysis Therapy, Tokyo, Japan
- Showa University Research Administration Center (SURAC); Division of Nephrology, Department of Medicine, School of Medicine; Department of Hygiene, Public Health and Preventive Medicine, Graduate School of Medicine, Showa University, Tokyo, Japan
| | - Masanori Abe
- Committee of Renal Data Registry of the Japanese Society for Dialysis Therapy, Tokyo, Japan
- Division of Nephrology, Hypertension and Endocrinology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Norio Hanafusa
- Committee of Renal Data Registry of the Japanese Society for Dialysis Therapy, Tokyo, Japan
- Department of Blood Purification, Tokyo Women's Medical University, Tokyo, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology, and Metabolism, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Takayuki Hamano
- Department of Nephrology, Nagoya City University, Graduate School of Medical Sciences, Nagoya, Aichi, Japan
- Department of Nephrology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Ketteler M, Bover J, Mazzaferro S. Treatment of secondary hyperparathyroidism in non-dialysis CKD: an appraisal 2022s. Nephrol Dial Transplant 2022; 38:1397-1404. [PMID: 35977397 DOI: 10.1093/ndt/gfac236] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Indexed: 11/12/2022] Open
Abstract
The situation of secondary hyperparathyroidism (sHPT) in CKD patients not on dialysis (ND-CKD) is probably best characterised by the KDIGO CKD-MBD Update 2017 guideline 4.2.1 stating that the optimal PTH levels is not known in these stages. Furthermore, new caution became recommended with regard to the routine use of active vitamin D analogues in early CKD stages and moderate sHPT phenotypes, due to their potential risks for hypercalcaemia and hyperphosphataemia aggravation. Nevertheless, there is still a substantial clinical need to prevent the development of parathyroid gland autonomy with its associated consequences of bone and vascular damage including fracture risks and cardiovascular events. Therefore, we now attempt to review the current guideline-based and clinical practice management of sHPT in ND-CKD including their strengths and weaknesses, favouring individualised approaches respecting calcium and phosphate homeostasis. We further comment on extended-release calcifediol (ERC) as a new differential therapeutic option now also available in Europe, and on a potentially novel understanding of a required vitamin D saturation in more advanced CKD stages. There is no doubt, however, that knowledge gaps will remain in this issue unless powerful RCTs with hard and meaningful endpoints are performed.
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Affiliation(s)
- Markus Ketteler
- Department of General Internal Medicine and Nephrology, Robert-Bosch-Krankenhaus, Stuttgart, Germany
| | - Jordi Bover
- Nephrology Department, University Hospital Germans Trias i Pujol (HGiTP), Badalona (Barcelona), Catalonia, Spain.,REMAR-IGTP Group, Germans Trias i Pujol Research Institute (IGTP), Can Ruti Campus, Badalona (Barcelona), Catalonia, Spain
| | - Sandro Mazzaferro
- Department of Translational and Precision Medicine, Sapienza University of Rome, Italy
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Bielopolski D, Wenziger C, Steinmetz T, Rozen Zvi B, Kalantar-Zadeh K, Streja E. Novel Protein to Phosphorous Ratio Score Predicts Mortality in Hemodialysis Patients. J Ren Nutr 2021; 32:450-457. [PMID: 34740537 DOI: 10.1053/j.jrn.2021.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/19/2021] [Accepted: 08/10/2021] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE Lowering serum phosphorus in people on hemodialysis may improve their survival. However, prior studies have shown that restricting dietary protein intake, a major source of phosphorus, is associated with higher mortality. We hypothesized that a novel metric that incorporates both these values commensurately can improve survival prediction. METHODS We used serum phosphorous and normalized protein catabolic rate (nPCR), a surrogate of dietary protein intake, to form a new metric R that was used to examine the associations with mortality in 63,016 people on hemodialysis (HD) of one year after treatment initiation. Survival models were adjusted for case-mix, malnutrition-inflammation cachexia syndrome (MICS), and residual kidney function (RKF). RESULTS Individuals treated with hemodialysis were divided into five groups in accordance with R value. Group 1 included sick individuals with high phosphorous and low nPCR. Group 5 included individuals with low phosphorous and high nPCR. After 1-year follow-up, survival difference between the groups reflected R value, where an increase in R was associated with improved survival. The association of R with mortality was strengthened by adjustment in demographic variables and attenuated after adjustment to MICS. Mortality associations in accordance with R were not influenced by residual kidney function (RKF). CONCLUSION The novel protein to phosphorus ratio score R predicts mortality in people on dialysis, probably reflecting both nutrition and inflammation state independent of RKF. The metric enables better phosphorus monitoring, although adequate dietary protein intake is ensured and may improve the prediction of outcomes in the clinical setting.
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Affiliation(s)
- Dana Bielopolski
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California, Irvine, School of Medicine, Irvine, CA; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Nephrology Institute, Rabin Medical Center, Petah Tiqva, Israel.
| | - Cachet Wenziger
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California, Irvine, School of Medicine, Irvine, CA
| | - Tali Steinmetz
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Nephrology Institute, Rabin Medical Center, Petah Tiqva, Israel
| | - Benaya Rozen Zvi
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Nephrology Institute, Rabin Medical Center, Petah Tiqva, Israel
| | - Kamyar Kalantar-Zadeh
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California, Irvine, School of Medicine, Irvine, CA
| | - Elani Streja
- Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California, Irvine, School of Medicine, Irvine, CA
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The Protein-Independent Role of Phosphate in the Progression of Chronic Kidney Disease. Toxins (Basel) 2021; 13:toxins13070503. [PMID: 34357974 PMCID: PMC8310030 DOI: 10.3390/toxins13070503] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 12/14/2022] Open
Abstract
Several factors contribute to renal-function decline in CKD patients, and the role of phosphate content in the diet is still a matter of debate. This study aims to analyze the mechanism by which phosphate, independent of protein, is associated with the progression of CKD. Adult Munich-Wistar rats were submitted to 5/6 nephrectomy (Nx), fed with a low-protein diet, and divided into two groups. Only phosphate content (low phosphate, LoP, 0.2%; high phosphate, HiP, 0.95%) differentiated diets. After sixty days, biochemical parameters and kidney histology were analyzed. The HiP group presented worse renal function, with higher levels of PTH, FGF-23, and fractional excretion of phosphate. In the histological analysis of the kidney tissue, they also showed a higher percentage of interstitial fibrosis, expression of α-actin, PCNA, and renal infiltration by macrophages. The LoP group presented higher expression of beclin-1 in renal tubule cells, a marker of autophagic flux, when compared to the HiP group. Our findings highlight the action of phosphate in the induction of kidney interstitial inflammation and fibrosis, contributing to the progression of renal disease. A possible effect of phosphate on the dysregulation of the renal cell autophagy mechanism needs further investigation with clinical studies.
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Ketteler M, Ambühl P. Where are we now? Emerging opportunities and challenges in the management of secondary hyperparathyroidism in patients with non-dialysis chronic kidney disease. J Nephrol 2021; 34:1405-1418. [PMID: 34170509 PMCID: PMC8494658 DOI: 10.1007/s40620-021-01082-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/24/2021] [Indexed: 12/20/2022]
Abstract
Abstract Rising levels of parathyroid hormone (PTH) are common in patients with chronic kidney disease (CKD) not on dialysis and are associated with an elevated risk of morbidity (including progression to dialysis) and mortality. However, there are several challenges for the clinical management of secondary hyperparathyroidism (SHPT) in this population. While no recognised target level for PTH currently exists, it is accepted that patients with non-dialysis CKD should receive early and regular monitoring of PTH from CKD stage G3a. However, studies indicate that adherence to monitoring recommendations in non-dialysis CKD may be suboptimal. SHPT is linked to vitamin D [25(OH)D] insufficiency in non-dialysis CKD, and correction of low 25(OH)D levels is a recognised management approach. A second challenge is that target 25(OH)D levels are unclear in this population, with recent evidence suggesting that the level of 25(OH)D above which suppression of PTH progressively diminishes may be considerably higher than that recommended for the general population. Few therapeutic agents are licensed for use in non-dialysis CKD patients with SHPT and optimal management remains controversial. Novel approaches include the development of calcifediol in an extended-release formulation, which has been shown to increase 25(OH)D gradually and provide a physiologically-regulated increase in 1,25(OH)2D that can reliably lower PTH in CKD stage G3–G4 without clinically meaningful increases in serum calcium and phosphate levels. Additional studies would be beneficial to assess the comparative effects of available treatments, and to more clearly elucidate the overall benefits of lowering PTH in non-dialysis CKD, particularly in terms of hard clinical outcomes. Graphic abstract ![]()
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Affiliation(s)
- Markus Ketteler
- Allgemeine Innere Medizin und Nephrologie, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
| | - Patrice Ambühl
- Institut für Nephrologie, Stadtspital Waid und Triemli Zürich, Zurich, Switzerland
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Parathyroid Hormone: A Uremic Toxin. Toxins (Basel) 2020; 12:toxins12030189. [PMID: 32192220 PMCID: PMC7150960 DOI: 10.3390/toxins12030189] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/08/2020] [Accepted: 03/08/2020] [Indexed: 12/27/2022] Open
Abstract
Parathyroid hormone (PTH) has an important role in the maintenance of serum calcium levels. It activates renal 1α-hydroxylase and increases the synthesis of the active form of vitamin D (1,25[OH]2D3). PTH promotes calcium release from the bone and enhances tubular calcium resorption through direct action on these sites. Hallmarks of secondary hyperparathyroidism associated with chronic kidney disease (CKD) include increase in serum fibroblast growth factor 23 (FGF-23), reduction in renal 1,25[OH]2D3 production with a decline in its serum levels, decrease in intestinal calcium absorption, and, at later stages, hyperphosphatemia and high levels of PTH. In this paper, we aim to critically discuss severe CKD-related hyperparathyroidism, in which PTH, through calcium-dependent and -independent mechanisms, leads to harmful effects and manifestations of the uremic syndrome, such as bone loss, skin and soft tissue calcification, cardiomyopathy, immunodeficiency, impairment of erythropoiesis, increase of energy expenditure, and muscle weakness.
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