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Endocrine Journal Apr 2024Bone secrets the hormone, fibroblast growth factor 23 (FGF23), as an endocrine organ to regulate blood phosphate level. Phosphate is an essential mineral for the human... (Review)
Review
Bone secrets the hormone, fibroblast growth factor 23 (FGF23), as an endocrine organ to regulate blood phosphate level. Phosphate is an essential mineral for the human body, and around 85% of phosphate is present in bone as a constituent of hydroxyapatite, Ca(PO)(OH). Because hypophosphatemia induces rickets/osteomalacia, and hyperphosphatemia results in ectopic calcification, blood phosphate (inorganic form) level must be regulated in a narrow range (2.5 mg/dL to 4.5 me/dL in adults). However, as yet it is unknown how bone senses changes in blood phosphate level, and how bone regulates the production of FGF23. Our previous data indicated that high extracellular phosphate phosphorylates FGF receptor 1 (FGFR1) in an unliganded manner, and its downstream intracellular signaling pathway regulates the expression of GALNT3. Furthermore, the post-translational modification of FGF23 protein via a gene product of GALNT3 is the main regulatory mechanism of enhanced FGF23 production due to high dietary phosphate. Therefore, our research group proposes that FGFR1 works as a phosphate-sensing receptor at least in the regulation of FGF23 production and blood phosphate level, and phosphate behaves as a first messenger. Phosphate is involved in various effects, such as stimulation of parathyroid hormone (PTH) synthesis, vascular calcification, and renal dysfunction. Several of these responses to phosphate are considered as phosphate toxicity. However, it is not clear whether FGFR1 is involved in these responses to phosphate. The elucidation of phosphate-sensing mechanisms may lead to the identification of treatment strategies for patients with abnormal phosphate metabolism.
Topics: Fibroblast Growth Factor-23; Humans; Phosphates; Fibroblast Growth Factors; Animals; Receptor, Fibroblast Growth Factor, Type 1; Signal Transduction; Bone and Bones; N-Acetylgalactosaminyltransferases; Hyperphosphatemia; Polypeptide N-acetylgalactosaminyltransferase
PubMed: 38556320
DOI: 10.1507/endocrj.EJ24-0082 -
Lanthanum hydroxide protects kidney through gut microbiota in a rat model of chronic kidney disease.Pharmacology Research & Perspectives Apr 2024The progression of chronic kidney diseases (CKD) is complex, influenced by a myriad of factors including gut microbiota. While emerging evidence suggests that gut...
The progression of chronic kidney diseases (CKD) is complex, influenced by a myriad of factors including gut microbiota. While emerging evidence suggests that gut microbiota can have beneficial effects in managing CKD, it is also recognized that dysbiosis may contribute to the progression of CKD and associated uremic complications. Our previous research has demonstrated the efficacy of lanthanum hydroxide in delaying kidney failure and preserving renal function. However, the role of lanthanum hydroxide in modulating gut microbiota in this context remains unclear. In our study, we induced CKD in rats using adenine, leading to gut microbial dysbiosis, kidney pathology, and disturbances in amino acid metabolism. In this adenine-induced CKD model with hyperphosphatemia, treatment with lanthanum hydroxide improved renal function. This improvement was associated with the restoration of gut microbial balance and an increase in urine ammonium metabolism. These results suggest that the therapeutic potential of lanthanum hydroxide in CKD may be partly due to its ability to reshape gut microbiota composition. This study underscores the significance of lanthanum hydroxide in kidney protection, attributing its benefits to the modulation of gut microbiota in a rat model of CKD.
Topics: Rats; Animals; Gastrointestinal Microbiome; Dysbiosis; Kidney; Renal Insufficiency, Chronic; Adenine; Lanthanum
PubMed: 38546116
DOI: 10.1002/prp2.1187 -
Biomedicines Mar 2024The amount of evidence indicates that hyperphosphataemia (HP) can induce endothelial damage and significantly impair endothelial nitric oxide synthase (eNOS) expression....
The amount of evidence indicates that hyperphosphataemia (HP) can induce endothelial damage and significantly impair endothelial nitric oxide synthase (eNOS) expression. There are no clinical studies that have assessed HP and its correlation with circulating eNOS concentration in patients with end-stage renal disease (ESRD). Our preliminary study aimed to evaluate the relationship between plasma inorganic phosphorus (P) levels and circulating plasma eNOS concentration in patients on haemodialysis (HD). A total of 50 patients on HD were enrolled to the study. They were divided into groups according to the tertiles of P. The examined HD group was also analysed and compared with controls as a whole group; then, the group was divided into patients with and without dyslipidaemia (D) as well as into those with and without type 2 diabetes mellitus (type 2 DM). A total of 26 age-matched healthy volunteers were included in the study as the control group. The plasma levels of eNOS in HD patients are reduced in comparison to those in healthy subjects. There was no difference in plasma eNOS concentrations between HD patients with type 2 DM and those without DM as well as between those with D and without D. In the entire group of HD patients, there were positive correlations between circulating levels of eNOS and plasma P concentrations. In HD patients with D, higher systolic and diastolic blood pressure were accompanied by decreased plasma eNOS concentrations. In conclusion, HP and high blood pressure appear to decrease the circulating eNOS levels. These findings demonstrate an additional negative impact of HP on eNOS activity.
PubMed: 38540300
DOI: 10.3390/biomedicines12030687 -
Cureus Feb 2024Wilson's disease (WD) encompasses diverse clinical symptoms involving the liver, nervous system, and kidneys. The fundamental cause of this condition is the build-up of...
Wilson's disease (WD) encompasses diverse clinical symptoms involving the liver, nervous system, and kidneys. The fundamental cause of this condition is the build-up of copper in organs, mainly the hepatic and brain parenchyma. Here, we are reporting the hospital presentation of a male patient in his 20s who had been experiencing severe irritability, abdominal pain, distension, and yellowish discoloration of the skin for the previous 75 days. Upon examination of blood pressure, a refractory carpopedal spasm was found in him. In addition to Kayser-Fleischer (KF) rings in his cornea, he exhibited elevated 24-hour urine copper and serum ceruloplasmin (CP). He was diagnosed as a case of WD with a rare association of hypoparathyroidism.
PubMed: 38516426
DOI: 10.7759/cureus.54516 -
Frontiers in Pharmacology 2024The application of ferric citrate therapy has yielded unexpected benefits in recent years for Chronic kidney disease patients suffering from hyperphosphatemia and iron... (Review)
Review
The application of ferric citrate therapy has yielded unexpected benefits in recent years for Chronic kidney disease patients suffering from hyperphosphatemia and iron deficiency -anaemia. Despite this, earlier research on the impact of ferric citrate on NDD-CKD has been contentious. The goal of the meta-analysis is to evaluate the evidence regarding the advantages and dangers of ferric citrate for the treatment of hyperphosphatemia and iron deficiency anaemia in NDD-CKD patients. Between the start of the study and June 2022, we searched PubMed, Embase, Cochrane, EBSCO, Scopus, Web of Science, Wan Fang Data, CNKI, and VIP databases for randomised controlled trials of iron citrate for hyperphosphatemia and anaemia in patients with NDD-CKD. For binary categorical data, risk ratios (OR) were employed, and for continuous variables, weighted mean differences The effect sizes for both count and measurement data were expressed using 95% confidence intervals The meta-analysis includes eight trials with a total of 1281 NDD-CKD patients. The phosphorus-lowering effect of ferric citrate was greater compared to the control group (WMD, -0.55, 95% CI, -0.81 to -0.28; I = 86%, < 0.001). Calcium (WMD, 0.092; 95% CI, -0.051 to 0.234; > 0.05; I = 61.9%), PTH (WMD, -0.10; 95% CI, -0.44 to 0.23; I = 75%, > 0.05) and iFGF23 (WMD, -7.62; 95% CI, -21.18 to 5.94; I = 20%, > 0.05) levels were not statistically different after ferric citrate treatment compared to control treatment. Furthermore, ferric citrate increased iron reserves and haemoglobin. The ferric citrate group had considerably greater levels than the controls. Ferric citrate, on the other hand, may raise the risk of constipation, diarrhoea, and nausea. This meta-analysis found that ferric citrate had a beneficial effect in the treatment of NDD-CKD, particularly in reducing blood phosphorus levels when compared to a control intervention. It also shown that ferric citrate has a favourable effect on iron intake and anaemia management. In terms of safety, ferric citrate may increase the likelihood of gastrointestinal side effects.
PubMed: 38515853
DOI: 10.3389/fphar.2024.1285012 -
Asian Biomedicine : Research, Reviews... Feb 2024Dietary protein restriction has been considered to be a nutritional-related strategy to reduce risk for end-stage kidney disease among patients with... (Review)
Review
Dietary protein restriction has been considered to be a nutritional-related strategy to reduce risk for end-stage kidney disease among patients with non-dialysis-dependent chronic kidney disease (CKD). However, there is insufficient evidence to recommend a particular type of protein to slow down the CKD progression. Recently, various plant-based diets could demonstrate some additional benefits such as a blood pressure-lowering effect, a reduction of metabolic acidosis as well as hyperphosphatemia, and gut-derived uremic toxins. Furthermore, the former concerns about the risk of undernutrition and hyperkalemia observed with plant-based diets may be inconsistent in real clinical practice. In this review, we summarize the current evidence of the proposed pleiotropic effects of plant-based diets and their associations with clinical outcomes among pre-dialysis CKD patients.
PubMed: 38515633
DOI: 10.2478/abm-2024-0002 -
BMC Genomics Mar 2024Atrial fibrillation (AF) is a prevalent arrhythmic condition resulting in increased stroke risk and is associated with high mortality. Electrolyte imbalance can increase... (Observational Study)
Observational Study
BACKGROUND
Atrial fibrillation (AF) is a prevalent arrhythmic condition resulting in increased stroke risk and is associated with high mortality. Electrolyte imbalance can increase the risk of AF, where the relationship between AF and serum electrolytes remains unclear.
METHODS
A total of 15,792 individuals were included in the observational study, with incident AF ascertainment in the Atherosclerosis Risk in Communities (ARIC) study. The Cox regression models were applied to calculate the hazard ratio (HR) and 95% confidence interval (CI) for AF based on different serum electrolyte levels. Mendelian randomization (MR) analyses were performed to examine the causal association.
RESULTS
In observational study, after a median 19.7 years of follow-up, a total of 2551 developed AF. After full adjustment, participants with serum potassium below the 5th percentile had a higher risk of AF relative to participants in the middle quintile. Serum magnesium was also inversely associated with the risk of AF. An increased incidence of AF was identified in individuals with higher serum phosphate percentiles. Serum calcium levels were not related to AF risk. Moreover, MR analysis indicated that genetically predicted serum electrolyte levels were not causally associated with AF risk. The odds ratio for AF were 0.999 for potassium, 1.044 for magnesium, 0.728 for phosphate, and 0.979 for calcium, respectively.
CONCLUSIONS
Serum electrolyte disorders such as hypokalemia, hypomagnesemia and hyperphosphatemia were associated with an increased risk of AF and may also serve to be prognostic factors. However, the present study did not support serum electrolytes as causal mediators for AF development.
Topics: Humans; Atrial Fibrillation; Risk Factors; Magnesium; Mendelian Randomization Analysis; Calcium; Potassium; Phosphates; Electrolytes; Genome-Wide Association Study
PubMed: 38493091
DOI: 10.1186/s12864-024-10197-2 -
Journal of Renal Nutrition : the... Mar 2024Hyperphosphatemia is a common complication in patients with kidney failure, despite the use of phosphate binders. Vitamin B3, either in the form of niacin or niacinamide...
OBJECTIVE
Hyperphosphatemia is a common complication in patients with kidney failure, despite the use of phosphate binders. Vitamin B3, either in the form of niacin or niacinamide (NAM), shows potential as "add-on" treatment to reduce serum phosphate concentrations in this population. NAM seems to lack many of the side effects that are observed with niacin. The aim of this study was to investigate whether NAM is an effective and acceptable treatment in reducing serum phosphate concentrations in patients with kidney failure.
METHODS
DiaNia was a double-blind placebo-controlled randomized crossover trial, comparing NAM (250-500 mg/day) to placebo as "add-on" treatment to an individual treatment with approved phosphate binders for 12 weeks in patients receiving hemodialysis. The primary outcome was serum phosphate concentrations, and the secondary outcomes were platelet counts as well as drop-outs due to side effects. Data were analyzed using both per-protocol and intention-to-treat analyses.
RESULTS
Mean age of the per-protocol population (n = 26) was 63.6 ± 17.2 years and 53.8% were men. NAM treatment significantly reduced serum phosphate with 0.59 mg/dL (p = .03). Linear mixed-effects models demonstrated superiority of 12 weeks NAM over 12 weeks placebo with a between-treatment difference of 0.77 mg/dL (95% CI 0.010, 1.43; P = .03). Similar results, although not significant, were found in the intention-to-treat population. We found no between-treatment differences in platelet counts and during the NAM treatment we observed 3 drop-outs due to side effects (8.6%).
CONCLUSION
NAM is effective in reducing serum phosphate concentrations in patients with kidney failure receiving hemodialysis. In addition, NAM is well-tolerated and seems not to increase the risk of thrombocytopenia. Thus, NAM can be valuable as "add-on" treatment to combat hyperphosphatemia in patients with kidney failure. However, more research in larger populations is needed to confirm this.
PubMed: 38492684
DOI: 10.1053/j.jrn.2024.02.005 -
International Journal of Molecular... Feb 2024Patients with chronic kidney disease (CKD) have a high prevalence of hyperphosphatemia, where uremic toxins like inorganic phosphate (Pi) induce a cardiovascular...
Inorganic Phosphate-Induced Extracellular Vesicles from Vascular Smooth Muscle Cells Contain Elevated Levels of Hyaluronic Acid, Which Enhance Their Interaction with Very Small Superparamagnetic Iron Oxide Particles.
Patients with chronic kidney disease (CKD) have a high prevalence of hyperphosphatemia, where uremic toxins like inorganic phosphate (Pi) induce a cardiovascular remodeling. Related disorders like atherosclerosis bear the risk of increased morbidity and mortality. We previously found that Pi stimulates the synthesis and sulfation of the negatively charged glycosaminoglycans (GAGs) heparan sulfate and chondroitin sulfate in vascular smooth muscle cells (VSMC). Similar GAG alterations were detected in VSMC-derived exosome-like extracellular vesicles (EV). These EV showed a strong interaction with very small superparamagnetic iron oxide particles (VSOP), which are used as imaging probes for experimental magnetic resonance imaging (MRI). Hyaluronic acid (HA) represents another negatively charged GAG which is supposed to function as binding motif for VSOP as well. We investigated the effects of Pi on the amounts of HA in cells and EV and studied the HA-dependent interaction between VSOP with cells and EV. Rat VSMC were treated with elevated concentrations of Pi. CKD in rats was induced by adenine feeding. EV were isolated from culture supernatants and rat plasma. We investigated the role of HA in binding VSOP to cells and EV via cell-binding studies, proton relaxometry, and analysis of cellular signaling, genes, proteins, and HA contents. Due to elevated HA contents, VSMC and EV showed an increased interaction with VSOP after Pi stimulation. Amongst others, Pi induced hyaluronan synthase (HAS)2 expression and activation of the Wnt pathway in VSMC. An alternative upregulation of HA by iloprost and an siRNA-mediated knockdown of HAS2 confirmed the importance of HA in cells and EV for VSOP binding. The in vitro-derived data were validated by analyses of plasma-derived EV from uremic rats. In conclusion, the inorganic uremic toxin Pi induces HA synthesis in cells and EV, which leads to an increased interaction with VSOP. HA might therefore be a potential molecular target structure for improved detection of pathologic tissue changes secondary to CKD like atherosclerosis or cardiomyopathy using EV, VSOP and MRI.
Topics: Humans; Animals; Rats; Hyaluronic Acid; Phosphates; Muscle, Smooth, Vascular; Extracellular Vesicles; Atherosclerosis; Renal Insufficiency, Chronic; Magnetic Iron Oxide Nanoparticles; Ferric Compounds
PubMed: 38473817
DOI: 10.3390/ijms25052571 -
BMC Nephrology Mar 2024Hyperphosphatemia is common in chronic kidney disease (CKD), associated with higher mortality in dialysis patients. Its impact in non-dialysis patients, especially those...
BACKGROUND
Hyperphosphatemia is common in chronic kidney disease (CKD), associated with higher mortality in dialysis patients. Its impact in non-dialysis patients, especially those with preserved kidney function, remains uncertain.
METHODS
A prospective cohort study was conducted using data from the National Health and Nutrition Examination Survey (2001-2008). Serum phosphorus was analyzed as a continuous variable, or categorized into three groups: < 3.5 mg/dL, 3.5 to < 4.5 mg/dL, and ≥ 4.5 mg/dL. Cox proportional hazards models were used to analyze the association between phosphorus with all-cause and cardiovascular disease (CVD) mortality, with or without adjustment for age, sex, race, hemoglobin, estimated glomerular filtration rate (eGFR), serum albumin, serum calcium, 25(OH)D, obesity, hypertension, diabetes, and CVD.
RESULTS
A total of 7694 participants were included in the analysis, representing 28 million CKD patients in the United States. During mean 92 months of follow up, 2708 all-cause deaths (including 969 CVD deaths) were observed. Per 1 mg/dL increase in phosphorus was associated with a 13% and 24% increased risk of all-cause mortality (hazard ratio [HR], 1.13; 95%CI, 1.02-1.24) and CVD mortality (HR, 1.24; 95%CI, 1.07-1.45), respectively. Compared with the < 3.5 mg/dL, phosphorus ≥ 4.5 mg/dL was associated with a 28% and 57% increased risk of all-cause mortality (HR, 1.28; 95%CI, 1.05-1.55) and CVD mortality (HR, 1.57; 95CI, 1.19-2.08), respectively. In participants with eGFR < 60 ml/min/1.73m, elevated phosphorus (≥ 4.5 mg/ dL) were significantly associated with increased risk of all-cause mortality (HR, 1.36; 95%CI, 1.07-1.72). No significant association was observed in eGFR ≥ 60 ml/min/1.73m group (HR, 1.31; 95%CI, 0.86-1.99). This correlation does not differ significantly between subgroups defined by eGFR level (P for interaction = 0.889).
CONCLUSION
Serum phosphorus above 4.5 mg/dL is significantly associated with a 28% and 57% increased risk of all-cause and CVD death in non-dialysis CKD patients, respectively. This relationship still demonstrated in patients with eGFR < 60 ml/min/1.73m. However, for population with eGFR ≥ 60 ml/min/1.73m, further verification is needed.
Topics: Humans; Renal Dialysis; Nutrition Surveys; Prospective Studies; Cardiovascular Diseases; Phosphorus; Renal Insufficiency, Chronic
PubMed: 38448815
DOI: 10.1186/s12882-024-03525-x