COSMOS: the dialysis scenario of CKD-MBD in Europe

Differences in association between hypoalbuminaemia and mortality among younger versus older patients on haemodialysis

Background

Ageing often affects biomarker production. Yet, clinical/optimal thresholds to guide clinical decisions do not consider this. Serum albumin decreases with age, but hypoalbuminaemia is defined as serum albumin <4.0 g/dl. This study explores whether age might affect serum albumin levels and its association with mortality in haemodialysis patients.

Methods

COSMOS (Current Management of Secondary Hyperparathyroidism: a Multicentre Observational Study) is a prospective, open-cohort, observational study of haemodialysis patients followed for 3 years. Binary logistic and linear regression were used to analyse the association between age and hypoalbuminaemia or serum albumin (continuous). Cox proportional hazard multivariate regression was used to examine the relationship between hypoalbuminaemia and mortality in patients younger and older than 65 years. Time-dependent receiver operating characteristic (ROC) curves were used to assess the discriminatory ability of serum albumin and optimal thresholds for predicting mortality.

Results

The present analysis included 5585 patients. The odds of experiencing hypoalbuminaemia increased with age [adjusted odds ratios = 1.56(95%CI: 1.31-1.86), 1.89(95%CI: 1.59-2.24), 2.68(95%CI: 2.22-3.23) for 56-65, 66-75, and >75 years, respectively (reference ≤55 years; P value for trend: <0.001)]. Survival analysis showed that the association between hypoalbuminaemia and mortality was weaker in patients aged ≥65 compared to <65 years [hazard ratios: 1.36(95%CI: 1.17-1.57) and 1.81(95%CI:1.42-2.31) respectively; P value for interaction 0.004]. The ability of albumin levels to predict mortality was consistently higher in younger patients. Optimal albumin thresholds for predicting mortality were 3.7 g/dl in patients younger than 65 years and 3.5 g/dl in patients 65 years and older.

Conclusions

Ageing is accompanied by lower albumin levels, and the association between hypoalbuminaemia and mortality may be modified by age. Different clinical thresholds that consider age may better discriminate risks associated with hypoalbuminaemia.

Effect of sodium zirconium cyclosilicate on hyperkalemia after parathyroidectomy in secondary hyperparathyroidism patients with maintenance hemodialysis: A randomized trial

BACKGROUND

Postoperative hyperkalemia is 1 common complication after parathyroidectomy (PTX), which requires close monitoring and prompt treatment. This study aimed to determine whether using sodium zirconium cyclosilicate (SZC) would lower the risk of hyperkalemia in patients with maintenance hemodialysis after PTX.

METHODS

Sixty-two patients with secondary hyperparathyroidism (SHPT) were randomly divided into the experimental and control groups. Patients in the experimental group were required to take 10 g of SZC before PTX. Laboratory chemistries were obtained before and after surgery.

RESULTS

Parathyroid hormone (PTH) decreased dramatically in the experimental and control groups after PTX. There were no significant differences in serum potassium ion (K+) between the 2 groups at 6 am on the day of surgery and immediately after surgery. However, serum potassium in the experimental group at 9 pm on the day of surgery was significantly lower than in the control group. Three patients with severe hyperkalemia in the control group received emergency hemodialysis or insulin and glucose treatment, while none in the experimental group required hemodialysis. Serum calcium levels declined immediately after the operation, but no significant differences were found between these 2 groups at all time points.

CONCLUSION

SZC has the potential to reduce the occurrence of hyperkalemia and avoid urgent hemodialysis after PTX. We recommended that SZC could be used routinely in SHPT patients on the day of PTX surgery.

[Etiopathogenetic features of bone metabolism in patients with diabetes mellitus and Charcot foot]

Diabetic neuropathy is one of the most common diabetes mellitus complications associated with mediocalcinosis of the lower extremities, a significant decrease in feet bone mineral density, and a high incidence of cardiovascular disease. In most cases, calcium-phosphorus metabolism changes occur in patients with diabetic neuroarthropathy, or Charcot foot, when we can observe feet local osteoporosis, which in 90% of cases associated with a vessel's calcification of the lower extremities in the majority of diabetes population. A large number of studies presented literature have demonstrated that patients with Charcot foot can have accelerated bone metabolism and increased bone resorption. Patients with Charcot foot often have crucial abnormalities in the calcium-phosphorus parameters, bone metabolism, and levels of vitamin D and its metabolites. In addition, the duration of diabetes mellitus, the degree of its compensation widely affects the development of its micro- and macrovascular complications, which could also accelerate the development of mineral and bone disorders in these types of patients. Multifactorial pathogenesis of these disorders complicates the management of patients with a long and complicated course of diabetes mellitus. This review discusses the peculiarities of vitamin D metabolism, the importance of timely diagnosis in phosphorus-calcium disorders, and the specifics of therapy in these patients. Special attention is paid to the timely diagnosis of the Charcot's foots acute stage based on the bone marrow edema by MRI evaluation and the possibility of reducing the immobilization period.

Secondary hyperparathyroidism in chronic kidney disease: pathophysiology, current treatments and investigational drugs

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.

Serum phosphate is associated with increased risk of bone fragility fractures in haemodialysis patients

BACKGROUND

Bone fragility fractures are associated with high morbidity and mortality. This study analysed the association between the current biochemical parameters of chronic kidney disease-mineral and bone disorders (CKD-MBD) and bone fragility fractures in the COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) project.

METHODS

COSMOS is a 3-year, multicentre, open cohort, prospective, observational study carried out in 6797 haemodialysis patients (227 centres from 20 European countries). The association of bone fragility fractures (outcome) with serum calcium, phosphate and parathyroid hormone (PTH) (exposure), was assessed using standard Cox proportional hazards regression and Cox proportional hazards regression for recurrent events. Additional analyses were performed considering all-cause mortality as a competitive event for bone fragility fracture occurrence. Multivariable models were used in all strategies, with the fully adjusted model including a total of 24 variables.

RESULTS

During a median follow-up of 24 months, 252 (4%) patients experienced at least one bone fragility fracture (incident bone fragility fracture rate 28.5 per 1000 patient-years). In the fractured and non-fractured patients, the percentage of men was 43.7% and 61.4%, mean age 68.1 and 63.8 years and a haemodialysis vintage of 55.9 and 38.3 months, respectively. Baseline serum phosphate >6.1 mg/dL (reference value 4.3-6.1 mg/dL) was significantly associated with a higher bone fragility fracture risk in both regression models {hazard ratio (HR) 1.53 [95% confidence interval (CI) 1.10-2.13] and HR 1.44 (95% CI 1.02-2.05)}. The significant association persisted after competitive risk analysis [subHR 1.42 (95% CI 1.02-1.98)] but the finding was not confirmed when serum phosphate was considered as a continuous variable. Baseline serum calcium showed no association with bone fragility fracture risk in any regression model. Baseline serum PTH >800 pg/mL was significantly associated with a higher bone fragility fracture risk in both regression models, but the association disappeared after a competitive risk analysis.

CONCLUSIONS

Hyperphosphatemia was independently and consistently associated with an increased bone fracture risk, suggesting serum phosphate could be a novel risk factor for bone fractures in haemodialysis patients.

Mineral and bone metabolism markers and mortality in diabetic patients on haemodialysis

BACKGROUND

Diabetic patients on haemodialysis have a higher risk of mortality than non-diabetic patients. The aim of this COSMOS (Current management of secondary hyperparathyroidism: a multicentre observational study) analysis was to assess whether bone and mineral laboratory values [calcium, phosphorus and parathyroid hormone (PTH)] contribute to this risk.

METHODS

COSMOS is a multicentre, open-cohort, 3-year prospective study, which includes 6797 patients from 227 randomly selected dialysis centres in 20 European countries. The association between mortality and calcium, phosphate or PTH was assessed using Cox proportional hazard regression models using both penalized splines smoothing and categorization according to KDIGO guidelines. The effect modification of the association between the relative risk of mortality and serum calcium, phosphate or PTH by diabetes was assessed.

RESULTS

There was a statistically significant effect modification of the association between the relative risk of mortality and serum PTH by diabetes (P = .011). The slope of the curve of the association between increasing values of PTH and relative risk of mortality was steeper for diabetic compared with non-diabetic patients, mainly for high levels of PTH. In addition, high serum PTH (>9 times the normal values) was significantly associated with a higher relative risk of mortality in diabetic patients but not in non-diabetic patients [1.53 (95% confidence interval 1.07-2.19) and 1.17 (95% confidence interval 0.91-1.52)]. No significant effect modification of the association between the relative risk of mortality and serum calcium or phosphate by diabetes was found (P = .2 and P = .059, respectively).

CONCLUSION

The results show a different association of PTH with the relative risk of mortality in diabetic and non-diabetic patients. These findings could have relevant implications for the diagnosis and treatment of chronic kidney disease-mineral and bone disorders.

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?

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.

Distribution, preparedness and management of Ukrainian adult refugees on dialysis-an international survey by the Renal Disaster Relief Task Force of the European Renal Association

BACKGROUND

Due to the Russian-Ukrainian war, some of the about 10 000 adults requiring dialysis in Ukraine fled their country to continue dialysis abroad. To better understand the needs of conflict-affected dialysis patients, the Renal Disaster Relief Task Force of the European Renal Association conducted a survey on distribution, preparedness and management of adults requiring dialysis who were displaced due to the war.

METHODS

A cross-sectional online survey was sent via National Nephrology Societies across Europe and disseminated to their dialysis centers. Fresenius Medical Care shared a set of aggregated data.

RESULTS

Data were received on 602 patients dialyzed in 24 countries. Most patients were dialyzed in Poland (45.0%), followed by Slovakia (18.1%), Czech Republic (7.8%) and Romania (6.3%). The interval between last dialysis and the first in the reporting center was 3.1 ± 1.6 days, but was ≥4 days in 28.1% of patients. Mean age was 48.1 ± 13.4 years, 43.5% were females. Medical records were carried by 63.9% of patients, 63.3% carried a list of medications, 60.4% carried the medications themselves and 44.0% carried their dialysis prescription, with 26.1% carrying all of these items and 16.1% carrying none. Upon presentation outside Ukraine, 33.9% of patients needed hospitalization. Dialysis therapy was not continued in the reporting center by 28.2% of patients until the end of the observation period.

CONCLUSIONS

We received information about approximately 6% of Ukrainian dialysis patients, who had fled their country by the end of August 2022. A substantial proportion were temporarily underdialyzed, carried incomplete medical information and needed hospitalization. The results of our survey may help to inform policies and targeted interventions to respond to the special needs of this vulnerable population during wars and other disasters in the future.

Novel Model of Oxalate Diet-Induced Chronic Kidney Disease in Dahl-Salt-Sensitive Rats

Diet-induced models of chronic kidney disease (CKD) offer several advantages, including clinical relevance and animal welfare, compared with surgical models. Oxalate is a plant-based, terminal toxic metabolite that is eliminated by the kidneys through glomerular filtration and tubular secretion. An increased load of dietary oxalate leads to supersaturation, calcium oxalate crystal formation, renal tubular obstruction, and eventually CKD. Dahl-Salt-Sensitive (SS) rats are a common strain used to study hypertensive renal disease; however, the characterization of other diet-induced models on this background would allow for comparative studies of CKD within the same strain. In the present study, we hypothesized that SS rats on a low-salt, oxalate rich diet would have increased renal injury and serve as novel, clinically relevant and reproducible CKD rat models. Ten-week-old male SS rats were fed either 0.2% salt normal chow (SS-NC) or a 0.2% salt diet containing 0.67% sodium oxalate (SS-OX) for five weeks.Real-time PCR demonstrated an increased expression of inflammatory marker interleukin-6 (IL-6) (p < 0.0001) and fibrotic marker Timp-1 metalloproteinase (p < 0.0001) in the renal cortex of SS-OX rat kidneys compared with SS-NC. The immunohistochemistry of kidney tissue demonstrated an increase in CD-68 levels, a marker of macrophage infiltration in SS-OX rats (p < 0.001). In addition, SS-OX rats displayed increased 24 h urinary protein excretion (UPE) (p < 0.01) as well as significant elevations in plasma Cystatin C (p < 0.01). Furthermore, the oxalate diet induced hypertension (p < 0.05). A renin-angiotensin-aldosterone system (RAAS) profiling (via liquid chromatography-mass spectrometry; LC-MS) in the SS-OX plasma showed significant (p < 0.05) increases in multiple RAAS metabolites including angiotensin (1-5), angiotensin (1-7), and aldosterone. The oxalate diet induces significant renal inflammation, fibrosis, and renal dysfunction as well as RAAS activation and hypertension in SS rats compared with a normal chow diet. This study introduces a novel diet-induced model to study hypertension and CKD that is more clinically translatable and reproducible than the currently available models.

Can the implementation of clinical practice guidelines improve clinical competence of physicians and kidney function of patients with type 2 diabetes mellitus?

Background

There are many clinical practice guidelines (CPGs) in Nephrology; however, there is no evidence that their availability has improved the clinical competence of physicians or the outcome of patients with chronic kidney disease (CKD). This study was aimed to evaluate the effect of implementation of CPGs for early CKD on family physicians (FP) clinical competence and subsequently on kidney function preservation of type 2 diabetes mellitus (DM2) patients at a primary healthcare setting.

Methods

A prospective educative intervention (40-h) based on CPGs for Prevention, Diagnosis and Treatment of Early CKD was applied to FP; a questionnaire to evaluate clinical competence was applied at the beginning and end of the educative intervention (0 and 2 months), and 12 months afterwards. DM2 patients with CKD were evaluated during 1-year of follow-up with estimated glomerular filtration rate (eGFR) and albuminuria.

Results

After educative intervention, there was a significant increase in FP clinical competence compared to baseline; although it was reduced after 1 year, it remained higher compared to baseline. One-hundred thirteen patients with early nephropathy (58 stage 1, 55 stage 2) and 28 with overt nephropathy (23 stage 3, 5 stage 4) were studied. At final evaluation, both groups maintained eGFR [(mean change) early 0.20 ± 19 pNS; overt 0.51 ± 13 mL/min pNS], whereas albuminuria/creatinuria (early -67 ± 155 p < 0.0001; overt -301 ± 596 mg/g p < 0.0001), systolic blood pressure (early -10 ± 18 p < 0.05; overt -8 ± 20 mmHg p < 0.05), and total cholesterol (early -11 ± 31 p < 0.05; overt -17 ± 38 mg/dL p < 0.05) decreased. Diastolic blood pressure, waist circumference and LDL-cholesterol were also controlled in early nephropathy patients.

Conclusions

CPGs for Prevention, Diagnosis and Treatment of CKD, by means of an educative intervention increases FP clinical competence and improves renal function in DM2 patients with CKD.

Safety and effectiveness of sucroferric oxyhydroxide in Spanish patients on dialysis: sub-analysis of the VERIFIE study

BACKGROUND AND AIMS

In this study, we show the results of the subset of Spanish patients of the VERIFIE study, the first post-marketing study assessing the long-term safety and effectiveness of sucroferric oxyhydroxide (SFOH) in patients with hyperphosphatemia undergoing dialysis during clinical practice.

PATIENTS AND METHODS

Patients undergoing hemodialysis and peritoneal dialysis with indication of SFOH treatment were included. Follow-up duration was 12-36 months after SFOH initiation. Primary safety variables were the incidence of adverse drug reactions (ADRs), medical events of special interest (MESIs), and variations in iron-related parameters. SFOH effectiveness was evaluated by the change in serum phosphorus levels.

RESULTS

A total of 286 patients were recruited and data from 282 were analyzed. Among those 282 patients, 161 (57.1%) withdrew the study prematurely and 52.5% received concomitant treatment with other phosphate binders. ADRs were observed in 35.1% of patients, the most common of which were gastrointestinal disorders (77.1%) and mild/moderate in severity (83.7%). MESIs were reported in 14.2% of patients, and 93.7% were mild/moderate. An increase in ferritin (386.66ng/mL vs 447.55ng/mL; p=0.0013) and transferrin saturation (28.07% vs 30.34%; p=0.043) was observed from baseline to the last visit (p=0.0013). Serum phosphorus levels progressively decreased from 5.69mg/dL at baseline to 4.84mg/dL at the last visit (p<0.0001), increasing by 32.2% the proportion of patients who achieved serum phosphorus levels ≤5.5mg/dL, with a mean daily SFOH dose of 1.98 pills/day.

CONCLUSIONS

SFOH showed a favorable effectiveness profile, a similar safety profile to that observed in the international study with most adverse events of mild/moderate severity, and a low daily pill burden in Spanish patients in dialysis.

Modified-release nicotinamide for the treatment of hyperphosphataemia in haemodialysis patients: 52-week efficacy and safety results of the phase III randomised controlled NOPHOS trial

BACKGROUND

We previously reported that modified-release nicotinamide (NAMR) was superior to placebo in reducing serum phosphate concentrations over 12 weeks in a large cohort of haemodialysis patients with hyperphosphataemia. Here, we report outcomes after 52 weeks of treatment.

METHODS

NOPHOS was a phase III, international, randomised, controlled, double-blind trial in parallel group design. NAMR (250-1500 mg/d) was investigated in comparison to placebo as an add-on therapy to an individual therapy with approved phosphate binders.

RESULTS

In the intention-to-treat population (NAMR: N = 539, placebo: N = 183), serum phosphate was significantly lower in the NAMR group compared to the placebo group at W24 (5.40 ± 1.55 mg/dl vs. 5.79 ± 1.37 mg/dl,  P < 0.001) with a mean difference of -0.39 mg/dl [95% CI -0.66, -0.13], but was comparable between the groups at W52 (mean difference -0.08 [95% CI -0.36, 0.20]). In the completer population (N = 358), statistical significance in favour of NAMR was reached at W24 and W52. The treatment effect was reduced in patients with high baseline serum intact parathyroid hormone (iPTH) compared to patients with low baseline serum iPTH. Compliant patients in the NAMR group had a more pronounced and sustained reduction in serum phosphate than non-compliant patients. NAMR treatment was associated with a significantly increased risk of thrombocytopenia, pruritus, anaemia, and diarrhoea. Herpes zoster occurred exclusively in patients randomised to NAMR.

CONCLUSIONS

NAMR combined with phosphate binders significantly reduced serum phosphate over the first 24 weeks of treatment, but the treatment effect was not maintained up to W52. Non-compliance may have contributed to reduced long-term efficacy. Several newly identified safety signals warrant further evaluation.

Real-World Evaluation of Calcimimetics for the Treatment of Secondary Hyperparathyroidism in Chronic Kidney Disease, in an Italian Clinical Setting

This Italian real-world data analysis evaluated the pharmaco-utilization of calcimimetics, cinacalcet or etelcalcetide, and the economic burden of secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD) patients. From 1 January 2010 to 30 June 2020, adult patients with: (i) ≥1 prescription of etelcalcetide or cinacalcet, (ii) ≥3 hemodialysis/week, and (iii) without parathyroidectomy, were included. Based on the drug firstly prescribed, patients were allocated into etelcalcetide- and cinacalcet-treated cohorts, and the propensity score matching (PSM) methodology was applied to abate potential cohorts’ unbalances. Overall, 1752 cinacalcet- and 527 etelcalcetide-treated patients were enrolled. In cinacalcet- and etelcalcetide-treated patients, respectively, the most frequent comorbidities were hypertension (75.3% and 74.4%), diabetes mellitus (21.0% and 21.3%), and cardiovascular disease (18.1% and 13.3%, p < 0.01). In covariate-balanced cohorts, the treatment adherence and persistence rates were significantly higher in the etelcalcetide-treated (80.1% and 62.7%, respectively) vs. cinacalcet-treated cohort (62.3% and 54.7%, respectively). After PSM, the total costs for the management of cinacalcet- and etelcalcetide-treated patients, respectively, averaged EUR 23,480 and EUR 22,958, with the disease-specific drug costs (EUR 2629 vs. EUR 2355, p < 0.05) and disease-specific hospitalization costs (EUR 1241 vs. EUR 855) in cinacalcet- and etelcalcetide-treated patients. These results showed that, in etelcalcetide-treated patients, a higher treatment adherence and persistence was found, with disease-specific costs savings, especially those related to drugs and hospitalizations.

Sucroferric oxyhydroxide for hyperphosphatemia: a review of real-world evidence

Hyperphosphatemia is a common complication in dialysis-dependent patients with chronic kidney disease. Most dialysis-dependent patients need oral phosphate binder therapy to control serum phosphorus concentrations. Most phosphate binders have a high daily pill burden, which may reduce treatment adherence and impair phosphorus control. Sucroferric oxyhydroxide is a potent iron-based phosphate binder approved for use in dialysis-dependent patients in 2013. A randomized controlled trial of sucroferric oxyhydroxide demonstrated its efficacy for reduction of serum phosphorus with a lower pill burden than sevelamer carbonate. Clinical trials carefully select patients, monitor adherence, and routinely titrate medications to a protocol-defined goal. Consequently, trials may not reflect real-world use of medications. Since its approval, we and others have performed retrospective and prospective analyses of sucroferric oxyhydroxide in real-world clinical practice in > 6400 hemodialysis and approximately 500 peritoneal dialysis patients in the USA and Europe. Consistent with the clinical trial data, real-world observational studies have demonstrated that sucroferric oxyhydroxide can effectively reduce serum phosphorus with a lower daily pill burden than most other phosphate binders. These studies have also shown sucroferric oxyhydroxide provides effective serum phosphorus control in different treatment settings, including as monotherapy in phosphate binder-naïve patients, in patients switching from other phosphate binders, or when used in combination with other phosphate binders. These observational studies indicate a favorable safety and tolerability profile, and minimal, if any, systemic iron absorption. This article reviews the key results from these observational studies of sucroferric oxyhydroxide and evaluates its role in the management of hyperphosphatemia in clinical practice.

Systematic Review and Meta-Analyses of the Effects of Phosphate-Lowering Agents in Nondialysis CKD

BACKGROUND

Benefits of phosphate-lowering interventions on clinical outcomes in patients with CKD are unclear; systematic reviews have predominantly involved patients on dialysis. This study aimed to summarize evidence from randomized controlled trials (RCTs) concerning benefits and risks of noncalcium-based phosphate-lowering treatment in nondialysis CKD.

METHODS

We conducted a systematic review and meta-analyses of RCTs involving noncalcium-based phosphate-lowering therapy compared with placebo, calcium-based binders, or no study medication, in adults with CKD not on dialysis or post-transplant. RCTs had ≥3 months follow-up and outcomes included biomarkers of mineral metabolism, cardiovascular parameters, and adverse events. Outcomes were meta-analyzed using the Sidik-Jonkman method for random effects. Unstandardized mean differences were used as effect sizes for continuous outcomes with common measurement units and Hedge's g standardized mean differences (SMD) otherwise. Odds ratios were used for binary outcomes. Cochrane risk of bias and GRADE assessment determined the certainty of evidence.

RESULTS

In total, 20 trials involving 2498 participants (median sample size 120, median follow-up 9 months) were eligible for inclusion. Overall, risk of bias was low. Compared with placebo, noncalcium-based phosphate binders reduced serum phosphate (12 trials, weighted mean difference -0.37; 95% CI, -0.58 to -0.15 mg/dl, low certainty evidence) and urinary phosphate excretion (eight trials, SMD -0.61; 95% CI, -0.90 to -0.31, low certainty evidence), but resulted in increased constipation (nine trials, log odds ratio [OR] 0.93; 95% CI, 0.02 to 1.83, low certainty evidence) and greater vascular calcification score (three trials, SMD, 0.47; 95% CI, 0.17 to 0.77, very low certainty evidence). Data for effects of phosphate-lowering therapy on cardiovascular events (log OR, 0.51; 95% CI, -0.51 to 1.17) and death were scant.

CONCLUSIONS

Noncalcium-based phosphate-lowering therapy reduced serum phosphate and urinary phosphate excretion, but there was an unclear effect on clinical outcomes and intermediate cardiovascular end points. Adequately powered RCTs are required to evaluate benefits and risks of phosphate-lowering therapy on patient-centered outcomes.

High ankle-brachial index predicts cardiovascular events and mortality in hemodialysis patients with severe secondary hyperparathyroidism

INTRODUCTION

Vascular calcification related to severe secondary hyperparathyroidism (SHPT) is an important cause of cardiovascular and bone complications, leading to high morbidity and mortality in patients with chronic kidney disease (CKD) undergoing hemodialysis (HD). The present study aimed to analyze whether ankle-brachial index (ABI), a non-invasive diagnostic tool, is able to predict cardiovascular outcomes in this population.

METHODS

We selected 88 adult patients on HD for at least 6 months, with serum iPTH>1,000pg/mL. We collected clinical data, biochemical and hormonal parameters, and ABI (sonar-Doppler). Calcification was assessed by lateral radiography of the abdomen and by simple vascular calcification score (SVCS). This cohort was monitored prospectively between 2012 and 2019 for cardiovascular outcomes (death, myocardial infarction (MI), stroke, and calciphylaxis) to estimate the accuracy of ABI in this setting.

RESULTS

The baseline values were: iPTH: 1770±689pg/mL, P: 5.8±1.2 mg/dL, corrected Ca: 9.7±0.8mg/dL, 25(OH)vit D: 25.1±10.9ng/mL. Sixty-five percent of patients had ABI>1.3 (ranging from 0.6 to 3.2); 66% had SVCS≥3, and 45% aortic calcification (Kauppila≥8). The prospective evaluation (51.6±24.0 months), provided the following cardiovascular outcomes: 11% of deaths, 17% of nonfatal MI, one stroke, and 3% of calciphylaxis. After adjustments, patients with ABI≥1.6 had 8.9-fold higher risk of cardiovascular events (p=0.035), and ABI≥1.8 had 12.2-fold higher risk of cardiovascular mortality (p=0.019).

CONCLUSION

The presence of vascular calcifications and arterial stiffness was highly prevalent in our population. We suggest that ABI, a simple and cost-effective diagnostic tool, could be used at an outpatient basis to predict cardiovascular events in patients with severe SHPT undergoing HD.

Chronic Kidney Disease-Mineral and Bone Disorders: Pathogenesis and Management

The key players of the chronic kidney disease-mineral and bone disorders (CKD-MBD) are calcium, phosphate, PTH, FGF23, and the vitamin D hormonal system. The progressive reduction of kidney function greatly modifies the tightly interrelated mechanisms that control these parameters. As a result, important changes occur in the bone and mineral hormonal axis, leading to changes in bone turnover with relevant consequences in clinical outcomes, such as decrease in bone mass with increased bone fragility and bone fractures and increased vascular and valvular calcification, also with great impact in the cardiovascular outcomes. So far, the knowledge of the mineral and bone disorders in CKD and the increased variety of efficacious therapies should lead to a better prevention and management of CKD-MBD.

The Interplay Between Nutrition, Metabolic, and Endocrine Disorders in Chronic Kidney Disease

The kidneys are responsible for maintaining our bodies' homeostasis through excretion, biodegradation, and synthesis of different hormones. Therefore, a decline in renal function often results in significant derangements in hormone levels. The most common metabolic and endocrine abnormalities seen in patients with chronic kidney disease include deficiencies in erythropoietin, calcitriol, triiodothyronine, testosterone, and estrogen. In addition, accumulation of hormones such as adiponectin, leptin, triglycerides, and prolactin also is seen. Subsequently, this can lead to the development of a wide range of clinical consequences including but not limited to anemia, hyperparathyroidism, insulin resistance, anorexia-cachexia, infertility, bone disorders, and cardiovascular diseases. These disorders can negatively affect the prognosis and quality of life of patients with chronic kidney disease, and, thus, early diagnosis, nutritional intervention, and pharmacologic treatment is imperative.

Efficacy and Safety of a Novel Nicotinamide Modified-Release Formulation in the Treatment of Refractory Hyperphosphatemia in Patients Receiving Hemodialysis-A Randomized Clinical Trial

INTRODUCTION

Despite widespread use of phosphate binders (PBs), phosphate control is insufficient in many hemodialysis patients. Preliminary clinical observations suggest that nicotinamide may act synergistically with PBs to improve phosphate control.

METHODS

This multinational, randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of nicotinamide modified release (NAMR) in combination with oral PB in a large cohort of hemodialysis patients with abnormal serum phosphate concentration (>4.5 mg/dl) despite treatment with PB. Patients entered a proof-of-efficacy phase (12 weeks [W12]) in which adjustments of relevant comedication were not permitted, followed by a safety extension phase for up to 52 weeks. Here, we report the results of the first phase.

RESULTS

The intention-to-treat (ITT) population consisted of 539 patients in the NAMR and 183 patients in the placebo group. NAMR and placebo were orally administered once daily (250-1500 mg/d). Mean age of patients was 61.8 years, and 63.0% were men. In the confirmatory analysis that estimated the difference in serum phosphate concentration after 12 weeks, NAMR proved superior over placebo with a significant difference of -0.51 mg/dl (95% confidence interval [CI] -0.72, -0.29; P < 0.0001). This effect was associated with significantly lower intact parathyroid hormone (iPTH) values (NAMR: 292.4±300.4 pg/ml vs. placebo: 337.0±302.7 pg/ml; P = 0.04) and an improved calcification propensity (T50 time; NAMR: 23.8±97.1 minutes vs. placebo: 2.3±100.7 minutes; P = 0.02). Diarrhea and pruritus were more frequent in the NAMR group.

CONCLUSION

NAMR combined with oral PB significantly improved phosphate control in hemodialysis patients.

Real-world safety and effectiveness of sucroferric oxyhydroxide for treatment of hyperphosphataemia in dialysis patients: a prospective observational study

Background

The iron-based phosphate binder (PB), sucroferric oxyhydroxide (SFOH), is indicated to control serum phosphorus levels in patients with chronic kidney disease on dialysis.

Methods

This non-interventional, prospective, multicentre, cohort study conducted in seven European countries evaluated the safety and effectiveness of SFOH in dialysis patients with hyperphosphataemia in routine practice. Safety outcomes included adverse drug reactions (ADRs) and changes in iron-related parameters. SFOH effectiveness was evaluated by changes-from-baseline (BL) in serum phosphorus and percentage of patients achieving in-target phosphorus levels.

Results

The safety analysis set included 1365 patients (mean observation: 420.3 ± 239.3 days). Overall, 682 (50.0%) patients discontinued the study. Mean SFOH dose during the observation period was 1172.7 ± 539.9 mg (2.3 pills/day). Overall, 617 (45.2%) patients received concomitant PB(s) during SFOH treatment. ADRs and serious ADRs were observed for 531 (38.9%) and 26 (1.9%) patients. Most frequent ADRs were diarrhoea (194 patients, 14.2%) and discoloured faeces (128 patients, 9.4%). Diarrhoea generally occurred early during SFOH treatment and was mostly mild and transient. Small increases from BL in serum ferritin were observed (ranging from +12 to +75 µg/L). SFOH treatment was associated with serum phosphorus reductions (6.3 ± 1.6 mg/dL at BL versus 5.3 ± 1.8 mg/dL at Month 30; ΔBL: −1.0 mg/dL, P < 0.01). Percentage of patients achieving serum phosphorus ≤4.5 mg/dL increased from 12.0% at BL to 34.8% at Month 30, while the percentage achieving serum phosphorus ≤5.5 mg/dL increased from 29.9% to 63.0%.

Conclusions

SFOH has a favourable safety and tolerability profile in a real-world setting, consistent with results of the Phase 3 study. Moreover, SFOH improved serum phosphorus control with a low daily pill burden.

Fibrosis in Chronic Kidney Disease: Pathogenesis and Consequences

Fibrosis is a process characterized by an excessive accumulation of the extracellular matrix as a response to different types of tissue injuries, which leads to organ dysfunction. The process can be initiated by multiple and different stimuli and pathogenic factors which trigger the cascade of reparation converging in molecular signals responsible of initiating and driving fibrosis. Though fibrosis can play a defensive role, in several circumstances at a certain stage, it can progressively become an uncontrolled irreversible and self-maintained process, named pathological fibrosis. Several systems, molecules and responses involved in the pathogenesis of the pathological fibrosis of chronic kidney disease (CKD) will be discussed in this review, putting special attention on inflammation, renin-angiotensin system (RAS), parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), Klotho, microRNAs (miRs), and the vitamin D hormonal system. All of them are key factors of the core and regulatory pathways which drive fibrosis, having a great negative kidney and cardiac impact in CKD.

Estimating hospital inpatient cost-savings with sucroferric oxyhydroxide in patients on chronic hemodialysis in five European countries: a cost analysis

AIMS

Hyperphosphatemia is common among patients with advanced chronic kidney disease (CKD) undergoing dialysis. The iron-based phosphate binder (PB), sucroferric oxyhydroxide (SO), has a low daily pill burden and is indicated for the control of serum phosphorus in these patients. In a retrospective database study, hemodialysis patients switched to long-term SO therapy had fewer hospitalizations compared with patients switched to other PB therapies. This economic analysis aimed to quantify potential cost-savings of reduced hospitalizations associated with SO for healthcare systems in five European countries.

MATERIALS AND METHODS

All-cause hospital admissions incidence data were sourced from a real-world retrospective database study comparing adult, in-center hemodialysis patients maintained on 2 years of SO therapy (mSO) versus patients who discontinued SO (dSO) within 90 days of their first prescription and switched to other PBs. A literature search was conducted to determine the cost per hospital admission for dialysis patients in the healthcare setting of each European country. A cost-model combined the incidence rate of all-cause hospital admissions and the cost per admission to estimate the country-specific inpatient costs for the mSO and dSO groups.

RESULTS

Annual inpatient cost-savings per patient in the mSO group versus the dSO group were €1,201, €2,097, €2,059, €1,512, and €3,068 in France, Germany, Italy, Spain, and the UK, respectively. When annual PB drug costs per patient were considered, the net annual economic cost-savings per patient were €327, €1,585, €1,022, €1,100, and €2,204, respectively.

LIMITATIONS

Hospital admissions data used in the analysis were observational in nature and derived from a US hemodialysis patient population; the effect of SO therapy on hospitalization rates for US and European hemodialysis patients may differ. The analysis did not consider indirect healthcare costs associated with hospitalizations.

CONCLUSION

SO therapy may offer substantial inpatient cost-savings by reducing all-cause hospital admissions attributable to uncontrolled hyperphosphatemia.

Survival with low- and high-flux dialysis

Background

Besides advances in haemodialysis (HD), mortality rates are still high. The effect of the different types of HD membranes on survival is still a controversial issue. The aim of this COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis was to survey, in HD patients, the relationship between the use of conventional low- or high-flux membranes and all-cause and cardiovascular mortality.

Methods

COSMOS is a multicentre, open-cohort, 3-year prospective study, designed to evaluate mineral and bone disorders in the European HD population. The present analysis included 5138 HD patients from 20 European countries, 3502 randomly selected at baseline (68.2%), plus 1636 new patients with <1 year on HD (31.8%) recruited to replace patients who died, were transplanted, switched to peritoneal dialysis or lost to follow-up by other reasons. Cox-regression analysis with time-dependent variables, propensity score matching and the use of an instrumental variable (facility-level analysis) were used.

Results

After adjustments using three different multivariate models, patients treated with high-flux membranes showed a lower all-cause and cardiovascular mortality risks {hazard ratio (HR) = 0.76 [95% confidence interval (CI) 0.61-0.96] and HR = 0.61 (95% CI 0.42-0.87), respectively}, that remained significant after matching by propensity score for all-cause mortality (HR = 0.69, 95% CI 0.52-0.93). However, a facility-level analysis showed no association between the case-mix-adjusted facility percentage of patients dialysed with high-flux membranes and all-cause and cardiovascular mortality.

Conclusions

High-flux dialysis was associated with a lower relative risk of all-cause and cardiovascular mortality. However, dialysis facilities using these dialysis membranes to a greater extent did not show better survival.

The real-world effectiveness of sucroferric oxyhydroxide in European hemodialysis patients: a 1-year retrospective database analysis

BACKGROUND

The iron-based phosphate binder (PB), sucroferric oxyhydroxide (SFOH), demonstrated its effectiveness for lowering serum phosphate levels, with low daily pill burden, in clinical trials of dialysis patients with hyperphosphatemia. This retrospective database analysis evaluated the real-world effectiveness of SFOH for controlling serum phosphate in European hemodialysis patients.

METHODS

De-identified patient data were extracted from a clinical database (EuCliD®) for adult hemodialysis patients from France, Italy, Portugal, Russia and Spain who were newly prescribed SFOH for up to 1 year as part of routine clinical care. Serum phosphate and pill burden were compared between baseline (3-month period before starting SFOH) and four consecutive quarterly periods of SFOH therapy (Q1-Q4; 12 months) in the overall cohort and three subgroups: PB-naïve patients treated with SFOH monotherapy (mSFOH), and PB-pretreated patients who were either switched to SFOH monotherapy (PB → mSFOH), or received SFOH in addition to another PB (PB + SFOH).

RESULTS

1096 hemodialysis patients (mean age: 60.6 years; 65.8% male) were analyzed, including 796, 188 and 53 patients in, respectively, the PB + SFOH, mSFOH, and PB → mSFOH groups. In the overall cohort, serum phosphate decreased significantly from 1.88 mmol/L at baseline to 1.77-1.69 mmol/L during Q1-Q4, and the proportion of patients achieving serum phosphate ≤1.78 mmol/L increased from 41.3% at baseline to 56.2-62.7% during SFOH treatment. Mean PB pill burden decreased from 6.3 pills/day at baseline to 5.0-5.3 pills/day during Q1-Q4. The subgroup analysis found the proportion of patients achieving serum phosphate ≤1.78 mmol/L increased significantly from baseline during SFOH treatment in the PB + SFOH group (from 38.1% up to 60.9% [Q2]) and the mSFOH group (from 49.5% up to 75.2% [Q2]), but there were no significant changes in the PB → mSFOH group. For the PB + SFOH group, serum phosphate reductions were achieved with a similar number of PB pills prescribed at baseline prior to SFOH treatment (6.5 vs 6.2 pills/day at Q4). SFOH daily pill burden was low across all 3 subgroups (2.1-2.8 pills/day).

CONCLUSION

In this real-world study of European hemodialysis patients, prescription of SFOH as monotherapy to PB-naïve patients, or in addition to existing PB therapy, was associated with significant improvements in serum phosphate control and a low daily pill burden.

Being elderly is not a contraindication of parathyroidectomy for renal hyperparathyroidism and chronic kidney disease-mineral and bone disorder

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) has more influence in the elderly. Parathyroidectomy remains the golden standard for this situation but has tended to be excluded for older patients for many reasons. This study aimed to evaluate the efficacy and safety of the surgery in the elderly population.

METHODS

156 patients were included and arranged into younger (≦65 years of age, n = 139) and elderly (>65 years of age, n = 17) groups. The change of bone mineral density (BMD) data, recovery potential {[(postoperative BMD) - (preoperative BMD)]/(preoperative BMD) ∗ 100%}, surgical successful rate and related complications were collected.

RESULTS

Both groups exhibited significant postoperative improvement on the BMD results. The recovery potential of the elderly was not lower than the younger group. High success rate and none of persistent vocal palsy, hypocalcemia or any sequela were also observed in the elderly.

CONCLUSIONS

Parathyroidectomy is an effective and safe intervention for the CKD-MBD in the elderly.

Characteristics of Patients Who Achieve Serum Phosphorus Control on Sucroferric Oxyhydroxide or Sevelamer Carbonate: A post hoc Analysis of a Phase 3 Study

INTRODUCTION

Control of hyperphosphatemia in patients on dialysis remains a major challenge.

OBJECTIVE

This study evaluated predictors of serum phosphorus (sP) control among dialysis patients treated with noncalcium, oral phosphate binder therapy in a phase 3 clinical trial.

METHODS

Post hoc analyses were performed using data for patients with hyperphosphatemia who received 52 weeks of treatment with sucroferric oxyhydroxide (SFOH) or sevelamer carbonate (sevelamer). Patients were categorized into those who achieved sP control (n = 302; defined as sP ≤ 5.5 mg/dL at week 52), and those with uncontrolled sP (n = 195; sP >5.5 mg/dL at week 52). Because SFOH and sevelamer have previously demonstrated similar effects on chronic kidney disease-mineral-bone disorder parameters in this study, the treatment groups were pooled.

RESULTS

Average age at baseline was higher among sP-controlled versus sP-uncontrolled patients (56.9 vs. 53.4 years; p = 0.005). Baseline sP levels were significantly lower among sP-controlled versus sP-uncontrolled patients (7.30 vs. 7.85 mg/dL; p < 0.001), and sP reductions from baseline were significantly greater in the sP-controlled group (-2.89 vs. -0.99 mg/dL at week 52; p < 0.001). Logistic regression analysis identified higher baseline sP levels (odds ratio [OR] = 0.86, 95% confidence interval [CI]: 0.765-0.960), no concomitant active vitamin D therapy use (OR = 0.51, 95% CI: 0.328-0.804), and higher body mass index at baseline (OR = 0.96, 95% CI: 0.937-0.992) as significant predictors of uncontrolled sP.

CONCLUSION

This analysis indicates that sP control may be more challenging in younger patients with high sP levels. Closer monitoring and management of serum phosphorus levels may be required in this population.

Changes in clinical indicators related to the transition from dialysis to kidney transplantation-data from the ERA-EDTA Registry

Background

Kidney transplantation should improve abnormalities that are common during dialysis treatment, like anaemia and mineral and bone disorder. However, its impact is incompletely understood. We therefore aimed to assess changes in clinical indicators after the transition from chronic dialysis to kidney transplantation.

Methods

We used European Renal Association–European Dialysis and Transplant Association Registry data and included adult dialysis patients for whom data on clinical indicators before and after transplantation (2005–15) were available. Linear mixed models were used to quantify the effect of transplantation and of time after transplantation for each indicator.

Results

In total, 16 312 patients were included. The mean age at transplantation was 50.1 (standard deviation 14.2) years, 62.9% were male and 70.2% were on haemodialysis before transplantation. Total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol and triglycerides increased right after transplantation but decreased thereafter. All other indicators normalized or approached the target range soon after transplantation and these improvements were sustained for the first 4 years of follow-up. In patients with higher estimated glomerular filtration rate (eGFR) levels (30–60 and >60 mL/min/1.73 m²), the improvement of haemoglobin, ferritin, ionized calcium, phosphate, parathyroid hormone, HDL cholesterol, triglycerides, albumin and C-reactive protein levels was more pronounced than in patients with a lower eGFR (<30 mL/min/1.73 m²).

Conclusions

Except for total cholesterol, LDL cholesterol and triglycerides, all clinical indicators improved after transplantation. These improvements were related to eGFR. Nevertheless, values remained out of range in a considerable proportion of patients and anaemia and hyperparathyroidism were still common problems. Further research is needed to understand the complex relationship between eGFR and the different clinical indicators.

Serum phosphate optimal timing and range associated with patients survival in haemodialysis: the COSMOS study

BACKGROUND

Serum phosphate is a key parameter in the management of chronic kidney disease-mineral and bone disorder (CKD-MBD). The timing of phosphate measurement is not standardized in the current guidelines. Since the optimal range of these biomarkers may vary depending on the duration of the interdialytic interval, in this analysis of the Current management of secondary hyperparathyroidism: a multicentre observational study (COSMOS), we assessed the influence of a 2- (midweek) or 3-day (post-weekend) dialysis interval for blood withdrawal on serum levels of CKD-MBD biomarkers and their association with mortality risk.

METHODS

The COSMOS cohort (6797 patients, CKD Stage 5D) was divided into two groups depending upon midweek or post-weekend blood collection. Univariate and multivariate Cox's models adjusted hazard ratios (HRs) by demographics and comorbidities, treatments and biochemical parameters from a patient/centre database collected at baseline and every 6 months for 3 years.

RESULTS

There were no differences in serum calcium or parathyroid hormone levels between midweek and post-weekend patients. However, in post-weekend patients, the mean serum phosphate levels were higher compared with midweek patients (5.5 ± 1.4 versus 5.2 ± 1.4 mg/dL, P < 0.001). Also, the range of serum phosphate with the lowest mortality risk [HR ≤ 1.1; midweek: 3.5-4.9 mg/dL (95% confidence interval, CI: 2.9-5.2 mg/dL); post-weekend: 3.8-5.7 mg/dL (95% CI: 3.0-6.4 mg/dL)] showed significant differences in the upper limit (P = 0.021).

CONCLUSION

Midweek and post-weekend serum phosphate levels and their target ranges associated with the lowest mortality risk differ. Thus, clinical guidelines should consider the timing of blood withdrawal when recommending optimal target ranges for serum phosphate and therapeutic strategies for phosphate control.

New scenarios in secondary hyperparathyroidism: etelcalcetide. Position paper of working group on CKD-MBD of the Italian Society of Nephrology

Bone mineral abnormalities (defined as Chronic Kidney Disease Mineral Bone Disorder; CKD-MBD) are prevalent and associated with a substantial risk burden and poor prognosis in CKD population. Several lines of evidence support the notion that a large proportion of patients receiving maintenance dialysis experience a suboptimal biochemical control of CKD-MBD. Although no study has ever demonstrated conclusively that CKD-MBD control is associated with improved survival, an expanding therapeutic armamentarium is available to correct bone mineral abnormalities. In this position paper of Lombardy Nephrologists, a summary of the state of art of CKD-MBD as well as a summary of the unmet clinical needs will be provided. Furthermore, this position paper will focus on the potential and drawbacks of a new injectable calcimimetic, etelcalcetide, a drug available in Italy since few months ago.

Bone and mineral metabolism at 55 haemodialysis centres in Lima

BACKGROUND

Mineral and bone metabolism disorders are common complications in haemodialysis patients that present significant geographical variability.

OBJECTIVES

The objective of this study was to assess these disorders for the first time in haemodialysis patients from Peru.

METHODS

The study included 1551 haemodialysis patients from 55 centres affiliated with the Social Health System of Peru in the city of Lima. Demographic data, comorbidities, treatments and biochemical parameters were collected from each patient. Serum calcium, phosphorus and PTH levels were categorised according to the recommended ranges in the KDOQI and KDIGO guidelines.

RESULTS

The mean age of the patients was 59.5±15.6 years, with a mean time on haemodialysis of 58.0±54.2 months. All patients were dialysed with a calcium concentration in the dialysis fluid of 3.5 mEq/l and 68.9% of patients were prescribed phosphate-binding agents (98.4% of them calcium carbonate). A high percentage of patients showed serum calcium above, and serum phosphorus below, the recommended ranges in the KDOQI guidelines (32.8% and 37.3%, respectively). More than half of the patients had serum PTH values below the recommended ranges of both the KDOQI and KDIGO guidelines (56.4% and 51.6%, respectively).

CONCLUSIONS

Patients included in this study were younger than those from other studies and showed both hypophosphataemia and suppressed PTH, probably due to an excessive calcium overload through dialysis fluid and the use of calcium-containing phosphate binding agents.

Detecting high-risk chronic kidney disease-mineral bone disorder phenotypes among patients on dialysis: a historical cohort study

BACKGROUND

The clinical management of chronic kidney disease-mineral bone disorder (CKD-MBD) remains extremely challenging, partially due to difficulties in defining high-risk phenotypes based on serum biomarkers. We evaluated the prevalence and outcomes of 27 mutually exclusive CKD-MBD phenotypes in a large, multi-national cohort of chronic dialysis patients over a 5-year follow-up study.

METHODS

In this historical cohort study, we enrolled all haemodialysis patients registered in EuCliD® on 1 July 2011 across 28 Europe, the Middle East and Africa (EMEA) and South American countries. We created 27 mutually exclusive phenotypes based on combinations of serum parathyroid hormone (PTH), phosphorus (P) and calcium (Ca) 6-month averages (L, low; T, target; H, high). We tested the association between CKD-MBD phenotypes and 5-year mortality and hospitalization risk by outcome risk score-adjusted proportional hazard regression.

RESULTS

We enrolled 35 721 eligible patients. Eastern European and South American countries generally achieved poorer CKD-MBD control when compared with Western European countries (prevalence ratio: 0.79; P < 0.001). There were 15 795 deaths [126.7 deaths/1000 person-years; 95% confidence interval (CI) 124.7-128.7]; 18 014 had at least one hospitalization (203.9 hospitalizations/1000 person-years; 95% CI 201.0-206.9); the incidence of the composite endpoint was 280.0 events/1000 person-years (95% CI 276.6-283.5). In the fully adjusted model, relative mortality risk ranged from hazard ratio (HR) = 1.07 (PTH/Ca/P: TLT) to HR = 1.59 (PTH/Ca/P: LTL), whereas the relative composite endpoint risk ranged from HR = 1.07 (PTH/Ca/P: TTH) to HR = 1.36 (PTH/Ca/P: LTL).

CONCLUSION

We identified several CKD-MBD phenotypes associated with reduced hospitalization-free survival and increased mortality. Ranking of relative risk estimates or excess events concurs in informing healthcare priority setting.

Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? Rationale and protocol for the IMpact of Phosphate Reduction On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study

INTRODUCTION

Patients with chronic kidney disease (CKD) are at heightened cardiovascular risk, which has been associated with abnormalities of bone and mineral metabolism. A deeper understanding of these abnormalities should facilitate improved treatment strategies and patient-level outcomes, but at present there are few large, randomised controlled clinical trials to guide management. Positive associations between serum phosphate and fibroblast growth factor 23 (FGF-23) and cardiovascular morbidity and mortality in both the general and CKD populations have resulted in clinical guidelines suggesting that serum phosphate be targeted towards the normal range, although few randomised and placebo-controlled studies have addressed clinical outcomes using interventions to improve phosphate control. Early preventive measures to reduce the development and progression of vascular calcification, left ventricular hypertrophy and arterial stiffness are crucial in patients with CKD.

METHODS AND ANALYSIS

We outline the rationale and protocol for an international, multicentre, randomised parallel-group trial assessing the impact of the non-calcium-based phosphate binder, lanthanum carbonate, compared with placebo on surrogate markers of cardiovascular disease in a predialysis CKD population-the IM pact of P hosphate R eduction O n V ascular E nd-points (IMPROVE)-CKD study. The primary objective of the IMPROVE-CKD study is to determine if the use of lanthanum carbonate reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when compared with placebo. The primary end-point of the study is change in arterial compliance measured by pulse wave velocity over a 96-week period. Secondary outcomes include change in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone and FGF-23 levels.

ETHICS AND DISSEMINATION

Ethical approval for the IMPROVE-CKD trial was obtained by each local Institutional Ethics Committee for all 17 participating sites in Australia, New Zealand and Malaysia prior to study commencement. Results of this clinical trial will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

ACTRN12610000650099.

[Short-term effects with sucroferric oxyhydroxide in hemodialysis patients: Experience in NephroCare France]

INTRODUCTION

Despite a better management of hyperphosphatemia in haemodialysis patients observed during the past years, most of them remain insufficiently treated and exposed to bone and cardiovascular complications that are associated with this biological abnormality. The availability of calcium-free phosphate binders among therapeutical options is confirmed to significantly reduce serum phosphate levels without the risk of excess exposure to calcium. Currently sucroferric oxyhydroxyde (SO) is the only iron-based phosphate binder available in France.

METHODS

A cohort of patients prescribed OHS has been extracted from the EUCLID 5 database between June 2016 and December 2017. The effects on bone mineral metabolism and ferritin have been retrospectively studied.

RESULTS

Two hundred and sixty-two patients with OHS prescription have been identified. The OHS treatment duration median was 4.3 months (1.84-10.99). The average midweek phosphatemia decreased significantly after OHS prescription (from 1.99 to 1.83 mmol/L ; P<0.0001) with a significant increase of the proportion of patients (12.1 to 25.7% ; P<0.0001) reaching the phosphate target of 1.5 mmol/L, without significant change in calcemia and PTH. Ferritinemia significantly increased from 362 to 427 μg/L in 3 months (P=0.0049). OHS therapy has been stopped and replaced in 18% of the cases.

DISCUSSION

Among the NephroCare cohort, OHS therapy was efficient to decrease phosphatemia and to increase significantly the proportion of patients in target. There were no short term changes in calcemia and PTH. The slight increase in ferritin confirms the findings of the phase III study and its extension. The effects on the pills count and the OHS side-effects are analyzed from literature. The risk of iron overload and the impact on the anemia management including EPO sparing are currently under study.

CONCLUSION

OHS therapy appears to be a new efficient alternative to non-calcium phosphate binders. A better knowledge of its side effects will help the patients and the physician to optimize the phosphate balance management. The slight increase in ferritin can be considered as an epiphenomenon because of the important iron needs and frequent check of this parameter in the anemia management.

Assessing the effect of oral activated vitamin D on overall survival in hemodialysis patients: a landmark analysis

BACKGROUND

Patients with end stage renal disease have a high all-cause and cardiovascular mortality. Secondary hyperparathyroidism and vitamin D deficiency are considered part of the mechanism for the excess mortality observed. We aimed to evaluate the relationship between vitamin D use and all-cause mortality.

METHODS

In this retrospective cohort study, we included all incident patients who started hemodialysis in Taiwan between 2001 and 2009. Patients were followed from landmark time, i.e., the 360th day from hemodialysis initiation, through the end of 2010 or death. We evaluated the association between activated vitamin D use or not before landmark time and all-cause mortality using conditional landmark analysis with Cox regression. We used group-based trajectory model to categorize high-dose versus average-dose users to evaluate dose-response relationships.

RESULTS

During the median follow-up of 1019 days from landmark time, vitamin D users had a lower crude mortality rate than non-users (8.98 versus 12.93 per 100 person-years). Compared with non-users, vitamin D users was associated with a lower risk of death in multivariate Cox model (HR 0.91 [95% CI, 0.87-0.95]) and after propensity score matching (HR 0.94 [95% CI, 0.90-0.98]). High-dose vitamin D users had a lower risk of death than conventional-dose users, HR 0.75 [95% CI, 0.63-0.89]. The association of vitamin D treatment with reduced mortality did not alter when we re-defined landmark time as the 180th day or repeated analyses in patients who underwent hemodialysis in the hospital setting.

CONCLUSIONS

Our findings supported the survival benefits of activated vitamin D among incident hemodialysis patients.

Targeting Gastrointestinal Transport Proteins to Control Hyperphosphatemia in Chronic Kidney Disease

Management of hyperphosphatemia in patients with dialysis-dependent chronic kidney disease remains a major challenge, requiring a multifaceted approach that includes dietary phosphate restriction, dialysis, and phosphate binders. However, these treatments fail to meet serum phosphate targets in many patients, potentially further exacerbating the significant morbidity and mortality burden associated with the disease. Recent advances in our understanding of the mechanisms underlying phosphate homeostasis have shed new light on the issue and suggest that gastrointestinal transport proteins may be promising targets for new hyperphosphatemia treatments. Drugs that inhibit or downregulate these transport proteins, and thus reduce phosphate uptake from the gut, may overcome some of the limitations of existing phosphate-lowering strategies, such as interdialytic rises in serum phosphate levels, poor adherence to dietary and phosphate-binder regimens, and maladaptive responses that can increase gastrointestinal phosphate absorption. Here, we review the latest preclinical and clinical data for two candidates in this novel drug class: tenapanor, a small-molecule inhibitor of the sodium/hydrogen ion-exchanger isoform 3, and nicotinamide, an inhibitor of sodium-phosphate-2b cotransporters. We also discuss how potential synergies in their mechanisms of action suggest that coadministering phosphate binders with sodium-phosphate-2b cotransporter inhibitors may yield additive benefits over traditional phosphate-binder therapy.

Summary of the 2018 ISN Frontiers Meeting: Kidney Disease and Cardiovascular Disease

International Society of Nephrology (ISN) Frontiers meetings build on the success of the ISN Nexus and Forefronts series by bringing together basic scientists, clinicians, and practitioners in a unique setting. This new event was organized to make more innovative science available to a global audience by removing regional barriers in accessing the latest knowledge. The first ISN Frontiers meeting was organized in partnership between the Japanese Society of Nephrology and the Japanese Society for Dialysis Therapy, which was held in Tokyo in February 2018. The meeting focused on the topic “Kidney Disease & Cardiovascular Disease,” which covered a broad range of scientific and clinical fields, including nephrology, cardiovascular diseases, dialysis, transplantation, chronic kidney disease (CKD)–mineral bone disease (MBD), diabetes, pediatric nephrology, nutrition, pharmacology, and nursing. A total of 1584 active physicians and scientists from 64 countries attended the meeting, and a number of leading physician scientists from different and related disciplines of clinical and basic research described and reviewed recent discoveries. This report summarizes the main highlights of the meeting lectures.

Risk of hospitalization associated with body mass index and weight changes among prevalent haemodialysis patients

The impact of body mass index (BMI) and body weight on hospitalization rates in haemodialysis patients is unknown. This study hypothesizes that being either underweight or obese is associated with a higher hospitalization rate. Observational study of 6296 European haemodialysis patients with prospective data collection and follow-up every six months for three years (COSMOS study). The risk of being hospitalized was estimated by a time-dependent Cox regression model and the annual risk (incidence rate ratios, IRR) by Poisson regression. We considered weight loss, weight gain and stable weight. Weight change analyses were also performed after patient stratification according to their baseline BMI. A total of 3096 patients were hospitalized at least once with 9731 hospitalizations in total. The hospitalization incidence (fully adjusted IRR 1.28, 95% CI [1.18-1.39]) was higher among underweight patients (BMI <20kg/m²) than patients of normal weight (BMI 20-25kg/m²), while the incidence of overweight (0.88 [0.83-0.93]) and obese patients (≥30kg/m², 0.85 [0.79-0.92]) was lower. Weight gain was associated with a reduced risk of hospitalization. Conversely, weight loss was associated with a higher hospitalization rate, particularly in underweight patients (IRR 2.85 [2.33-3.47]). Underweight haemodialysis patients were at increased risk of hospitalization, while overweight and obese patients were less likely to be hospitalized. Short-term weight loss in underweight individuals was associated with a strikingly high hospitalization rate.

Evaluation of prevalence, biochemical profile, and drugs associated with chronic kidney disease-mineral and bone disorder in 11 dialysis centers

Introduction:

The diagnosis and treatment of mineral and bone disorder of chronic kidney disease (CKD-MBD) is a challenge for nephrologists and health managers. The aim of this study was to evaluate the prevalence, biochemical profile, and drugs associated with CKD-MBD.

Methods:

Cross-sectional study between July and November 2013, with 1134 patients on dialysis. Sociodemographic, clinical, and laboratory data were compared between groups based on levels of intact parathyroid hormone (iPTH) (< 150, 150-300, 301-600, 601-1000, and > 1001 pg/mL).

Results:

The mean age was 57.3 ± 14.4 years. The prevalence of iPTH < 150 pg/mL was 23.4% and iPTH > 601 pg/mL was 27.1%. The comparison between the groups showed that the level of iPTH decreased with increasing age. Diabetic patients had a higher prevalence of iPTH < 150 pg/mL (27.6%). Hyperphosphatemia (> 5.5 mg/dL) was observed in 35.8%. Calcium carbonate was used by 50.5%, sevelamer by 14.7%, 40% of patients had used some form of vitamin D and 3.5% used cinacalcet. Linear regression analysis showed a significant negative association between iPTH, age, and diabetes mellitus and a significant positive association between iPTH and dialysis time.

Conclusion:

The prevalence of patients outside the target for iPTH was 50.5%. There was a high prevalence of hyperphosphatemia (35.8%), and the minority of patients were using active vitamin D, vitamin D analogs, selective vitamin D receptor activators, and cinacalcet. These data indicate the need for better compliance with clinical guidelines and public policies on the supply of drugs associated with CKD-MBD.

Cost-effectiveness of dedicated dietitians for hyperphosphatemia management among hemodialysis patients in Lebanon: results from the Nutrition Education for Management of Osteodystrophy trial

AIM

To assess the cost-effectiveness of nutrition education by dedicated dietitians (DD) for hyperphosphatemia management among hemodialysis patients.

MATERIALS AND METHODS

This was a trial-based economic evaluation in 12 Lebanese hospital-based units. In total, 545 prevalent patients were cluster randomized to DD, trained hospital dietitian (THD), and existing practice (EP) groups. During Phase I (6 months), DD (n = 116) received intensive education by DD trained on renal nutrition, THD (n = 299) received care from trained hospital dietitians, and EP (n = 130) received usual care from untrained hospital dietitians. Patients were followed-up during Phase II (6 months).

RESULTS

At baseline, EP had the lowest weekly hemodialysis time, and DD had the highest serum phosphorus and malnutrition-inflammation score. The additional costs of the intervention were low compared with the societal costs (DD: $76.7, $21,007.7; EP: $4.6, $18,675.4; THD: $17.4, $20,078.6, respectively). Between Phases I and II, DD showed the greatest decline in services use and societal costs (DD: -$2,364.0; EP: -$1,727.7; THD: -$1,105.7). At endline, DD experienced the highest decrease in adjusted serum phosphorus (DD: -0.32; EP: +0.16; THD: +0.04 mg/dL), no difference in quality-adjusted life-years (QALY), and the highest societal costs. DD had a cost-effectiveness ratio of $7,853.6 per 1 mg decrease in phosphorus, compared with EP; and was dominated by THD. Regarding QALY, DD was dominated by EP and THD. The results were sensitive to changes in key parameters.

LIMITATIONS

The analysis depended on numerous assumptions. Interpreting the results is limited by the significant baseline differences in key parameters, suggestive of higher baseline societal costs in DD.

CONCLUSIONS

DD yielded the greatest effectiveness and decrease in societal costs, but did not affect QALY. Regarding serum phosphorus, DD was likely to be cost-effective compared with EP, but had a low cost-effectiveness probability compared with THD. Regarding QALY, DD was not likely to be cost-effective. Assessing the long-term cost-effectiveness of DD, on similar groups, is recommended.

Correlation of lanthanum dosage with lanthanum deposition in the gastroduodenal mucosa of dialysis patients

Lanthanum (La) deposition has been observed in gastrointestinal mucosa of dialysis patients treated with La carbonate to treat hyperphosphatemia in the 6 years since its authorization in Japan. We investigated gastrointestinal biopsies from 112 dialysis patients, and found 15 cases of histiocytic aggregation with crystalloids and one case of duodenitis with histiocyte aggregation without crystalloids in the 30 patients treated with La carbonate. No histiocytic lesions were observed in the 82 patients without La carbonate administration. So far in total 70 cases of La deposition in the alimentary tract have been reported, including our 16 cases. Neither clinical nor histological findings other than histiocytic aggregation were specific in the patients with La deposition. We also compared the groups with and without La deposition, revealing that the daily and total doses of La carbonate showed statistically significant correlations with La deposition. However the causality with their histologic features, e.g. intestinal metaplasia and degree of inflammation, were inconclusive between the two groups. Although no critical symptoms have been reported, it is necessary to accumulate more cases to clarify the mechanism of La deposition, because dialysis patients must take phosphate buffers for a long period.

Trajectories of CKD-MBD biochemical parameters over a 2-year period following diagnosis of secondary hyperparathyroidism: a pharmacoepidemiological study

OBJECTIVES

To define groups of patients according to the changes of biochemical parameters, that is, serum calcium, phosphate and parathyroid hormone (PTH), over a 2-year follow-up period using group-based multi-trajectory modeling (GBMM) among a cohort of dialysis patients with newly diagnosed secondary hyperparathyroidism (SHPT) (ie, PTH≥500 ng/L for the first time) and to compare their patient characteristics and treatments.

DESIGN

Pharmacoepidemiological study.

SETTING

In the 12 dialysis units located in the French region of Lorraine.

PARTICIPANTS

A total of 269 dialysis patients with newly diagnosed SHPT were prospectively included from December 2009 to May 2012 and followed-up for 2 years.

RESULTS

We identified four distinct trajectory groups: 'rapid PTH drop' experiencing a rapid and sharp decrease (over weeks) in PTH level associated with decreasing phosphate level within normal range (n=34; 12.7%), 'gradual PTH decrease' experiencing a gradual and continuous decrease (over months) in PTH level and maintaining phosphate at a middle level throughout the study (n=98; 36.4%), 'slow PTH decrease with high phosphate' experiencing a slow decrease in PTH level associated with a relatively high phosphate level (n=105; 39.0%) and 'uncontrolled SHPT' with high levels of PTH and phosphate throughout the study (n=32; 11.9%). Patients in the 'uncontrolled SHPT' group were significantly (p<0.00001) younger than patients in other groups. Kidney Disease Improving Global Outcomes (KDIGO) targets for PTH, phosphate and calcium were reached simultaneously for 14.9% of patients at baseline and 16.7% at the end of the study. Patients were given cinacalcet more frequently at months 3 and 6 in the 'rapid PTH drop' and at month 24 in the 'uncontrolled SHPT' groups.

CONCLUSIONS

Over 2 years following a new SHPT diagnosis, a younger age and a higher rate of alkaline phosphatase were associated to a continuous uncontrolled SHPT. Patients with the lowest PTH at the end of the follow-up tended to receive more often cinacalcet.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov number, NCT02888639, post results.

Elemental calcium intake associated with calcium acetate/calcium carbonate in the treatment of hyperphosphatemia

Background

Calcium-based and non-calcium-based phosphate binders have similar efficacy in the treatment of hyperphosphatemia; however, calcium-based binders may be associated with hypercalcemia, vascular calcification, and adynamic bone disease.

Scope

A post hoc analysis was carried out of data from a 16-week, Phase IV study of patients with end-stage renal disease (ESRD) who switched to lanthanum carbonate monotherapy from baseline calcium acetate/calcium carbonate monotherapy. Of the intent-to-treat population (N=2520), 752 patients with recorded dose data for calcium acetate (n=551)/calcium carbonate (n=201) at baseline and lanthanum carbonate at week 16 were studied. Elemental calcium intake, serum phosphate, corrected serum calcium, and serum intact parathyroid hormone levels were analyzed.

Findings

Of the 551 patients with calcium acetate dose data, 271 (49.2%) had an elemental calcium intake of at least 1.5 g/day at baseline, and 142 (25.8%) had an intake of at least 2.0 g/day. Mean (95% confidence interval [CI]) serum phosphate levels were 6.1 (5.89, 6.21) mg/dL at baseline and 6.2 (6.04, 6.38) mg/dL at 16 weeks; mean (95% CI) corrected serum calcium levels were 9.3 (9.16, 9.44) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively. Of the 201 patients with calcium carbonate dose data, 117 (58.2%) had an elemental calcium intake of at least 1.5 g/day, and 76 (37.8%) had an intake of at least 2.0 g/day. Mean (95% CI) serum phosphate levels were 5.8 (5.52, 6.06) mg/dL at baseline and 5.8 (5.53, 6.05) mg/dL at week 16; mean (95% CI) corrected serum calcium levels were 9.7 (9.15, 10.25) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively.

Conclusion

Calcium acetate/calcium carbonate phosphate binders, taken to control serum phosphate levels, may result in high levels of elemental calcium intake. This may lead to complications related to calcium balance.

Safety and efficacy of denosumab in osteoporotic hemodialysed patients

BACKGROUND AND AIMS

In elderly subjects, renal insufficiency and osteoporosis often coexist with high risk of fracture and elevated socio-economic burden. Today a large number of effective anti-osteoporotic drugs are available but generally they are contraindicated in patients with chronic kidney disease (CKD) because of their progressive accumulation. Denosumab, instead, does not require dose adjustments for different degrees of renal impairment so it can be a valid treatment in osteoporotic patients with CKD. Limited data are available in the literature concerning the use of denosumab in hemodialysis (HD). The aim of our study was, therefore, to study the efficacy and tolerability of this drug in this particular subset of patients.

METHODS

We retrospectively reviewed the charts of 12 osteoporotic HD patients who received a single 60-mg subcutaneous dose of denosumab every 6 months for an observation period of 24 months. Serum electrolyte, markers of bone turnover and quantitative ultrasound (QUS) were evaluated.

RESULTS

Over 24 months, we observed a gradual improvement of bone metabolism: β-CrossLaps from 2567.08 ± 1264 to 1492.5 ± 1182.5 pg/ml; bone alkaline phosphatase (BALP) from 33.5 ± 28.8 to 11.8 ± 3.7 mcg/l, and of QUS index (T-score from -5.33 ± 1.58 to -4.84 ± 1.2; risk of fracture from 13.9 ± 4.7 to 11.07 ± 5.3 %). Few cases of hypocalcemia were detected, more significant after the first and second injection, but with careful monitoring of serum calcium and rapid therapy adjustment we could easily manage serum Ca levels.

CONCLUSIONS

Our pilot experience highlights the safety and efficacy of denosumab in the treatment of osteoporosis in HD patients, potentially supporting its use to reduce the burden of fractures in this patient population.

Association between Hemodialysis Patient Outcomes and Compliance with KDOQI and KDIGO Targets for Mineral and Bone Metabolism

BACKGROUND

Increased mortality of hemodialysis (HD) patients is associated with chronic kidney disease-mineral and bone disorders (CKD-MBD), and therefore, their correction may improve patient survival. Differences in targets recommended by KDOQI and KDIGO CKD-MBD guidelines directed us to compare the relative numbers of patients achieving these targets and to examine possible associations between compliance with the targets and patient outcome.

METHODS

A total of 1,744 patients (61.2% males, aged 58.7 ± 12.5 years) dialyzed in 20 HD centers in Serbia were monitored for 3 years. The number of participants achieving KDOQI/KDIGO guideline targets for serum phosphorus, calcium, and iPTH was determined. The Cox proportional hazards model was used to select variables significantly associated with risk of time to death.

RESULTS

A majority of patients were dialyzed thrice weekly for 4 h; 86.3% of them used phosphate binders and 49.3% vitamin D3. Proportions of patients achieving KDOQI and KDIGO targets were 49.5 and 44.4% for phosphorus, 53.2 and 76.7% for calcium, 21 and 42.8% for iPTH. Multivariate Cox analysis selected serum phosphorus level outside the KDIGO target, as well as serum iPTH levels outside KDOQI and KDIGO targets as significant mortality predictors. Areas under the receiver operating characteristic curves showed that achievement of both guideline targets for iPTH had similar survival predictive values.

CONCLUSION

Serum phosphorus levels outside KDIGO targets and iPTH levels outside both KDOQI and KDIGO targets were associated with a significantly higher risk of death. These findings may be useful in the management of CKD-MBD and for establishing local guidelines.

Effect of parathyroid hormone on serum magnesium levels: the neglected relationship in hemodialysis patients with secondary hyperparathyroidism

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is an important complication in patients with end-stage renal disease. Since recent studies have shown that magnesium (Mg) disturbance plays an important role in CKD-MBD and cardiovascular mortality, the interest on magnesium has grown recently. Although much concern focused on the effect of Mg on parathyroid hormone (PTH) levels, however, the influence of PTH on serum Mg levels is nearly unexplored. To evaluate the effect of PTH on serum Mg levels, we first described the relationship between serum Mg and PTH in secondary hyperparathyroidism. Besides, we also monitored the changes of serum Mg concentration after parathyroidectomy (PTX) in 23 patients. In our study, we found that hypermagnesemia (>2.5 mg/dL) occurred in up to 44% of cases and hypomagnesemia did not present. No statistically significant correlations were found between serum Mg levels and PTH (r = -0.143, p = 0.134). Correlation analysis and regression analysis suggested that the derangement of magnesium homeostasis was consistent with the derangement of calcium/phosphorus homeostasis. However, after PTX, serum magnesium levels dropped immediately after the surgery, minimally at the first day and gradually restored from the third day. The changes of serum Mg after surgery was positive correlated with the changes of serum phosphate (r = 0.558, p = 0.003). Taken altogether, our data suggested that the therapeutic strategies to achieve optimum serum magnesium levels in CKD-MBD should take into account the varying stages of disease development since PTH could also influence magnesium metabolism and this problem might be important in severe secondary hyperparathyroidism.