Sevelamer carbonate in the treatment of hyperphosphatemia in patients with chronic kidney disease on hemodialysis

Surgical Aortic Valve Replacement and Renal Dysfunction: From Acute Kidney Injury to Chronic Disease

Background: Surgical aortic valve replacement (SAVR) is often complicated by acute kidney injury (AKI). Identifying patients at risk of AKI is important to start nephroprotective strategies or renal replacement therapy (RRT). This study investigated the incidence and risk factors of post-operative AKI in SAVR patients. Chronic kidney disease (CKD) developed in the post-cardiac-surgery follow-up period was also assessed. Methods: A total of 462 SAVR patients were retrospectively enrolled. The primary endpoint was the occurrence rate of AKI after surgery. Kidney recovery, during two planned outpatient clinic nephrological visits within 12 months after the surgery, was assessed. Results: A total of 76 patients experienced an AKI event. A Kaplan-Meier analysis revealed that subjects with CKD stage IV had a time to progression of 2.7 days, compared to patients with stages I-II, who were characterized by the slowest progression time, >11.2 days. A Cox regression indicated that CKD stages predicted a higher risk of AKI independently of other variables. During their ICU stay, 23 patients died, representing 5% of the population, most of them requiring RRT during their ICU stay. A severe CKD before the surgery was closely related to perioperative mortality. During the follow-up period, 21 patients with AKI worsened their CKD stage. Conclusions: AKI represents a common complication for SAVR patients in the early post-operative period, prolonging their ICU stay, with negative effects on survival, especially if RRT was required. Pre-operative CKD >3 stage is an independent risk factor for AKI in patients undergoing SAVR.

Novel Therapeutic Approaches in the Management of Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive and incurable disease that impairs kidney function. Its prevalence is estimated to affect up to 800 million individuals within the general population, and patients with diabetes and hypertension are particularly at risk. This disorder disrupts the physiological mechanisms of the body, including water and electrolyte balance, blood pressure regulation, the excretion of toxins, and vitamin D metabolism. Consequently, patients are exposed to risks such as hyperkalemia, hyperphosphatemia, metabolic acidosis, and blood pressure abnormalities. These risks can be reduced by implementing appropriate diagnostic methods, followed by non-pharmacological (such as physical activity, dietary, and lifestyle adjustment) and pharmacological strategies after diagnosis. Selecting the appropriate diet and suitable pharmacological treatment is imperative in maintaining kidney function as long as possible. Drugs such as finerenone, canakinumab, and pentoxifylline hold promise for improved outcomes among CKD patients. When these interventions prove insufficient, renal replacement therapy becomes essential. This is particularly critical in preserving residual renal function while awaiting renal transplantation or for patients deemed ineligible for such a procedure. The aim of this study is to present the current state of knowledge and recent advances, providing novel insights into the treatment of chronic kidney disease.

The Impact of Volume Overload on the Longitudinal Change of Adipose and Lean Tissue Mass in Incident Chinese Peritoneal Dialysis Patients

Patients treated with peritoneal dialysis (PD) experience complex body composition changes that are not adequately reflected by traditional anthropometric parameters. While lean and adipose tissue mass can be readily assessed by bioimpedance spectroscopy (BIS), there is concern about the potential confounding effect of volume overload on these measurements. This study aimed to assess the influence of fluid status (by echocardiography) on body composition parameters measured by BIS and to describe the longitudinal changes in adipose and lean tissue mass. We conducted a prospective observational study in a tertiary hospital. Incident Chinese PD patients underwent baseline echocardiography and repeated BIS measurements at baseline and 12 months later. Among 101 PD patients, lean tissue index (LTI) or fat tissue index (FTI) was not associated with echocardiographic parameters that reflected left ventricular filling pressure (surrogate of volume status). Sixty-eight patients with repeated BIS had a significant increase in body weight and FTI, while LTI remained similar. Gains in fat mass were significantly associated with muscle wasting (beta = −0.71, p < 0.0001). Moreover, progressive fluid accumulation independently predicted decrease in FTI (beta = −0.35, p < 0.0001) but not LTI. Body composition assessments by BIS were not affected by fluid status and should be considered as part of comprehensive nutrition assessment in PD patients.

Systematic review and meta-analysis of potential pleiotropic effects of sevelamer in chronic kidney disease: Beyond phosphate control

Sevelamer, has been shown to have many pleiotropic actions on lipid panel, various inflammatory markers, and blood glucose levels in chronic kidney disease patients. We conducted a systematic review and meta-analysis to compare these pleiotropic effects of sevelamer to other phosphate binders used in chronic kidney disease patients. The relevant randomized controlled trials published from 1 January 2001 to 31 November 2019 on the following databases: Cochrane Central Register of Controlled Trials published in The Cochrane Library, PubMed, Scopus and Google Scholar were identified. All the included studies were independently assessed for eligibility and risk of bias. The modified data extraction form of Cochrane was used. This review included 44 studies for qualitative analysis and 28 reports for quantitative analysis. A meta-analysis of three studies (n = 180) showed that glycated haemoglobin had significantly decreased in sevelamer-treated patients (MD: 0.5%; p = <.001). Compared with calcium-based phosphate binders, sevelamer showed a significant reduction in low-density lipoprotein (MD: -19.43 mg/dL; p = <.001) and total cholesterol (MD: -19.98 mg/dL; p < .001). A significant increase in high-density lipoprotein (MD: 1.29 mg/dL; p = .05) was also prominent in sevelamer treated patients. However, we were not able to observe a significant change in other biochemical parameters such as TG, CRP, hs-CRP, FGF-23, IL-6 and albumin as, no statistically significant difference was observed.

Comparison of Sevelamer and Calcium Carbonate in Prevention of Hypomagnesemia in Hemodialysis Patients

BACKGROUND

Chronic kidney disease (CKD) is a life-threatening disease with numerous complications. Hemodialysis (HD) patients are prone to magnesium deficiency due to malnutrition, which can cause cardiovascular complications and increase mortality. The present study aimed to investigate the effects of sevelamer and calcium carbonate, as phosphate binders, on serum levels of magnesium, calcium, and phosphorus in HD patients.

METHODS

A parallel clinical trial was conducted on 54 patients undergoing HD at Kosar Hospital of Semnan. The inclusion criteria were end-stage renal disease (ESRD), alternative HD treatment for at least 3 months 3 times a week, and serum phosphate levels greater than 4.5 mg/dL. The participants were randomly assigned to two groups of sevelamer (n = 27) and calcium carbonate (n = 27). If the participants were taking a phosphate binder, they were asked to stop it for 3 weeks. Participants in the sevelamer group received 800 mg of sevelamer at most three times a day and those in the calcium carbonate group were treated with 500 mg of calcium carbonate at most 3 times a day. Before and 3 months after the intervention, the serum levels of calcium, magnesium, and phosphorus were measured through the Arsenazo method using the Pars Azmun kit in the Selectra auto-analyzer. Twenty-one patients in the sevelamer group and 22 patients in the calcium carbonate group finished the study.

RESULTS

The results showed that calcium carbonate and sevelamer increased serum magnesium level by 0.20 (P = 0.028) and 0.26 (P = 0.002), on average, which were statistically significant. The administration of calcium carbonate did not significantly change serum calcium levels (P = 0.53), whereas sevelamer reduced serum calcium levels by 0.23 (P = 0.017), on average. This reduction was statistically significant. The results also indicated that none of the calcium carbonate (P = 0.099) and sevelamer (P = 0.543) caused significant changes in serum phosphorus levels. The study findings showed no significant difference between the two groups in terms of changes in the serum levels of magnesium (0.590), calcium (0.116), and phosphorus (0.113).

CONCLUSIONS

Both drugs (Sevelamer and calcium carbonate) prevented hypomagnesemia and increased serum magnesium levels, but no significant differences were found in blood levels of calcium, phosphorus, and magnesium compared to the two drugs. Considering the effect of magnesium on cardiovascular diseases, increasing the serum magnesium levels through the administration of calcium carbonate and sevelamer can prevent the likelihood of cardiovascular diseases. However, none of the studied drugs was superior to the other in this regard.

Intradialysis hypotension and hypertension in patients with end stage kidney disease in Nigeria: risk factors and clinical correlates

Background

Many shortcomings associated with haemodialysis for instance, intradialysis blood pressure changes, often lead to inadequate dialysis dose. Measures are needed to improve on this.

Objectives

To determine the risk factors and clinical correlates of intradialysis blood pressure variations.

Methods

Maintenance haemodialysis sessions for 232 consented patients with end stage kidney disease who had 1248 sessions were studied. Data collected was from history, examination findings, serum electrolytes and hematocrit. Blood pressure reading was taken manually at rest. Statistical analysis was with SPSS 22. Chi square and t-test were used to compare proportions and means respectively while regression analysis was used to determine predictors of blood pressure changes.

Results

The mean age of participants was 49.9 ± 4.6. More participants (38.8%) had hypertension associated CKD, than chronic glomerulonephritis, (37.9%). Majority (60.7%) had internal jugular catheter. Intradialysis hypertension was commoner than intradialysis hypotension (24.4% versus 19.4%). Intradialysis hypotension was commoner in females, diabetics and with less frequent dialysis while intradialysis hypertension was commoner in males, frequent erythropoietin use. The mean dialysis dose (Kt/V) was 1.02 ± 0.4, with 0.68 ± 0.1 for intradialysis hypotension and 0.84 ± 0.2 for intradialysis hypertension.

Conclusion

Risk factors for intradialysis hypertension were males, frequent erythropoietin use while for intradialysis hypotension, were female gender and less frequent dialysis. Effective intra and inter-dialytic blood pressure control with adequate pre dialysis work up should be carried out to lessen the degree, burden and outcome of these variations.

Funding

None declared.

A novel assay to measure calcification propensity: from laboratory to humans

Cardiovascular calcification (CVC) contributes to morbidity and mortality in patients undergoing dialysis. We examined the pharmacodynamic effects of SNF472, a calcification inhibitor, on plasma calcium phosphate crystallization using spectrometric measurements, and its correlations with effects on CVC in rats or humans. Rats (N = 38) injected with vitamin D (days 1–3) to induce CVC were infused with saline or SNF472 (days 1–12). Inhibition of CVC was 50–65% with SNF472 3 mg/kg and ~ 80% with SNF472 10 or 30 mg/kg. SNF472 dose-dependently inhibited calcium phosphate crystallization, which correlated with inhibition of CVC (r = 0.628, P = 0.005). In patients with calciphylaxis (N = 14), infusion of SNF472 (~ 7 mg/kg) during hemodialysis for 12 weeks inhibited calcium phosphate crystallization by nearly 70%. In patients with CVC (N = 274), infusion of SNF472 during hemodialysis for 52 weeks inhibited calcium phosphate crystallization (placebo: 15%; 300 mg: 61%; 600 mg: 75%), which correlated with inhibition of CVC (r = 0.401, P = 0.003). These findings show a direct correlation between inhibition of calcium phosphate crystallization in plasma and inhibition of CVC both in a rat model and in humans, supporting the use of the pharmacodynamic assay in clinical trials as a potentially predictive tool to evaluate the activity of calcification inhibitors.

Educational nursing intervention to reduce the hyperphosphatemia in patients on hemodialysis

Objective:

to evaluate the effectiveness of an educational nursing intervention to reduce hyperphosphataemia in chronic renal patients on hemodialysis.

Method:

quasi-experimental study with 63 hyperphosphatemic patients on hemodialysis. The intervention consisted of developing and providing a printed and illustrated manual to patients containing information on disease control. The participant was asked to complete a daily checklist with the aim to reinforce aspects provided in the manual. Laboratory tests and itching intensity were analyzed at the beginning of the study, and at 30 and 60 days after the educational intervention.

Results:

the mean age of participants was 58±13.1 years, with a treatment time of 51.1±44.7 months. A reduction in serum phosphorus values of 7.06 ± 1.43 to 5.80 ± 1.53 (p <0.001) and the intensity of itching after the intervention was observed.

Conclusion:

the educational nursing intervention was effective in reducing phosphate and decreasing itching in hyperphosphatemic patients.

Advances in pharmacotherapy for hyperphosphatemia in renal disease

INTRODUCTION

Hyperphosphatemia in chronic kidney disease (CKD) is considered as an independent risk factor for surrogate clinical end points like vascular calcification (VC) and bone disease, or hard clinical outcomes like cardiovascular events. Various treatment options are available for phosphate removal or reduction. Calcium-based phosphate binders (CBB) with their possible positive calcium balance became culprits for progressive VC and increased mortality risk. Non-calcium-based binders (NCBB) treatment allowed a comparable control of hyperphosphatemia with a lower risk of hypercalcemia and a slower progression of VC. Recent data have shown a 22% risk reduction in all-cause mortality with NCBB compared to CBB treatment. The appropriate timing of phosphate binder initiation in CKD patients is still unclear. Recent reports in patients with CKD stages 3b-4 showed increased VC progression when actively treated compared to placebo and a positive calcium, but no negative phosphate balance.

AREAS COVERED

This review discusses the advantages and disadvantages of the pharmacological options to treat hyperphosphatemia.

EXPERT OPINION

The use of phosphate binders is essential in preventing morbidity and mortality in dialysis patients. The choice of phosphate binder takes into account CKD stage, the presence of other components of CKD-mineral and bone disorders, concomitant therapies and drug side-effect profile.

Sevelamer revisited: pleiotropic effects on endothelial and cardiovascular risk factors in chronic kidney disease and end-stage renal disease

Endothelial dysfunction underlies multiple cardiovascular consequences of chronic kidney disease (CKD) and antecedent diabetes or hypertension. Endothelial insults in CKD or end-stage renal disease (ESRD) patients include uremic toxins, serum uric acid, hyperphosphatemia, reactive oxygen species, and advanced glycation endproducts (AGEs). Sevelamer carbonate, a calcium-free intestinally nonabsorbed polymer, is approved for hyperphosphatemic dialysis patients in the US and hyperphosphatemic stage 3-5 CKD patients in many other countries. Sevelamer has been observed investigationally to reduce absorption of AGEs, bacterial toxins, and bile acids, suggesting that it may reduce inflammatory, oxidative, and atherogenic stimuli in addition to its on-label action of lowering serum phosphate. Some studies also suggest that noncalcium binders may contribute less to vascular calcification than calcium-based binders. Exploratory sevelamer carbonate use in patients with stages 2-4 diabetic CKD significantly reduced HbA1c, AGEs, fibroblast growth factor (FGF)-23, and total and low-density lipoprotein (LDL) cholesterol versus calcium carbonate; inflammatory markers decreased and defenses against AGEs increased. Sevelamer has also been observed to reduce circulating FGF-23, potentially reducing risk of left ventricular hypertrophy. Sevelamer but not calcium-based binders in exploratory studies increases flow-mediated vasodilation, a marker of improved endothelial function, in patients with CKD. In contrast, lanthanum carbonate and calcium carbonate effects on FMV did not differ in hemodialysis recipients. The recent independent-CKD randomized trial compared sevelamer versus calcium carbonate in predialysis CKD patients (investigational in the US, on-label in European participants); sevelamer reduced 36-month mortality and the composite endpoint of mortality or dialysis inception. Similarly, independent-HD in incident dialysis patients showed improved survival with 24 months of sevelamer versus calcium-based binders. This review discusses recent exploratory evidence for pleiotropic effects of sevelamer on endothelial function in CKD or ESRD. Endothelial effects of sevelamer may contribute mechanistically to the improved survival observed in some studies of CKD and ESRD patients.

Phosphate binders and metabolic acidosis in patients undergoing maintenance hemodialysis—sevelamer hydrochloride, calcium carbonate, and bixalomer

The serum bicarbonate (HCO3(-)) levels are decreased in chronic hemodialysis (HD) patients treated with sevelamer hydrochloride (SH). We assessed the effects of bixalomer on the chronic metabolic acidosis in these patients. We examined 12 of the 122 consecutive Japanese patients with end-stage renal disease on HD, who orally ingested a dose of SH (≥2250 mg), and an arterial blood gas analysis and biochemical analysis were performed before HD. Patients whose serum HCO3(-) levels were under 18 mmol/L were changed from SH to the same dose of bixalomer. A total of 12 patients were treated with a large amount of SH. Metabolic acidosis (a serum HCO3(-) level under 18 mmol/L) was found in eight patients. These patients were also treated with or without small dose of calcium carbonate (1.2 ± 1.1 g). The dose of SH was changed to that of bixalomer. After 1 month, the serum HCO3(-) levels increased from 16.3 ± 1.4 to 19.6 ± 1.7 mmol/L (P < 0.05). Metabolic acidosis was not observed in four patients (serum HCO3(-) level: 20.3 ± 0.7 mmol/L) likely because they were taking 3 g of calcium carbonate with SH. In the present study, the development of chronic metabolic acidosis was induced by HCl containing phosphate binders, such as SH, and partially ameliorated by calcium carbonate, then subsequently improved after changing the treatment to bixalomer.

Differential effects of phosphate binders on pre-dialysis serum bicarbonate in end-stage kidney disease patients on maintenance haemodialysis

Background

Phosphate binders’ constituents have alkalotic or acidotic properties and may contribute to acid base balance in haemodialysis patients. This study aimed to investigate the differential effects of phosphate binders on pre-dialysis serum bicarbonate in End Stage Kidney Disease patients on maintenance haemodialysis.

Methods

Stable out-patients having satellite haemodialysis for at least 3 months were retrospectively studied for 18 months, excluding those with other medical causes for metabolic acidosis. Blood results were censored for inpatient episodes, at the time of death, renal transplant or dialysis modality change. Multivariable multilevel mixed-effects linear regression was used and five groups of phosphate binders were compared: Group A(Calcium (Ca) and/or Aluminium (Al) binders); B(Sevelamer hydrochloride (SH) alone); C(lanthanum carbonate (LC) alone); D(SH and Ca/Al), E(LC and Ca/Al).

Results

Of 320 patients, 292 were eligible for analysis with a mean follow-up of 15.54 (standard deviation, SD 3.98) months. Similar mean pre-dialysis serum levels of bicarbonate were observed at all 6 month-interval analyses. At 18^th months, observed mean serum bicarbonate levels in mmol/L were Group B: 21.58 (SD 2.82, P<0.001), C: 23.29 (SD 2.80, P=0.02), D: 21.56 (SD 3.00, P<0.001), and E: 21.29 (SD 3.62, P=0.92) compared with Group A: 22.98 (SD 2.77). Mean serum bicarbonate was related to total SH dose in mmol/L: 22.34 (SD 2.56) for SH <2.5 g/day, 21.61 (SD 2.62) for SH 2.5-4.8 g/day, 21.04 (SD 3.31) for SH >4.8 g/day compared with 22.85 (SD 2.91) for non-users; P-trend<0.001.

Conclusions

Phosphate binders’ constituents may contribute to/protect against a predisposition to pre-dialysis metabolic acidosis. This may be dose dependant in patients taking Sevelamer Hydrochloride.