Mortality in kidney disease patients treated with phosphate binders: a randomized study

BACKGROUND AND OBJECTIVES

Dietary phosphorous overload and excessive calcium intake from calcium-containing phosphate binders promote coronary artery calcification (CAC) that may contribute to high mortality of dialysis patients. CAC has been found in patients in early stages of nondialysis-dependent CKD. In this population, no study has evaluated the potential role of phosphorus binders on mortality. This study aimed to evaluate all-cause mortality as the primary end point in nondialysis-dependent CKD patients randomized to different phosphate binders; secondary end points were dialysis inception and the composite end point of all-cause mortality and dialysis inception.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a randomized, multicenter, nonblinded pilot study. Consecutive outpatients (n=212; stage 3-4 CKD) were randomized to either sevelamer (n=107) or calcium carbonate (n=105). Phosphorus concentration was maintained between 2.7 and 4.6 mg/dl for patients with stage 3-4 CKD and between 3.5 and 5.5 mg/dl for patients with stage 5 CKD. The CAC score was assessed by computed tomography at study entry and after 6, 12, 18, and 24 months. All-cause mortality, dialysis inception, and the composite end point were recorded for up to 36 months.

RESULTS

In patients randomized to sevelamer, all-cause mortality and the composite end point were lower; a nonsignificant trend was noted for dialysis inception.

CONCLUSIONS

Sevelamer provided benefits in all-cause mortality and in the composite end point of death or dialysis inception but not advantages in dialysis inception. Larger studies are needed to confirm these results.

Sevelamer versus calcium carbonate in incident hemodialysis patients: results of an open-label 24-month randomized clinical trial

BACKGROUND

Whether the use of sevelamer rather than a calcium-containing phosphate binder improves cardiovascular (CV) survival in patients receiving dialysis remains to be elucidated.

STUDY DESIGN

Open-label randomized controlled trial with parallel groups.

SETTINGS & PARTICIPANTS

466 incident hemodialysis patients recruited from 18 centers in Italy.

INTERVENTION

Study participants were randomly assigned in a 1:1 fashion to receive either sevelamer or a calcium-containing phosphate binder (although not required by the protocol, all patients in this group received calcium carbonate) for 24 months.

OUTCOMES

All individuals were followed up until completion of 36 months of follow-up or censoring. CV death due to cardiac arrhythmias was regarded as the primary end point.

MEASUREMENTS

Blind event adjudication.

RESULTS

At baseline, patients allocated to sevelamer had higher serum phosphorus (mean, 5.6 ± 1.7 [SD] vs 4.8 ± 1.4 mg/dL) and C-reactive protein levels (mean, 8.8 ± 13.4 vs 5.9 ± 6.8 mg/dL) and lower coronary artery calcification scores (median, 19 [IQR, 0-30] vs 30 [IQR, 7-180]). At study completion, serum phosphate levels were lower in the sevelamer arm (median dosages, 4,800 and 2,000 mg/d for sevelamer and calcium carbonate, respectively). After a mean follow-up of 28 ± 10 months, 128 deaths were recorded (29 and 88 due to cardiac arrhythmias and all-cause CV death). Sevelamer-treated patients experienced lower CV mortality due to cardiac arrhythmias compared with patients treated with calcium carbonate (HR, 0.06; 95% CI, 0.01-0.25; P < 0.001). Similar results were noted for all-cause CV mortality and all-cause mortality, but not for non-CV mortality. Adjustments for potential confounders did not affect results.

LIMITATIONS

Open-label design, higher baseline coronary artery calcification burden in calcium carbonate-treated patients, different mineral metabolism control in sevelamer-treated patients, overall lower than expected mortality.

CONCLUSIONS

These results show that sevelamer compared to a calcium-containing phosphate binder improves survival in a cohort of incident hemodialysis patients. However, the better outcomes in the sevelamer group may be due to better phosphate control rather than reduction in calcium load.

Prognosis of CKD patients receiving outpatient nephrology care in Italy

BACKGROUND AND OBJECTIVES

Prognosis in nondialysis chronic kidney disease (CKD) patients under regular nephrology care is rarely investigated. Design, setting, participants, & measurements We prospectively followed from 2003 to death or June 2010 a cohort of 1248 patients with CKD stages 3 to 5 and previous nephrology care ≥1 year in 25 Italian outpatient nephrology clinics. Cumulative incidence of ESRD or death before ESRD were estimated using the competing-risk approach.

RESULTS

Estimated rates (per 100 patient-years) of ESRD and death 8.3 (95% confidence interval [CI], 7.4 to 9.2) and 5.9 (95% CI 5.2 to 6.6), respectively. Risk of ESRD and death increased progressively from stages 3 to 5. ESRD was more frequent than death in stage 4 and 5 CKD, whereas the opposite was true in stage 3 CKD. Younger age, lower body mass index, proteinuria, and high phosphate predicted ESRD, whereas older age, diabetes, previous cardiovascular disease, ESRD, proteinuria, high uric acid, and anemia predicted death (P < 0.05 for all). Among modifiable risk factors, proteinuria accounted for the greatest contribution to the model fit for either outcome.

CONCLUSIONS

In patients receiving continuity of care in Italian nephrology clinics, ESRD was a more frequent outcome than death in stage 4 and 5 CKD, but the opposite was true in stage 3. Outcomes were predicted by modifiable risk factors specific to CKD. Proteinuria used in conjunction with estimated GFR refined risk stratification. These findings provide information, specific to CKD patients under regular outpatient nephrology care, for risk stratification that complement recent observations in the general population.

Supplementation of Short-Chain Fatty Acid, Sodium Propionate, in Patients on Maintenance Hemodialysis: Beneficial Effects on Inflammatory Parameters and Gut-Derived Uremic Toxins, A Pilot Study (PLAN Study)

BACKGROUND

In end-stage renal disease (ESRD), gut-derived uremic toxins play a crucial role in the systemic inflammation and oxidative stress promoting the excess morbidity and mortality. The biochemical derangement is in part a consequence of an insufficient generation of short-chain fatty acids (SCFA) due to the dysbiosis of the gut and an insufficient consumption of the fermentable complex carbohydrates.

AIM OF THE STUDY

The primary end-point was to evaluate the potential efficacy of SCFA (specifically, sodium propionate (SP)) for patients on maintenance hemodialysis (MHD) on systemic inflammation. Secondary end-points included potential attenuation of oxidative stress markers, insulin resistance and production of gut-derived uremic toxins indoxyl sulfate and p-cresol sulfate, as well as health status after SP supplementation.

STUDY DESIGN

We performed a single-center non-randomized pilot study in 20 MHD patients. They received the food additive SP with a daily intake of 2 × 500 mg in the form of capsules for 12 weeks. Pre-dialysis blood samples were taken at the beginning, after six weeks and at the end of the administration period, as well as four weeks after withdrawal of the treatment.

RESULTS

The subjects revealed a significant decline of inflammatory parameters C-reactive protein (-46%), interleukin IL-2 (-27%) and IL-17 (-15%). The inflammatory parameters IL-6 and IFN-gamma showed a mild non-significant reduction and the anti-inflammatory cytokine IL-10 increased significantly (+71%). While the concentration of bacterial endotoxins and TNF-α remained unchanged, the gut-derived uremic toxins, indoxyl sulfate (-30%) and p-cresyl sulfate (-50%), revealed a significant decline. The SP supplementation reduced the parameters of oxidative stress malondialdehyde (-32%) and glutathione peroxidase activity (-28%). The serum insulin levels dropped by 30% and the HOMA-index by 32%. The reduction of inflammatory parameters was associated with a lowering of ferritin and a significant increase in transferrin saturation (TSAT). Four weeks after the end of the treatment phase, all improved parameters deteriorated again. Evaluation of the psycho-physical performance with the short form 36 (SF-36) questionnaire showed an enhancement in the self-reported physical functioning, general health, vitality and mental health. The SP supplementation was well tolerated and without important side effects. No patient had left the study due to intolerance to the medication. The SP supplementation in MHD patients reduced pro-inflammatory parameters and oxidative stress and improved insulin resistance and iron metabolism. Furthermore, SP effectively lowered the important gut-derived uremic toxins indoxyl and p-cresol sulfate. These improvements were associated with a better quality of life. Further controlled studies are required in a larger cohort to evaluate the clinical outcome.

Correction of metabolic acidosis improves insulin resistance in chronic kidney disease

Background

Correction of metabolic acidosis (MA) with nutritional therapy or bicarbonate administration is widely used in chronic kidney disease (CKD) patients. However, it is unknown whether these interventions reduce insulin resistance (IR) in diabetic patients with CKD. We sought to evaluate the effect of MA correction on endogenous insulin action in diabetic type 2 (DM2) CKD patients.

Methods

A total of 145 CKD subjects (83 men e 62 women) with DM2 treated with oral antidiabetic drugs were included in the study and followed up to 1 year. All patients were randomly assigned 1:1 to either open-label (A) oral bicarbonate to achieve serum bicarbonate levels of 24–28 mmol/L (treatment group) or (B) no treatment (control group). The Homeostatic model assessment (HOMA) index was used to evaluate IR at study inception and conclusion. Parametric and non-parametric tests as well as linear regression were used.

Results

At baseline no differences in demographic and clinical characteristics between the two groups was observed. Average dose of bicarbonate in the treatment group was 0.7 ± 0.2 mmol/kg. Treated patients showed a better metabolic control as confirmed by lower insulin levels (13.4 ± 5.2 vs 19.9 ± 6.3; for treated and control subjects respectively; p < 0.001), Homa-IR (5.9[5.0-7.0] vs 6.3[5.3–8.2]; p = 0.01) and need for oral antidiabetic drugs. The serum bicarbonate and HOMA-IR relationship was non-linear and the largest HOMA-IR reduction was noted for serum bicarbonate levels between 24 and 28 mmol/l. Adjustment for confounders, suggests that serum bicarbonate rather than treatment drives the effect on HOMA-IR.

Conclusions

Serum bicarbonate is related to IR and the largest HOMA-IR reduction is noted for serum bicarbonate between 24 and 28 mmol/l. Treatment with bicarbonate influences IR. However, changes in serum bicarbonate explains the effect of treatment on HOMA index. Future efforts are required to validate these results in diabetic and non-diabetic CKD patients.

Trial registration

The trial was registered at www.clinicaltrial.gov (Use of Bicarbonate in Chronic Renal Insufficiency (UBI) study - NCT01640119)

Blood pressure variability and outcomes in chronic kidney disease

BACKGROUND

We investigated the effects of visit-to-visit systolic blood pressure variability (SBPV) on both mortality and dialysis inception in a cohort of chronic kidney disease (CKD) patients not requiring dialysis therapy. Furthermore, we also explored the carry-over effect of visit-to-visit SBPV on mortality after dialysis initiation.

METHODS

We conducted a longitudinal retrospective, observational, multi-centre study in three tertiary care nephrology outpatient clinics. All the ambulatory CKD patients admitted to the outpatient clinics from 1 January 2004 to 31 December 2005 were screened for study eligibility. We selected all consecutive patients older than 18 years of age with a mean estimated glomerular filtration rate of <60 mL/min/m(2), free from cardiovascular disease. SBPV was defined as the ratio of the SD to the mean SBP of five values recorded during a run-in phase of 4-5 months. Data on dialysis inception and mortality were recorded through 31 December 2010.

RESULTS

Overall, we selected a cohort of 374 elderly (median age: 79 years) subjects. A total of 232 (62%) and 103 (29%) patients were male and had diabetes, respectively. A significant association between SBPV and the risk of death but not of CKD progression to dialysis was noted at univariate and after multivariable adjustments (hazard ratio for all-cause mortality per 1% increase in SBPV: 1.05; 95% confidence interval: 1.02-1.09; P = 0.001). Notably, no lethal event was recorded after dialysis initiation.

CONCLUSIONS

Current findings suggest that SBPV may be of use for risk stratification in CKD patients.

Simultaneous PET/MR head-neck cancer imaging: Preliminary clinical experience and multiparametric evaluation

PURPOSE

To evaluate the role of simultaneous hybrid PET/MR imaging and to correlate metabolic PET data with morpho-functional parameters derived by MRI in patients with head-neck cancer.

METHODS

Forty-four patients, with histologically confirmed head and neck malignancy (22 primary tumors and 22 follow-up) were studied. Patients initially received a clinical exam and endoscopy with direct biopsy. Next patients underwent whole body PET/CT followed by PET/MR of the head/neck region. PET and MRI studies were separately evaluated by two blinded groups (both included one radiologist and one nuclear physician) in order to define the presence or absence of lesions/recurrences. Regions of interest (ROIs) analysis was conducted on the primary lesion at the level of maximum size on metabolic (SUV and MTV), diffusion (ADC) and perfusion (K(trans), Ve, kep and iAUC) parameters.

RESULTS

PET/MR examinations were successfully performed on all 44 patients. Agreement between the two blinded groups was found in anatomic allocation of lesions by PET/MR (Primary tumors: Cohen's kappa 0.93;

FOLLOW-UP

Cohen's kappa 0.89). There was a significant correlation between CT-SUV measures and MR (e.g., CT-SUV VOI vs.

MR-SUV VOI

ρ=0.97, p<0.001 for the entire sample). There was also significant positive correlations between the ROI area, SUV measures, and the metabolic parameters (SUV and MTV) obtained during both PET/CT and PET/MR. A significant negative correlation was observed between ADC and K(trans) values in the primary tumors. In addition, a significant negative correlation existed between MR SUV and ADC in recurrent tumors.

CONCLUSION

Our study demonstrates the feasibility of PET/MR imaging for primary tumors and recurrent tumors evaluations of head/neck malignant lesions. When assessing HNC, PET/MR allows simultaneous collection of multiparametric metabolic and functional data. This technique therefore allows for a more complete characterization of malignant lesions.

Kidney Disease in HIV Infection

Antiretroviral therapy (ART) has significantly improved life expectancy of infected subjects, generating a new epidemiological setting of people aging withHuman Immunodeficiency Virus (HIV). People living with HIV (PLWH), having longer life expectancy, now face several age-related conditions as well as side effects of long-term exposure of ART. Chronic kidney disease (CKD) is a common comorbidity in this population. CKD is a relentlessly progressive disease that may evolve toward end-stage renal disease (ESRD) and significantly affect quality of life and risk of death. Herein, we review current understanding of renal involvement in PLWH, mechanisms and risk factors for CKD as well as strategies for early recognition of renal dysfunction and best care of CKD.

Very low-protein diet plus ketoacids in chronic kidney disease and risk of death during end-stage renal disease: a historical cohort controlled study

BACKGROUND

Very low-protein intake during chronic kidney disease (CKD) improves metabolic disorders and may delay dialysis start without compromising nutritional status, but concerns have been raised on a possible negative effect on survival during dialysis. This study aimed at evaluating whether a very low-protein diet during CKD is associated with a greater risk of death while on dialysis treatment.

METHODS

This is an historical, cohort, controlled study, enrolling patients at dialysis start previously treated in a tertiary nephrology clinic with a very low-protein diet supplemented with amino acids and ketoacids (s-VLPD group, n = 184) or without s-VLPD [tertiary nephrology care (TNC) group, n = 334] and unselected patients [control (CON) group, n = 9.092]. The major outcome was survival rate during end-stage renal disease associated to s-VLPD treatment during CKD. The propensity score methods and Cox regression model were used to match groups at the start of dialysis to perform survival analysis and estimate adjusted hazard ratio (HR).

RESULTS

In s-VLPD, TNC and CON groups, average age was 67.5, 66.0 and 66.3 years, respectively (P = 0.521) and male prevalence was 55, 55 and 62%, respectively (P = 0.004). Diabetes prevalence differed in the three groups (P < 0.001), being 18, 17 and 31% in s-VLPD, CON and TNC, respectively. A different prevalence of cardiovascular (CV) disease was found (P < 0.001), being similar in TNC and CON (31 and 25%) and higher in s-VLPD (41%). Median follow-up during renal replacement therapy (RRT) was 36, 32 and 36 months in the three groups. Adjusted HR estimated on matched propensity patients was 0.59 (0.45-0.78) for s-VLPD versus CON. Subgroup analysis showed a lower mortality risk in s-VLPD versus matched-CON in younger patients (<70 years) and those without CV disease. No significant difference in HRs was found between s-VLPD and TNC.

CONCLUSION

s-VLPD during CKD does not increase mortality in the subsequent RRT period.

Coronary artery calcification progression is associated with arterial stiffness and cardiac repolarization deterioration in hemodialysis patients

BACKGROUND/AIMS

Evidence suggests that vascular calcification (VC) portends poor cardiovascular (CV) prognosis in patients undergoing maintenance dialysis (CKD-5). Nonetheless, how VC might predispose to CV mortality still remains to be clarified. Herein, we report on the association between coronary artery calcification (CAC) progression and changes in cardiac repolarization as well as arterial stiffness.

METHODS

132 patients new to dialysis were identified. Demographic and clinical characteristics were collected at study entry and during the 12-month follow-up. CAC, 12-lead ECG and pulse wave velocity (PWV) were assessed at baseline and study completion. Uni- and multivariable analyses were applied to detect factors associated with worsening of cardiac repolarization (QTd) and arterial stiffness (PWV).

RESULTS

Uni- and multivariable analyses revealed that CAC progression was associated with a significant increase in both QTd and PWV. Every 20-unit increase in the CAC score corresponded to a significant 23% (95% CI 1.12-1.27; p < 0.001) and 32% (95% CI 1.09-1.37; p < 0.01) increase in the risk of experiencing a 1-m/s increase in PWV and 1 ms in QTd, respectively.

CONCLUSION

VC is a marker of vasculopathy and appears to be associated with cardiac repolarization and arterial stiffness abnormalities in CKD-5 patients.

No additional benefit of prescribing a very low-protein diet in patients with advanced chronic kidney disease under regular nephrology care: a pragmatic, randomized, controlled trial

BACKGROUND

Whether a very low-protein diet supplemented with ketoanalogues (sVLPD), compared with a standard low-protein diet (LPD), improves outcomes in patients with chronic kidney disease (CKD) under stable nephrology care is undefined.

OBJECTIVES

To compare the effectiveness of sVLPD compared with LPD in patients regularly seen in tertiary nephrology care.

METHODS

Participants were patients with CKD stages 4-5, followed for at least 6 mo, randomly allocated to receive sVLPD or LPD [0.35 or 0.60 g/kg ideal body weight (IBW)/d, respectively], stratified by center and CKD stage. The primary outcome was time to renal death, defined as the first event between end-stage renal disease (ESRD) and all-cause mortality; secondary outcomes were the single components of the primary outcome, cardiovascular outcome, and nutritional status.

RESULTS

We analyzed 223 patients (sVLPD, n = 107; LPD, n = 116). Mean age was 64 y, 61% were male, and 35% had diabetes. Median protein intake (PI), which was 0.8 g/kg IBW/d at baseline in both groups, was 0.83 and 0.60 g/kg IBW/d in LPD and sVLPD, respectively, during the trial with a large decrease only in sVLPD (P = 0.011). During a median of 74.2 mo, we recorded 180 renal deaths (141 dialysis and 39 deaths before dialysis). Risk of renal death did not differ in sVLPD compared with LPD (HR: 1.17; 95% CI: 0.88, 1.57; P = 0.28). No difference was observed for ESRD (HR: 1.12; 95% CI: 0.81, 1.56; P = 0.51), mortality (HR: 0.95; 95% CI: 0.62, 1.45; P = 0.82), or time to fatal/nonfatal cardiovascular events (P = 0.2, log-rank test). After 36 mo, still active patients were 45 in sVLPD and 56 in LPD. No change of nutritional status emerged during the study in any arm.

CONCLUSIONS

This long-term pragmatic trial found that in patients with CKD under stable nephrology care, adherence to protein restriction is low. Prescribing sVLPD compared with standard LPD is safe but does not provide additional advantage to the kidney or patient survival.

Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients with Chronic Kidney Disease: Role of Anticoagulation Therapy

Atrial fibrillation (AF) and chronic kidney disease (CKD) are strictly related; several independent risk factors of AF are often frequent in CKD patients. AF prevalence is very common among these patients, ranging between 15% and 20% in advanced stages of CKD. Moreover, the results of several studies showed that AF patients with end stage renal disease (ESRD) have a higher mortality rate than patients with preserved renal function due to an increased incidence of stroke and an unpredicted elevated hemorrhagic risk. Direct oral anticoagulants (DOACs) are currently contraindicated in patients with ESRD and vitamin K antagonists (VKAs), remaining the only drugs allowed, although they show numerous critical issues such as a narrow therapeutic window, increased tissue calcification and an unfavorable risk/benefit ratio with low stroke prevention effect and augmented risk of major bleeding. The purpose of this review is to shed light on the applications of DOAC therapy in CKD patients, especially in ESRD patients.

Development and Validation of Bioimpedance Analysis Prediction Equations for Dry Weight in Hemodialysis Patients

BACKGROUND

Accurate assessment of hydration status and specification of dry weight (DW) are major problems in the clinical treatment of hemodialysis (HD) patients. Bioelectrical impedance analysis (BIA) has been recognized as a noninvasive and simple technique for the determination of DW in HD patients.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

This study was designed to develop and validate BIA prediction equations for DW in HD patients. It included white adults (1540 disease-free adults with normal body mass index [BMI] and 456 prevalent and 27 incident HD patients). All participants underwent at least one single-frequency BIA measurement (800 muA and 50 kHz alternating sinusoidal current with a standard tetrapolar technique). The BIA variable measured was resistance (R). Data of 1463 (95% of the cohort) disease-free individuals with normal BMI (prediction sample) were used to establish best-fitting BIA prediction equations of body weight. The latter were cross-validated in the residual 5% subset (77 individuals) of the same cohort (validation sample).

RESULTS

Multiple regression analysis showed a significant relationship among body weight, R, age, and height in 739 men (R(2) = 0.82, P < 0.0001) and among body weight, R, and height in 724 women (R(2) = 0.68, P < 0.0001) in the prediction sample. The Bland Altman analysis showed a mean difference between predicted and measured body weight of 0.3 +/- 1.0 kg (95% confidence interval +/- 2.0 kg) in the validation sample. The BIA prediction equations that were obtained in disease-free individuals with normal BMI were applied to a cohort of 456 prevalent HD patients: The mean difference between achieved and estimated DW was 0.1 +/- 1.0 kg (P = 0.53) in men and -0.3 +/- 1.0 (P = 0.76) in women. Finally, BIA prediction equations were tested in a cohort of 27 incident HD patients. The mean difference between predicted and achieved DW was -0.6 +/- 1.0 kg (P = 0.76) in men and 0.6 +/- 1.0 (P = 0.50) in women.

CONCLUSIONS

This study was able to develop and validate BIA prediction equations for DW in HD patients. They seem to be a promising tool; however, they still need external validation.

Infectious Complications in Renal Transplant Recipients

Renal transplantation has become a well-established therapeutic option for end-stage renal disease, but infectious diseases remain a significant cause of morbidity and mortality. Although a wide variety of pathogens may cause infection, viral ones must be regarded as the single most important class of infections. Progress has been made both in the prevention and the early recognition treatment of infections that are closely linked to rejection. Immunosuppressive therapy is central to the pathogenesis of both. Because of the particular characteristics of transplant recipients, it is desirable to establish a close collaboration between nephrologists, surgeons, and infectious disease specialists for the management of these patients. In this article, we describe the different kinds of infectious disease that may affect patients with kidney transplant and the fundamental principles of clinical management, particularly our experience in Polyoma virus (BK) infection.

Parathyroid hormone may be an early predictor of low serum hemoglobin concentration in patients with not advanced stages of chronic kidney disease

Background

Parathyroid hormone (PTH) has been associated with anemia only in dialysis patients with severe hyperparathyroidism. Whether an association between PTH and hemoglobin also exists in patients with chronic kidney disease not on dialysis (CKD-patients) is still unclear. In this study we evaluated the association between PTH and hemoglobin in CKD-patients without severe secondary hyperparathyroidism.

Methods

Hospitalized patients and outpatients (N = 979) were retrospectively evaluated and categorized according to PTH quartile and serum hemoglobin (<12.0, <11.0, <10.0 g/dl). Gender, diabetes, glomerular filtration rate (GFR), hemoglobin, PTH, markers of mineral metabolism, inflammation, iron status and nutrition were variables of adjustment in univariate and multivariate analysis.

Results

An inverse association (p = 0.001) was observed between PTH and hemoglobin in patients as a whole, in diabetics, and in patients with GFR ≤60 ml/min. PTH was the single predictor of low hemoglobin in patients as a whole (unstandardized beta −2.12; p = 0.005), in diabetics (unstandardized beta −8.86; p = 0.007) and in patients with GFR ≤60 ml/min (unstandardized beta −2.52; p = 0.006). For each increase of quartile of PTH the risk of having hemoglobin level <10.0 mg/dl was more than doubled [hazard ratio (HR) 2.79, 95 % confidence interval (CI) 2.00–3.88; p = 0.001]. The receiver operating characteristic curve showed that PTH ≥122 pg/ml had 67 % sensitivity and 75 % specificity in predicting hemoglobin level <10.0 g/dl with area under the curve of 0.758 (95 % CI 0.73–0.78).

Conclusions

This study shows a significant inverse association between PTH and hemoglobin levels across the whole spectrum of non-dialysis CKD and a doubled risk of having serum hemoglobin <10.0 mg/dl in the absence of severely deranged PTH concentration. These findings may have clinical relevance in ascertaining the cause of unexplained low hemoglobin levels in CKD-patients.

Economic evaluation of sevelamer for the treatment of hyperphosphatemia in chronic kidney disease patients not on dialysis in the United Kingdom

OBJECTIVES

To determine the cost effectiveness of sevelamer vs calcium carbonate in patients with chronic kidney disease and not on dialysis (CKD-ND) from the perspective of the National Health Service (NHS) in the UK.

METHODS

A Markov decision analytic model was developed to estimate (1) total life years (LYs), quality-adjusted life years (QALYs), and costs for patients treated with sevelamer or calcium carbonate; and (2) incremental costs per LY gained (LYG) and per QALY gained for sevelamer vs calcium carbonate. Data informing probability transitions to all-cause death and dialysis inception in CKD-ND patients were taken directly from the INDEPENDENT-CKD study and were extrapolated beyond the 3-year clinical trial using Weibull regression analysis. Estimates of health utility and costs (in £2011) were derived from the published literature.

RESULTS

Over a lifetime horizon, sevelamer treatment resulted in a gain of 2.05 LYs and 1.56 QALYs per patient, an increase of £37,282 in total costs per patient vs calcium carbonate (3.5% discount), and a per-patient cost of £18,193/LYG and £23,878/QALY gained. Results were robust to alternative assumptions in key parameters; results were most sensitive to alternative assumptions regarding the mean daily dose of sevelamer, impact of sevelamer on dialysis initiation, cost of dialysis, and health utility estimates. The probabilistic sensitivity analysis showed that sevelamer was cost-effective vs calcium carbonate in 93% of simulations at a willingness-to-pay threshold of £30,000/QALY gained.

LIMITATIONS

While the model simulated a real-world clinical setting, this analysis was subject to limitations common to all decision analytic models, in that it used a mix of data sources and relied on several assumptions. Not all variables that impact real-world outcomes and costs were included in this model.

CONCLUSIONS

Sevelamer is a cost-effective option compared to calcium carbonate for the first-line treatment of hyperphosphatemia in CKD-ND patients in the UK.

QT interval in CKD and haemodialysis patients

Cardiovascular (CV) disease is the leading cause of morbidity and mortality in chronic kidney disease (CKD) patients. Although about half of the deaths are due to CV causes, only a minority are directly linked to myocardial infarction and it is estimated that cardiac arrest or cardiac arrhythmias account for about a quarter of all deaths registered in dialysis patients. Thus, simple non-invasive tools such as electrocardiogram (ECG) may detect those patients at increased risk for arrhythmias. The QT interval on the standard 12-lead ECG is the time from ventricular depolarization (Q wave onset) to cardiac repolarization completion (end of the T wave) and represents a marker of cardiac repolarization defects. Numerous studies suggest a direct association between QT abnormalities and poor prognosis in the general population, CKD patients and dialysis patients. Of note, multivariable adjustments for different traditional and CKD-specific risk factors for CV events attenuate but do not cancel these associations. We herein review the clinical significance of simple non-invasive tools such as the QT tract on ECG for detecting those patients at increased risk of CV event and possibly for treatment individualization.

The treatment of type 2 diabetes mellitus in patients with chronic kidney disease: What to expect from new oral hypoglycemic agents

Worldwide, an estimated 200 million people have chronic kidney disease (CKD), whose most common causes include hypertension, arteriosclerosis, and diabetes. About 40% of patients with diabetes develop CKD and intensive blood glucose control through pharmacological intervention can delay CKD progression. Standard therapies for the treatment of type 2 diabetes mellitus include metformin, sulfonylureas, meglitinides, thiazolidinediones, and insulin. While these drugs have an important role in the management of type 2 diabetes, only the thiazolidinedione pioglitazone can be used across the spectrum of CKD (stages 2-5) and without dose adjustment. Newer therapies, particularly dipeptidyl peptidase-IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitors, are increasingly being used in the treatment of type 2 diabetes; however, a major consideration is whether these newer therapies can also be used safely and effectively across the spectrum of renal impairment.

Therapy of hyperhomocysteinemia in hemodialysis patients: effects of folates and N-acetylcysteine

OBJECTIVE

Uremia represents a state where hyperhomocysteinemia is resistant to folate therapy, thus undermining intervention trials' efficacy. N-acetylcysteine (NAC), an antioxidant, in addition to folates (5-methyltetrahydrofolate, MTHF), was tested in a population of hemodialysis patients.

DESIGN

The study is an open, parallel, intervention study.

SETTING

Ambulatory chronic hemodialysis patients.

SUBJECTS

Clinically stable chronic hemodialysis patients, on hemodialysis since more than 3 months, undergoing a folate washout. Control group on standard therapy (n = 50).

INTERVENTION

One group was treated with intravenous MTHF (MTHF group, n = 48). A second group was represented by patients treated with MTHF, and, during the course of 10 hemodialysis sessions, NAC was administered intravenous (MTHF + NAC group, n = 47).

MAIN OUTCOME MEASURE

Plasma homocysteine measured before and after dialysis at the first and the last treatment.

RESULTS

At the end of the study, there was a significant decrease in predialysis plasma homocysteine levels in the MTHF group and MTHF + NAC group, compared with the control group, but no significant difference between the MTHF group and MTHF + NAC group. A significant decrease in postdialysis plasma homocysteine levels in MTHF + NAC group (10.27 ± 0.94 μmol/L, 95% confidence interval: 8.37-12.17) compared with the MTHF group (16.23 ± 0.83, 95% confidence interval: 14.55-17.90) was present. In the MTHF + NAC group, 64% of patients reached a postdialysis homocysteine level <12 μmol/L, compared with 19% in the MTHF group and 16% in the control group.

CONCLUSIONS

NAC therapy induces a significant additional decrease in homocysteine removal during dialysis. The advantage is limited to the time of administration.

Nutritional support in the tertiary care of patients affected by chronic renal insufficiency: report of a step-wise, personalized, pragmatic approach

Background

Dietary treatment is helpful in CKD patients, but nutritional interventions are scarcely implemented. The main concern of the renal diets is its feasibility with regards to daily clinical practice especially in the elderly and co-morbid patients. This study aimed to evaluate the effects of a pragmatic, step-wise, personalized nutritional support in the management of CKD patients on tertiary care.

Methods

This is a case-control study. It included 823 prevalent out-patients affected by CKD stage 3b to 5 not-in-dialysis, followed by tertiary care in nephrology clinics; 305 patients (190 males, aged 70 ± 12 years) received nutritional support (nutritional treatment Group, NTG); 518 patients (281 males, aged 73 ± 13 years) who did not receive any dietary therapy, formed the control group (CG). In the NTG patients the dietary interventions were assigned in order to prevent or correct abnormalities and to maintain a good nutritional status. They included manipulation of sodium, phosphate, energy and protein dietary intakes while paying special attention to each patient’s dietary habits.

Results

Phosphate and BUN levels were lower in the NTG than in the CG, especially in stage 4 and 5. The prevalence of hyperphosphatemia was lower in the NTG than in CG in stage 5 (13.3 % vs 53.3 %, p < 001, respectively), in stage 4 (4.1 % vs 18.3 % vs, p < 0.001) and stage 3b (2.8 % vs 9.5 % p < 0.05). Serum albumin was higher in NTG than in CG especially in stage 5 . The use of calcium-free intestinal phosphate binders was significantly lower in NTG than in CG (11 % vs 19 % p < 0.01), as well as that of Erythropoiesis stimulating agents (11 % vs 19 %, p < 0.01), and active Vitamin D preparations (13 % vs 21 %, p < 0.01).

Conclusions

This case-control study shows the usefulness of a nutritional support in addition to the pharmacological good practice in CKD patients on tertiary care. Lower phosphate and BUN levels are obtained together with maintenance of serum albumin levels. In addition, a lower need of erythropoiesis stimulating agents, phosphate binders and active Vitamin D preparations was detected in NTG. This study suggests that a nutritional support may be useful in the management of the world-wide growing CKD burden.

Sevelamer is cost-saving vs. calcium carbonate in non-dialysis-dependent CKD patients in italy: a patient-level cost-effectiveness analysis of the INDEPENDENT study

OBJECTIVES

To conduct a cost-effectiveness analysis of sevelamer versus calcium carbonate in patients with non-dialysis-dependent CKD (NDD-CKD) from the Italian NHS perspective using patient-level data from the INDEPENDENT-CKD study.

METHODS

Patient-level data on all-cause mortality, dialysis inception and phosphate binder dose were obtained for all 107 sevelamer and 105 calcium carbonate patients from the INDEPENDENT-CKD study. Hospitalization and frequency of dialysis data were collected post hoc for all patients via a retrospective chart review. Phosphate binder, hospitalization, and dialysis costs were expressed in 2012 euros using hospital pharmacy, Italian diagnosis-related group and ambulatory tariffs, respectively. Total life years (LYs) and costs per treatment group were calculated for the 3-year period of the study. Bootstrapping was used to estimate confidence intervals around outcomes, costs, and cost-effectiveness and to calculate the cost-effectiveness acceptability curve. A subgroup analysis of patients who did not initiate dialysis during the INDEPENDENT-CKD study was also conducted.

RESULTS

Sevelamer was associated with 0.06 additional LYs (95% CI -0.04 to 0.16) and cost savings of EUR -5,615 (95% CI -10,066 to -1,164) per patient compared with calcium carbonate. On the basis of the bootstrap analysis, sevelamer was dominant compared to calcium carbonate in 87.1% of 10,000 bootstrap replicates. Similar results were observed in the subgroup analysis. RESULTS were driven by a significant reduction in all-cause mortality and significantly fewer hospitalizations in the sevelamer group, which offset the higher acquisition cost for sevelamer.

CONCLUSIONS

Sevelamer provides more LYs and is less costly than calcium carbonate in patients with NDD-CKD in Italy.

Etelcalcetide in Patients on Hemodialysis with Severe Secondary Hyperparathyroidism. Multicenter Study in "Real Life"

Etelcalcetide is a new calcimimetic indicated for the treatment of secondary hyperparathyroidism (SHPT) in dialysis patients. Etelcalcetide efficacy in SHPT has been ascertained only in randomized controlled trials. This multicenter study was carried out in "real world" setting that is different from randomized controlled trials (RCTs) to (1) evaluate the effectiveness of etelcalcetide in SHPT, (2) to assess calcium, phosphorus, alkaline phosphatase changes, (3) to register gastrointestinal side effects. Data were collected from twenty-three dialysis units with n = 1190 patients on the charge. From this cohort, n = 168 (14%) patients were on treatment with etelcalcetide, and they were evaluated for statistics. A median weekly dose of etelcalcetide was 15 mg (7.5-45 mg). Patients were either naïve (33%) or switched from cinacalcet to obtain better control of SHPT with reduced side effects or pills burden. Serum parathyroid hormone (PTH) declined over time from a median value of 636 pg/mL to 357 pg/mL. The median time for responders (intact PTH (iPTH) range: two to nine times the upper normal limit) was 53 days; the percentage of responders increased (from baseline 27% to 63%) being similar in switched-patients and naïve-patients. Few patients had symptomatic hypocalcemia requiring etelcalcetide withdrawal (four cases (3%) at 30-day control, two cases (2%) at 60-day, one case (1%) at 90-day control). Side effects with etelcalcetide were lower (3-4%) than that registered during cinacalcet treatment (53%). Etelcalcetide is a new therapeutic option for SHPT with low side effects and pills burden. Etelcalcetide may improve adherence to therapy, avoiding unremitting SHP. It remains to be assessed whether etelcalcetide may reduce parathyroidectomy, vascular calcification, or mortality. Being etelcalcetide very potent in suppressing PTH levels, even in severe SHPT, future studies should evaluate the potential risk of more adynamic bone disease during long-term therapy.