Anemia and mortality in hemodialysis patients: Accounting for morbidity and treatment variables updated over time

Cardiovascular complications in chronic kidney disease: a review from the European Renal and Cardiovascular Medicine Working Group of the European Renal Association

Chronic kidney disease (CKD) is classified into five stages with kidney failure being the most severe stage (stage G5). CKD conveys a high risk for coronary artery disease, heart failure, arrhythmias, and sudden cardiac death. Cardiovascular complications are the most common causes of death in patients with kidney failure (stage G5) who are maintained on regular dialysis treatment. Because of the high death rate attributable to cardiovascular (CV) disease, most patients with progressive CKD die before reaching kidney failure. Classical risk factors implicated in CV disease are involved in the early stages of CKD. In intermediate and late stages, non-traditional risk factors, including iso-osmotic and non-osmotic sodium retention, volume expansion, anaemia, inflammation, malnutrition, sympathetic overactivity, mineral bone disorders, accumulation of a class of endogenous compounds called 'uremic toxins', and a variety of hormonal disorders are the main factors that accelerate the progression of CV disease in these patients. Arterial disease in CKD patients is characterized by an almost unique propensity to calcification and vascular stiffness. Left ventricular hypertrophy, a major risk factor for heart failure, occurs early in CKD and reaches a prevalence of 70-80% in patients with kidney failure. Recent clinical trials have shown the potential benefits of hypoxia-inducible factor prolyl hydroxylase inhibitors, especially as an oral agent in CKD patients. Likewise, the value of proactively administered intravenous iron for safely treating anaemia in dialysis patients has been shown. Sodium/glucose cotransporter-2 inhibitors are now fully emerged as a class of drugs that substantially reduces the risk for CV complications in patients who are already being treated with adequate doses of inhibitors of the renin-angiotensin system. Concerted efforts are being made by major scientific societies to advance basic and clinical research on CV disease in patients with CKD, a research area that remains insufficiently explored.

Clinical Significance of Trace Element Zinc in Patients with Chronic Kidney Disease

The trace element zinc is essential for diverse physiological processes in humans. Zinc deficiency can impair growth, skin reproduction, immune function, maintenance of taste, glucose metabolism, and neurological function. Patients with chronic kidney disease (CKD) are susceptible to zinc deficiency, which is associated with erythropoiesis-stimulating agent (ESA) hypo-responsive anemia, nutritional problems, and cardiovascular diseases as well as non-specific symptoms such as dermatitis, prolonged wound healing, taste disturbance, appetite loss, or cognitive decline. Thus, zinc supplementation may be useful for the treatment of its deficiency, although it often causes copper deficiency, which is characterized by several severe disorders including cytopenia and myelopathy. In this review article, we mainly discuss the significant roles of zinc and the association between zinc deficiency and the pathogenesis of complications in patients with CKD.

Hemoglobin and Clinical Outcomes in Hemodialysis: An Analysis of US Medicare Data From 2018 to 2020

Rationale & Objective

Anemia management in patients treated with maintenance dialysis remains a challenge. We sought to update information in this area by evaluating the association between hemoglobin and various outcome and utilization measures using data-rich Medicare sources.

Study Design

Observational cohort study using data from the Consolidated Renal Operations in a Web-enabled Network and Medicare claims.

Setting & Participants

We studied 371,250 prevalent patients treated with hemodialysis, covering 3,326,072 patient-months in 2019.

Exposure

Monthly patient hemoglobin concentrations.

Outcomes

We examined several outcomes, including mortality, all-cause hospitalization, cause-specific hospitalization, and emergency department utilization in the month following the exposure measurement.

Analytical Approach

For each monthly observation period, we calculated unadjusted and adjusted (for demographics and comorbid condition) hazard ratios using Cox regression.

Results

The hemoglobin concentration was <10.5 g/dL for 40% of observations. We found an inverse association between mortality and hemoglobin measured over a range from <9 g/dL (HR, 2.53; 95% CI, 2.45-2.61; P < 0.0001, reference = 10.5-11 g/dL) to 11-11.5 g/dL (HR, 0.92; 95% CI, 0.89-0.96; P < 0.0001). Mortality risk started to increase at hemoglobin levels >11.5 g/dL. All-cause hospitalization, cause-specific hospitalization (including cardiovascular, infection, and several subcategories including coronavirus disease 2019 hospitalization), and emergency department utilization were inversely associated with hemoglobin concentration, with risk reduction stabilizing at hemoglobin levels of approximately 11.5-12 g/dL and higher.

Limitations

As with prior observational studies, the observed associations are not necessarily causal.

Conclusions

In a large US hemodialysis population, there were better clinical outcomes at higher hemoglobin concentrations over short exposure and follow-up periods, consistent with other observational studies that generally used longer exposure and follow-up times. Mortality risk increased at hemoglobin concentrations >11.5 g/dL, consistent with findings from erythropoiesis-stimulating agent clinical trials. The apparently beneficial short-term effects associated with higher hemoglobin concentrations suggest that hemoglobin measurements capture unmeasured elements of patient risk.

A systemic review and meta-analysis on the efficacy and safety of ferumoxytol for anemia in chronic kidney disease patients

PURPOSE

To evaluate the efficacy of ferumoxytol, relative to conventional iron supplement formulations, on hemoglobin levels, ferritin level, and adverse event incidence in chronic kidney disease patients.

METHODS

We performed a systematic search of six academic databases (EMBASE, CENTRAL, Scopus, PubMed, Web of sciences, and MEDLINE), adhering to PRISMA guidelines. We performed a meta-analysis on relevant studies to evaluate the overall influence of ferumoxytol, relative to conventional iron supplement formulations, on hemoglobin levels, ferritin level, and treatment related treatment emergent adverse events (TEAEs) incidence in chronic kidney disease patients.

RESULTS

Seven eligible studies were identified from a total of 1397 studies. These studies contained data on 3315 participants with chronic kidney disease (mean age: 59.2 ± 4.6 years). A meta-analysis revealed that ferumoxytol administration had positive effects on hemoglobin levels (Hedge's g statistic: 0.51) and ferritin level (0.88), transferrin saturation (0.39). Besides, we also report reduced incidence of treatment related TEAEs (-0.24) for patients consuming ferumoxytol as compared conventional iron supplement formulations.

CONCLUSIONS

This meta-analysis provides preliminary evidence that ferumoxytol use exerts beneficial effects on the overall hematological outcomes in patients with chronic kidney disease. This study also reports improved treatment related safety profile for ferumoxytol when compared with conventional iron formulations. The findings from this study can have direct implications in forming best practice guidelines for managing anemia in patients with chronic kidney disease.

Efficacy, Safety and Pharmacoeconomic Analysis of Intravenous Ferric Carboxymaltose in Anemic Hemodialysis Patients Unresponsive to Ferric Gluconate Treatment: A Multicenter Retrospective Study

Patients undergoing hemodialysis with iron deficiency anemia (IDA) receiving treatment with erythropoiesis-stimulating agents (ESAs) who were intolerant or non-responsive to intravenous (i.v.) ferric gluconate (FG) (hemoglobin; Hb values < 10.5 g/dL or increase in <1 g/dL) or % transferrin saturation; TSAT of <20%) in the previous 6 months were switched to i.v. ferric carboxymaltose (FCM). Changes in iron status parameters, economic and safety measures were also assessed. Seventy-seven hemodialysis patients aged 68 ± 15 years were included. Erythropoietin resistance index decreased from 24.2 ± 14.6 at pre-switch to 20.4 ± 14.6 after 6 months of FCM treatment and Hb levels ≥10.5 g/dL improved from 61% to 75.3% patients (p = 0.042). A 1 g/dL increase in Hb levels was also seen in 26% of patients as well as a 37.7% increase in patients achieving >20% increase in TSAT after FCM. Levels of Hb, TSAT and ferritin parameters increased during FCM treatment with a concomitant decrease in ESA. A mixed-model analysis, which also considered gender, confirmed these trends. Safety variables remained stable, no hypersensitivity reaction was recorded and only one patient reported an adverse event after FCM. FCM treatment was associated with a cost saving of 11.11 EUR/patient/month. These results confirm the efficacy, safety and cost-effectiveness of FCM in correcting IDA in hemodialysis patients.

Association between haemoglobin concentration and intradialytic hypotension in patients undergoing maintenance haemodialysis: a retrospective cohort study

OBJECTIVES

Haemoglobin concentration is a potentially modifiable factor that may help lower the risk of intradialytic hypotension (IDH), but its association with IDH is not well understood. This study aimed to clarify the relationship between haemoglobin concentration and IDH.

DESIGN

Retrospective cohort study.

SETTING

We evaluated patients undergoing maintenance haemodialysis in December 2017 at Rakuwakai Otowa Kinen Hospital.

PARTICIPANTS

A total of 543 patients were included. We defined exposure according to the following five categories depending on haemoglobin concentrations by 1.0 increments: <9.0, ≥9.0 to <10.0, 10.0 to <11.0, ≥11.0 to <12.0 and ≥12.0 g/dL.

PRIMARY OUTCOME MEASURE

The primary outcome of interest was the development of IDH, defined as any nadir <100 mm Hg if the pre-dialysis systolic blood pressure (SBP) was ≥160 mm Hg or any nadir <90 mm Hg if the pre-dialysis SBP was <160 mm Hg (IDH_nadir).

RESULTS

Overall, IDH_nadir occurred in 14.3% (465/3250) of the sessions. With a haemoglobin concentration of ≥10.0 to <11.0 g/dL set as reference, the adjusted ORs for IDH_nadir were 0.82 (95% CI, 0.32 to 2.15), 1.16 (95% CI, 0.56 to 2.39), 1.26 (95% CI, 0.68 to 2.36) and 3.01 (95% CI, 1.50 to 6.07) for haemoglobin concentrations of <9.0, ≥9.0 to <10.0, ≥11.0 to <12.0 and ≥12.0 g/dL, respectively. In the cubic spline analysis, a high haemoglobin concentration was associated with the development of IDH_nadir.

CONCLUSION

High haemoglobin concentration is associated with IDH, and thus, the upper limit of haemoglobin concentration should be closely monitored in patients with IDH.

The association between the serum uric acid to creatinine ratio and all-cause mortality in elderly hemodialysis patients

BACKGROUND

Elderly hemodialysis patients have a higher rate of mortality than nonelderly hemodialysis patients. Recent studies shown that the serum uric acid to creatinine ratio (SUA/Scr) was associated with all-cause mortality in general adults. The purpose of the present study was to investigate the association between the SUA/Scr and all-cause and cardiovascular disease mortality among elderly hemodialysis patients.

METHODS

A total of 222 patients (≥ 60 years) who received hemodialysis more than 8 h per week at Taizhou Second People's Hospital for at least 3 months were enrolled in the present study from January 2015 to December 2019. Clinical characteristics including age, sex and height et. al, were obtained from the hemodialysis database. The laboratory data, including albumin (ALB), total cholesterol (TC), serum uric acid (SUA), serum creatinine (Scr) and so on, were collected before hemodialysis and analyzed by automatic biochemical analyzer. Survival information was recorded during the follow-up period. Multiple Cox regression was carried out to analyze the association between SUA/Scr and all-cause mortality. The survival rate of each group was calculated by the Kaplan-Meier method, and the ratio of survival curves was analyzed by the log-rank test. The contribution of SUA/Scr for predicting all-cause mortality risk was evaluated by net reclassification improvement (NRI).

RESULTS

During the 19-month observation period, 78 patients died. Individuals in the nonsurviving group had significantly older ages (P < 0.001), body mass index (BMI) (P = 0.004), serum creatinine (P = 0.005) and prealbumin (P = 0.006) than surviving patients. After adjusting for age, sex, BMI, prealbumin, dialysis vintage, dialysis frequency, single-pool Kt/V (spKt/V), DM, hypertension and comorbidities, a higher ratio of SUA/Scr was independently associated with a higher risk of all-cause mortality (HR: 1.292; 95% CI: 1.013-1.648; P = 0.039). The predict value on all-cause mortality of SUA/Scr was superior to SUA (additive NRI = 0.214, P = 0.015) and Scr (additive NRI = 0.476, P < 0.001) among elderly hemodialysis patients.

CONCLUSION

The serum uric acid to creatinine ratio is strongly associated with all-cause mortality in elderly hemodialysis patients which is more predictive than SUA or Scr alone.

An omics approach to study trace metals in sera of hemodialysis patients treated with erythropoiesis stimulating agents

Hemodialysis (HD) represents a life-sustaining treatment for patients with end stage renal disease. However, it is associated with several complications, including anemia. Erythropoiesis stimulating agents (ESA) are often administered to HD patients with renal anemia, but a relevant proportion of them fail to respond to the therapy. Since trace metals are involved in several biological processes and their blood levels can be altered by hemodialysis, we study the possible association between serum trace metal concentrations and ratios with the administration and response to ESA. For this study, data and sample information of 110 HD patients were downloaded from the UC San-Diego Metabolomics Workbench public repository (PR000565). The blood serum levels (and ratios) of antimony, cadmium, copper, manganese, molybdenum, nickel, selenium, tin and zinc were studied applying an omics statistical approach. The Random Forest model was able to discriminate HD dependent patients treated and not treated with ESA, with an accuracy of 71.7% (95% CI 71.5-71.9%). Logistic regression analysis identifies alterations of Mn, Mo, Cd, Sn, and several of their ratios as characteristic of patients treated with ESA. Moreover, patients with scarce response to ESA showed to be characterized by reduced Mn to Ni and Mn to Sb ratios. In conclusion, our results show that trace metals, in particular manganese, play a role in the mechanisms underlying human response to ESA, and if further confirmed, the re-equilibration of their physiological levels could contribute to a better management of HD patients hopefully reducing their morbidity and mortality.

Shortcoming of Measuring Patient Satisfaction's Association With Anemia-Based Cardiovascular Risk in End-Stage Kidney Disease Patients

Background

Patient-reported humanistic outcomes like patient satisfaction are becoming more important in clinical practice, but their use has limitations. Improvements are needed to better demonstrate how patient satisfaction and clinical outcomes are associated. The objective of the study was to observe the correlation between patient’s hemoglobin and patient satisfaction.

Methods

A cross-sectional study was conducted at a University Hospital hemodialysis unit among end-stage kidney disease (ESKD) patients on maintenance hemodialysis in February and March, 2021. During this time period patient satisfaction was measured using an instrument from the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) study. Spearman’s correlation coefficient was used to find a correlation between patient satisfaction domains and hemoglobin. P value was set at 0.05, and SPSS version 26 was used for the analysis.

Results

Out of 41 patients studied, their satisfaction on care by interprofessional staff was 77.3%, information received was 68.8%, and effectiveness of care was 71.3% for “very good” and “excellent” responses combined. Out of 40 patients, hemoglobin levels were lower in 17 (42.5%) and higher in seven (17.5%) patients than the optimal range of 10 - 12 g/dL. Spearman’s correlation coefficients were not statistically significant for anemia and any patient satisfaction domain (r_s: 0.244, 0.101, 0.048, respectively for the three domains). Spearman’s correlation coefficients were high or moderate between patient satisfaction domains; interprofessional staff with information (r_s: 0.745, P value < 0.001) and interprofessional staff with the effectiveness of care (r_s: 0.619, P value < 0.001). Information domain had a moderate correlation with the effectiveness of care (r_s: 0.527, P value < 0.001).

Conclusions

No correlation was observed between patient satisfaction with hemoglobin. Although patient satisfaction among hemodialysis patients was mostly “very good” or “excellent”, nearly half of the patients were anemic, and some had higher hemoglobin than the target. Since both of these groups have higher cardiovascular risk this provides an opportunity for the development of patient satisfaction tools with greater sensitivity to awareness of patients’ cardiovascular risk.

Erratum: Interdialytic Weight Gain Effects on Hemoglobin Concentration and Cardiovascular Events

[This corrects the article DOI: 10.1016/j.ekir.2021.05.015.][This corrects the article DOI: 10.1016/j.ekir.2020.07.027.].

Ultrafiltration rate adjusted to body weight and mortality in hemodialysis patients

BACKGROUND AND AIMS

Mortality among hemodialysis patients remains high. An elevated ultrafiltration rate adjusted by weight (UFR/W) has been associated with hypotension and higher risk of death and/or cardiovascular events.

METHODS

We evaluated the association between UFR/W and mortality in 215 hemodialysis patients. The mean follow-up was 28 ± 6.12 months. We collected patients' baseline characteristics and mean UFR/W throughout the follow-up.

RESULTS

Mean UFR/W was 9.0 ± 2,4 and tertiles 7.1 y 10.1 mL/kg/h. We divided our population according to the percentage of sessions with UFR/W above the limits described in the literature associated with increased mortality (10.0 ml/kg/h and 13.0 mL/kg/h). Patients with higher UFR/W were younger, with higher interdialytic weight gain and weight reduction percentage but lower dry, pre and post dialysis weight. Throughout the follow-up, 46 (21.4%) patients died, the majority over 70 years old, diabetic or with cardiovascular disease. There were neither differences regarding mortality between groups nor differences in UFR/W among patients who died and those who did not. Contrary to previous studies, we did not find an association between UFR/W and mortality, maybe due to a higher prevalence in the use of cardiovascular protection drugs and lower UFR/W.

CONCLUSIONS

The highest UFR/W were observed in younger patients with lower weight and were not associated with an increased mortality.

Relationships among the Dosage of Erythropoiesis-Stimulating Agents, Erythropoietin Resistance Index, and Mortality in Maintenance Hemodialysis Patients

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) constitute an important treatment option for anemia in hemodialysis (HD) patients. We investigated the relationships among the dosage of ESA, erythropoietin resistance index (ERI) scores, and mortality in Chinese MHD patients.

METHODS

This multicenter observational retrospective study included MHD patients from 16 blood purification centers (n = 824) who underwent HD in 2011-2015 and were followed up until December 31, 2016. We collected demographic variables, HD parameters, laboratory values, and ESA dosages. Patients were grouped into quartiles according to ESA dosage to study the effect of ESA dosage on all-cause mortality. The ERI was calculated as follows: ESA (IU/week)/weight (kg)/hemoglobin levels (g/dL). We also compared outcomes among the patients stratified into quartiles according to ERI scores. We used the Cox proportional hazards model to measure the relationships between the ESA dosage, ERI scores, and all-cause mortality. Using propensity score matching, we compared mortality between groups according to ERI scores, classified as either > or ≤12.80.

RESULTS

In total, 824 patients were enrolled in the study; 200 (24.3%) all-cause deaths occurred within the observation period. Kaplan-Meier analyses showed that patients administered high dosages of ESAs had significantly worse survival than those administered low dosages of ESAs. A multivariate Cox regression identified that high dosages of ESAs could significantly predict mortality (ESA dosage >10,000.0 IU/week, HR = 1.59, 95% confidence intervals (CIs) (1.04, 2.42), and p = 0.031). Our analysis also indicated a significant increase in the risk of mortality in patients with high ERI scores. Propensity score matching-analyses confirmed that ERI > 12.80 could significantly predict mortality (HR = 1.56, 95% CI [1.11, 2.18], and p = 0.010).

CONCLUSIONS

Our data suggested that ESA dosages >10,000.0 IU/week in the first 3 months constitute an independent predictor of all-cause mortality among Chinese MHD patients. A higher degree of resistance to ESA was related to a higher risk of all-cause mortality.

Development and Validation of a Transfusion Risk Score for Patients Receiving Maintenance Hemodialysis

BACKGROUND

In patients on dialysis with anemia, avoiding red blood cell transfusions is preferable. We sought to develop and validate a novel transfusion prediction risk score for patients receiving maintenance hemodialysis.

METHODS

This retrospective cohort study used United States Renal Data System data to create a model development cohort (patients who were point prevalent and on hemodialysis on November 1, 2012) and a validation cohort (patients who were point prevalent and on hemodialysis on August 1, 2013). We characterized comorbidity, inflammatory conditions, hospitalizations, anemia and anemia management, iron parameters, intravenous iron use, and vitamin D use during a 6-month baseline period to predict subsequent 3-month transfusion risk. We used logistic least absolute shrinkage and selection operator regression. In an exploratory analysis, model results were used to calculate a score to predict 6- and 12-month hospitalization and mortality.

RESULTS

Variables most predictive of transfusion were prior transfusion, hemoglobin, ferritin, and number of hospital days in the baseline period. The resulting c-statistic in the validation cohort was 0.74, indicating relatively good predictive power. The score was associated with a significantly increased risk of subsequent mortality (hazard ratios 1.0, 1.22, 1.26, 1.54, 1.71, grouped from lowest to highest score), but not with hospitalization.

CONCLUSIONS

We developed a transfusion prediction risk score with good performance characteristics that was associated with mortality. This score could be further developed into a clinically useful application, allowing clinicians to identify patients on hemodialysis most likely to benefit from a timely, proactive anemia treatment approach, with the goal of avoiding red blood cell transfusions and attendant risks of adverse clinical outcomes.

Ultrafiltration rate adjusted to body weight and mortality in hemodialysis patients

BACKGROUND AND AIMS

Mortality among hemodialysis patients remains high. An elevated ultrafiltration rate adjusted by weight (UFR/W) has been associated with hypotension and higher risk of death and/or cardiovascular events.

METHODS

We evaluated the association between UFR/W and mortality in 215 hemodialysis patients. The mean follow-up was 28 ± 6.12 months. We collected patientś baseline characteristics and mean UFR/W throughout the follow-up.

RESULTS

Mean UFR/W was 9.0 ± 2,4 and tertiles 7.1 y 10.1 mL/kg/h. We divided our population according to the percentage of sessions with UFR/W above the limits described in the literature associated with increased mortality (10.0 mL/kg/h and 13.0 mL/kg/h). Patients with higher UFR/W were younger, with higher interdialytic weight gain and weight reduction percentage but lower dry, pre and post dialysis weight. Throughout the follow-up, 46 (21.4%) patients died, the majority over 70 years old, diabetic or with cardiovascular disease. There were neither differences regarding mortality between groups nor differences in UFR/W among patients who died and those who did not. Contrary to previous studies, we did not find an association between UFR/W and mortality, maybe due to a higher prevalence in the use of cardiovascular protection drugs and lower UFR/W.

CONCLUSIONS

The highest UFR/W were observed in younger patients with lower weight and were not associated with an increased mortality.

Roxadustat for Treating Anemia in Patients with CKD Not on Dialysis: Results from a Randomized Phase 3 Study

BACKGROUND

Current anemia therapies for patients with non-dialysis-dependent CKD may require injection and medical visits. Roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, stimulates erythropoiesis and improves iron homeostasis.

METHODS

In this double-blind phase 3 study, we randomized patients with non-dialysis-dependent CKD stages 3-5 and hemoglobin <10.0 g/dl (1:1) to thrice-weekly 70-mg oral roxadustat or placebo. Doses were titrated throughout the study based on hemoglobin levels. The primary efficacy end point was mean change from baseline in hemoglobin averaged over weeks 28-52 versus placebo, irrespective of rescue therapy use. We assessed patients for adverse events.

RESULTS

The study included 2781 patients, 1393 who received roxadustat and 1388 who received placebo. Mean baseline hemoglobin was 9.1 g/dl for both groups. The mean change in hemoglobin from baseline was 1.75 g/dl (95% confidence interval [95% CI], 1.68 to 1.81) with roxadustat versus 0.40 g/dl (95% CI, 0.33 to 0.47) with placebo, (P<0.001). Among 411 patients with baseline elevated high-sensitivity C-reactive protein, mean change in hemoglobin from baseline was 1.75 g/dl (95% CI, 1.58 to 1.92) with roxadustat versus 0.62 g/dl (95% CI, 0.44 to 0.80) with placebo, (P<0.001). Roxadustat reduced the risk of red blood cell transfusion by 63% (hazard ratio, 0.37; 95% CI, 0.30 to 0.44). The most common adverse events with roxadustat and placebo, respectively, were ESKD (21.0% versus 20.5%), urinary tract infection (12.8% versus 8.0%), pneumonia (11.9% versus 9.4%), and hypertension (11.5% versus 9.1%).

CONCLUSIONS

Roxadustat effectively increased hemoglobin in patients with non-dialysis-dependent CKD and reduced the need for red blood cell transfusion, with an adverse event profile comparable to that of placebo.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With CKD, Not on Dialysis, NCT02174627.

Interdialytic Weight Gain Effects on Hemoglobin Concentration and Cardiovascular Events

Introduction

Although predialysis hemoglobin concentration is affected by interdialytic weight gain (IDWG), the interaction between these parameters is not well understood.

Methods

Using data from the Japanese Dialysis Outcomes and Practice Pattern Study phases 1-5, we analyzed patients who underwent maintenance hemodialysis. The exposure variable was hemoglobin concentration, and the effect modifier was IDWG at baseline. These 2 categorical variables were then combined and analyzed. The primary outcome was major adverse cardiovascular events (MACEs). Hazard ratios were estimated using a Cox model for the association between exposure and MACEs after adjusting for potential confounders. We examined additive interactions between hemoglobin concentration and IDWG by calculating the relative excess risk due to interaction, which is defined as a departure from the additivity of effects.

Results

A total of 8234 patients were enrolled. During a median follow-up of 2.1 years, 1062 (12.9%) patients developed MACEs. In IDWG categories of <6%, adjusted hazard ratios for MACEs tended to be lower as hemoglobin concentration increased. In IDWG categories of ≥6%, point estimation of MACEs with hemoglobin concentration of ≥11.0 g/dl-<12.0 g/dl was higher than that with hemoglobin concentration of ≥10.0 g/dl-<11.0 g/dl. The relative excess risk due to interaction was 0.22 (95% confidence interval 0.02-0.42) between IDWG category of ≥6% and hemoglobin categories of ≥11.0 g/dl-<12.0 g/dl, indicating a synergistic interaction.

Conclusions

The association between hemoglobin concentration and MACEs differed across IDWG. Consideration should be given to the upper limit of hemoglobin concentration in patients with high IDWG.

The Impact of CKD Anaemia on Patients: Incidence, Risk Factors, and Clinical Outcomes-A Systematic Literature Review

Anaemia is a common consequence of chronic kidney disease (CKD); however, the risk factors for its development and its impact on outcomes have not been well synthesised. Therefore, we undertook a systematic review to fully characterise the risk factors associated with the presence of anaemia in patients with CKD and a contemporary synthesis of the risks of adverse outcomes in patients with CKD and anaemia. We searched MEDLINE, EMBASE, and the Cochrane Library from 2002 until 2018 for studies reporting the incidence or prevalence of anaemia and associated risk factors and/or associations between haemoglobin (Hb) or anaemia and mortality, major adverse cardiac events (MACE), hospitalisation, or CKD progression in adult patients with CKD. Extracted data were summarised as risk factors related to the incidence or prevalence of anaemia or the risk (hazard ratio (HR)) of outcome by Hb level (<10, 10-12, >12 g/dL) in patients not on dialysis and in those receiving dialysis. 191 studies met the predefined inclusion criteria. The risk factor most associated with the prevalence of anaemia was CKD stage, followed by age and sex. Mean HRs (95% CI) for all-cause mortality in patients with CKD on dialysis with Hb <10, 10-12, and >12 g/dL were 1.56 (1.43-1.71), 1.17 (1.09-1.26), and 0.91 (0.87-0.96), respectively. Similar patterns were observed for nondialysis patients and for the risks of hospitalisation, MACE, and CKD progression. This is the first known systematic review to quantify the risk of adverse clinical outcomes based on Hb level in patients with CKD. Anaemia was consistently associated with greater mortality, hospitalisation, MACE, and CKD progression in patients with CKD, and risk increased with anaemia severity. Effective treatments that not only treat the anaemia but also reduce the risk of adverse clinical outcomes are essential to help reduce the burden of anaemia and its management in CKD.

Frailty in hemodialysis and prediction of poor short-term outcome: mortality, hospitalization and visits to hospital emergency services

Background: Frailty is an aging-associated state of increased vulnerability, which raises the risk of adverse outcomes. Chronic kidney disease is associated with higher prevalence of frailty. Our aim was to estimate frailty prevalence in a hemodialysis population and its influence on short-term outcomes.

Design: Observational prospective longitudinal study of 277 prevalent hemodialysis patients. Frailty was estimated through the Edmonton Frail Scale (EFS). Demographic and clinical data, comorbidity index, and laboratory parameters were recorded. A 29-month follow-up was conducted on mortality, including hospitalization, and visits to hospital emergency services in the first 12 months of this period.

Results: According to the EFS, 82 patients (29.6%) were frail, 53 (19.1%) were vulnerable, and 142 (51.3%) were non-frail. During follow-up, 58.5% frail patients, 30.2% vulnerable, and 16.2% non-frail ones died (p < .005). In the analysis of survival using an adjusted Cox model, a higher hazard of mortality was observed in frail than in non-frail patients (HR 2.34; 95% CI 1.39–3.95; p = .001). During follow-up the hospitalization rate was 852 episodes/1000 patient-years for frail patients, 784 episodes/1000 patient-years for vulnerable patients, and 417 episodes/1000 patient-years for non-frail patients (p = .0005). The incidence ratio of visits to emergency services was 3216, 1735, and 1545 visits/1000 patient-years for each group (p < .001).

Conclusions: Hemodialysis patients present high frailty prevalence. Frailty is associated with poor short-term outcomes and higher rates of mortality, visits to hospital emergency services, and hospitalization.

A Microfluidic Deformability Assessment of Pathological Red Blood Cells Flowing in a Hyperbolic Converging Microchannel

The loss of the red blood cells (RBCs) deformability is related with many human diseases, such as malaria, hereditary spherocytosis, sickle cell disease, or renal diseases. Hence, during the last years, a variety of technologies have been proposed to gain insights into the factors affecting the RBCs deformability and their possible direct association with several blood pathologies. In this work, we present a simple microfluidic tool that provides the assessment of motions and deformations of RBCs of end-stage kidney disease (ESKD) patients, under a well-controlled microenvironment. All of the flow studies were performed within a hyperbolic converging microchannels where single-cell deformability was assessed under a controlled homogeneous extensional flow field. By using a passive microfluidic device, RBCs passing through a hyperbolic-shaped contraction were measured by a high-speed video microscopy system, and the velocities and deformability ratios (DR) calculated. Blood samples from 27 individuals, including seven healthy controls and 20 having ESKD with or without diabetes, were analysed. The obtained data indicates that the proposed device is able to detect changes in DR of the RBCs, allowing for distinguishing the samples from the healthy controls and the patients. Overall, the deformability of ESKD patients with and without diabetes type II is lower in comparison with the RBCs from the healthy controls, with this difference being more evident for the group of ESKD patients with diabetes. RBCs from ESKD patients without diabetes elongate on average 8% less, within the hyperbolic contraction, as compared to healthy controls; whereas, RBCs from ESKD patients with diabetes elongate on average 14% less than the healthy controls. The proposed strategy can be easily transformed into a simple and inexpensive diagnostic microfluidic system to assess blood cells deformability due to the huge progress in image processing and high-speed microvisualization technology.

Haemoglobin concentration and survival of haemodialysis patients before and after experiencing cardiovascular disease: a cohort study from Japanese dialysis outcomes and practice pattern study (J-DOPPS)

OBJECTIVES

Differences in the association of haemoglobin concentration with mortality or adverse cardiovascular events in haemodialysis patients before and after experiencing cardiovascular disease are unclear. We aimed to assess the influence of cardiovascular-comorbid condition on the association between haemoglobin concentration and mortality.

DESIGN

A prospective cohort study.

SETTING

The Dialysis Outcomes and Practice Patterns Study Dialysis in phases 2 to 4 (2002 to 2011), including 80 randomly selected dialysis facilities in Japan (J-DOPPS).

PARTICIPANTS

5515 adult haemodialysis patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was all-cause mortality. Cardiovascular mortality and adverse cardiovascular events were also evaluated. The association of these outcomes with haemoglobin concentration, categorised into six classes by 1.0 g/dL units, and cardiovascular-comorbid condition, treated as a time-dependent variable updated every 4 months, was evaluated. Adjusted hazard ratios (aHRs) were computed using a time-dependent Cox model with interaction test for cardiovascular comorbidity.

RESULTS

Over a median 2.0 years, 847 all-cause and 326 cardiovascular deaths, and 1000 adverse cardiovascular events occurred. Compared with haemoglobin 11.0 to 11.9 g/dL, the aHRs of mortality at the lowest range (<9.0 g/dL) were 1.29 (95% CI 0.95 to 1.76) and 2.11 (95% CI 1.47 to 3.06) in cardiovascular-comorbid and non-cardiovascular-comorbid patients, respectively (p=0.04 for cardiovascular-comorbid interaction), with increased cardiovascular mortality in both groups. At the second-lowest range (9.0 to 9.9 g/dL), mortality was increased only in non-cardiovascular-comorbid patients. Respective risks for mortality and adverse cardiovascular events at the second-highest range (12.0 to 12.9 g/dL) were non-significant but increased in both groups, while adverse cardiovascular events were increased at the highest range (≥13.0 g/dL) in non-cardiovascular-comorbid patients.

CONCLUSIONS

The association of low haemoglobin concentration with all-cause mortality differed between haemodialysis patients with and without cardiovascular comorbidity. Cardiovascular-comorbid condition should be considered when the association of haemoglobin concentration with mortality is addressed.

Association between Severe Anemia and Outcomes of Hemodialysis Vascular Access

BACKGROUND

The vast majority of patients undergoing hemodialysis (HD) are anemic. The severity of anemia in these patients may influence the postoperative outcomes and the durability of vascular access. Thus, the purpose of this study is to assess the association between anemia and adverse outcomes in patients undergoing HD access placement (arteriovenous grafts and fistula).

METHODS

Patients with chronic kidney disease stages IV and V recorded in the Vascular Quality Initiative Hemodialysis database between 2011 and 2017 were included. Patients were divided into 3 study groups based on preoperative hemoglobin (Hgb) levels: normal/mild anemia (Hgb: females ≥10 g/dL, males ≥12 g/dL), moderate anemia (Hgb: females: 7-9.9 g/dL, males: 9-11.9 g/dL), and severe anemia (Hgb: females<7 g/dL, males<9 g/dL). Multivariable logistic and Cox regression analyses were implemented to evaluate the association between anemia and 30-day mortality and primary patency (PP) at 1 year.

RESULTS

A total of 28,000 patients undergoing HD access surgery were identified (normal/mild [42%], moderate [49%], and severe [9%] anemia). Postoperative bleeding (2.1% vs. 2.2% vs. 2.2%) and 30-day outcomes including swelling (0.4% vs. 0.5% vs. 0.7%) and wound infection (0.4% vs. 0.3% vs. 0.1%) were similar in mild/normal, moderate, and severe anemia groups, respectively (All P > 0.05). However, 30-day mortality was significantly higher in patients with severe anemia compared with normal/mild and moderate anemia (2.1% vs. 1.1% and 1.1%, P < 0.001). After adjusting for potential confounders, severe anemia was associated with 90% higher risk of 30-day mortality (odds ratio [95% confidence interval]: 1.90 [1.20-3.00], P = 0.006) and 17% increase in PP loss at 1 year (adjusted hazard ratio [95% confidence interval]: 1.17 [1.02-1.35], P = 0.01) compared with the normal/mild anemia group. However, no significant difference was seen between normal/mild and moderate anemia.

CONCLUSIONS

In this large study of patients undergoing HD access placement, severe anemia was associated with 90% increased risk of 30-day mortality and 17% increased risk of loss of PP compared with those with normal/mild anemia. Management of severe anemia before surgery might be indicated to reduce operative mortality and improve the durability of HD access.

Exploring causality mechanism in the joint analysis of longitudinal and survival data

In many biomedical studies, disease progress is monitored by a biomarker over time, eg, repeated measures of CD4 in AIDS and hemoglobin in end-stage renal disease patients. The endpoint of interest, eg, death or diagnosis of a specific disease, is correlated with the longitudinal biomarker. In this paper, we examine and compare different models of longitudinal and survival data to investigate causal mechanisms, specifically, those related to the role of random effects. We illustrate the methods by data from two clinical trials: an AIDS study and a liver cirrhosis study.

Continuous erythropoiesis receptor activator (CERA) for the anaemia of chronic kidney disease

BACKGROUND

Continuous erythropoiesis receptor activator (CERA) is a newer, longer acting ESA which might be preferred to other ESAs (epoetin or darbepoetin) based on its lower frequency of administration. Different dosing requirements and molecular characteristics of CERA compared with other ESAs may lead to different health outcomes (mortality, cardiovascular events, quality of life) in people with anaemia and chronic kidney disease (CKD).

OBJECTIVES

To assess benefits and harms of CERA compared with other epoetins (darbepoetin alfa and epoetin alfa or beta) or placebo/no treatment or CERA with differing strategy of administration for anaemia in individuals with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 13 June 2017 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least three months' duration, comparing CERA with a different ESA (darbepoetin alfa or epoetin alfa or beta) or placebo or standard care or versus CERA with different strategies for administration in people with any stage of CKD.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent investigators. We summarised patient-centred outcomes (all-cause and cardiovascular mortality, major adverse cardiovascular events, red cell blood transfusion, iron therapy, cancer, hypertension, seizures, dialysis vascular access thrombosis, drug injection-related events, hyperkalaemia and health-related quality of life and haemoglobin levels) using random effects meta-analysis. Treatment estimates were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean differences or standardized mean difference with 95% CI for continuous outcomes.

MAIN RESULTS

We included 27 studies involving 5410 adults with CKD. Seven studies (1273 participants) involved people not requiring dialysis, 19 studies (4209 participants) involved people treated with dialysis and one study (71 participants) evaluated treatment in recipients of a kidney transplant. Treatment was given for 24 weeks on average. No data were available for children with CKD. Studies were generally at high or unclear risk of bias from allocation concealment and blinding of outcomes. Only two studies masked participants and investigators to treatment allocation. One study compared CERA with placebo, nine studies CERA with epoetin alfa or beta, nine studies CERA with darbepoetin alfa, and two studies compared CERA with epoetin alfa or beta and darbepoetin alfa. Three studies assessed the effects of differing frequencies of CERA administration and five assessed differing CERA doses.There was low certainty evidence that CERA had little or no effects on mortality (RR 1.07, 95% CI 0.73 to 1.57; RR 1.11, 95% CI 0.75 to 1.65), major adverse cardiovascular events (RR 5.09, 95% CI 0.25 to 105.23; RR 5.56, 95% CI 0.99 to 31.30), hypertension (RR 1.01, 95% CI 0.75 to 1.37; RR 1.00, 95% CI 0.79 to 1.28), need for blood transfusion (RR 1.02, 95% CI 0.72 to 1.46; RR 0.94, 95% CI 0.55 to 1.61), or additional iron therapy (RR 1.03, 95% CI 0.91 to 1.15; RR 0.99, 95% CI 0.95 to 1.03) compared to epoetin alfa/beta or darbepoetin alfa respectively. There was insufficient evidence to compare the effect of CERA to placebo on clinical outcomes. Only one low quality study reported that CERA compared to placebo might lead to little or no difference in the risk of major cardiovascular events (RR 2.97, 95% CI 0.31 to 28.18) and hypertension ((RR 0.73, 95% CI 0.35 to 1.52). There was low certainty evidence that different doses (higher versus lower) or frequency (twice versus once monthly) of CERA administration had little or no different effect on all-cause mortality (RR 3.95, 95% CI 0.17 to 91.61; RR 0.97, 95% CI 0.56 to 1.66), hypertension (RR 0.45, 95% CI 0.08 to 2.52; RR 0.85, 95% CI 0.60 to 1.21), and blood cell transfusions (RR 4.16, 95% CI 0.89 to 19.53; RR 0.91, 95% CI 0.51 to 1.62). No studies reported comparative treatment effects of different ESAs on health-related quality of life.

AUTHORS' CONCLUSIONS

There is low certainty evidence that CERA has little or no effects on patient-centred outcomes compared with placebo, epoetin alfa or beta or darbepoetin alfa for adults with CKD. The effects of CERA among children who have CKD have not studied in RCTs.

Pathological and molecular mechanisms underlying resistance to recombinant human erythropoietin therapy in the remnant kidney rat model of chronic kidney disease associated anemia

Anemia of chronic kidney disease (CKD) can be corrected by treatment with recombinant human erythropoietin (rHuEPO); however, some patients become hyporesponsive. The molecular mechanisms underlying this resistance remain to be elucidated. Our aim was to study hyporesponsiveness to rHuEPO therapy using the remnant kidney rat model of anemia associated with CKD induced by 5/6 nephrectomy. At starting, male Wistar rats were divided in 3 groups, for a 3-week protocol: Sham, CRF (vehicle) and two rHuEPO (200 k/kg body weight [BW]/week) treated groups; at the end of protocol, the rHuEPO treated rats were subdivided in responders (CRF200) and non-responders (CRF200NR), according to their hematologic response; blood, cellular and tissue studies were performed. The CRF200 group achieved correction of anemia, while the CRF200NR group developed anemia, after an initial response (1st week) to rHuEPO therapy. CRF and CRF200NR groups presented a trend to higher serum CRP levels; CRF200NR showed also high levels of renal inflammatory markers, such as interleukin (IL)-6, IL-1β, nuclear factor kappa B, connective tissue growth factor (CTGF) and transforming growth factor beta 1 (TGF-β1); no changes were found in iron metabolism. Our data suggest that the development of anemia/rHuEPO hyporesponsiveness is associated with a higher systemic and renal inflammatory condition, favoring hypoxia and triggering an increase in renal expression of HIF-1α, TGF-β1 and CTGF that will further aggravate renal fibrosis, which will enhance the inflammatory response, creating a cycle that promotes disease progression. New therapeutic strategies to reduce inflammation in CKD patients could improve the response to rHuEPO therapy and reduce hyporesponsiveness.

Predictor of cardiovascular risks in end stage renal failure patients on maintenance dialysis

Objective:

Cardiovascular disease (CVD) is the main cause of morbidity and premature mortality in end stage renal failure patients (ESRD) receiving dialysis. The aim of our study was to evaluate the impact of various risk factors in this group of high CVD risk patients in local population.

Methods:

We carried out a cross-sectional retrospective study in a single hospital. A total of 136 ESRF patients, consisted of 43 haemodialysis (HD) and 93 continuous ambulatory peritoneal dialysis (CAPD) patients, were recruited and followed up for 36 months duration. Midweek clinical and laboratory data were collected. The occurrence of existing and new CVD events was recorded.

Results:

Multiple Logistic Regression showed pre-existing cardiovascular event (odds ratio, 4.124; 95% confidence interval [CI], 0.990 to 17.187), elevated total cholesterol level (odds ratio, 0.550; 95% CI, 0.315 to 0.963), elevated serum phosphate level (odds ratio, 5.862; 95% CI, 1.041 to 33.024) and elevated random blood glucose level (odds ratio, 1.193; 95% CI, 1.012 to 1.406) were significantly associated with occurrence of CVD events.

Conclusions:

History of cardiovascular event before the initiation of dialysis, elevated level of serum phosphate and random blood glucose levels are the risk factors of CVD whereas paradoxically a high total cholesterol level has CVD protective effect towards the ESRF patients.

The Korean Clinical Research Center for End-Stage Renal Disease Study Validates the Association of Hemoglobin and Erythropoiesis-Stimulating Agent Dose with Mortality in Hemodialysis Patients

Background

Anemia is an important risk factor for mortality in hemodialysis (HD) patients. However, higher hemoglobin (Hb) is not necessarily better, as seen in several studies. This study aimed to validate the clinical use of an Hb target of 10–11 g/dL in Korean HD patients.

Methods

A total of 1,276 HD patients from the Clinical Research Center (CRC) for End-Stage Renal Disease (ESRD) were investigated in a prospective observational study. Cox proportional hazard analysis was conducted for each category of time-dependent Hb level and erythropoiesis-stimulating agent (ESA) dose, with subgroup analysis stratified by age and diabetes status.

Results

Using a reference Hb level of 10–11 g/dL, the hazard ratios (HRs) of death were 5.12 (95% confidence interval [CI], 2.62–10.02, P <0.05) for Hb level <9.0 g/dL, and 2.03 (CI, 1.16–3.69, P <0.05) for Hb level 9.0–10.0 g/dL, after adjustment for multiple clinical variables. However, an Hb level ≥11 g/dL was not associated with decreased mortality risk. In an adjusted model categorized by Hb and ESA dose, the risk of death at an Hb level <10 g/dL and a higher dose of ESA (≥126 U/kg/week) had an HR of 2.25 (CI, 1.03–4.92, P <0.05), as compared to Hb level 10–11 g/dL and a lower dose of ESA. In subgroup analysis, those older than 65 years or who were diabetic had greater risk for mortality only in Hb category <9.0 g/dL. However, there was no significant interaction between age or diabetes status and Hb.

Conclusion

Using CRC-ESRD data, we validated the association between Hb and ESA dose and mortality in Korean HD patients. The clinical practice target of an Hb of 10–11 g/dL before the new KDIGO guideline era seems reasonable considering its survival benefit in HD patients.

Relationship of Neutrophil-to-Lymphocyte Ratio and Serum Albumin Levels with C-Reactive Protein in Hemodialysis Patients: Results from 2 International Cohort Studies

BACKGROUND/AIM

The neutrophil-to-lymphocyte ratio (NLR), defined as the neutrophil count divided by lymphocyte count, is an inexpensive and readily available parameter, which may serve as a surrogate for inflammation markers, such as C-reactive protein (CRP). The aim of this study was to determine the utility of NLR in the prediction of elevated CRP levels in hemodialysis (HD) patients.

METHODS

We analyzed 43,272 HD patients from 2 distinct cohorts within the Monitoring Dialysis Outcomes research collaboration in whom contemporaneous measurements of neutrophil and lymphocyte counts, serum albumin and CRP levels were available. Logistic regression was used to determine the relationship of trichotomized NLR (<2.5, 2.5-5 and >5.0) and albumin levels (<3.1, 3.1-4.0 and >4.0 g/dl) with elevated CRP levels (>10.0, >20.0 and >30.0 mg/l). Congruence of the prediction models was examined by comparing the regression parameters and by cross-validating each regression equation within the other cohort.

RESULTS

We found that NLR >5.0 vs. <2.5 (cohort 1: OR 2.3; p < 0.0001 and cohort 2: OR 2.0; p < 0.0001) was associated with CRP levels >10.0 mg/l. Stepwise increase in odds ratio for CRP >10.0 mg/l was observed with the combination of high NLR and low albumin levels (NLR >5.0 and albumin <3.1) (cohort 1: OR 7.6; p < 0.0001 and cohort 2: OR 11.9; p < 0.0001). Cross-validation of the 2 regression models revealed a predictive accuracy of 0.68 and 0.69 in the respective cohorts.

CONCLUSION

This study suggests that NLR could serve as a potential surrogate marker for CRP. Our results may add to diagnostic abilities in settings where CRP is not measured routinely in HD patients. NLR is easy to integrate into daily practice and may be used as a marker of systemic inflammation.

"Out of Sight, Out of Mind": The Failed Renal Allograft as a Cause of ESA Resistance

Approximately 10% of patients treated with erythropoiesis‐stimulating agents (ESAs) for the anemia of chronic kidney disease are unresponsive or relatively resistant to therapy. The etiology of this is usually linked to iron deficiency or an independent underlying illness. We describe a hemodialysis patient with a failed renal transplant 1.5 years earlier, who developed progressive erythropoietin resistance and anemia without an apparent cause. He simultaneously developed nonspecific malaise and fatigue. By exclusion, the only possible cause of these signs and symptoms was inflammation from acute and chronic rejection in the retained failed renal allograft. Following pulse steroids and transplant nephrectomy, the patient's symptoms resolved and both his hemoglobin improved and his erythropoietin requirements decreased significantly. The patient never required a blood transfusion and was successfully relisted for a deceased donor renal transplant. Hence, inflammation from a retained transplant allograft may be an under‐recognized cause of erythropoietin resistance in dialysis patients. Although transplant nephrectomy remains a controversial practice due to concerns of alloantibody production, it may be considered in patients with failed renal allografts and anemia refractory to treatment with ESAs.

Iron-hepcidin dysmetabolism, anemia and renal hypoxia, inflammation and fibrosis in the remnant kidney rat model

Anemia is a common complication of chronic kidney disease (CKD) that develops early and its severity increases as renal function declines. It is mainly due to a reduced production of erythropoietin (EPO) by the kidneys; however, there are evidences that iron metabolism disturbances increase as CKD progresses. Our aim was to study the mechanisms underlying the development of anemia of CKD, as well as renal damage, in the remnant kidney rat model of CKD induced by 5/6 nephrectomy. This model of CKD presented a sustained degree of renal dysfunction, with mild and advanced glomerular and tubulointerstitial lesions. Anemia developed 3 weeks after nephrectomy and persisted throughout the protocol. The remnant kidney was still able to produce EPO and the liver showed an increased EPO gene expression. In spite of the increased EPO blood levels, anemia persisted and was linked to low serum iron and transferrin levels, while serum interleukin (IL)-6 and high sensitivity C-reactive protein (hs-CRP) levels showed the absence of systemic inflammation. The increased expression of duodenal ferroportin favours iron absorption; however, serum iron is reduced which might be due to iron leakage through advanced kidney lesions, as showed by tubular iron accumulation. Our data suggest that the persistence of anemia may result from disturbances in iron metabolism and by an altered activity/function of EPO as a result of kidney cell damage and a local inflammatory milieu, as showed by the increased gene expression of different inflammatory proteins in the remnant kidney. In addition, this anemia and the associated kidney hypoxia favour the development of fibrosis, angiogenesis and inflammation that may underlie a resistance to EPO stimuli and reduced iron availability. These findings might contribute to open new windows to identify putative therapeutic targets for this condition, as well as for recombinant human EPO (rHuEPO) resistance, which occurs in a considerable percentage of CKD patients.

Use of Aspirin in normalization of recombinant human erythropoietin-mediated hyper-reactivity of platelets in rats

Objectives:

The cytokine erythropoietin is the primary stimulator of erythropoiesis and recombinant human erythropoietin (rHuEPO), which is widely used in the treatment of anemia associated with advanced chronic kidney disease (CKD). Adverse cardiovascular outcomes have been observed during clinical trials of anemia correction with rHuEPO in CKD patients. We investigated the effects of short-term, high-dose treatment with rHuEPO on platelet reactivity and effects of aspirin on platelet reactivity in healthy rats.

Materials and Methods:

Animals received three daily dose of rHuEPO (25 μg/kg s.c.). Platelets were isolated after 48 h of last dose of rHuEPO to study the arachidonic acid-induced platelet aggregation. Aspirin (75 mg/kg p.o.) was given to animals just before 1 h of isolation of platelets.

Results:

In rats, treatment with rHuEPO increased platelet reactivity and platelet count. The increased platelet reactivity was paralleled by decreased time-to-occlusion (TTO) in arterial thrombosis model, and decreased bleeding time after tail transection in rats. Treatment with rHuEPO followed by single dose of aspirin showed significant reduction in TTO and bleeding time as compared with aspirin-treated group.

Conclusions:

These findings suggest that rHuEPO increases platelet reactivity and aspirin normalizes the hyper-reactive platelet and may reduce the cardiovascular events associated with rHuEPO in CKD patients.

Role of alpha-lipoic acid in the management of anemia in patients with chronic renal failure undergoing hemodialysis

Introduction

Anemia associated with chronic kidney disease is a serious complication necessitating expenditure of huge medical efforts and resources. This study investigates the role of alpha-lipoic acid (ALA) in end stage renal disease patients undergoing hemodialysis. By the virtue of its antioxidative effects, ALA is expected to act as an erythropoietin (EPO) adjuvant, and also has extended beneficial effects on endothelial dysfunction.

Methods

Forty-four patients undergoing hemodialysis and receiving EPO were randomized into two groups: the first group received ALA 600 mg once daily for 3 months; while the other group represented the control group. Parameters measured at baseline and at end of study were hemoglobin, EPO doses, EPO resistance index (ERI), iron store indices, malondialdehyde, oxidized low-density lipoprotein (ox-LDL), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and asymmetric dimethylarginine (ADMA), as well as routine laboratory follow-up.

Results

EPO doses and ERI were significantly decreased in the treatment group, while they did not change in the control group. Hemoglobin, iron store indices, malondialdehyde, oxidized ox-LDL, IL-6, TNF-α, and ADMA were similar in both treatment and control groups at baseline, and did not change by the end of study period. Likewise, routine laboratory measures were not affected by the treatment.

Conclusion

ALA could be used in hemodialysis patients to reduce requirements for EPO. However, larger and longer term studies are required to clarify the exact role of ALA in hemodialysis as well as in pre-hemodialysis patients.

Hepatitis C virus treatment and survival in patients with hepatitis C and human immunodeficiency virus co-infection and baseline anaemia

The impact of pretreatment anaemia on survival in individuals with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection is not known. Moreover, HCV treatment is offered less frequently to individuals with anaemia, due to haematological side effects of the treatment regimen. This study aimed to determine the effect of HCV treatment on survival among HCV/HIV co-infected individuals with pretreatment anaemia using the Electronically Retrieved Cohort of HCV-Infected Veterans (ERCHIVES). Individuals with HCV/HIV co-infection were included in current analyses. Participants were considered treated if they were prescribed ≥ 4 weeks of HCV treatment. All-cause mortality data were obtained using record linkage. Survival analyses were performed using Cox proportional hazard models. Among 5000 HCV/HIV co-infected individuals, 1671 (33.4%) had pretreatment anaemia. In a follow-up period of up to 7 years (19,500 person-years), individuals with anaemia had significantly higher mortality rate compared with those without anaemia [144.2 (95% CI: 134.5-154.7) vs 47.5 (44.0-51.2) per 1000 person-years, respectively]. Among individuals with anaemia, HCV treatment was associated with significantly lower mortality rate [66.6 (44.3-100.2) vs 149.6 (139.2-160.5) per 1000 person-years, for treated vs untreated, respectively]. Treatment remained associated with substantial survival benefit after taking into account the effect of multiple comorbidities (hazards ratio: 0.34, 95% CI: 0.21-0.62). These data suggest that HCV/HIV co-infected individuals with pretreatment anaemia have significantly higher mortality compared with those without anaemia. HCV treatment is associated with substantial survival benefit in this group. Additional studies are needed to determine strategies to improve HCV treatment rates among this group.

Relationship between responsiveness to erythropoiesis-stimulating agent and long-term outcomes in chronic hemodialysis patients: a single-center cohort study

BACKGROUND

Responsiveness to erythropoietin-stimulating agent (ESA) may be associated with mortality risk in hemodialysis (HD) patients. The aim of the present study was to assess the relationship between responsiveness to ESA and long-term outcome in chronic HD patients.

METHODS

Patients on HD therapy for more than 6 months were enrolled in this cohort study. The first year was used to assess the longitudinal dialysis status of patients; the subsequent years were used to assess the time-dependent risk of all-cause mortality. Hazard ratios were estimated using a Cox proportional model for the association between ESA dose and hemoglobin (Hb) level and mortality, adjusting for potential confounders. The ESA resistance index (ERI) was determined as the weekly weight-adjusted dose of ESA divided by Hb concentration. Patients were divided into three groups by tertiles of ERI.

RESULTS

Of the 320 subjects enrolled, 105 died during the follow-up period of 70.4 ± 29.0 months. When subjects were stratified by epoetin dose and Hb level into four groups, those who had low Hb despite a high dose of epoetin were associated with the highest risk of mortality among the four groups (adjusted hazard ratio 1.86; 95 % confidence interval 1.25-2.75). These highest risk subjects had older age, lower body mass index, and lower serum levels of albumin, triglyceride, and transferring saturation. The impact of serum albumin and serum ferritin on mortality risk in an adjusted Cox proportional hazards model was in accordance with low Hb and higher ESA. There was no significant difference between the mortality risk and tertile of ERI.

CONCLUSIONS

High ESA dose and low Hb level were associated with an increased risk of all-cause mortality. However, the responsiveness to ESA estimated by ERI was not related to mortality risk. These findings suggest that the responsiveness to ESA should be evaluated by different methods in HD patients.

An economic evaluation of intravenous versus oral iron supplementation in people on haemodialysis

BACKGROUND

Iron supplementation can be administered either intravenously or orally in patients with chronic kidney disease (CKD) and iron deficiency anaemia, but practice varies widely. The aim of this study was to estimate the health care costs and benefits of parenteral iron compared with oral iron in haemodialysis patients receiving erythropoiesis-stimulating agents (ESAs).

METHODS

Using broad health care funder perspective, a probabilistic Markov model was constructed to compare the cost-effectiveness and cost-utility of parenteral iron therapy versus oral iron for the management of haemodialysis patients with relative iron deficiency. A series of one-way, multi-way and probabilistic sensitivity analyses were conducted to assess the robustness of the model structure and the extent in which the model's assumptions were sensitive to the uncertainties within the input variables.

RESULTS

Compared with oral iron, the incremental cost-effectiveness ratios (ICERs) for parenteral iron were $74,760 per life year saved and $34,660 per quality-adjusted life year (QALY) gained. A series of one-way sensitivity analyses show that the ICER is most sensitive to the probability of achieving haemoglobin (Hb) targets using supplemental iron with a consequential decrease in the standard ESA doses and the relative increased risk in all-cause mortality associated with low Hb levels (Hb < 9.0 g/dL). If the willingness-to-pay threshold was set at $50,000/QALY, the proportions of simulations that showed parenteral iron was cost-effective compared with oral iron were over 90%.

CONCLUSIONS

Assuming that there is an overall increased mortality risk associated with very low Hb level (<9.0 g/dL), using parenteral iron to achieve an Hb target between 9.5 and 12 g/L is cost-effective compared with oral iron therapy among haemodialysis patients with relative iron deficiency.

Association of base excision repair gene polymorphisms with ESRD risk in a Chinese population

The base excision repair (BER) pathway, containing OGG1, MTH1 and MUTYH, is a major protector from oxidative DNA damage in humans, while 8-oxoguanine (8-OHdG), an index of DNA oxidation, is increased in maintenance hemodialysis (HD) patients. Four polymorphisms of BER genes, OGG1 c.977C > G (rs1052133), MTH1 c.247G > A (rs4866), MUTYH c.972G > C (rs3219489), and AluYb8MUTYH (rs10527342), were examined in 337 HD patients and 404 healthy controls. And the 8-OHdG levels in leukocyte DNA were examined in 116 HD patients. The distribution of MUTYH c.972 GG or AluYb8MUTYH differed between the two groups and was associated with a moderately increased risk for end-stage renal disease (ESRD) (P = 0.013 and 0.034, resp.). The average 8-OHdG/10⁶ dG value was significantly higher in patients with the OGG1 c.977G, MUTYH c.972G or AluYb8MUTYH alleles (P < 0.001 via ANOVA). Further analysis showed that combination of MUTYH c.972GG with OGG1 c.977GG or AluYb8MUTYH increased both the risk for ESRD and leukocyte DNA 8-OHdG levels in HD patients. Our study showed that MUTYH c.972GG, AluYb8MUTYH, and combination of OGG1 c.977GG increased the risk for ESRD development in China and suggested that DNA oxidative damage might be involved in such process.

Prevalence, characteristics and prognostic significance of anemia in daily practice

BACKGROUND

The prevalence of anemia has been studied in well-defined populations, but no large study is available for less restricted populations with various disorders.

DESIGN

Two-phase nationwide study: (i) a cross-sectional study including 1351 patients aimed to define the prevalence and characteristics of anemic patients seen in France, and (ii) a prospective longitudinal study of 398 anemic patients aimed to define factors associated with survival.

RESULTS

Anemia was present in 874 (65%) patients according to WHO criteria, and 573 (42%) patients had hemoglobin levels <110 g/l. Characteristics independently associated with anemia were the presence of cancer, hematological disorder, renal failure and inflammatory syndrome. Baseline factors negatively associated with the 3-month survival were cancer, older age and a lower target hemoglobin level defined at baseline. Negative predictive factors at Month 3 of the 6-month survival were older age and the absence of correction of anemia according to the target hemoglobin level defined at baseline.

CONCLUSION

Anemia is frequent and is associated with cancer, hematological disorders, renal failure and inflammatory syndrome. At baseline, prognostic factors of 3-month survival include cancer, older age and lower target hemoglobin level, whereas reaching the target hemoglobin level at Month 3 has a favorable prognostic impact on 6-month survival.

Anemia and mortality in older persons: does the type of anemia affect survival?

Anemia is a common condition among community-dwelling older adults. The present study investigates the effect of type of anemia on subsequent mortality. We analyzed data from participants of the Third National Health and Nutrition Survey who were aged ≥50 and had valid hemoglobin levels determined by laboratory measurement. Anemia was defined by World Health Organization criteria. 7,171 subjects met our inclusion criterion. Of those with anemia (n = 862, deaths = 491), 24% had nutritional anemia, 11% had anemia of chronic renal disease, 26% had anemia of chronic inflammation, and 39% had unexplained anemia. We found an overall relative risk (RR) for mortality of 1.8 (p < 0.001) comparing those with anemia to those without, after adjusting for age, sex, and race. After we controlled for a number of chronic medical conditions, the overall RR was 1.6. Compared to persons without anemia, we found the following RRs for the type of anemia: nutritional (2.34, p < 0.0001), chronic renal disease (1.70, p < 0.0001), chronic inflammation (1.48, p < 0.0001), and unexplained (1.26, p < 0.01). Anemia is common although not severe in older non-institutionalized adults. When compared with non-anemic older adults, those with nutritional anemia or anemia due to chronic renal disease have the highest mortality risk.

[Influence of hemoglobin level and dose of administered recombinant human beta erythropoietin on survival of hemodialysis patients]

BACKGROUND/AIM

In patients with end-stage renal disease, treatment with erythropoietin lowers cardiovascular morbidity, improves quality of life and patient survival. The aim of this study was to determine the difference in survival of hemodialysis patients treated with recombinant human beta erythropoietin and patients without this treatment, and to determine the influence of hemoglobin level and erythropoietin dose on the survival of these patients.

METHOD

The study included 291 patients undergoing maintenance hemodialysis, 122 were on erythropoietin therapy, 169 patients formed control group. The study was performed at the Clinic for Nephrology and Clinical Immunology, Clinical Center of Vojvodina, during a 69-month period. We analyzed basic demographic parameters, dialysis duration, underlying disease, comorbidities, death causes, blood-work parameters and erythropoietin dosage. Descriptive statistics, Anova, Manova, discriminant function analysis, Cox regressional model and Kaplan Meier survival curves were used as statistical methods.

RESULTS

Average age and dialysis duration in the experimental group were 47.88 +/- 13.32 years, and 45.76 +/- 46.73 months, respectively and in the control group 58.73 +/- 12.67 years and 62.80 +/- 55.23 months, respectively. Average level of hemoglobin and hematocrit in the group in which erythropoietin had been administered was 11.40 +/- 8.39 g/dL and 0.35 +/- 0.04/L, while the control group these values were 8.52 +/- 7.73 g/dL and 0.26 +/- 0.04/L, respectively. Average monthly dosage of erythropoietin was 21 587 +/- 10 183.36 IJ/month. Significant difference in survival was determined (p < 0.05) between the stated patient groups. A significant difference (p < 0.05) was found in survival of the patients in which erythropoietin was administered regarding hemoglobin level (< 100 g/L/100-110 g/L/110-120 g/L/ > 120 g/L), as well as in regard of erythropoietin dose applied (< 20 000 IJ/20 000-40 000 IJ/ > 40 000 IJ/month).

CONCLUSION

Best survival was noted in patients with hemoglobin > 120 g/L and erythropoietin dose < 20 000 IJ/month.

Erythropoiesis-stimulating agent responsiveness and mortality in hemodialysis patients: results from a cohort study from the dialysis registry in Japan

BACKGROUND

Patient responsiveness to erythropoiesis-stimulating agents (ESAs), notoriously difficult to measure, has attracted attention for its association with mortality. We defined categories of ESA responsiveness and attempted to clarify their association with mortality.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

Data from Japan's dialysis registry (2005-2006), including 95,460 adult hemodialysis patients who received ESAs.

PREDICTOR

We defined 6 categories of ESA responsiveness based on a combination of ESA dosage (low [<6,000 U/wk] or high [≥6,000 U/wk]) and hemoglobin level (low [<10 g/dL], medium [10-11.9 g/dL], or high [≥12 g/dL]), with medium hemoglobin level and low-dose ESA therapy as the reference category.

OUTCOMES

All-cause and cardiovascular mortality during 1-year follow-up.

MEASUREMENTS

HRs were estimated using a Cox model for the association between responsiveness categories and mortality, adjusting for potential confounders such as age, sex, postdialysis weight, dialysis duration, comorbid conditions, serum albumin level, and transferrin saturation.

RESULTS

Median ESA dosage (4,500-5,999 U/wk) was used as a cutoff point, and mean hemoglobin level was 10.1 g/dL in our cohort. Of 95,460 patients during follow-up, 7,205 (7.5%) died of all causes, including 5,586 (5.9%) cardiovascular deaths. Low hemoglobin levels and high-dose ESA therapy were both associated with all-cause mortality (adjusted HRs, 1.18 [95% CI, 1.09-1.27] for low hemoglobin level with low-dose ESA and 1.44 [95% CI, 1.34-1.55] for medium hemoglobin level with high-dose ESA). Adjusted HRs for high-dose ESA with low hemoglobin level (hyporesponsiveness) were 1.94 (95% CI, 1.82-2.07) for all-cause and 2.02 (95% CI, 1.88-2.17) for cardiovascular mortality. We also noted the interaction between ESA dosage and hemoglobin level on all-cause mortality (likelihood ratio test, P = 0.002).

LIMITATIONS

Potential residual confounding from unmeasured factors and single measurement of predictors.

CONCLUSIONS

Mortality can be affected by ESA responsiveness, which may include independent and interactive effects of ESA dose and hemoglobin level. Responsiveness category has prognostic importance and clinical relevance in anemia management.

Prophylactic use of omeprazole associated with a reduced risk of peptic ulcer disease among maintenance hemodialysis patients

BACKGROUND

Patients undergoing maintenance hemodialysis (MHD) have a high prevalence of peptic ulcer disease (PUD). Omeprazole is a proton pump inhibitor with proven efficacy in the prevention and treatment of PUD. However, there is little data on the prophylactic use of omeprazole in reducing the risk of PUD among MHD patients.

METHODS

This prospective study included 93 patients undergoing MHD at Zen-Ho Dialysis Center between July 2008 and December 2009. Fifty-three patients were assigned to receive 20 mg of omeprazole daily for 18 months and 40 patients served as control. The Kaplan-Meier method was applied to calculate the cumulative incidence of PUD.

RESULTS

The per-protocol population comprised 85 patients (omeprazole group, 49; control group, 36). Both groups had similar baseline characteristics. The need for endoscopy was found to be significantly less (10.2 vs. 44.4%, p = 0.001) in the omeprazole group than in the control group. Dialysis patients in the omeprazole group required fewer blood transfusions and erythropoietin doses than did the control group patients. Kaplan-Meier analysis revealed a higher cumulative ulcer rate in the control group (log-rank test, p = 0.04). However, omeprazole did not reduce the risk of PUD in MHD patients on regular aspirin or warfarin.

CONCLUSIONS

We conclude that prophylactic use of omeprazole might be effective to lower the incidence of PUD among MHD patients without regular aspirin or warfarin use. Further large-scale controlled trials should be carried out to confirm our findings.

Iron overdose: a contributor to adverse outcomes in randomized trials of anemia correction in CKD

Administration of intravenous iron to supplement erythropoiesis stimulating agents (ESAs) has become a common practice in the management of anemia in patients with end-stage renal disease. Randomized clinical trials of anemia correction in this population have shown more adverse outcomes in CKD and ESRD patients assigned to the higher hemoglobin targets. Retrospective analysis of these trials suggests that morbidity is higher in subjects who fail to achieve the designated hemoglobin target and are typically exposed to higher doses of ESAs and iron than those that easily achieve the intended targets. Intravenous iron administration circumvents the natural biologic mechanisms for handling and utilization of iron. There is in vitro and in vivo evidence that intravenous iron preparations can cause oxidative stress, endothelial dysfunction, inflammation, impaired immunity, and renal injury. Since iron overload is known to promote endothelial dysfunction, cardiovascular disease, and immune dysfunction which are the leading causes of premature mortality in CKD and ESRD patients, it is imperative to exercise caution with the use of IV iron preparations in this population. The present review is intended to provide a brief overview of the potential adverse effects of the overzealous use of these agents.