Anaemia management in non-dialysis chronic kidney disease (CKD) patients: a multicentre prospective study in renal clinics

Efficacy and Safety of Oral Supplementation with Liposomal Iron in Non-Dialysis Chronic Kidney Disease Patients with Iron Deficiency

INTRODUCTION

Iron deficiency is common in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). Oral iron supplementation is recommended in these patients, but it is associated with a higher incidence of gastrointestinal adverse reactions. Liposomal iron therapy has been proposed as a new iron formulation, improving iron bioavailability with less side effects; however, few data are available in patients with NDD-CKD.

METHODS

We designed a single-arm pilot study to evaluate the efficacy of liposomal iron administered for six months in correcting iron deficiency (defined as serum ferritin < 100 ng/mL and/or transferrin saturation < 20%) in patients with NDD-CKD stages 1-5. The primary endpoints were the achievement of serum ferritin ≥ 100 ng/mL and transferrin saturation ≥ 20%. Secondary outcomes were hemoglobin (Hb) changes and the safety of liposomal iron.

RESULTS

The efficacy population included 34/38 patients, who completed at least one visit after baseline. Liposomal iron increased the achievement of transferrin saturation targets from 11.8% at baseline to 50.0% at month 6 (p = 0.002), while no significant correction of serum ferritin (p = 0.214) and Hb was found (p = 0.465). When patients were stratified by anemia (Hb < 12 g/dL in women and Hb < 13 g/dL in men), a significant improvement of transferrin saturation was observed only in anemic patients (from 13.3 ± 5.8% to 20.2 ± 8.1%, p = 0.012). Hb values slightly increased at month 6 only in anemic patients (+0.60 g/dL, 95%CI -0.27 to +1.48), but not in those without anemia (+0.08 g/dL, 95%CI -0.73 to +0.88). In patients taking at least one dose of liposomal iron (safety population, n = 38), the study drug was discontinued in eight patients due to death (n = 2), a switch to intravenous iron (n = 2), and the occurrence of side effects (n = 4).

CONCLUSIONS

The use of liposomal iron in patients with NDD-CKD is associated with a partial correction of transferrin saturation, with no significant effect on iron storage and Hb levels.

Consensus commentary and position of the Italian Society of Nephrology on KDIGO controversies conference on novel anemia therapies in chronic kidney disease

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new drugs developed for the treatment of anemia associated with chronic kidney disease (CKD). This class of drugs stimulates endogenous erythropoietin production and, at the same time, improves iron absorption and mobilization of iron stores (less evident with daprodustat, vadadustat and enarodustat). Several studies have been published in the last few years showing that these agents are not inferior to standard therapy in correcting anemia associated with CKD. The efficacy of HIF-PHIs is coupled with a safety profile comparable to that of standard erythropoiesis stimulating agent (ESA) treatment. However, studies with HIF-PHIs were not long enough to definitively exclude the impact of new drugs on adverse events, such as cancer, death and possibly cardiovascular events, that usually occur after a long follow-up period. Kidney Disease: Improving Global Outcomes (KDIGO) recently reported the conclusions of the Controversies Conference on HIF-PHIs held in 2021. The goal of the present position paper endorsed by the Italian Society of Nephrology is to better adapt the conclusions of the latest KDIGO Conference on HIF-PHIs to the Italian context by reviewing the efficacy and safety of HIF-PHIs as well as their use in subpopulations of interest as emerged from more recent publications not discussed during the KDIGO Conference.

A novel scenario in the therapeutic management of anemia of chronic kidney disease: placement and use of roxadustat

Anemia is a frequent and early chronic kidney disease (CKD) complication. Its management is currently based on oral or intravenous iron supplements, erythropoiesis-stimulating agents, and red blood cell transfusions, when the benefits of transfusion outweigh the risks. Anemia in CKD patients is underdiagnosed and undertreated. Current standard of care is associated with challenges and therefore new treatment approaches have been sought. Hypoxia-inducible factor-prolyl-hydroxylase enzyme inhibitors are a new class of orally administered drugs used to treat anemia associated with CKD. Small-molecule hypoxia-inducible factor-prolyl-hydroxylase inhibitors have a novel mechanism of action that activates the hypoxia-inducible factor (oxygen-sensing) pathway resulting in a coordinated erythropoietic response, leading to increased endogenous erythropoietin production, improved iron absorption and transport, and reduced hepcidin. Roxadustat is the first hypoxia-inducible factor-prolyl-hydroxylase inhibitor approved by the European Medicines Agency (EMA) and reimbursed in Italy by the Italian Medicines Agency (AIFA) for the treatment of adult patients with symptomatic CKD-related anemia. This authorization was based on the outcome of a globally-conducted phase 3 clinical trial program comprising eight pivotal multicenter randomized studies. In the absence of up-to-date guidelines, we performed a critical appraisal of the placement and use of roxadustat in this therapeutic context.

Efficacy and safety of hypoxia-inducible factor prolyl hydroxylase inhibitors in patients with chronic kidney disease: meta-analysis of phase 3 randomized controlled trials

Background

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new therapeutic agents for anaemia in chronic kidney disease (CKD). We evaluated by meta-analysis and meta-regression the efficacy and safety of HIF-PHIs in patients with CKD-related anaemia.

Methods

We selected phase 3 randomized clinical trials (RCTs) comparing HIF-PHIs and erythropoiesis-stimulating agents (ESAs) in dialysis and non-dialysis patients. Efficacy outcomes were the changes from baseline of haemoglobin, iron parameters (hepcidin, serum iron, TIBC, TSAT, ferritin) and intravenous iron dose; as safety outcomes we considered cancer, adjudicated major adverse cardiovascular events (MACE), MACE+ (MACE plus hospitalization for hearth failure or unstable angina or thromboembolic event), thrombotic events (deep vein thrombosis, pulmonary embolism), arterovenous fistula (AVF) thrombosis and death.

Results

We included 26 RCTs with 24 387 patients. Random effect meta-analysis of the unstandardized mean difference between HIF-PHIs and ESAs showed a significant change in haemoglobin levels from baseline of 0.10 g/dL (95% CI 0.02 to 0.17). Meta-regression analysis showed a significantly higher haemoglobin change for HIF-PHIs in younger patients and versus short-acting ESA (0.21 g/dL, 95% CI 0.12 to 0.29 versus -0.01, 95% CI -0.09 to 0.07 in studies using long-acting ESA, P < .001). No significant effect on heterogeneity was found for type of HIF-PHIs. In comparison with ESAs, HIF-PHIs induced a significant decline in hepcidin and ferritin and a significant increase in serum iron and TIBC, while TSAT did not change; intravenous iron dose was lower with HIF-PHI (-3.1 mg/week, 95% CI -5.6 to -0.6, P = .020). Rate ratio of cancer (0.93, 95% CI 0.76 to 1.13), MACE (1.00, 95% CI 0.94 to 1.07), MACE+ (1.01, 95% CI 0.95 to 1.06), thrombotic events (1.08, 95% CI 0.84 to 1.38), AVF thrombosis (1.02, 95% CI 0.93 to 1.13) and death (1.02, 95% CI 0.95 to 1.13) did not differ between HIF-PHIs and ESAs.

Conclusions

HIF-PHIs at the doses selected for the comparisons are effective in correcting anaemia in comparison with ESA therapy with a significant impact on iron metabolism without notable difference among various agents. No safety signals emerge with use of HIF-PHIs.

Comparison of the different monosodium urate crystals in the preparation process and pro-inflammation

OBJECTIVES

The deposition of monosodium urate (MSU) crystals within synovial joints and tissues is the initiating factor for gout arthritis. Thus, MSU crystals are a vital tool for studying gout's molecular mechanism in animal and cellular models. This study mainly compared the excellence and worseness of MSU crystals prepared by different processes and the degree of inflammation induced by MSU crystals.

METHODS

MSU crystals were prepared using neutralization, alkali titration, and acid titration methods. The crystals' shape, length, quality, and uniformity were observed by polarized light microscopy and calculated by the software Image J. The foot pad and air pouch models were used to assess the different degrees of inflammation induced by the MSU crystals prepared by the three different methods at different time points. Paw swelling was evaluated by caliper. In air pouch lavage fluid, inflammatory cell recruitment was measured by hemocytometer, and the level of IL-1β, TNF-α, and IL-18 by ELISA. Inflammatory cell infiltration was assayed by immunohistochemistry of air pouch synovial slices.

RESULTS

For the preparation of MSU crystals with the same uric acid, the quantity acquired by the alkalization method was highest, followed by neutralization, with the acid titration method being the lowest. The crystals prepared by neutralization were the longest. The swelling index of the foot pad induced by MSU crystals prepared by acid titration was significantly lower than that of the other methods at 24 h. The inflammatory cell recruitment and level of IL-1β, TNF-α, and IL-18 in air pouch lavage fluid were lowest in animals with crystals prepared by acid titration. IL-1β secretion induced by MSU crystals prepared by acid titration was significantly lower than that of the other two groups, but there was no significant difference in IL-18 secretion between the three groups in THP-1 macrophages and BMDMs.

CONCLUSIONS

All three methods can successfully prepare MSU crystals, but the levels of inflammation induced by the crystals prepared by the three methods were not identical. The degree of inflammation induced by MSU crystals prepared by neutralization and alkalization is greater than by acid titration, but the quantity of MSU crystals obtained by the alkalization method is higher and less time-consuming. Apparently, the window of inflammation triggered by acid titration preparation is shorter compared to other forms of crystal preparation. Overall, MSU crystals prepared by the alkaline method should be recommended for studying the molecular mechanisms of gout in animal and cellular models.

Efficiency of ferric carboxymaltose in non-dialysis CKD patients and its impact on kidney function: a prospective observational study

BACKGROUND

Iron deficiency anemia occurs in most patients with non-dialysis chronic kidney disease (ND-CKD). Previous studies have suggested that intravenous (IV) iron therapy is more effective than oral iron in these patients. Clinical evidence relating the effects of IV iron on renal function is, however, limited.

METHODS

Prospective observational study of adult patients with ND-CKD, anemia, iron deficiency, and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², treated with a single dose of 500 mg or 1000 mg of ferric carboxymaltose (FCM) and followed-up for 24 weeks. Primary outcome was FCM efficacy, assessed by comparing Hb, TSAT and ferritin at 24 weeks with those at baseline. Secondary outcome was FCM impact on renal function, evaluated by comparing eGFR over the same period.

RESULTS

One hundred and forty patients were recruited: seventy-eight (55.7%) were treated with 1000 mg and 62 (44.3%) with 500 mg of FCM. 24 weeks after FCM administration, Hb increased 1.54 ± 1.99 g/dL (95% CI 1.09-1.99, p = 001) in the group treated with 1000 mg and 0.86 ± 1.4 g/dL (95% CI 0.53-1.22, p = 0.001) in those treated with 500 mg. TSAT increased in both groups but more in those treated with 1000 mg, and ferritin only increased in the latter. Estimated GFR showed a significant increase of 1.55 ± 6.86 mL/min/m² (95% CI 0.05-3.09, p = 0.049), from a baseline of 27.73 ± 17.23 to 28.88 ± 18.02 mL/min/m² in the group treated with 1000 mg.

CONCLUSIONS

Our findings suggested that IV FCM therapy was effective in improving serum iron levels and anemia in ND-CKD stage 3 to 5 patients. Higher doses seem to be necessary to replace depleted iron stores. In our cohort, IV FCM therapy was associated with an improvement in renal function, particularly in those treated with higher doses of FCM.

Prevalence, incidence, and treatment of anaemia in patients with non-dialysis-dependent chronic kidney disease: findings from a retrospective real-world study in Italy

BACKGROUND

Limited data are available on the epidemiology and clinical management of anaemia in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD).

METHODS

This retrospective observational study was based on records from databases of five Local Health Units across Italy. Adults with reported NDD-CKD stage 3a-5 between 1 January 2014 and 31 December 2016 were identified. Annual prevalence and incidence of anaemia (age- and sex-standardised) and clinical management (erythropoiesis-stimulating agents [ESAs], intravenous [IV] iron, and blood transfusions) were evaluated. Eligibility for ESAs was defined by ≥ 2 records of Hb < 10 g/dL, or < 11 g/dL over 6 months.

RESULTS

Overall, 101,143 individuals with NDD-CKD (3a-5) recorded between 2014 and 2016 were identified, of whom 40,020 (39.6%) were anaemic. Prevalence of anaemia was 33.8% in 2016 and incidence of anaemia was stable (11.4-12.4%) from 2014 to 2016. Prevalence and incidence of anaemia increased with CKD stage. Among eligible patients, 12.8% with Hb < 11 g/dL and 15.5% with Hb < 10 g/dL received ESAs, and the proportion treated increased with CKD stage. Among ESA-treated patients with at least 2 years of follow up, 18.4% and 19.3% received IV iron in the Hb < 11 and < 10 g/dL groups, respectively, and 16.5% and 19.4% received blood transfusions. Corresponding proportions for the overall anaemic cohort were 9.0% and 11.3%, respectively.

CONCLUSIONS

Anaemia is a significant issue in patients with NDD-CKD. Low rates of ESA treatment indicate a potential treatment gap and suggest that anaemia may not be adequately controlled in many patients.

Real-Life Anemia Management Among Patients with Non-Dialysis-Dependent Chronic Kidney Disease in Three European Countries

Background

Anemia is prevalent among patients with chronic kidney disease (CKD), yet current evidence indicates that treatment may not adhere to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. We aimed to document the management of patients with non-dialysis-dependent (NDD)-CKD receiving erythropoiesis-stimulating agent (ESA) therapy in Europe.

Methods

This retrospective, observational study extracted information from medical records in Germany, Spain, and the UK. Eligible patients were adults with NDD-CKD stages 3b-5 who initiated ESA therapy for anemia between January and December 2015. Anemia was defined as hemoglobin (Hb) <13.0 g/dL (males) or <12.0 g/dL (females). Data regarding ESA treatment, treatment response, concomitant iron therapy and blood transfusions were extracted up to 24 months post-ESA initiation, and data on CKD progression until abstraction date.

Results

Eight hundred and forty-eight medical records were abstracted. Approximately 40% received no iron therapy prior to ESA initiation. At ESA initiation, mean ± standard deviation Hb level was 9.8 ± 1.0 g/dL. Most patients received darbepoetin alfa, and switching between ESAs was rare (8.5% of patients). Concomitant intravenous and oral iron therapy was prescribed for 36% and 42% of patients, respectively, during initial ESA therapy. Mean Hb levels reached the target level (10-12 g/dL) within 3-6 months of ESA initiation. Hb, transferrin saturation, and ferritin levels were infrequently monitored from 3 months post-ESA initiation. Rates of blood transfusion, dialysis, and diagnosis of end-stage renal disease were 16.4%, 19.3%, and 24.6%, respectively. Rates of kidney transplant and death were 4.8% and 8.8%, respectively.

Conclusion

Among ESA-treated patients, ESA initiation was in accordance with KDIGO guidelines, but subsequent monitoring of Hb and iron deficiency were suboptimal.

Preferences for Anaemia Treatment Attributes among Patients with Non-Dialysis-Dependent Chronic Kidney Disease

INTRODUCTION

Information about patient preferences for the treatment of anaemia associated with chronic kidney disease (CKD) is scarce. Hence, our aim was to examine how patients with non-dialysis-dependent CKD valued attributes of alternative hypothetical anaemia treatments.

METHODS

A discrete choice experiment (DCE) was conducted in adult patients who reported a clinical diagnosis of CKD-related anaemia. Treatment attributes included mode and frequency of administration, need for iron supplementation, risk of gastrointestinal side effects, risk of major cardiovascular events and impact on energy levels (as defined by the vitality section of the SF-6D health index). Logit models were used to analyse patients' preferences.

RESULTS

The DCE was completed by 200 patients in four countries. Patients preferred an oral mode of administration. Patients were willing to tolerate a 5.1% (95% CI 2.0-8.3%) increase in the risk of a major cardiovascular event and an 11.7% (95% CI 5.0-18.5%) increase in the risk of gastrointestinal side effects to switch from an at-home subcutaneous injection administered once every 2 weeks to an at-home oral pill administered three times a week. Patients were willing to tolerate a 20.3% (95% CI 15.0-25.6%) increase in the risk of gastrointestinal side effects and an 8.9% (95% CI 6.1-11.7%) increase in the risk of a major cardiovascular event to transition from 'Sometimes having a lot of energy' to 'Always having a lot of energy'.

CONCLUSIONS

Patients with non-dialysis-dependent CKD-related anaemia demonstrated clear treatment preferences and were willing to accept increased gastrointestinal or cardiovascular risks in exchange for more energy or an oral treatment.

Whether Renal Pathology Is an Independent Predictor for End-Stage Renal Disease in Diabetic Kidney Disease Patients with Nephrotic Range Proteinuria: A Biopsy-Based Study

Aims: To investigate whether renal pathology is an independent predictor for end-stage renal disease (ESRD) in diabetic kidney diseases (DKD) with nephrotic range proteinuria. Methods: A total of 199 DKD patients with nephrotic range proteinuria underwent renal biopsy and were divided into an ESRD group and a non-ESRD group. A Kaplan−Meier analysis was used to compare renal survival rate, and univariate and multivariate Cox proportional hazard analyses were used to determine the predictors of the ESRD. Results: The mean age of included patients was 51.49 ± 9.12 years and 113 patients (56.8%) progressed to ESRD. The median follow-up period was 16 (12−28) months. The glomerular pathology class III is the most common type (54.3%). In the Kaplan−Meier analysis, compared with patients without ESRD, patients with ESRD had a longer duration of diabetes (≥6 years), lower eGFR (<60 mL/min/1.73 m2), lower albumin (<30 g/L), lower hemoglobin (<120 g/L), and a higher grade of glomerular stage (class III + IV vs. class I + II) (p < 0.05). The hemoglobin and e-GFR, but not the histopathological damage, were significantly associated with a higher risk of ESRD in both the univariate and multivariate Cox analyses. Conclusions: In patients with diabetic kidney disease characterized by nephrotic range proteinuria, histopathological damage (glomerular alterations, interstitial fibrosis and tubular atrophy (IFTA), interstitial inflammation, and arteriolar hyalinosis) is not associated with poor renal outcomes, but hemoglobin and e-GFR could predict poor renal outcomes.

Anemia and iron in internal medicine: an Italian survey and a review on iron intravenous therapy in medical patients

In Italy, Internal Medicine Units hospitalize approximately 1,300,000 patients, often elderly and comorbid. The prevalent diagnoses are respiratory diseases, heart failure, or pneumonia. As a matter of fact, anemia is probably underestimated in the compilation of the official discharge forms (SDO) according to ICD-9 diagnostic codes. We promoted a survey among the Members the Italian Scientific Society of Internal Medicine (FADOI) with the aim to investigate the prevalence of anemia and iron deficiency, over than certain aspects related to the therapeutic management of patients with anemia. Furthermore, we performed a review summarizing current evidence for iron intravenous therapy in these patients. According to the survey, anemia is present in around half of the patients hospitalized in Internal Medicine, and about a quarter of them shows iron metabolism alterations. In the evaluation of iron metabolism, the dosage of ferritin is the most requested exam, whereas transferrin saturation is less considered. By focusing on some categories of patients, the awareness of the usefulness of intravenous iron therapy in patients with heart failure seems to be sufficiently common (76% of physicians), while it seems lower (60%) in the management of patients with chronic kidney disease (CKD) and anemia. Finally, more than 75% of the physicians answered that, in their hospital, there are few outpatients’ offices or diagnostic pathways dedicated to patients with anemia. Anemia due to absolute or functional iron deficiency is particularly prevalent in Internal Medicine inpatients. For this reason, an accurate evaluation of iron profile and an adequate iron therapy is mandatory in these patients. Recent studies show that, in patients with heart failure, intravenous iron therapy is an effective way of improving patients’ health, regardless of the presence of anemia. Similarly, iron therapy results fundamental to optimize erythropoiesis-stimulating agent efficacy in patients with chronic renal failure. In the next future, other therapeutic aspects of intravenous iron therapy will be probably clarified by several interesting ongoing studies focused on these patients.

[Prevalence of malnutrition and absolute and functional iron deficiency anemia in nondialysis-dependent chronic kidney disease and hemodialysis Algerian patients]

In chronic kidney disease, anemia and malnutrition coupled with inflammation as malnutrition-inflammation complex syndrom are common and considered as morbidity-mortality factors. The link between these two factors has been described at length in the literature highlighting an association of malnutrition with iron deficiency considered itself as one of the causes of anemia in chronic kidney disease (non-dialysis and hemodialysis). Our study aims to know the prevalence of these two factors in a population of chronic kidney disease (non-dialysis and hemodialysis) of Algiers and to highlight the possible associations between them.

PATIENTS AND METHODS

This is a multicentre, cross-sectional and descriptive study carried out over a period of 6months (August 2018 to January 2019). Anemia and malnutrition were assessed by various biological and clinical tools such as the malnutrition inflammation score and the International Society of Renal Nutrition and Metabolism criteria. Statistical tests were performed on the R studio software, considering P<0.05 as a statistically significant value.

RESULTS

Two hundred and nine patients on chronic kidney disease were included (90 non dialysis and 119 hemodialysis). The median age was 70 (IQR=16) for non dialysis and 56 (IQR=16.5) for hemodialysis. The prevalence of anemia was 66.66% (n=60) in non dialysis and 70.58% (n=84) in hemodialysis. Absolute iron deficiency anemia was higher in non dialysis (48.33%; n=29) while functional iron deficiency anemia was higher in hemodialysis (34.52%; n=29). The prevalence of malnutrition by malnutrition inflammation score was relatively low. Only functional iron deficiency anemia was associated with malnutrition.

CONCLUSION

The prevalence of anemia was higher in Algerian chronic kidney disease (non-dialysis and hemodialysis) unlike malnutrition which remains associated with functional iron deficiency anemia.

Epidemiology and outcomes in patients with anemia of CKD not on dialysis from a large US healthcare system database: a retrospective observational study

Background

Optimal management of anemia of chronic kidney disease (CKD) remains controversial. This retrospective study aimed to describe the epidemiology and selected clinical outcomes of anemia in patients with CKD in the US.

Methods

Data were extracted from Henry Ford Health System databases. Adults with stages 3a–5 CKD not on dialysis (estimated glomerular filtration rate < 60 mL/min/1.73m²) between January 1, 2013 and December 31, 2017 were identified. Patients on renal replacement therapy or with active cancer or bleeding were excluded. Patients were followed for ≥12 months until December 31, 2018. Outcomes included incidence rates per 100 person-years (PY) of anemia (hemoglobin < 10 g/dL), renal and major adverse cardiovascular events, and of bleeding and hospitalization outcomes. Adjusted Cox proportional hazards models identified factors associated with outcomes after 1 and 5 years.

Results

Among the study cohort (N = 50,701), prevalence of anemia at baseline was 23.0%. Treatments used by these patients included erythropoiesis-stimulating agents (4.1%), iron replacement (24.2%), and red blood cell transfusions (11.0%). Anemia incidence rates per 100 PY in patients without baseline anemia were 7.4 and 9.7 after 1 and 5 years, respectively. Baseline anemia was associated with increased risk of renal and major cardiovascular events, hospitalizations (all-cause and for bleeding), and transfusion requirements. Increasing CKD stage was associated with increased risk of incident anemia, renal and major adverse cardiovascular events, and hospitalizations.

Conclusions

Anemia was a prevalent condition associated with adverse renal, cardiovascular, and bleeding/hospitalization outcomes in US patients with CKD. Anemia treatment was infrequent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02778-8.

Clinical interpretation of serum hepcidin-25 in inflammation and renal dysfunction

•

log[hepcidin]:log[ferritin] ratio may serve as a biomarker for iron deficiency in complex cases.

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Hepcidin testing is not warranted in patients with CRP > 10 mg/l and/or eGFR < 30 ml/min/1.73 m².

•

Inflammation is not a determinant of serum hepcidin-25 in the setting of renal dysfunction.

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eGFR is not a major determinant of serum hepcidin-25 concentration in patient with eGFR ≥ 30 ml/min/1.73 m².

Introduction

Hepcidin is a hormone that regulates systemic iron homeostasis. Serum hepcidin levels are under the influence of various stimuli, particularly inflammation and renal dysfunction. The measurement of hepcidin in circulation is a potentially useful clinical tool in the diagnosis, monitoring and treatment of iron metabolism disorder, although clinical interpretation of hepcidin level remains difficult. We evaluated he diagnostic potential and limitations of hepcidin-25 by investigating its relationship with iron and hematological indices, inflammation, and renal dysfunction.

Methods

This retrospective study included 220 adult patients not requiring dialysis. Variations of biologically active hepcidin-25 were examined using a mass spectrometry-based assay in various inflammatory and renal states. The log[hepcidin]:log[ferritin] ratio was calculated as an hepcidin index.

Results

In 220 adult patients not requiring dialysis, variation in hepcidin-25 level was significantly larger once CRP exceeded 10 mg/l (p < 0.001). Inflammation was not a determinant of hepcidin-25 in the setting of renal dysfunction. Hepcidin-25 median (7.37 nM) and variance were significantly higher (p < 0.001), once estimated glomerular filtration rate (eGFR) dropped below 30 ml/min/1.73 m². The log[hepcidin]:log[ferritin] index normalized hepcidin levels. Patients with iron deficiency have a notably lower index when compared to controls (-0.66 vs 0.3).

Conclusion

Severe renal dysfunction (eGFR < 30) affected hepcidin-25 expression and clearance to variable degree between individuals. Although, hepcidin-25 testing is not warranted in patients with infection, inflammatory autoimmune conditions (CRP > 10 mg/l) and/or severe renal dysfunction (eGFR < 30), the hepcidin index may serve as a potential biomarker for iron deficiency in complex cases.

Evaluation of iron status in anemic pre-dialysis chronic kidney disease patients

Background

Data on iron status are generally less readily available in pre-dialysis chronic kidney disease (CKD) patients than in the hemodialysis population. In Nigeria, little is known about iron indices in patients with CKD.

Aims

The aim of this study was to evaluate the iron status among anemic pre-dialysis patients with CKD.

Patients and Methods

Using a cross-sectional study design, we evaluated serum ferritin and transferrin saturation (TSAT) among 63 pre-dialysis CKD patients with anemia attending our outpatient nephrology clinic. CKD was defined as a glomerular filtration rate less than 60 ml/min/1.73 m² for 3 months or more, while anemia was defined as a hemoglobin concentration (Hb) less than 11 g/dl.

Results

The mean age of the study participants was 52.5 ± 12.7 years and 33 (52.4%) of the patients were females. The most common causes of CKD were hypertension (44.4%) and diabetic nephropathy (30.6%). The mean Hb, mean serum ferritin, and mean TSAT were 9.2 ± 1.1 g/dl, 106.6 ± 72.7 ng/ml, and 24.3% ± 7.9%, respectively. There was no significant difference in median ferritin (91[interquartile range: 54-133] ng/ml versus 106 [interquartile range: 45-151; P=0.75) and mean TSAT (24.9 ± 7.2 % versus 23.8 ± 7.7 %; P=0.54) between male and female study participants; Half (50.8%) of the study participants had absolute iron deficiency (serum ferritin <100 ng/ml) and 6.3% had functional iron deficiency (ferritin >100 ng/ml and TSAT <20%).

Conclusion

Iron deficiency is common among anemic adult Nigerian pre-dialysis CKD patients. Results of iron studies should guide therapy when correcting anemia in these patients.

Anemia and its predictors among adult non-dialysis chronic kidney disease patients in Southern Ethiopia: a cross-sectional study

BACKGROUND

Anemia is an adverse outcome and common complication in chronic kidney disease patients. This is usually associated with iron deficiency, inflammation and blood loss. However, little is known about the prevalence of anemia and its predictors among chronic kidney disease patients in Southern Ethiopia. This study aimed to determine anemia and its predictors among adult non-dialysis chronic kidney disease patients in Southern Ethiopia.

METHODS

A cross-sectional study was conducted on 384 chronic kidney disease patients from February to April 2019. Socio-demographic and clinical data were collected using questionnaires and medical records. Adjusted hemoglobin was taken to define anemia using the level of Hgb <13 mg/dL for males and <12 mg/dL for females; and blood films and serum ferritin were done for anemic participants. SPSS version 25.0 was used for data analysis. Frequency distribution tables and graphs were used to describe descriptive statistics. A bivariate logistic regression model was used to determine the predictors; p <.05 was considered statistically significant.

RESULTS

Overall prevalence of anemia was 44.0% (95% CI: 39.0%, 48.9%); of which 7.1%, 62.1% and 30.8% of anemic patients had mild, moderate and severe anemia, respectively. The prevalence of anemia increased from 20.6% in stage 2 to 100% in stage 5. Morphologically, normocytic normochromic anemia was the most predominant type. Cardiovascular disease (AOR = 2.37, 95% CI: 1.35, 4.16), diabetes mellitus (AOR = 2.77, 95% CI: 1.08, 7.14), stage 3b chronic kidney disease (AOR = 2.74, 95% CI: 1.31, 5.73) and stage 4 and 5 chronic kidney disease patients (AOR = 7.11, 95% CI: 3.22, 15.72) showed significant association with anemia.

CONCLUSION

Anemia was a severe public health problem and associated with cardiovascular disease, diabetes mellitus and stages of chronic kidney disease. Thus, early diagnosis, treatment and prevention of anemia are recommended.

Iron Inhibits the Translation and Activity of the Renal Epithelial Sodium Channel

Hypertension is associated with an increased renal expression and activity of the epithelial sodium channel (ENaC) and iron deficiency. Distal tubules absorb iron, causing perturbations that may influence local responses. In this observational study, we investigated the relationship between iron content and ENaC expression and activity using two cell lines and hepcidin knockout mice (a murine model of iron overload). We found that iron did not transcriptionally regulate ENaC in hepcidin knockout mice or in vitro in collecting duct cells. However, the renal tubules of hepcidin knockout mice have a lower expression of ENaC protein. ENaC activity in cultured Xenopus 2F3 cells and mpkCCD cells was inhibited by iron, which could be reversed by iron chelation. Thus, our novel findings implicate iron as a regulator of ENaC protein and its activity.

New-Onset Anemia and Associated Risk of ESKD and Death in Non-Dialysis CKD Patients: A Multi-Cohort Observational Study

Background

Anemia is a common complication of chronic kidney disease (CKD), but its incidence in nephrology settings is poorly investigated. Similarly, the risks of adverse outcomes associated with new-onset anemia are not known.

Methods

We performed a pooled analysis of three observational cohort studies including 1031 non-anemic CKD patients with eGFR <60 mL/min/1.73 m² regularly followed in renal clinics. We estimated the incidence of mild anemia (hemoglobin 11–12 g/dL in women and 11–13 g/dL in men) and severe anemia (hemoglobin <11 g/dL or use of erythropoiesis-stimulating agents) during a 3-year follow-up period. Thereafter we estimated the risk of end-stage kidney disease (ESKD) and all-cause death associated with new-onset mild and severe anemia.

Results

The mean age was 63 ± 14 years, 60% were men and 20% had diabetes. The mean estimated glomerular filtration rate (eGFR) was 37 ± 13 mL/min/1.73 m² and the median proteinuria was 0.4 g/day [interquartile range (IQR) 0.1–1.1]. The incidence of mild and severe anemia was 13.7/100 patients-year and 6.2/100 patients-year, respectively. Basal predictors of either mild or severe anemia were diabetes, lower hemoglobin, higher serum phosphate, eGFR <30 mL/min/1.73 m² and proteinuria >0.50 g/day. Male sex, moderate CKD (eGFR 30–44 mL/min/1.73 m²) and moderate proteinuria (0.15–0.50 g/day) predicted only mild anemia. The incidence of anemia increased progressively with CKD stages (from 8.77 to 76.59/100 patients-year) and the proteinuria category (from 13.99 to 25.02/100 patients-year). During a median follow-up of 3.1 years, 232 patients reached ESKD and 135 died. Compared with non-anemic patients, mild anemia was associated with a higher adjusted risk of ESKD {hazard ratio [HR] 1.42 [95% confidence interval (CI) 1.02–1.98]} and all-cause death [HR 1.55 (95% CI 1.04–2.32)]. Severe anemia was associated with an even higher risk of ESKD [HR 1.73 (95% CI 1.20–2.51)] and death [HR 1.83 (95% CI 1.05–3.19)].

Conclusions

New-onset anemia is frequent, particularly in patients with more severe renal damage and in those with diabetes mellitus. The occurrence of anemia, even of a mild degree, is associated with mortality risk and faster progression towards ESKD.

Anemia: A Connection Between Heart Failure and Kidney Failure

Erythropoiesis-stimulating agents (ESAs) have improved the quality of life and reduced the need for transfusions in patients with chronic kidney disease. However, randomized trials showed no benefit but possible safety issues following high doses of ESAs given to reach normal hemoglobin levels. Iron therapy is used together with ESA; when given proactively, it may reduce the risk of mortality and cardiovascular events in hemodialysis patients. Recent trials also showed benefits of intravenous iron therapy in patients with heart failure. New drugs for correcting anemia may retain the present efficacy of ESAs as antianemic drugs and reduce cardiovascular risks.

Controversies in optimal anemia management: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Conference

In chronic kidney disease, anemia and disordered iron homeostasis are prevalent and associated with significant adverse consequences. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) issued an anemia guideline for managing the diagnosis, evaluation, and treatment of anemia in chronic kidney disease. Since then, new data have accrued from basic research, epidemiological studies, and randomized trials that warrant a re-examination of previous recommendations. Therefore, in 2019, KDIGO decided to convene 2 Controversies Conferences to review the latest evidence, explore new and ongoing controversies, assess change implications for the current KDIGO anemia guideline, and propose a research agenda. The first conference, described here, focused mainly on iron-related issues, including the contribution of disordered iron homeostasis to the anemia of chronic kidney disease, diagnostic challenges, available and emerging iron therapies, treatment targets, and patient outcomes. The second conference will discuss issues more specifically related to erythropoiesis-stimulating agents, including epoetins, and hypoxia-inducible factor-prolyl hydroxylase inhibitors. Here we provide a concise overview of the consensus points and controversies resulting from the first conference and prioritize key questions that need to be answered by future research.

Types of erythropoiesis-stimulating agents and risk of end-stage kidney disease and death in patients with non-dialysis chronic kidney disease

BACKGROUND

Despite the widespread use of erythropoiesis-stimulating agents (ESAs) to treat anaemia, the risk of adverse outcomes associated with the use of different types of ESAs in non-dialysis chronic kidney disease (CKD) is poorly investigated.

METHODS

From a pooled cohort of four observational studies, we selected CKD patients receiving short-acting (epoetin α/β; n = 299) or long-acting ESAs (darbepoetin and methoxy polyethylene glycol-epoetin β; n = 403). The primary composite endpoint was end-stage kidney disease (ESKD; dialysis or transplantation) or all-cause death. Multivariable Cox models were used to estimate the relative risk of the primary endpoint between short- and long-acting ESA users.

RESULTS

During follow-up [median 3.6 years (interquartile range 2.1-6.3)], the primary endpoint was registered in 401 patients [166 (72%) in the short-acting ESA group and 235 (58%) in the long-acting ESA group]. In the highest tertile of short-acting ESA dose, the adjusted risk of primary endpoint was 2-fold higher {hazard ratio [HR] 2.07 [95% confidence interval (CI) 1.37-3.12]} than in the lowest tertile, whereas it did not change across tertiles of dose for long-acting ESA patients. Furthermore, the comparison of ESA type in each tertile of ESA dose disclosed a significant difference only in the highest tertile, where the risk of the primary endpoint was significantly higher in patients receiving short-acting ESAs [HR 1.56 (95% CI 1.09-2.24); P = 0.016]. Results were confirmed when ESA dose was analysed as continuous variable with a significant difference in the primary endpoint between short- and long-acting ESAs for doses >105 IU/kg/week.

CONCLUSIONS

Among non-dialysis CKD patients, the use of a short-acting ESA may be associated with an increased risk of ESKD or death versus long-acting ESAs when higher ESA doses are prescribed.

Anemia in Chronic Kidney Disease: From Pathophysiology and Current Treatments, to Future Agents

Anemia is a common complication in chronic kidney disease (CKD), and is associated with a reduced quality of life, and an increased morbidity and mortality. The mechanisms involved in anemia associated to CKD are diverse and complex. They include a decrease in endogenous erythropoietin (EPO) production, absolute and/or functional iron deficiency, and inflammation with increased hepcidin levels, among others. Patients are most commonly managed with oral or intravenous iron supplements and with erythropoiesis stimulating agents (ESA). However, these treatments have associated risks, and sometimes are insufficiently effective. Nonetheless, in the last years, there have been some remarkable advances in the treatment of CKD-related anemia, which have raised great expectations. On the one hand, a novel family of drugs has been developed: the hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). These agents induce, among other effects, an increase in the production of endogenous EPO, improve iron availability and reduce hepcidin levels. Some of them have already received marketing authorization. On the other hand, recent clinical trials have elucidated important aspects of iron supplementation, which may change the treatment targets in the future. This article reviews the current knowledge of the pathophysiology CKD-related anemia, current and future therapies, the trends in patient management and the unmet goals.

Ferric Carboxymatose in Non-Hemodialysis CKD Patients: A Longitudinal Cohort Study

No information is available on the efficacy of ferric carboxymaltose (FCM) in real-world CKD patients outside the hemodialysis setting. We prospectively followed 59 non-hemodialysis CKD patients with iron deficient anemia (IDA: hemoglobin <12.0/<13.5 g/dL in women/men and TSAT < 20% and/or ferritin < 100 ng/mL) who were intolerant or non-responders to oral iron. Patients received ferric carboxymaltose (FCM) (single dose of 500 mg) followed by additional doses if iron deficiency persisted. We evaluated efficacy of FCM in terms of increase of hemoglobin, ferritin, and TSAT levels. Direct and indirect costs of FCM were also analyzed in comparison with a hypothetical scenario where same amount of iron as ferric gluconate (FG) was administered intravenously. During the 24 weeks of study, 847 ± 428 mg of FCM per patient were administered. IDA improved after four weeks of FCM and remained stable thereafter. At week-24, mean change (95%CI) from baseline of hemoglobin, ferritin and TSAT were +1.16 g/dL (0.55–1.77), +104 ng/mL (40–168) and +9.5% (5.8–13.2), respectively. These changes were independent from ESA use and clinical setting (non-dialysis CKD, peritoneal dialysis and kidney transplant). Among ESA-treated patients (n = 24), ESA doses significantly decreased by 26% with treatment and stopped either temporarily or persistently in nine patients. FCM, compared to a FG-based scenario, was associated with a cost saving of 288 euros/patient/24 weeks. Saving was the same in ESA users/non-users. Therefore, in non-hemodialysis CKD patients, FCM effectively corrects IDA and allows remarkable cost savings in terms of societal, healthcare and patient perspective.

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.

ESA, Iron Therapy and New Drugs: Are There New Perspectives in the Treatment of Anaemia?

Anemia is a well-known consequence of chronic kidney disease (CKD); it is mainly due to a relative insufficiency of erythropoietin synthesis by the failing kidneys. Over the years, the combination of erythropoiesis stimulating agents (ESA) and iron has become the standard of care of anemia. All ESAs effectively increase hemoglobin (Hb) levels in a substantial percentage of patients. However, in the last decade, their use has been surrounded by safety issues in increased cardiovascular risk, especially when used at high doses in inflamed and hyporesponsive patients. This has led to the definition of a more cautious Hb target. Iron deficiency is very frequent in CKD patients, with a higher frequency in non-dialysis patients. Traditionally, iron supplementation is mostly used as supportive therapy for anemia control. However, the concept is growing that intravenous iron therapy per se could be beneficial in the presence of heart failure. A new class of drugs, prolyl hydroxylase domain (PHD) inhibitors (PHD inhibitors) is becoming available for the treatment of anemia in CKD patients. Theoretically, these agents have a number of advantages, the main ones being that of stimulating the synthesis of endogenous erythropoietin and increasing iron availability. The impact of their future use in clinical practice is still to be defined. Another possible strategy could be targeting serum hepcidin and its related pathways. This possibility is fascinating from the scientific point of view, but at present its development phase is still far from clinical application.

Predictive effect of salt intake on patient and kidney survival in non-dialysis CKD: competing risk analysis in older versus younger patients under nephrology care

BACKGROUND

The optimal level of salt intake remains ill-defined in non-dialysis chronic kidney disease (CKD) patients under regular nephrology care. This unanswered question becomes critical in older patients who are exposed to higher risk of worsening of cardiorenal disease due to volemic changes.

METHODS

In this pooled analysis of four prospective studies in CKD, we compared the risk of all-cause mortality and end-stage kidney disease (ESKD) between patients ≤65 and >65 years of age stratified by salt intake level (<6, 6-8 and >8 g/day) estimated from two measurements of 24-h urinary sodium.

RESULTS

The cohort included 1785 patients. The estimated glomerular filtration rate was 37 ± 21 mL/min/1.73 m2 overall, 41 ± 25 in younger patients and 34 ± 16 in older patients (P < 0.001). The median 24-h urinary sodium excretion was 143 mEq [interquartile range (IQR) 109-182] in all, 147 (112-185) in younger patients and 140 (106-179) in older patients (P = 0.012). Salt intake was ≤6, 6-8 and >8 g sodium chloride/day in 21.9, 26.2 and 52.0% of older patients and 18.6, 25.2 and 56.2% in younger patients, respectively (P = 0.145). During a median follow-up of 4.07 years we registered 383 ESKD and 260 all-cause deaths. In the whole cohort, the risks of ESKD and all-cause death did not differ by salt intake level. In older patients, ESKD risk [multi-adjusted hazard ratio (HR) and 95% confidence interval (CI)] was significantly lower at salt intakes of 6-8 g/day [HR 0.577 (95% CI 0.361-0.924)] and >8 g/day [HR 0.564 (95% CI 0.382-0.833)] versus the reference group (<6 g/day). Mortality risk was higher in older versus younger patients, with no difference across salt intake categories. No effect of salt intake on ESKD and mortality was observed in younger patients.

CONCLUSIONS

CKD patients under nephrology care show a moderate salt intake (8.4 g/day) that is lower in older versus younger patients. In this context, older patients are not exposed to higher mortality across different levels of salt intake, while salt intake <6 g/day poses a greater risk of ESKD.

Reclassification of chronic kidney disease patients for end-stage renal disease risk by proteinuria indexed to estimated glomerular filtration rate: multicentre prospective study in nephrology clinics

BACKGROUND

In non-dialysis chronic kidney disease (CKD), absolute proteinuria (Uprot) depends on the extent of kidney damage and residual glomerular filtration rate (GFR). We therefore evaluated, as compared with Uprot, the strength of association of proteinuria indexed to estimated GFR (eGFR) with end-stage renal disease (ESRD) risk.

METHODS

In a multi-cohort prospective study in 3957 CKD patients of Stages G3-G5 referred to nephrology clinics, we tested two multivariable Cox models for ESRD risk, with either Uprot (g/24 h) or filtration-adjusted proteinuria (F-Uprot) calculated as Uprot/eGFR ×100.

RESULTS

Mean ± SD age was 67 ± 14 years, males 60%, diabetics 29%, cardiovascular disease (CVD) 34%, eGFR 32 ± 13 mL/min/1.73 m2, median (interquartile range) Uprot 0.41 (0.12-1.29) g/24 h and F-Uprot 1.41 (0.36-4.93) g/24 h per 100 mL/min/1.73 m2 eGFR. Over a median follow-up of 44 months, 862 patients reached ESRD. At competing risk analysis, ESRD risk progressively increased when F-Uprot was 1.0-4.9 and ≥5.0 versus <1.0 g/24 h per 100 mL/min/1.73 m2 eGFR in Stages G3a-G4 (P < 0.001) and Stage G5 (P = 0.002). Multivariable Cox analysis showed that Uprot predicts ESRD in Stages G3a-G4 while in G5 the effect was not significant; conversely, F-Uprot significantly predicted ESRD at all stages. The F-Uprot model allowed a significantly better prediction versus the Uprot model according to Akaike information criterion. Net reclassification improvement was 12.2% (95% confidence interval 4.2-21.1), with higher reclassification in elderly, diabetes and CVD, as well as in diabetic nephropathy and glomerulonephritis, and in CKD Stages G4 and G5.

CONCLUSIONS

In patients referred to nephrology clinics, F-Uprot predicts ESRD at all stages of overt CKD and improves, as compared with Uprot, reclassification of patients for renal risk, especially in more advanced and complicated disease.

Liposomal iron in moderate chronic kidney disease

INTRODUCTION AND OBJECTIVE

The optimal iron supplementation route of administration (intravenous vs oral) in patients with chronic kidney disease (CKD) not on dialysis is a hot topic of debate. An oral preparation (liposomal iron, FeSu) has recently been developed with high bioavailability and low incidence of side effects. The objective was to evaluate the efficacy of FeSu in patients with stage 3 CKD and gastrointestinal intolerance to conventional oral iron therapy.

MATERIAL AND METHODS

Prospective observational study of patients with stable stage 3 CKD and gastrointestinal intolerance to conventional oral iron therapy. An oral 30mg/day dose of FeSu was administered for 12 months. The primary outcome measure was haemoglobin increase at 6 and 12 months. Treatment adherence and adverse effects were also evaluated.

RESULTS

37 patients aged 72.6±14.7 years and with an estimated glomerular filtration rate (eGFR) of 42±10ml/min/1.73m² were included. 32 patients had received previous treatment with conventional oral formulations, 73% of which exhibited gastrointestinal intolerance with treatment adherence of 9.4%. After 6 months with FeSu, an increase in haemoglobin was observed versus baseline, which was sustained at 12 months (0.49±0.19 and 0.36±0.19g/dl, respectively, P<.05), despite a significant eGFR decrease of 3.16±1.16 and 4.20±1.28ml/min/1.73 m² at 6 and 12 months, respectively. None of the patients experienced adverse reactions that required the treatment to be suspended. Adherence was 100% at both 6 and 12 months.

CONCLUSIONS

FeSu is effective in a cohort of patients with stage 3 CKD with similar characteristics to the general population of moderate CKD patients, with a low rate of adverse reactions and excellent tolerability.

Etiological spectrum of anemia in non-dialysis-dependent chronic kidney disease: A single-center study from India

A retrospective study was conducted over seven years and it aimed to find out various causes of anemia among patients with chronic kidney disease (CKD). The study included nondialysis-dependent adult CKD patients who underwent anemia evaluation. A total of 584 patients were studied. Three hundred and twenty-one (55%) patients were male and 263 (45%) were female. The mean age of the patients was 55.5 ± 14 years. One hundred and seventy-eight (30.5%) had a diabetic CKD and 406 (69.5%) had a nondiabetic CKD. Seventy-two (12.3%) patients were in CKD Stage 3, 193 (33%) patients in CKD Stage 4, and 319 (54.6%) patients in CKD Stage 5. The mean hemoglobin was 9.2 ± 2.2 g/dL. There was a progressive fall in hemoglobin with increasing severity of CKD and in CKD Stage 3, 4, and 5 the mean hemoglobin was 10 ± 2.2, 9.4 ± 2.1, and 8.4 ± 1.9 g/dL, respectively (P = 0.001). Most (47.4%) patients had moderate anemia followed by anemia of mild (31.4%) and severe (21.4%) degrees. Three hundred and seven (52.6%) patients had percent transferrin saturation (TSAT) <20% (functional iron deficiency). One hundred and sixty-two (27.7%) patients had serum ferritin <100 ng/mL (absolute iron deficiency); 334 (57.2%) patients had serum ferritin 100-500 ng/mL, but in 175 (52.4%) of them, TSAT was <20%; 88 (15.1%) patients had serum ferritin >500 ng/mL (58 (65.6%) were C-reactive protein (CRP) + and 55 (62.5%) had TSAT <20%). Overall, 392 (67.1%) patients had functional or absolute iron deficiency. One-third of the patients had elevated CRP levels. The anemia was macrocytic in 20.4% suggesting deficiency of folic acid and/or Vitamin B₁₂. A high proportion (74.6%) of patients with normocytic anemia had iron deficiency. In the majority of nondialysis-dependent CKD patients, the etiology of anemia may be multifactorial; therefore, the treatment should be determined by documented causes of anemia.

The effect of vitamin D supplementation on hemoglobin concentration: a systematic review and meta-analysis

AIMS

The purpose of this review was to investigate the effect of vitamin D supplements on hemoglobin concentration in subjects aged 17.5-68 years old; using randomized controlled trials (RCTs).

METHODS

Relevant RCT studies were identified from January 2000 to January 2019 by using MeSH terms in PubMed, Embase, Cochrane Library, Clinical trials, Scopus databases and gray literature. The studies were reviewed systematically, and quality assessments were evaluated by the guidelines of the Cochrane risk of bias. The effect of vitamin D supplements (n = 14) on hemoglobin concentration was considered as primary outcome, while its effects on the levels of ferritin, transferrin saturation and iron status were derived as secondary outcomes. In total, 1385 subjects with age range of 17.5 to 68 years old were examined for 3 h to 6 months; Mean (standard deviation) or median interquartile changes in the hemoglobin concentration in each treatment group was recorded for meta-analysis.

RESULTS

Fourteen RCTs met the inclusion criteria. Current study findings propose that vitamin D supplementation leads to a non-significant reduction in hemoglobin levels in subjects (17.5-68 years old) [std. mean difference (SMD): 0.01; 95% CI: - 0.28, 0.29; P = 0.95], also it has no significant effect on ferritin concentrations [std. mean difference (SMD): -0.01; 95% CI: [- 0.20, 0.18; P = 0.91]. However, vitamin D supplementation demonstrated positive effects on transferrin saturation [mean difference (MD): 1.54; 95% CI: 0.31, 2.76; P = 0.01] and iron status [std. mean difference (SMD): 0.24; 95% CI: - 0.09, 0.39; P = 0.002].

CONCLUSION

Current review concluded that supplementation with vitamin D had no significant effect on hemoglobin and ferritin levels while positive effects on transferrin saturation and iron status were observed. Further clinical studies are required to determine the actual effect of this intervention on hemoglobin levels.

Unraveling Cardiovascular Risk in Renal Patients: A New Take on Old Tale

Chronic kidney disease (CKD), defined by an estimated glomerular filtration rate <60 ml/min/1.73 m² and/or an increase in urine protein excretion (i.e., albuminuria), is an important public health problem. Prevalence and incidence of CKD have risen by 87 and 89%, worldwide, over the last three decades. The onset of either albuminuria and eGFR reduction has found to predict higher cardiovascular (CV) risk, being this association strong, independent from traditional CV risk factors and reproducible across different setting of patients. Indeed, this relationship is present not only in high risk cohorts of CKD patients under regular nephrology care and in those with hypertension or type 2 diabetes, but also in general, otherwise healthy population. As underlying mechanisms of damage, it has hypothesized and partially proved that eGFR reduction and albuminuria can directly promote endothelial dysfunction, accelerate atherosclerosis and the deleterious effects of hypertension. Moreover, the predictive accuracy of risk prediction models was consistently improved when eGFR and albuminuria have been added to the traditional CV risk factors (i.e., Framingham risk score). These important findings led to consider CKD as an equivalent CV risk. Although it is hard to accept this definition in absence of additional reports from scientific Literature, a great effort has been done to reduce the CV risk in CKD patients. A large number of clinical trials have tested the effect of drugs on CV risk reduction. The targets used in these trials were different, including blood pressure, lipids, albuminuria, inflammation, and glucose. All these trials have determined an overall better control of CV risk, performed by clinicians. However, a non-negligible residual risk is still present and has been attributed to: (1) missed response to study treatment in a consistent portion of patients, (2) role of many CV risk factors in CKD patients not yet completely investigated. These combined observations provide a strong argument that kidney measures should be regularly included in individual prediction models for improving CV risk stratification. Further studies are needed to identify high risk patients and novel therapeutic targets to improve CV protection in CKD patients.

Prevalence, correlates and outcomes of absolute and functional iron deficiency anemia in nondialysis-dependent chronic kidney disease

Background

Anemia is associated with adverse outcomes in those with chronic kidney disease (CKD). We examined the association of absolute and functional iron deficiency anemia (IDA) with adverse outcomes (cardiovascular hospitalization, dialysis and mortality) in those with nondialysis-dependent CKD.

Methods

Nondialysis-dependent CKD patients followed in the US Veterans Administration with hemoglobin level measured within 90 days of the date of the second estimated glomerular filtration rate &lt;60 mL/min/1.73 m2 were included. Logistic regression, multivariate Cox proportional hazards and Poisson regression models adjusted for demographics and comorbidities were used to assess the prevalence and correlates of absolute [transferrin saturation (TSAT) ≤20%, ferritin &lt;100 ng/mL] and functional (TSA T≤20%, ferritin &gt;100–500 ng/mL) IDA and the associations of absolute and functional IDA with mortality, dialysis and cardiovascular hospitalization.

Results

Of 933 463 patients with CKD, 20.6% had anemia. Among those with anemia, 23.6% of patients had both TSAT and ferritin level measured, of whom 30% had absolute IDA and 19% had functional IDA. Absolute IDA in CKD was not associated with an increased risk of mortality or dialysis but was associated with a higher risk of 1-year {risk ratio [RR] 1.20 [95% confidence interval (CI) 1.12–1.28]} and 2-year cardiovascular hospitalization [RR 1.11 (95% CI 1.05–1.17)]. CKD patients with functional IDA had a higher risk of mortality [hazard ratio (HR) 1.11 (95% CI 1.07–1.14)] along with a higher risk of 1-year [RR 1.21 (95% CI 1.1–1.30)] and 2-year cardiovascular hospitalization [RR 1.13 (95% CI 1.07–1.21)]. Ferritin &gt;500 ng/mL (treated as a separate category) was only associated with an increased risk of mortality [HR 1.38 (95% CI 1.26–1.51)].

Conclusions

In a large population of CKD patients with anemia, absolute and functional IDA were associated with various clinical covariates. Functional IDA was associated with an increased risk of mortality and cardiovascular hospitalization, but absolute IDA was associated only with a higher risk of hospitalization.

Cardiorenal prognosis by residual proteinuria level in diabetic chronic kidney disease: pooled analysis of four cohort studies

Background

No study has assessed whether the prognosis of coexisting diabetes mellitus and chronic kidney disease (DM-CKD) is dictated by DM per se or by the extent of proteinuria.

Methods

In this pooled analysis of four prospective studies in CKD patients treated with drugs inhibiting the renin-angiotensin system, we compared the risk of all-cause mortality, fatal and non-fatal cardiovascular (CV) events and end-stage renal disease (ESRD) between patients with (n = 693) and without diabetes (n = 1481) stratified by proteinuria level (<0.15, 0.15-0.49, 0.5-1 and  >1 g/day).

Results

The group with DM-CKD was older (69 ± 11 versus 65 ± 15 years), had a higher body mass index (29.6 ± 5.4 versus 27.5 ± 4.8 kg/m2) and systolic blood pressure (143 ± 19 versus 136 ± 18 mmHg), prevalent CV disease (48% versus 29%) and lower estimated glomerular filtration rate (34.5 ± 17.9 versus 36.6 ± 19.0 mL/min/1.73 m2). During 4.07 years of follow-up, there were 466 patients with ESRD, 334 deaths and 401 CV events occurred. In the subgroup with urine protein <0.15 g/day (N = 662), the risks of ESRD, CV events and mortality were similar in diabetic and non-diabetic patients. Conversely, in DM-CKD patients, the mortality risk was higher in proteinuric patients {hazard ratio 1.92 [95% confidence interval (CI) 1.25-2.95); 1.99 (1.26-3.15) and 1.98 (1.28-3.06) for proteinuria 0.15-0.49, 0.5-1 and >1 g/day, respectively}, whereas in non-diabetics the mortality risk increased only for proteinuria 0.5-1 g/day [HR 1.60 (95% CI 1.07-2.40)] and >1 g/day [HR 1.69 (95% CI1.20-2.55)]. In both groups, CV risk had a trend similar to that of mortality. ESRD risk increased progressively across strata >0.5 g/day independent of diabetic status.

Conclusions

We provide evidence that patients with non-proteinuric DM-CKD are not exposed to higher cardiorenal risk. In contrast, in the presence of moderate proteinuria and diabetes per se is associated with a higher risk of mortality and CV events, whereas the entity of abnormal proteinuria modulates ESRD risk independent of diabetes.

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.

Sex Differences in the Progression of CKD Among Older Patients: Pooled Analysis of 4 Cohort Studies

RATIONALE & OBJECTIVE

Data for the association of sex with chronic kidney disease (CKD) progression are conflicting, a relationship this study sought to examine.

STUDY DESIGN

Pooled analysis of 4 Italian observational cohort studies.

SETTING & PARTICIPANTS

1,311 older men and 1,024 older women with estimated glomerular filtration rate (eGFR)<45mL/min/1.73m² followed up in renal clinics.

PREDICTOR

Sex.

OUTCOMES

End-stage kidney disease (ESKD), defined as maintenance dialysis or kidney transplantation, as the primary outcome; all-cause mortality and eGFR decline as secondary outcomes.

ANALYTICAL APPROACH

Cox proportional hazard analysis to estimate the relative risk for ESKD and mortality and linear mixed models to estimate the rate of eGFR decline.

RESULTS

Age, systolic blood pressure, and use of renin-angiotensin system inhibitors were similar in men and women. Baseline eGFRs were 27.6±10.2 in men and 26.0±10.6mL/min/1.73m² in women (P<0.001), while median proteinuria was lower in women (protein excretion, 0.45 [IQR, 0.14-1.10] g/d) compared with men (0.69 [IQR 0.19-1.60] g/d; P<0.001). During a median follow-up of 4.2 years, 757 developed ESKD (59.4% men) and 471 died (58.4% men). The adjusted risks for ESKD and mortality were higher in men (HRs of 1.50 [95% CI, 1.28-1.77] and 1.30 [95% CI, 1.06-1.60], respectively). This finding was consistent across CKD stages. We observed a significant interaction between sex and proteinuria, with the risk for ESKD in men being significantly greater than for women at a level of proteinuria of ∼0.5g/d or greater. The slope of decline in eGFR was steeper in men (-2.09; 95% CI, -2.21 to-1.97mL/min/1.73m² per year) than in women (-1.79; 95% CI, -1.92 to-1.66mL/min/1.73m² per year; P<0.001). Although sex differences in eGFR decline were not different across CKD stages (P=0.3), the difference in slopes between men and women was progressively larger with proteinuria >0.5g/d (P = 0.04).

LIMITATIONS

Residual confounding; only whites were included.

CONCLUSIONS

Excess renal risk in men may, at least in part, be related to higher levels of proteinuria in men compared with women.

Generalizability of SPRINT-CKD cohort to CKD patients referred to renal clinics

BACKGROUND

The Systolic Blood Pressure Intervention Trial-CKD substudy (SPRINT-CKD) has suggested a lower blood pressure (BP) target in CKD patients. However, it is questionable whether the SPRINT-CKD results may be generalized to CKD patients under nephrology care.

METHODS

To compare SPRINT-CKD cohort versus referred CKD patients in terms of patients' risk profile and outcomes, we pooled four prospective cohorts of consecutive CKD patients referred to 40 Italian renal clinics. We implemented the same inclusion/exclusion criteria adopted in SPRINT and same endpoints: (1) a composite of fatal and non-fatal cardiovascular (CV) events (2) all-cause mortality and (3) ESRD (composite of chronic dialysis, transplantation or 50% eGFR decline). Findings were compared with those attained in the control arm of SPRINT-CKD trial that mirrored standard BP management in clinical practice.

RESULTS

Out of 2847 patients referred to renal clinics, only 20.1% (n = 571) were identified as eligible for SPRINT-CKD. Age (72 ± 9 years), gender (42.2% female) and systolic BP (142 ± 10 mmHg) did not differ from the SPRINT-CKD while referred patients had a worse risk profile at baseline: larger prevalence of prior CV disease (25.7% versus 19.5%), higher Framingham risk score (31.9 ± 14.6% versus 27.2 ± 24.7%) and lower GFR (38 ± 11 versus 48 ± 10 mL/min/1.73 m²). During 4.0 years of follow-up, 86 CV events (50 fatal), 78 all-cause death and 59 ESRD occurred with annual incidence rates higher than those observed in the SPRINT-CKD control group (CV events 4.18 vs 3.19; all-cause death 3.64 vs 2.21; ESRD 2.80 vs 0.41%/year).

CONCLUSIONS

The SPRINT-CKD cohort is poorly representative of the CKD population under nephrology care, thus suggesting that conclusions may not apply to patients referred to nephrologist.

Competing-Risk Analysis of Death and End Stage Kidney Disease by Hyperkalaemia Status in Non-Dialysis Chronic Kidney Disease Patients Receiving Stable Nephrology Care

Hyperkalaemia burden in non-dialysis chronic kidney disease (CKD) under nephrology care is undefined. We prospectively followed 2443 patients with two visits (referral and control with 12-month interval) in 46 nephrology clinics. Patients were stratified in four categories of hyperkalaemia (serum potassium, sK ≥ 5.0 mEq/L) by sK at visit 1 and 2: Absent (no-no), Resolving (yes-no), New Onset (no-yes), Persistent (yes-yes). We assessed competing risks of end stage kidney disease (ESKD) and death after visit 2. Age was 65 ± 15 years, eGFR 35 ± 17 mL/min/1.73 m², proteinuria 0.40 (0.14–1.21) g/24 h. In the two visits sK was 4.8 ± 0.6 and levels ≥6 mEq/L were observed in 4%. Hyperkalaemia was absent in 46%, resolving 17%, new onset 15% and persistent 22%. Renin-angiotensin-system inhibitors (RASI) were prescribed in 79% patients. During 3.6-year follow-up, 567 patients reached ESKD and 349 died. Multivariable competing risk analysis (sub-hazard ratio-sHR, 95% Confidence Interval-CI) evidenced that new onset (sHR 1.34, 95% CI 1.05–1.72) and persistent (sHR 1.27, 95% CI 1.02–1.58) hyperkalaemia predicted higher ESKD risk versus absent, independently from main determinants of outcome including eGFR change. Conversely, no effect on mortality was observed. Results were confirmed by testing sK as continuous variable. Therefore, in CKD under nephrology care, mild-to-moderate hyperkalaemia status is common (37%) and predicts per se higher ESKD risk but not mortality.

Iron deficiency in chronic kidney disease patients with diabetes mellitus

BACKGROUNDS

Iron deficiency has been studied extensively in patients with chronic kidney disease on hemodialysis therapy. However, few studies looked at iron treatment in the non-dialysis chronic kidney disease population.

METHODS

Five hundred and eighty patients were studied (247 were diabetic persons). Patients were divided into 4 groups: non-diabetic subjects without CKD, non-diabetic ones with GFR < 60 mL/min, diabetic persons without CKD and diabetic ones with GFR < 60 mL/min). Iron deficiency was diagnosed when serum ferritin level was <100 mg/dl. It was defined as diminished iron availability when ferritin was above 100 mg/dl and serum transferrin saturation (TSAT) was <20%.

RESULTS

Anemia was more frequent in the diabetic CKD patients group (52.4%, p < 0.001). Anemia prevalence was also higher in all CKD patients as well as in diabetic patients compared with non-diabetic ones. Iron deficiency was more frequent in diabetic patients. Among CKD diabetic patients the prevalence of iron deficiency was higher than in non-diabetic CKD ones. Diminished iron availability prevalence was higher in non-diabetic patients. Logistic regression analysis showed that only sex and diabetes mellitus were independently associated with iron deficiency.

CONCLUSIONS

Anemia was more common in diabetic CKD patients. Diabetes mellitus was independently associated with iron deficiency. Surprisingly, diminished iron availability was not more frequent in diabetic patients. The physio-pathological mechanisms that could explain these findings remain to be elucidated.

The Divalent Elements Changes in Early Stages of Chronic Kidney Disease

As the glomerular filtration rate (GFR) decreases, it can cause imbalance in some divalent elements. These imbalances can cause increased oxidative stress in patients with renal impairment. The aim of present study was to investigate the changes of these divalent elements with CKD progression. One hundred and ninety-four patients with chronic kidney diseases (CKD) were divided into five stages, stage 1, 2, 3a, 3b, 4, and were recruited into this study. The divalent elements, calcium, magnesium, phosphorus, as well as iron, zinc, and copper were determined in clinical chemistry analyzer. Higher CKD stages were found to be associated with increased levels of phosphorus and copper; P_trend values were 0.002 and 0.004, respectively. Also, higher CKD stages were associated with decreased levels of zinc; P_trend value was 0.002, after adjustment for age, gender, smoke, education, diabetes, hypertension, and BMI. Decreased levels of zinc and elevated levels of phosphorus and copper might increase the oxidative stress and complications in CKD patients. Future randomized studies are needed to show whether adjusting dietary intake of phosphorus, copper, and zinc might affect the progression of CKD.

Measurement properties of the Short Form-36 (SF-36) and the Functional Assessment of Cancer Therapy - Anemia (FACT-An) in patients with anemia associated with chronic kidney disease

BACKGROUND

Anemia is a common and debilitating manifestation of chronic kidney disease (CKD). Data from two clinical trials in patients with anemia of CKD were used to assess the measurement properties of the Medical Outcomes Survey Short Form-36 version 2 (hereafter SF-36) and the Functional Assessment of Cancer Therapy-Anemia (FACT-An). The Vitality and Physical functioning domains of the SF-36 and the FACT-An Total, Fatigue and Anemia subscales were identified as domains relevant to CKD-associated anemia.

METHODS

A total of 204 patients aged 18-80 years were included in the analyses that included internal consistency (Cronbach's alpha), test-retest reliability (intraclass correlation coefficients [ICCs]), convergent and known-groups validity, responsiveness, and estimates of important change.

RESULTS

Both the SF-36 and the FACT-An had strong psychometric properties with high internal consistency (Cronbach's alpha: 0.69-0.93 and 0.79-0.95), and test-retest reliability (ICCs: 0.64-0.83 and 0.72-0.88). Convergent validity, measured by correlation coefficients between similar concepts in SF-36 and FACT-An, ranged from 0.52 to 0.77. Correlations with hemoglobin (Hb) levels were modest at baseline; by Week 9, the correlations with Hb were somewhat higher, r = 0.23 (p < 0.05) for SF-36 Vitality, r = 0.22 (p < 0.05) for FACT-An Total, r = 0.26 (p < 0.001) for FACT-Fatigue and r = 0.22 (p < 0.01) for Anemia. Correlations with Hb at Week 13/17 were r = 0.28 (p < 0.001) for SF-36 Vitality and r = 0.25 (p < 0.05) for Role Physical; FACT-An Total correlation was r = 0.33 (p < 0.0001), Anemia was r = 0.28 (p < 0.001), and Fatigue was r = 0.30 (p < 0.001). The SF-36 domains and Component Summary scores (p < 0.05-p < 0.0001) demonstrated ability to detect change. For the FACT-An, significant differences (p < 0.05-p < 0.0001) were observed between responder and non-responder change scores: important change score estimates ranged from 2 to 4 for Vitality and 2-3 for Physical functioning. Important change scores were also estimated for the FACT-An Total score (6-9), the Anemia (3-5), and Fatigue subscale (2-4).

CONCLUSIONS

Both the SF-36 Vitality and Physical function scales and the FACT-An Total, Fatigue and Anemia scales, are reliable and valid measures for assessing health-related quality of life in anemia associated with CKD.

Iron deficiency across chronic kidney disease stages: Is there a reverse gender pattern?

In non-dialysis chronic kidney disease patients, looking for iron deficiency is highly variable in practice and there is a great variability regarding the cutoffs used to treat iron deficiency. The aim of this study is to investigate the degree of iron deficiency in non-dialysis chronic kidney disease patients on erythropoiesis-stimulating agents. We included all non-dialysis chronic kidney disease patients that applied to the Lebanese Ministry of Public Health for erythropoiesis-stimulating agents’ coverage during a 5-month period. Iron requirement was assessed based on two guidelines’ target-to-treat cutoffs: 1-ferritin <100 ng/ml and/or TSAT < 20% (KDOQI 2006), 2- ferritin ≤500 ng/ml and TSAT ≤30% (KDIGO 2012). A total of 238 CKD patients were included over 5 months. All patients had a ferritin level in their record and 64% had an available TSAT. Median age was 71.0 (59.8–79.3) years and 61.8% were female. All had an eGFR<60 ml/min. The proportion of patients found to require iron therapy ranged between 48 and 78% with a trend towards higher values when using KDIGO-based criteria. Using ANCOVA test, inverse normal transformations of ferritin and TSAT showed a reverse pattern between men and women with women being more iron deficient in the early stage. Iron deficiency is highly prevalent in non-dialysis chronic kidney disease patients on erythropoiesis-stimulating agents’ therapy. These findings reflect a lack in effective iron supplementation when managing anemia in pre-dialysis patients, especially in men at advanced stages. Renal societies should spread awareness about iron deficiency screening in those patients.

Iron Balance and the Role of Hepcidin in Chronic Kidney Disease

The hepatic iron-regulatory hormone hepcidin and its receptor, the cellular iron exporter ferroportin, constitute a feedback-regulated mechanism that maintains adequate plasma concentrations of iron-transferrin for erythropoiesis and other functions, ensures sufficient iron stores, and avoids iron toxicity and iron-dependent microbial pathogenesis. In chronic kidney disease, inflammation and impaired renal clearance increase plasma hepcidin, inhibiting duodenal iron absorption and sequestering iron in macrophages. These effects of hepcidin can cause systemic iron deficiency, decreased availability of iron for erythropoiesis, and resistance to endogenous and exogenous erythropoietin. Together with impaired renal production of erythropoietin, hepcidin-mediated iron restriction contributes to anemia of chronic kidney disease.

Quality of care and practice patterns in anaemia management at specialist kidney clinics in Ireland: a national study

Background

Although anaemia is a common complication of advanced chronic kidney disease (CKD), knowledge of quality of care and management practices in specialist clinics varies. We examined anaemia practices at specialist nephrology clinics within the Irish health system and evaluated the opinions of practicing nephrologists.

Methods

A multicentre cross-sectional study was conducted at specialist nephrology clinics across six geographic regions in Ireland. Clinical characteristics and treatment practices were evaluated in a sample of 530 patients with CKD. An accompanying national survey questionnaire captured opinions and treatment strategies of nephrologists on anaemia management.

Results

The prevalence of anaemia [defined as haemoglobin (Hb) <12.0 g/dL] was 37.8%, which increased significantly with advancing CKD (from 21% to 63%; P < 0.01) and varied across clinical sites (from 36% to 62%; P < 0.026). Iron deficiency (ID) was present in 46% of all patients tested and 86% of them were not on treatment. More than 45% of anaemic patients were not tested for ID. Respondents differed in their selection of clinical guidelines, threshold targets for erythropoiesis-stimulating agent (ESA) and intravenous iron therapy and anaemia management algorithms were absent in 47% of the clinics. The unexpectedly low rates of ESA use (4.7%) and iron therapy (10.2%) in clinical practice were in contrast to survey responses where 63% of nephrologists indicated ESA therapy initiation when Hb was <10.0 g/dL and 46% indicated commencement of iron therapy for ferritin <150 ng/mL.

Conclusion

This study highlights substantial variability in the management of anaemia and ID at specialist nephrology clinics with low testing rates for ID, high rates of anaemia and ID and underutilization of effective treatments. Variability in the adoption and implementation of different clinical guidelines was evident.

Epidemiology of low-proteinuric chronic kidney disease in renal clinics

CKD patients with low-grade proteinuria (LP) are common in nephrology clinics. However, prevalence, characteristics, and the competing risks of ESRD and death as the specific determinants, are still unknown. We analyzed epidemiological features of LP status in a prospective cohort of 2,340 patients with CKD stage III-V referred from ≥6 months in 40 nephrology clinics in Italy. LP status was defined as proteinuria <0.5 g/24h according to current KDIGO guidelines. Patients with higher proteinuria constituted the control group (CON). LP patients were 54.5% of the whole cohort. As compared to CON, LP were older (70.0±12.1 vs 65.4±14.1 y), and less likely to be male (55.8 vs 62.0%) and diabetic (27.6 vs 34.1%), and had hypertension as the most common cause of CKD (39.8%). They had higher eGFR (34.8±13.5 vs 26.8±13.2 mL/min/1.73m²) and hemoglobin (12.7±1.7 vs 12.3±1.7 g/dL), while systolic blood pressure (137±18 vs 140±18 mmHg) and serum phosphorus (3.7±0.8 vs 3.9±0.8 mg/dL) were lower [P<0.001 for all comparisons]. Over a median follow-up of 48 months, an inverse relative risk of ESRD and death was observed in LP (death>>ESRD; P = 0.002) versus CON (ESRD>>death; P<0.0001). Modifiable risk factors were also different in LP, with smoking, lower hemoglobin, and proteinuria being associated with higher mortality risk while lower BMI and higher phosphorus predicting ESRD at multivariable Cox analyses [P<0.05 for all]. Therefore, in nephrology clinics, LP patients are the majority and show distinctive basal features. More important, they are more exposed to death than ESRD and do present specific modifiable determinants of either outcome; indeed, in LP, while smoking plays a role for mortality, lower BMI and higher phosphorus levels -even if in the normal range- are predictors of ESRD. These data support the need to further study the low proteinuric CKD population to guide management.

[Diagnostic approach to iron deficiency anemia]

Anemia affects a fourth of the global population, with iron deficiency remaining the primary cause. It is associated with diminished work capacity, fatigue, impaired cognitive function, and can negatively impact the course of diseases like chronic heart failure or chronic kidney disease. Treatment options include oral and intravenous iron; however, conditions such as inflammatory bowel disease, celiac disease, or autoimmune gastritis can diminish the efficacy of oral iron. Timely recognition of iron deficiency anemia and administration of appropriate therapy not only improves quality of life, but also reduces the need for blood transfusions. Proper selection of iron-deficient patients for whom further diagnostic testing is necessary facilitates identification of underlying diseases that require specific treatment, and avoids unnecessary invasive testing.

Controversial issues in CKD clinical practice: position statement of the CKD-treatment working group of the Italian Society of Nephrology

This position paper of the study group "Conservative treatment of Chronic Kidney Disease-CKD" of the Italian Society of Nephrology addresses major practical, unresolved, issues related to the conservative treatment of chronic renal disease. Specifically, controversial topics from everyday clinical nephrology practice which cannot find a clear, definitive answer in the current literature or in nephrology guidelines are discussed. The paper reports the point of view of the study group. Concise and practical advice is given on several common issues: renal biopsy in diabetes; dual blockade of the renin-angiotensin-aldosterone system (RAAS); management of iron deficiency; low protein diet; dietary salt intake; bicarbonate supplementation; treatment of obesity; the choice of conservative therapy vs. dialysis. For each topic synthetic statements, guideline-style, are reported.

Low-protein diets for chronic kidney disease patients: the Italian experience

BACKGROUND

Nutritional treatment has always represented a major feature of CKD management. Over the decades, the use of nutritional treatment in CKD patients has been marked by several goals. The first of these include the attainment of metabolic and fluid control together with the prevention and correction of signs, symptoms and complications of advanced CKD. The aim of this first stage is the prevention of malnutrition and a delay in the commencement of dialysis. Subsequently, nutritional manipulations have also been applied in association with other therapeutic interventions in an attempt to control several cardiovascular risk factors associated with CKD and to improve the patient's overall outcome. Over time and in reference to multiple aims, the modalities of nutritional treatment have been focused not only on protein intake but also on other nutrients.

DISCUSSION

This paper describes the pathophysiological basis and rationale of nutritional treatment in CKD and also provides a report on extensive experience in the field of renal diets in Italy, with special attention given to approaches in clinical practice and management. Italian nephrologists have a longstanding tradition in implementing low protein diets in the treatment of CKD patients, with the principle objective of alleviating uremic symptoms, improving nutritional status and also a possibility of slowing down the progression of CKD or delaying the start of dialysis. A renewed interest in this field is based on the aim of implementing a wider nutritional therapy other than only reducing the protein intake, paying careful attention to factors such as energy intake, the quality of proteins and phosphate and sodium intakes, making today's low-protein diet program much more ambitious than previous. The motivation was the reduction in progression of renal insufficiency through reduction of proteinuria, a better control of blood pressure values and also through correction of metabolic acidosis. One major goal of the flexible and innovative Italian approach to the low-protein diet in CKD patients is the improvement of patient adherence, a crucial factor in the successful implementation of a low-protein diet program.

Anaemia management and mortality risk in newly visiting patients with chronic kidney disease in Japan: The CKD-ROUTE study

AIM

To investigate the association between iron deficiency anaemia and mortality risk and assess the changes in anaemia and iron status after primary management by a nephrologist.

METHODS

In this prospective cohort study, we stratified 951 non-dialysis chronic kidney disease (CKD) G2-G5 patients newly visiting 16 nephrology centres into four groups according to the presence of anaemia with or without iron deficiency. All-cause mortality, cardiovascular (CV)-related mortality, and a change in anaemia and iron status after specialized primary care were the endpoints evaluated.

RESULTS

During a median follow-up time of 19 months, the number of all-cause deaths and CV-related deaths were 56 and 26, respectively. Compared with the control group, the groups with isolated anaemia and iron deficiency anaemia had significantly higher all-cause mortalities (isolated anaemia: hazard ratio (HR), 3.37; 95% confidence intervals (CI), 1.76-6.44; iron deficiency anaemia: HR, 3.11; 95% CI, 1.21-8.01) and CV-related mortalities (isolated anaemia: HR, 3.64; 95% CI, 1.36-9.73; iron deficiency anaemia: HR, 3.86; 95% CI, 1.11-13.41). In the isolated anaemia group, erythropoietin-stimulating agent (ESA) prescriptions significantly increased to approximately 70%. However, in patients with both anaemia and iron deficiency, iron prescriptions only increased to 48.1%.

CONCLUSIONS

Iron deficiency anaemia and isolated anaemia were associated with all-cause and CV-related mortality. The absence of relative increase in iron prescriptions suggests that iron deficiency should be accurately assessed and iron supplementation should be appropriately used to manage anaemia in non-dialysis patients with CKD.

Assessment of serum bioactive hepcidin-25, soluble transferrin receptor and their ratio in predialysis patients: Correlation with the response to intravenous ferric carboxymaltose

BACKGROUND

No reliable biomarker exists to predict responsiveness to intravenous (IV) iron (Fe) in iron deficient patients with CKD. We aimed to investigate the clinical value of bioactive Hepcidin-25 and soluble Transferrin Receptor (sTfR) levels in predialysis patients.

PATIENTS AND METHODS

In this prospective study 78 stable stage III-IV CKD predialysis patients with (responders) (40 patients) and without (non-responders) (38 patients) adequate erythropoiesis after IV administration of ferric-carboxymaltose (FCM). Patients were divided in two groups according to their response to IV administration of ferric-carboxymaltose (FCM). Along with measurements of common hematologic and blood chemistry parameters, determinations of sTfR and bioactive Hepcidin-25 were performed.

RESULTS

Hepcidin-25 levels were lower in the responders (p=0.025), while sTfR and sTfR/Hepcidin-25 ratio were higher (p<0.01 and p=0.002 respectively). Diagnostic efficacy indicated cut off point of 1.49 for Hepcidin-25 had sensitivity 84% and specificity 48%, while cut off point of 1.21 for sTfR/Hepcidin-25 ratio had sensitivity 82% and specificity 52% to predict correctly response to iron supplementation therapy. Furthermore, log sTfR/Hepcidin-25 correlated negatively with hs-CRP (p=0.005) and IL-6 (p<0.04) in non-responders, while such correlations were not found in responders (p>0.05).

CONCLUSIONS

These results suggest that lower Hepcidin-25, as well as higher sTfR and sTfR/Hepcidin-25 ratio were significant predictors of favorable hemoglobin response within a month after IV administration of FCM in patients with CKD. Further experiments and clinical studies in other groups of patients are needed to better elucidate the role of Hepcidin-25 and sTfR/Hepcidin-25 ratio as predictors of response to intravenous iron administration.