Iron Deficiency in CKD Without Concomitant Anemia

The prognostic value of serum hepcidin-25 in predicting cardiovascular events among maintenance hemodialysis patients: insights from the INFINITY cohort

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality among maintenance hemodialysis patients, with iron metabolism disorders, particularly involving hepcidin, contributing to this heightened risk. This study aimed to evaluate whether serum hepcidin-25 levels are associated with the incidence of new CVD events in maintenance hemodialysis patients, using a novel, clinically applicable assay.

METHODS

In this prospective, multicenter observational study, 567 maintenance hemodialysis patients from the INFINITY Cohort in Japan were followed for one year. Serum hepcidin-25 levels were measured using a latex turbidimetric immunoassay. The primary outcome was the incidence of new CVD events, including myocardial infarction, angina, and stroke. Logistic regression and Cox proportional hazards models were used to identify factors associated with new CVD events.

RESULTS

During the one-year follow-up, 42 patients (7.4%) experienced new CVD events. Patients with new CVD events had significantly lower serum hepcidin-25 levels compared to those without events (19.0 vs. 37.8 ng/mL, P < 0.05). Multivariate logistic regression analysis revealed that lower hepcidin-25 levels (odds ratio 0.82, 95% confidence interval 0.72-0.94, P = 0.0036), higher glycoalbumin levels, and lower high-density lipoprotein cholesterol levels were independently associated with increased CVD risk.

CONCLUSIONS

Lower serum hepcidin-25 levels were independently associated with an increased risk of new CVD events in maintenance hemodialysis patients. Serum hepcidin-25 may serve as a potential biomarker for predicting cardiovascular risk, and addressing iron deficiency could help mitigate this risk.

Anemia Management in the Cardiorenal Patient: A Nephrological Perspective

Heart failure (HF) and chronic kidney disease (CKD) frequently coexist, sharing significant overlap in prevalence and pathophysiological mechanisms. This coexistence, termed cardiorenal syndrome (CRS), often leads to anemia, which exacerbates both HF and CKD, thereby increasing morbidity and death. Managing anemia in CRS is complex due to conflicting guidelines and the multifactorial nature of the condition. Anemia in CRS is influenced by factors such as inadequate erythropoietin production, iron deficiency, reduced red blood cell life span, and chronic inflammation, which inhibit iron absorption and mobilization. This interplay of mechanisms worsens anemia, further aggravating HF and CKD. Anemia significantly impacts the prognosis of both HF and CKD, and recent trials have shown that hemoglobin increases, particularly with sodium-glucose cotransporter 2 inhibitors, can improve outcomes in patients with HF and CKD. Iron deficiency is also prevalent in both patients with HF and patients with CKD and is associated with poorer exercise capacity and a higher mortality rate. Guidelines for diagnosing and treating iron deficiency differ between HF and CKD. Furthermore, treatment of anemia in CRS is controversial: While sodium-glucose cotransporter 2 inhibitors and intravenous iron has shown consistent benefits in patients with CRS, normalization of hemoglobin with erythropoiesis-stimulating agents improves symptoms and quality of life but have not consistently demonstrated cardiovascular benefits. There are no definitive guidelines for anemia management in CRS. Treatment should address HF, CKD, and anemia concurrently. A proposed algorithm includes correcting iron deficiency, initiating sodium-glucose cotransporter 2 inhibitors, and considering erythropoiesis-stimulating agents if hemoglobin remains <10 g/dL. Further research is needed to optimize anemia management strategies in patients with CRS.

Association of iron deficiency with kidney outcome and all-cause mortality in chronic kidney disease patients without anemia

BACKGROUND

Iron deficiency is prevalent in patients with chronic kidney disease (CKD), even in those without anemia. However, the effects of iron deficiency on CKD progression and all-cause mortality in non-dialysis-dependent CKD (NDD-CKD) patients without anemia remain incompletely understood.

METHODS

This multicenter retrospective nationwide cohort study included adult patients with non-anemia NDD-CKD from 24 hospitals across China. The study investigated the associations between serum ferritin or transferrin saturation (TSAT) levels and the risks of CKD progression and all-cause mortality.

RESULTS

Among 18,878 patients with NDD-CKD, 9,989 patients were included in the kidney outcome analysis, and 18,481 patients in the all-cause mortality analysis. Of the patients with the measurement, 2,450 (27.2%) had ferritin levels ≤ 100ng/mL and 2,440 (13.1%) had a TSAT level ≤ 20%. Compared with patients with TSAT level of > 20%, those with TSAT level of ≤ 20% had significantly higher risks of CKD progression (adjusted hazard ratio [aHR]: 1.66, 95% confidence intervals [CI]: 1.16-2.37; P = 0.005) and all-cause mortality (aHR: 2.21, 95% CI: 1.36-3.57; P = 0.001). The robustness of results was supported by subgroup analyses. However, there was no significant association found between ferritin levels and the risk of CKD progression or all-cause mortality (P > 0.05).

CONCLUSION

Iron deficiency was prevalent in NDD-CKD patients without anemia, and TSAT could be a modifiable risk factor of CKD progression and all-cause mortality. The screening of iron biomarkers, especially TSAT, in the early stage of NDD-CKD is important to assess and improve prognosis.

Iron-Deficiency Anemia in Chronic Kidney Disease: A Literature Review of Its Pathophysiology, Diagnosis, and Management

Anemia is a prevalent complication of chronic kidney disease (CKD) and is associated with increased mortality and reduced health-related quality of life. The iron-rich protein hemoglobin, which the body utilizes to carry oxygen, deteriorates in anemia. Because hemoglobin is a protein that contains iron, disturbances in iron homeostasis can lead to iron-deficiency anemia (IDA). CKD frequently results in anemia, which is linked to a poor prognosis. Nevertheless, whether anemia per se or other comorbidities are the reason for this connection remains unclear. Uncertainty surrounds whether distinct forms of IDA can forecast CKD outcomes. Physicians, nurse practitioners, physician assistants, and registered nurses work as a team to manage anemia in patients with CKD. Individuals with CKD can benefit from the involvement of different specialties along the treatment continuum, and dietitians/nutritionists can play a significant role in enhancing management through multidisciplinary care. This literature review aims to deliver a comprehensive overview of IDA in CKD, concentrating on its diagnosis. It addresses the pathophysiology, complications associated with iron deficiency, and the available diagnostic tests for IDA in CKD. Furthermore, we analyze the literature that has contributed to developing current practice guidelines for treating IDA in CKD and encouraging multidisciplinary team collaboration in managing IDA in CKD.

Assessment of iron metabolism and iron deficiency in incident patients on incident continuous ambulatory peritoneal dialysis

Objective

The aim of this study was to investigate iron status and iron deficiency in incident continuous ambulatory peritoneal dialysis (CAPD) patients and identify influencing factors.

Methods

Patients with end-stage renal disease were enrolled. Clinical data of iron metabolism and biochemical and dialysis parameters during the first peritoneal dialysis evaluation were collected. Serum ferritin (SF) and transferrin saturation (TSAT) levels were evaluated, and independent influencing factors were identified by correlation and regression analyses.

Results

Of 1,128 adult CAPD patients, 41.2% had iron deficiency (ID), 15.7% had absolute iron deficiency, and 8.2% had functional iron deficiency. The average SF level was (276.8 ± 277.9) μg/L, and iron saturation was (29.8 ± 12.7)%. Additionally, 50.2 and 69.3% of patients reached targets in SF level and iron saturation recommended by the Chinese Society of Nephrology. SF level and TSAT were not correlated with estimated glomerular filtration rate, whereas negatively correlated with platelet count and inflammatory factors. Low platelet count, presence of diabetes mellitus and high interleukin 6 levels were independent factors of lower TSAT.

Conclusions

ID is common in patients with CAPD. Women and those with thrombocytopenia, diabetes, and inflammation are at higher risk for iron storage or reduced iron utilization. In the initial CAPD stage, a reasonable iron supplement strategy may be established for CAPD patients with high-risk factors.

Iron Deficiency in Newly Referred Patients With Chronic Renal Failure

Addressing iron deficiency is the key to managing anemia in patients with chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) and hypoxia-inducible factor prolyl-hydroxylase inhibitors (HIF-PHIs) are being prescribed to an increasing number of patients with CKD by primary physicians following the emergence of newer agents for the management of renal anemia. Among the 361 (average age: 76.8±12.1 years; 54.0% males) patients with stages 4 and 5 CKD newly referred to the nephrology department of our hospital between 2018 and 2023 who had evaluable transferrin saturation (TSAT) and ferritin levels, 169 patients (47%) had iron deficiency (ferritin <100 ng/mL or ferritin 100-300 ng/mL with TSAT <20%). The estimated glomerular filtration rate (eGFR), hemoglobin level, TSAT, and median ferritin level were 17.0±7.0 mL/min/1.73 m², 10.8±2.1 g/dL, 27.5±13.1%, and 130 ng/mL, respectively. ESAs, HIF-PHIs, and iron supplements were prescribed to 35 (9.7%), 17 (4.7%), and 35 (9.4%) patients, respectively. No significant differences were observed between the iron indices of the ESA group; however, the serum ferritin levels in the HIF-PHIs group were significantly lower than in those in the no-medication group (P=0.02). Multivariable logistic regression analysis revealed that age, female sex, eGFR, medications for renal anemia, and a history of ischemic heart disease were associated with iron deficiency (P<0.05). Although patients with renal failure tend to exhibit anemia, attention should be paid to iron deficiency anemia in addition to renal anemia, especially in patients with renal failure and a history of ischemic heart disease.

Anaemia in CKD-treatment standard

Anaemia is one of the most common complications of chronic kidney disease (CKD), having a significant impact on quality of life, and is also associated with a number of adverse clinical outcomes. Its pathogenesis is multifactorial, caused largely by an inadequate production of erythropoietin from the diseased kidneys, with iron deficiency, inflammation, shortened red cell lifespan and enhanced blood loss also being contributory factors. The management of this condition was transformed in the late 1980s by the advent of recombinant human erythropoietin (epoetin), and treatment paradigms have developed over the last three decades, largely focusing on a combination of epoetin or its analogues (erythropoiesis-stimulating agents; ESAs) along with iron supplementation, often administered intravenously due to increased hepcidin levels limiting iron absorption from the gut. Indeed, in patients with early CKD and iron deficiency, iron per se may be sufficient to improve the anaemia, delaying the need for ESA therapy. Other causes of anaemia should be excluded and corrected (if possible) before resorting to treatment with ESAs and iron. More recently, the hypoxia-inducible factor-prolyl hydroxylase inhibitors have entered the therapeutic arena; these are orally active agents that upregulate endogenous erythropoietin production as well as a number of iron-regulatory genes which may also enhance erythropoiesis. The latter drugs are highly efficacious, and may have advantages in inflammatory conditions causing resistance to conventional ESA therapy, but concerns exist regarding their safety, particularly in the longer term. This article reviews the current standards of treatment, as well as recent novel developments in the management of anaemia in CKD.

Functional iron deficiency anemia was associated with higher mortality in chronic kidney disease patients: the NHANES III follow-up study

Anemia, a common complication of chronic kidney disease (CKD), is associated with poor prognosis. However, it is not completely clear whether this association is caused by anemia per se or other comorbidities. Whether different types of iron deficiency anemia can predict the outcomes of CKD remains unclear. The dataset from NHANES III was analyzed and Cox multivariate regression models and propensity score matching (PSM) method were used to evaluate the effect of anemia on mortality. Of 4103 patients with CKD, 14.6% had anemia. Among those with anemia, 38.8% had absolute iron deficiency (AID), and 19.8% had functional iron deficiency (FID). During the median follow-up time of 13.8 years, 2964 deaths and 804 cardiovascular deaths were observed. Anemia was robustly associated with a high risk of all-cause mortality in CKD patients after adjusting covariates by two multivariate regression models (Model 1: HR = 1.485, 95%CI:1.340-1.647, p < 0.001; Model 2: HR = 1.391, 95%CI:1.250-1.546, p < 0.001). In the PSM cohort, anemia was still an independent risk factor for all-cause mortality (Model 1: HR = 1.443, 95%CI: 1.256-1.656, p < 0.001; Model 2: HR = 1.357, 95%CI:1.177-1.564, p < 0.001). In the CKD population, anemia patients with FID had the highest risk of mortality than the other anemia groups (p < 0.05), while AID had a mortality rate similar to those without anemia (p > 0.05). In conclusion, anemia was associated with a worse prognosis in patients with CKD, which may be attributed to the higher mortality risk of FID rather than AID. AID wasn't associated with a higher mortality rate compared with CKD patients without anemia.

[The Effects of Therapy for Iron Deficiency in Patients With Different Etiologies of Heart Failure and Concomitant Diseases]

Iron deficiency (ID) in patients with heart failure (HF) is a factor for unfavorable course and prognosis of the disease. The significance of ID in the diagnosis and treatment of HF has previously been demonstrated by multiple studies and meta-analyses. Therapy for ID in patients with HF is one of the most relevant and discussed issues. The use of intravenous iron medicinal products for the treatment of ID is currently being actively studied in patients of various categories; attempts are being made to specify the indications for use to produce the greatest effect on the prognosis and quality of life of HF patients.

Patient reported outcome measures and cardiovascular outcomes following high dose modern intravenous iron in non-dialysis dependent chronic kidney disease: secondary analysis of ExplorIRON-CKD

Intravenous iron is commonly used to treat iron deficiency anemia in non-dialysis chronic kidney disease (ND-CKD). There is a paucity of information on the potential impact of intravenous iron on patient reported outcome measures, functional status and markers of cardiovascular health. As part of the secondary analysis of this double-blind exploratory randomized controlled trial focusing on patients with iron deficiency (+ /- anemia) and ND-CKD (serum ferritin < 200 µg/L or transferrin saturation ≤ 20% and serum ferritin 200-299 µg/L; CKD stages: 3a-5), 26 patients were randomized in a 1:1 ratio to receive ferric derisomaltose or ferric carboxymaltose. Participants received 1000 mg at baseline and 500-1000 mg at one month to achieve iron repletion. Quality of life and fatigue status were assessed using the Short-Form (36) questionnaire and the fatigue severity scale. Functional status was evaluated using the Duke Activity Status Index and the 1-min-sit-to-stand test. Cardiac markers such as NT-proBNP, Troponin T and pulse wave velocity were monitored. Intravenous iron was associated with similar improvements in most domains of the Short-Form (36) questionnaire, fatigue status, and 1-min-sit-to-stand ability increased significantly by the end of the trial in both groups (p < 0.001). Markers of cardiac function remained stable, with no arterial stiffness impact. Longer term studies are required to further evaluate the impact of intravenous iron on quality of life and cardiac safety in patients with ND-CKD.

Association between iron status markers and kidney outcome in patients with chronic kidney disease

Several studies conducted in patients with various stages of chronic kidney disease (CKD) have investigated the association of iron status markers, such as transferrin saturation (TSAT) and serum ferritin, with kidney outcomes. However, the associations were inconsistent and remain strongly debated. Therefore, we aimed to investigate whether TSAT and serum ferritin levels were associated with kidney outcome in such a population. In this study, 890 patients who were admitted for the evaluation of and education for CKD were prospectively followed. Primary kidney outcome was a composite of doubling of serum creatinine, end-stage kidney disease, or death due to kidney failure. Participants were divided into quartiles (Q1-Q4) according to TSAT or serum ferritin levels. During a median follow-up period of 2.8 years, kidney events occurred in 358 patients. In the multivariable Cox analyses, compared with Q3 of TSAT, the hazard ratios (95% confidence intervals) for Q1, Q2, and Q4 were 1.20 (0.87, 1.66), 1.38 (1.01, 1.87), and 1.14 (0.82, 1.59), respectively. Compared with Q2 of serum ferritin, lower and higher quartiles had a significantly increased risk for kidney outcome; hazard ratios (95% confidence intervals) for Q1, Q3, and Q4 were 1.64 (1.18, 2.27), 1.71 (1.24, 2.37), and 1.52 (1.10, 2.10), respectively. A Fine-Gray model with death before kidney events as a competing risk showed results similar to the above. In CKD, lower and higher ferritin levels were independent risk factors for kidney disease progression.

Unresolved aspects in the management of renal anemia, a Delphi consensus of the Anemia Group of the S.E.N

Anemia is a common complication of chronic kidney disease (CKD) and is associated with a decrease in quality of life and an increased risk of transfusions, morbidity and mortality, and progression of CKD. The Anemia Working Group of the Sociedad Española de Nefrología conducted a Delphi study among experts in anemia in CKD to agree on relevant unanswered questions by existing evidence. The RAND/UCLA consensus methodology was used. We defined 15 questions with a PICO structure, followed by a review in scientific literature databases. Statements to each question were developed based on that literature review. Nineteen experts evaluated them using an iterative Two-Round Delphi-like process. Sixteen statements were agreed in response to 8 questions related to iron deficiency and supplementation with Fe (impact and management of iron deficiency with or without anemia, iron deficiency markers, safety of i.v. iron) and 7 related to erythropoiesis stimulating agents (ESAs) and/or hypoxia-inducible factor stabilizers (HIF), reaching consensus on all of them (individualization of the Hb objective, impact and management of resistance to ESA, ESA in the immediate post-transplant period and HIF stabilizers: impact on ferrokinetics, interaction with inflammation and cardiovascular safety). There is a need for clinical studies addressing the effects of correction of iron deficiency independently of anemia and the impact of anemia treatment with various ESA on quality of life, progression of CKD and cardiovascular events.

Ferric Carboxymaltose in Iron-Deficient Patients with Hospitalized Heart Failure and Reduced Kidney Function

BACKGROUND

Reduced kidney function is common among patients with heart failure. In patients with heart failure and/or kidney disease, iron deficiency is an independent predictor of adverse outcomes. In the AFFIRM-AHF trial, patients with acute heart failure with iron deficiency treated with intravenous ferric carboxymaltose demonstrated reduced risk of heart failure hospitalization, with improved quality of life. We aimed to further characterize the impact of ferric carboxymaltose among patients with coexisting kidney impairment.

METHODS

The double-blind, placebo-controlled AFFIRM-AHF trial randomized 1132 stabilized adults with acute heart failure (left ventricular ejection fraction <50%) and iron deficiency. Patients on dialysis were excluded. The primary end point was a composite of total heart failure hospitalizations and cardiovascular death during the 52-week follow-up period. Additional end points included cardiovascular hospitalizations, total heart failure hospitalizations, and days lost to heart failure hospitalizations or cardiovascular death. For this subgroup analysis, patients were stratified according to baseline eGFR.

RESULTS

Overall, 60% of patients had an eGFR <60 ml/min per 1.73 m 2 (the lower eGFR subgroup). These patients were significantly older, more likely to be female and to have ischemic heart failure, and had higher baseline serum phosphate levels and higher rates of anemia. For all end points, event rates were higher in the lower eGFR group. In the lower eGFR group, the annualized event rates for the primary composite outcome were 68.96 and 86.30 per 100 patient-years in the ferric carboxymaltose and placebo arms, respectively (rate ratio, 0.76; 95% confidence interval, 0.54 to 1.06). The treatment effect was similar in the higher eGFR subgroup (rate ratio, 0.65; 95% confidence interval, 0.42 to 1.02; Pinteraction = 0.60). A similar pattern was observed for all end points ( Pinteraction > 0.05).

CONCLUSIONS

In a cohort of patients with acute heart failure, left ventricular ejection fraction <50%, and iron deficiency, the safety and efficacy of ferric carboxymaltose were consistent across a range of eGFR values.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Study to Compare Ferric Carboxymaltose With Placebo in Patients With Acute Heart Failure and Iron Deficiency (Affirm-AHF), NCT02937454 .

A Randomized Trial of Intravenous Iron Supplementation and Exercise on Exercise Capacity in Iron-Deficient Nonanemic Patients With CKD

Introduction

Patients with chronic kidney disease (CKD) are often iron deficient, even when not anemic. This trial evaluated whether iron supplementation enhances exercise capacity of nonanemic patients with CKD who have iron-deficiency.

Methods

Prospective, multicenter double-blind randomized controlled trial of nondialysis patients with CKD and iron-deficiency but without anemia (Hemoglobin [Hb] >110 g/l). Patients were assigned 1:1 to intravenous (IV) iron therapy, or placebo. An 8-week exercise program commenced at week 4. The primary outcome was the mean between-group difference in 6-minute walk test (6MWT) at 4 weeks. Secondary outcomes included 6MWT at 12 weeks, transferrin saturation (TSAT), serum ferritin (SF), Hb, renal function, muscle strength, functional capacity, quality of life, and adverse events at baseline, 4 weeks, and at 12 weeks. Mean between-group differences were analyzed using analysis of covariance models.

Results

Among 75 randomized patients, mean (SD) age for iron therapy (n = 37) versus placebo (n = 38) was 54 (16) versus 61 (12) years; estimated glomerular filtration rate (eGFR) (34 [12] vs. 35 [11] ml/min per 1.73 m2], TSAT (23 [12] vs. 21 [6])%; SF (57 [64] vs. 62 [33]) μg/l; Hb (122.4 [9.2] vs. 127 [13.2] g/l); 6MWT (384 [95] vs. 469 [142] meters) at baseline, respectively. No significant mean between-group difference was observed in 6MWT distance at 4 weeks. There were significant increases in SF and TSAT at 4 and 12 weeks (P < 0.02), and Hb at 12 weeks (P = 0.009). There were no between-group differences in other secondary outcomes and no adverse events attributable to iron therapy.

Conclusion

This trial did not demonstrate beneficial effects of IV iron therapy on exercise capacity at 4 weeks. A larger study is needed to confirm if IV iron is beneficial in nondialysis patients with CKD who are iron-deficient.

[Management of iron deficiency in chronic kidney disease: Review and proposed algorithm]

Iron deficiency is very common in chronic kidney disease, even before the dialysis stage. It is an independent factor of morbidity and mortality in patients with non-dialysis chronic kidney disease. During chronic kidney disease, iron deficiency is defined by a transferrin saturation <20% and/or a serum ferritin <100 μg/L. In France, about half of non-dialysis chronic kidney disease patients have absolute iron deficiency (transferrin saturation <20% and serum ferritin <100 μg/L) and/or functional iron deficiency (transferrin saturation <20% and serum ferritin >100 μg/L). Despite this, iron deficiency is usually not investigated. In fact, more than 60% of nephrologists do not assess iron status at least once a year. In addition, iron deficiency is rarely treated: only 12% of patients are prescribed oral or intravenous iron. Early detection and treatment are fundamental and should be systematic. In order to help improve the management of iron deficiency among non-dialysis chronic kidney disease patients, we propose an algorithm that takes into account current recommendations and the most recent data from the literature. Initial blood test requires the measurement of hemoglobin concentration, transferrin saturation and serum ferritin. A transferrin saturation <20% establishes the diagnosis of iron deficiency and the serum ferritin level points towards an absolute or functional deficiency. The combination of both values makes it possible to adapt the treatment, particularly in an inflammatory context where oral iron is not effective.

The effect of intravenous iron supplementation on exercise capacity in iron-deficient but not anaemic patients with chronic kidney disease: study design and baseline data for a multicentre prospective double-blind randomised controlled trial

BACKGROUND

Many people living with chronic kidney disease (CKD) are iron deficient, even though they may not be anaemic. The Iron and Muscle study aims to evaluate whether iron supplementation reduces symptoms of fatigue, improves muscle metabolism, and leads to enhanced exercise capacity and physical function. We report here the trial design and baseline characteristics.

METHODS

This is a prospective, double-blind multicentre randomised controlled trial (RCT) including 75 non-dialysis stage 3-4 CKD patients with iron deficiency but without anaemia. Patients were randomly (1:1) assigned to either: i) intravenous iron therapy, or ii) placebo, with concurrent recruitment of eight CKD non-iron deficient participants and six healthy volunteers. The primary outcome of the study is the six-minute walk test (6MWT) distance between baseline and four-weeks. An additional exercise training programme for patients in both groups was initiated and completed between 4 and 12 weeks, to determine the effect of iron repletion compared to placebo treatment in the context of patients undertaking an exercise programme. Additional secondary outcomes include fatigue, physical function, muscle strength, muscle metabolism, quality of life, resting blood pressure, clinical chemistry, safety and harms associated with the iron therapy intervention and the exercise training intervention, and hospitalisations. All outcomes were conducted at baseline, 4, and 12 weeks, with a nested qualitative study, to investigate the experience of living with iron deficiency and intervention acceptability. The cohort have been recruited and baseline assessments undertaken.

RESULTS

Seventy-five individuals were recruited. 44% of the randomised cohort were male, the mean (SD) age was 58 (14) years, and 56% were White. Body mass index was 31 (7) kg/m²; serum ferritin was 59 (45) μg/L, transferrin saturation was 22 (10) %, and haemoglobin was 125 (12) g/L at randomisation for the whole group. Estimated glomerular filtration rate was 35 (12) mL/min/1.73 m² and the baseline 6MWT distance was 429 (174) m.

CONCLUSION

The results from this study will address a substantial knowledge gap in the effects of intravenous iron therapy, and offer potential clinical treatment options, to improve exercise capacity, physical function, fatigue, and muscle metabolism, for non-dialysis patients with CKD who are iron-deficient but not anaemic. It will also offer insight into the potential novel effects of an 8-week exercise training programme.

TRIAL REGISTRATION

EudraCT: 2018-000,144-25 Registered 28/01/2019.

Intravenous Iron-Carbohydrate Nanoparticles and Their Similars. What Do We Choose?

Anemia is highly prevalent worldwide and iron deficiency is the first cause. Iron deficiency has not only hematologic effects but also non-hematologic effects - immune, metabolic, cognitive dysfunctions and poor cardiovascular and renal outcomes - which generally precede anemia. Iron therapy not only significantly improves the hematological parameters but also has non-hematologic benefits. Given that its efficacy and safety has been revealed over the years, intravenous (IV) iron therapy is frequently used. Intravenous iron products are nanoparticles largely consisting in an iron core surrounded by a carbohydrate shell. They are classified as non-biological complex molecules, being different from small commonly used molecules, with properties and biological behavior impossible to be completely characterized only by physicochemical analysis. To date, there is no appropriate regulatory evaluation system for these medicines and several follow-on versions of the IV iron originators (e.g., iron sucrose) were approved using the same regulatory pathway as for generics. Because of this vulnerability in an adequate pathway for approval, both non-clinical and clinical studies suggested no therapeutic equivalence (thus no interchangeability) between iron sucrose originator (Venofer®), and iron sucrose similars. In this review we aimed to underline the importance of intravenous iron therapy as well as raise awareness regarding the differences between nanomedicines and their intended similar but not identical copies. The potential implications of these differences impact patients (safety, efficacy) but also the medical system (higher costs).