Strategies for iron supplementation: oral versus intravenous

Preoperative intravenous versus oral iron supplementation for elective surgery: evidence based on 12 randomized trials

AIM

This study aims to clarify hematological parameters, transfusion requirements, and adverse events of preoperative intravenous (IVIS) versus oral iron supplementation (OIS) in elective surgery patients.

METHODS

We conducted a comprehensive literature search across multiple databases up to 10 December 2023. Twelve RCTs involving 930 participants met our eligibility criteria. Our analysis focused on post-treatment hemoglobin levels, changes in hemoglobin from baseline, ferritin levels, hemoglobin attainment rates, transfusion requirements, and adverse events. We employed the random-effects model for data synthesis, calculating pooled standard mean differences (SMD) or mean differences (MD) or risk ratios (RR) with 95% confidence intervals (CI). Methodological quality was assessed using the Cochrane ROB 2 tool. The GRADE approach evaluated the confidence in effect estimates.

FINDINGS

IVIS significantly improved post-treatment hemoglobin levels (MD = 0.77 g/dL, 95% CI [0.30 to 1.23]), hemoglobin increments (MD = 0.69 g/dL, 95% CI [0.01 to 1.37]), and ferritin levels (MD = 260.03 ng/mL, 95% CI [119.65 to 400.42]) compared to OIS. IVIS also led to a higher hemoglobin attainment rate (RR = 1.88, 95% CI [1.24 to 2.86]). No significant differences were noted in transfusion rates or volumes. IVIS was associated with fewer digestive (RR = 0.10, 95% CI [0.05 to 0.22]; I2 = 0%) but more pain-related adverse events (RR = 7.79, 95% CI [1.78 to 34.07]; I2 = 0%). Hospital stay durations and mortality rates were similar between the two groups.

INTERPRETATION

IVIS offers a superior improvement in hematological parameters for elective surgery patients but not reducing transfusion needs compared to OIS. While IVIS has fewer digestive adverse events, it increases pain-related complications. These findings highlight the importance of personalized approaches in selecting iron supplementation methods, carefully balancing time, efficacy, and adverse event profiles.

REGISTRATION

PROSPERO CRD42023483284.

Oral Liposomal Iron Versus Injectable Iron Sucrose for Anemia Treatment in Non-dialysis Chronic Kidney Disease Patients: A Non-inferiority Study

Introduction Anemia is a prevalent and persistent complication in chronic kidney disease (CKD), particularly in advanced stages, contributing to the deterioration of renal function and diminishing patients' quality of life. Iron supplementation constitutes a cornerstone of anemia management in this population. Among various iron formulations, liposomal iron has emerged as a promising option due to its enhanced efficacy in replenishing iron reserves and improved tolerability. Objective This study aims to assess the comparative effects of intravenous and liposomal oral iron on hemoglobin levels in non-dialysis CKD patients. Additionally, it seeks to evaluate the rate of hemoglobin correction, iron reserve status during treatment, and therapeutic tolerance to these interventions. Materials and methods A randomized controlled trial enrolled CKD patients (stages 3-5, not on dialysis) with iron deficiency anemia (hemoglobin ≤ 12 g/dL, ferritin ≤ 100 ng/mL, transferrin saturation ≤ 25%). Participants were allocated to receive either daily oral liposomal iron (Group OS) at a dosage of 30 mg or intravenous iron-hydroxide sucrose complex weekly (Group IV) for three months. Follow-up extended through the treatment phase and two months post-withdrawal. Results Thirty-one CKD patients were randomized into two groups: 14 received intravenous iron (IV group) and 17 received oral iron (OS group). After excluding four patients, the final cohort comprised 27 individuals (IV group: n=13, OS group: n=14). Both iron treatments resulted in progressive hemoglobin increases, with the IV group showing a mean increase of 14.65% (p=0.049) compared to 4.78% (p=0.003) in the OS group. Secondary analysis revealed significant increases in ferritin levels (p<0.001) and transferrin saturation (TSAT) levels (p=0.031) in the IV group. Post-treatment follow-up demonstrated stable hemoglobin levels in the OS group and a consistent increase in ferritin levels in the IV group. Adverse reactions predominantly included hypotension in the IV group (4 (30.7%)) and constipation in the OS group (4 (28.4%)). Discussion and conclusion Anemia remains a significant challenge in CKD patients. Our study compares oral liposomal iron to injectable iron for anemia treatment, aiming to minimize hospitalizations for iron infusion, preserve venous capital, and mitigate potential harmful side effects. We found oral liposomal iron to be a safe and effective option for correcting anemia in non-dialysis CKD patients, albeit with lower efficacy in replenishing iron stores compared to IV iron. Comparative analysis with similar studies supports the non-inferiority of oral liposomal iron, although IV iron retains superiority in replenishing iron reserves.

Gastric stability of bare and chitosan-fabricated ferritin and its bio-mineral: implication for potential dietary iron supplements

Iron deficiency anaemia (IDA), the most widespread nutritional disorder, is a persistent global health issue affecting millions, especially in resource-limited geographies. Oral iron supplementation is usually the first choice for exogenous iron administration owing to its convenience, effectiveness and low cost. However, commercially available iron supplementations are often associated with oxidative stress, gastrointestinal side effects, infections and solubility issues. Herein, we aim to address these limitations by employing ferritin proteins-self-assembled nanocaged architectures functioning as a soluble cellular iron repository-as a non-toxic and biocompatible alternative. Our in vitro studies based on PAGE and TEM indicate that bare ferritin proteins are resistant to gastric conditions but their cage integrity is compromised under longer incubation periods and at higher concentrations of pepsin, which is a critical component of gastric juice. To ensure the safe delivery of encapsulated iron cargo, with minimal cage disintegration/degradation and iron leakage along the gastrointestinal tract, we fabricated the surface of ferritin with chitosan. Further, the stoichiometry and absorptivity of iron-chelator complexes at both gastric and circumneutral pH were estimated using Job's plot. Unlike bipyridyl, deferiprone exhibited pH dependency. In vitro kinetics was studied to evaluate iron release from bare and chitosan-fabricated ferritins employing both reductive (in the presence of ascorbate and bipyridyl) and non-reductive (direct chelation by deferiprone) pathways to determine their bio-mineral stabilities. Chitosan-decorated ferritin displayed superior cage integrity and iron retention capability over bare ferritin in simulated gastric fluid. The ability of ferritins to naturally facilitate controlled iron release in conjugation with enteric coating provided by chitosan may mitigate the aforementioned side effects and enhance iron absorption in the intestine. The results of the current study could pave the way for the development of an oral formulation based on ferritin-caged iron bio-mineral that can be a promising alternative for the treatment of IDA, offering better therapeutic outcomes.

Iron Deficiency in Pulmonary Hypertension

Pulmonary hypertension (PH) is a complex cardiovascular condition that is characterized by elevated pulmonary arterial pressure, which leads to significant morbidity and mortality. Among the various factors that influence the pathophysiology and progression of PH, iron deficiency has become a critical, yet often overlooked, element. In this review, the prevalence, implications, and therapeutic potential of addressing iron deficiency in patients with PH are elucidated.Iron deficiency, which is prevalent in a significant proportion of patients with PH, has been associated with worsened clinical outcomes, including diminished exercise capacity, impaired oxygen transport and utilization, and compromised right ventricular function. The pathophysiological linkages between iron deficiency and PH are multifaceted and involve alterations in oxygen sensing, endothelial function, and metabolic disturbances.In this review, the evidence from recent clinical trials and studies that assess the impact of iron supplementation, both oral and intravenous, on PH outcomes is critically analyzed. Although some studies suggest improvements in exercise capacity and hemodynamic parameters following iron repletion, the responses appear variable and are not universally beneficial. This review highlights the complexities of iron metabolism in PH and the challenges in effectively diagnosing and treating iron deficiency in this patient population.Furthermore, the potential mechanisms through which iron supplementation might influence pulmonary vascular and right ventricular function, emphasizing the need for personalized treatment approaches are discussed. In this review, the importance of recognizing iron deficiency in the management of patients with PH is highlighted, and further research is warranted to establish comprehensive, evidence-based guidelines for iron supplementation in this unique patient cohort. The ultimate goal of this review is to improve clinical outcomes and quality of life for patients suffering from this debilitating condition.

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.

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.

The Association of Intravenous Iron Administered the Day before Total Knee Arthroplasty with Postoperative Anemia and Functional Recovery

Background and Objectives: Total knee arthroplasty (TKA) involves blood loss, increasing the risk of postoperative anemia and delayed functional recovery. Intravenous (IV) iron supplementation limits postoperative anemia; however, the effectiveness of IV iron, administered one day before TKA, on postoperative anemia and functional recovery has scarcely been studied. Materials and Methods: We conducted a retrospective cohort study with propensity score matching using two consecutive groups of patients who underwent TKA using tranexamic acid: the iron group received 500 mg ferric derisomaltose intravenously one day before surgery (n = 46); the non-iron group did not (n = 46). Hemoglobin (Hb) level was determined at postoperative days (PODs) 2, 4, 6, 14, and 30. Ferritin, transferrin saturation (TSAT), and functional iron deficiency anemia (IDA) rate were measured at PODs 2, 4, 6, and 14. Length of hospital stay and transfusion rate were also evaluated. Results: The iron group had higher Hb levels at PODs 6, 14, and 30 and higher ferritin and TSAT at PODs 2, 4, 6, and 14. The functional IDA rate was significantly higher in the non-iron group at PODs 2, 4, 6, and 14. Length of hospital stay was significantly shorter in the iron group; however, the rate of transfusion did not differ between the two groups. Conclusions: IV iron administered one day before TKA was associated with postoperative anemia recovery and length of hospital stay; however, it did not lower the postoperative transfusion rate.

Case report: Rapid onset, ischemic-type gastritis after initiating oral iron supplementation

Oral iron supplements are commonly administered to patients with chronic iron deficiency anemia. This approach is generally well-tolerated, causing only mild adverse effects. Rarely, oral iron supplementation can cause more severe symptoms, one of the most concerning being acute gastritis. This predominantly affects elderly patients and is extremely uncommon in young, otherwise healthy people. Here, we report the case of a 43-year-old woman who presented with upper gastrointestinal (GI) symptoms and iron deficiency anemia and was started on oral iron supplementation following the resolution of her acute symptoms. She soon re-presented with a severe, Helicobacter pylori-negative gastritis with iron deposition on histology. These new onset symptoms resolved rapidly with cessation of iron supplements, consistent with iron pill gastritis. In addition to the limited body of literature describing iron pill gastritis, this case serves as a reminder that any patient receiving oral iron supplementation is at a potential risk for gastritis, particularly in the setting of an ongoing GI pathology. Hence, it is important to provide continued follow-up for patients receiving iron supplementation regardless of age or comorbidity, particularly in the weeks following the start of the treatment.

Quercetin attenuates neurotoxicity induced by iron oxide nanoparticles

Iron oxide nanoparticles (IONPs) have been proposed as targeted carriers to deliver therapeutic molecules in the central nervous system (CNS). However, IONPs may damage neural tissue via free iron accumulation, protein aggregation, and oxidative stress. Neuroprotective effects of quercetin (QC) have been proven due to its antioxidant and anti-inflammatory properties. However, poor solubility and low bioavailability of QC have also led researchers to make various QC-involved nanoparticles to overcome these limitations. We wondered how high doses or prolonged treatment with quercetin conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) could improve cognitive dysfunction and promote neurogenesis without any toxicity. It can be explained that the QC inhibits protein aggregation and acts against iron overload via iron-chelating activity, iron homeostasis genes regulation, radical scavenging, and attenuation of Fenton/Haber-Weiss reaction. In this review, first, we present brain iron homeostasis, molecular mechanisms of iron overload that induced neurotoxicity, and the role of iron in dementia-associated diseases. Then by providing evidence of IONPs neurotoxicity, we discuss how QC neutralizes IONPs neurotoxicity, and finally, we make a brief comparison between QC and conventional iron chelators. In this review, we highlight that QC as supplementation and especially in conjugated form reduces iron oxide nanoparticles neurotoxicity in clinical application.

Biodegradable Zinc Oxide Nanoparticles Doped with Iron as Carriers of Exogenous Iron in the Living Organism

Iron plays an important role in various crucial processes in the body and its deficiency is considered currently as a serious health problem. Thus, iron supplementation strategies for both humans and animals need to be effective and safe. According to our previous studies, zinc-based nanoparticles provide safe, biodegradable, fast and efficient transport system of orally given substances to the tissues. In the current manuscript we present results of a study aimed at investigation of the ZnO nanoparticle-based Fe supplementation system (average size 100 × 250 nm). Nanostructures were orally (gavage) administered to adult mice. Animals were sacrificed at different time points with collection of blood and internal organs for analyses (tissue iron concentration, hepatic level of hepcidin, blood parameters, liver and spleen levels of ferritin, histopathology). Initial experiment was performed to compare the biological effect of doping type (Fe³⁺ doping vs. a mixture of Fe³⁺ and Fe²⁺). Then, the effect of acute/chronic exposure models was determined. The increase in ferritin, along with improved, crucial hematological parameters and lack of the influence on hepcidin expression indicated the chronic application of Fe^3+,2+ doped ZnO nanostructures to be the most effective among tested.

Efficacy and safety of ferric citrate hydrate compared with sodium ferrous citrate in Japanese patients with iron deficiency anemia: a randomized, double-blind, phase 3 non-inferiority study

Oral iron preparations are used as first-line treatment for iron deficiency anemia (IDA), but their gastrointestinal side effects prevent patients from appropriate adherence. We recently conducted a randomized, double-blind, phase 3 non-inferiority study to evaluate the efficacy and safety of two dosages of ferric citrate hydrate (FC) compared with sodium ferrous citrate (SF) in patients with IDA. FC at both 500 and 1000 mg/day was non-inferior to SF at 100 mg/day in terms of the change in the hemoglobin concentration at Week 7 from baseline. Logistic regression analysis suggested that the cumulative proportion of patients who achieved the target hemoglobin concentration (≥ 13.0 g/dL in male patients and ≥ 12.0 g/dL in female patients) at Week 7 was highest among those treated with FC at 1000 mg/day, followed by SF at 100 mg/day and FC at 500 mg/day. Both dosages of FC were well tolerated in patients with IDA. The incidences of nausea and vomiting were significantly lower in the FC treatment groups than in the SF group. In conclusion, FC has potential to be an oral iron preparation with sufficient efficacy for the treatment of IDA and a lower risk of nausea and vomiting.

Iron deficiency in pulmonary arterial hypertension: prevalence and potential usefulness of oral supplementation

BACKGROUND

The aim of this study was to evaluate the prevalence of iron depletion in a prevalent population of patients with pulmonary arterial hypertension (PAH) and to gain preliminary insights on the possibility of its treatment with oral drugs.

METHODS

Iron status was determined in 31 consecutive prevalent idiopathic patients with PAH. Iron depletion was defined as serum iron <10 mmol/L and decreased transferrin saturation irrespective of the coexistence of anaemia. Patients underwent laboratory examinations, 6-min walking test and echocardiography in the same day. A subgroup of iron depleted patients received one oral capsule/day containing 30 mg of pyrophosphate sucrosomial iron for 16 weeks. After this period all patients were re-evaluated.

RESULTS

Iron depletion was observed in 22 patients (71%), of whom 6 were also anaemic and 16 were not anaemic. Iron depletion was associated with higher systolic pulmonary artery pressure (60 [50-90] vs. 45 [40-50] mmHg, p = .007), greater prevalence of moderate to severe tricuspid regurgitation (36% vs. 0%, p = .039), lower tricuspid annular plane systolic excursion (23 [21-24] vs. 19 [18-20] mm; p = .025]) and higher left ventricular eccentricity index (1.35 vs. 1, p = .042). After 16 weeks of treatment, 6-min walking distance significantly improved (500 [390-500] vs. 530 [410-550] metres; p = .043).

CONCLUSIONS

Iron deficiency is highly prevalent in patients with PAH and is associated with worse clinical conditions. Treatment with oral sucrosomial iron is a therapeutic option which should be further investigated in future trials.

Evaluation of the Physicochemical Properties of the Iron Nanoparticle Drug Products: Brand and Generic Sodium Ferric Gluconate

Complex iron nanoparticle-based drugs are one of the oldest and most frequently administered classes of nanomedicines. In the US, there are seven FDA-approved iron nanoparticle reference drug products, of which one also has an approved generic drug product (i.e., sodium ferric gluconate (SFG)). These products are indicated for the treatment of iron deficiency anemia and are administered intravenously. On the molecular level, iron nanomedicines are colloids composed of an iron oxide core with a carbohydrate coating. This formulation makes nanomedicines more complex than conventional small molecule drugs. As such, these products are often referred to as nonbiological complex drugs (e.g., by the nonbiological complex drugs (NBCD) working group) or complex drug products (e.g., by the FDA). Herein, we report a comprehensive study of the physiochemical properties of the iron nanoparticle product SFG. SFG is the single drug for which both an innovator (Ferrlecit) and generic product are available in the US, allowing for comparative studies to be performed. Measurements focused on the iron core of SFG included optical spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), X-ray powder diffraction (XRPD), ⁵⁷Fe Mössbauer spectroscopy, and X-ray absorbance spectroscopy (XAS). The analysis revealed similar ferric-iron-oxide structures. Measurements focused on the carbohydrate shell comprised of the gluconate ligands included forced acid degradation, dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and gel permeation chromatography (GPC). Such analysis revealed differences in composition for the innovator versus the generic SFG. These studies have the potential to contribute to future quality assessment of iron complex products and will inform on a pharmacokinetic study of two therapeutically equivalent iron gluconate products.

Refining Treatment Strategies for Iron Deficient Athletes

Iron deficiency (ID) is a prevailing nutritional concern amongst the athletic population due to the increased iron demands of this group. Athletes' ability to replenish taxed iron stores is challenging due to the low bioavailability of dietary sources, and the interaction between exercise and hepcidin, the primary iron-regulatory hormone. To date, copious research has explored the link between exercise and iron regulation, with a more recent focus on optimising iron treatment applications. Currently, oral iron supplementation is typically the first avenue of iron replacement therapy beyond nutritional intervention, for treatment of ID athletes. However, many athletes encounter associated gastrointestinal side-effects which can deter them from fulfilling a full-term oral iron treatment plan, generally resulting in sub-optimal treatment efficacy. Consequently, various strategies (e.g. dosage, composition, timing) of oral iron supplementation have been investigated with the goal of increasing fractional iron absorption, reducing gastric irritation, and ultimately improving the efficacy of oral iron therapy. This review explores the various treatment strategies pertinent to athletes and concludes a contemporary strategy of oral iron therapy entailing morning supplementation, ideally within the 30 min following morning exercise, and in athletes experiencing gut sensitivity, consumed on alternate days or at lower doses.

Oral versus Intravenous Iron Supplementation in Peritoneal Dialysis Patients

The vast majority of erythropoietin (EPO)–treated peritoneal dialysis (PD) patients require iron supplementation. Most authors and clinical practice guidelines recommend primary oral iron supplementation in PD patients because it is more practical and less expensive. However, numerous studies have clearly demonstrated that oral iron therapy is unable to maintain EPO-treated PD patients in positive iron balance. Once patients become iron-deficient, intravenous iron administration has been found to more effectively augment iron stores and hematologic response than does oral therapy.

We recently performed a prospective, cross-over trial in 28 iron-replete PD patients and showed that twice-monthly outpatient iron polymaltose infusions (200 mg) were a practical and safe alternative to oral iron. That treatment produced significant increases in hemoglobin concentration and body iron stores. The additional expense of intravenous iron therapy was completely offset by reductions in EPO dosage.

Careful monitoring of iron stores is important in patients receiving intravenous iron supplementation in view of epidemiologic links with infection and cardiovascular disease. Nevertheless, a growing body of evidence suggests that, as has been found for hemodialysis patients, intravenous iron therapy is superior to oral iron supplementation in EPO-treated PD patients.

Preliminary Studies on Biodegradable Zinc Oxide Nanoparticles Doped with Fe as a Potential Form of Iron Delivery to the Living Organism

Iron is the crucial element for living organisms and its deficiency is described as the most common nutritional disorder all over the world. Nowadays, more effective and safe iron supplementation strategies for both humans and animals become one of the most important challenges in the therapy of nutritional deficiencies. Our previous in vivo studies confirmed safety and biodegradability of in-house manufactured zinc oxide-based nanoparticles and their rapid distribution to majority of organs and tissues in the body. In vitro examinations performed on Caco-2 cell line, a model of epithelial cells of the gastrointestinal tract, revealed a low toxicity of studied nanomaterials. In the current study, we investigated biodegradable zinc oxide nanoparticles doped with Fe(III) as a perspective supplementation strategy for iron deficiency. Biodegradable ZnO:Fe nanoparticles were intra-gastrically administered to adult mice and following 24 h, animals were sacrificed with collection of internal organs for further analyses. The iron concentration measured with atomic absorption spectrometry and histological staining (Perl's method) showed a rapid distribution of iron-doped nanoparticles to tissues specifically related with iron homeostasis. Accumulation of iron was also visible within hepatocytes and around blood vessels within the spleen, which might indicate the transfer of Fe-doped nanoparticles from the bloodstream into the tissue. Reassuming, preliminary results obtained in the current study suggest that biodegradable ZnO nanoparticles doped with Fe might be a good carriers of exogenous iron in the living body. Therefore, subsequent investigations focus on determination an exact mechanisms related with an iron deposition in the tissue and influence of nanoparticle carriers on iron metabolism are required.

Iron III isomaltose induced hypersensitivity reaction

Iron isomaltose is considered as safe form of iron with no test dose recommended. Here, we are describing the case of a patient who experienced allergic reaction with this formulation of iron. A 35-year-old South Asian woman experienced allergic reaction, she had mild wheeze on examination of chest. She was given intranasal oxygen at 2 L/min. She was given intravenous acetaminophen 1 g for pain relief, 45.4 mg intravenous chlorphenaramine and intravenous 100 mg hydrocortisone. Within half an hour, all her symptoms improved and her hypoxia resolved. Her chest wheezing also disappeared. Iron isomaltose, although relatively safe, can cause allergic reaction. Intravenous iron can cause allergic reaction therefore it should be administered at the facility where trained staff is present so that necessary treatment can be given in case of hypersensitivity reaction.

Health-related quality of life in patients with iron deficiency anemia: impact of treatment with intravenous iron

Most physicians appear to be aware of the health consequences of advanced anemia, especially in the acute setting, frequently responding with a not inconsequential therapeutic default of transfusion. In contrast, the profound impact that chronic anemia, of any degree, may have on a patient’s performance is underappreciated. The focus of this review is to 1) delineate the consistent and broad impact of anemia on patient quality of life as documented by multiple well-validated patient-reported outcome instruments and 2) demonstrate the essential normalization of the debilitation as assessed by these instruments following the administration of intravenous iron.

Role of iron metabolism in heart failure: From iron deficiency to iron overload

Iron metabolism is a balancing act, and biological systems have evolved exquisite regulatory mechanisms to maintain iron homeostasis. Iron metabolism disorders are widespread health problems on a global scale and range from iron deficiency to iron-overload. Both types of iron disorders are linked to heart failure. Iron play a fundamental role in mitochondrial function and various enzyme functions and iron deficiency has a particular negative impact on mitochondria function. Given the high-energy demand of the heart, iron deficiency has a particularly negative impact on heart function and exacerbates heart failure. Iron-overload can result from excessive gut absorption of iron or frequent use of blood transfusions and is typically seen in patients with congenital anemias, sickle cell anemia and beta-thalassemia major, or in patients with primary hemochromatosis. This review provides an overview of normal iron metabolism, mechanisms underlying development of iron disorders in relation to heart failure, including iron-overload cardiomyopathy, and clinical perspective on the treatment options for iron metabolism disorders.

The effect of perioperative intravenously administered iron isomaltoside 1000 (Monofer®) on transfusion requirements for patients undergoing complex valvular heart surgery: study protocol for a randomized controlled trial

Background

Anemia is a frequent complication after cardiac surgery especially following reoperation due to previous prosthetic valve failure or multiple valve surgery (including combined coronary artery bypass grafting). This trial explores whether intravenously administered iron isomaltoside 1000 (Monofer®) results in better clinical outcomes in patients undergoing complex heart valve surgery who are expected to receive transfusion.

Methods/design

In this prospective, single-center, double-blinded, randomized controlled trial, 214 patients undergoing reoperation or multiple valve surgery are randomly allocated to either the iron isomaltoside 1000 (IVFe) or the control group from August 2016 to August 2018. The IVFe group receives iron isomaltoside 1000 mg (maximum dose 20 mg/kg) intravenously 3 days before and after the surgery. The control group receives an equivalent volume of normal saline. The primary endpoint is transfusion requirement (more than 1 unit of packed erythrocytes) for postoperative care until discharge and secondary endpoint are major complications, such as delayed ventilator therapy, acute kidney injury, and mortality. Reticulocyte count, plasma hepcidin, iron profiles (serum iron, serum ferritin, total iron-binding capacity, transferrin, transferrin saturation), coagulation profiles, urinary analysis, and chemical profiles are measured for three preoperative baseline-data days and just before surgery, except for hepcidin. After surgery, daily routine basic laboratory tests are measured just before discharge and reticulocyte count, iron profiles, and hepcidin are repeatedly checked for three postoperative days.

Discussions

From our study, we can clarify the following points: the first is the perioperative IVFe effect on the demand for transfusion, and clinical outcomes in reoperation or complex valve surgery and the second is the role of hepcidin in the effect of IVFe on the hemoglobin level increase.

Trial registration

ClinicalTrials.gov, Identifier: NCT02862665. Registered on August 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2545-3) contains supplementary material, which is available to authorized users.

Novel Flaxseed Gum Nanocomposites Are Slow Release Iron Supplements

Nanocomposites, based on iron salts and soluble flaxseed gum (FG), were prepared as potential treatments of iron deficiency anemia (IDA). FG was extracted, characterized, and formulated into iron-loading nanocomposites via ion-exchange against FeCl₃, Fe₂(SO₄)₃, FeCl₂, and FeSO₄·7H₂O. FG-iron nanocomposites preparation condition was optimized, and physicochemical properties of the nanocomposites were investigated. In vitro release kinetics of iron in simulated gastric fluid (SGF) was also evaluated. FG heteropolysaccharide, consisting of rhamnose (33.73%), arabinose (24.35%), xylose (14.23%), glucose (4.54%), and galactose (23.15%) monosaccharides, linked together via varieties of glycosidic bonds, was a good recipient for both ferric and ferrous irons under screened conditions (i.e., 80 °C, 2 h, I/G = 1:2). Iron loaded contents in the nanocomposites prepared from FG-FeCl₃, FG-Fe₂(SO₄)₃, FG-FeCl₂, and FG-FeSO₄·7H₂O were 25.51%, 10.36%, 5.83%, and 22.83%, respectively. Iron in these nanocomposites was mostly in a bound state, especially in FG-FeCl₃, due to chelation forming bonds between iron and polysaccharide hydroxyl or carboxyl groups and formed stable polysaccharide-iron crystal network structures. Free iron ions were effectively removed by ethanol treatments. Because of chelation, the nanocomposites delayed iron release in SGF and the release kinetics were consistent with Korsmeyer-Peppas model. This indicates that such complexes might reduce side effects of free iron in human stomach. Altogether, this study indicates that these synthetic FG-iron nanocomposites might be developed as novel iron supplements for iron deficiency, in which FG-FeCl₃ is considered as the best option.

Iron Treatment Strategies in Nondialysis CKD

In contrast to managing patients on hemodialysis in whom iron strategies are more focused on intravenous iron, nondialysis chronic kidney disease (CKD) patients may receive either oral or intravenous iron. There are advantages and disadvantages for both strategies. Oral iron is simple and cheap to administer and does not require hospital visits, but is poorly absorbed in advanced CKD and is associated with unpleasant gastrointestinal side effects. Intravenous iron, on the other hand, guarantees iron bioavailability and avoids problems of variable absorption of iron from the gastrointestinal tract, but requires specialist clinic services. Intravenous iron also is associated with hypersensitivity reactions, albeit very rarely. The efficacy of intravenous iron in improving hemoglobin, ferritin, and transferrin saturation is well established, and superior to oral iron, but the long-term safety of this route of administration has not been established and there are theoretical concerns that patients may be exposed to increased oxidative stress and exacerbation of infections. The final choice of iron management strategy will depend on individual physician preference, as well as the facilities that are available.

Iron Therapy in Heart Failure: Ready for Primetime?

There is an increasing awareness of the prevalence of iron deficiency (ID) in patients with heart failure (HF) and its contributory role in the morbidity and mortality of HF. It is important to note that many HF patients have ID without being anaemic, hence it is vital to screen for ID even in patients with haemoglobin within the normal laboratory range. This review summarises the pathophysiology and epidemiology of ID in HF before discussing the evidence for iron replacement therapy in HF patients. Finally, it discusses the ongoing large outcome trials evaluating iron replacement in HF.

Iron sucrose: assessing the similarity between the originator drug and its intended copies

Iron sucrose (IS) is a complex nanocolloidal intravenous suspension used in the treatment of iron-deficiency anemia. Follow-on IS products (iron sucrose similars (ISSs)) have obtained marketing authorization by the generic pathway, implying that identical copies of IS may be manufactured. However, recent prospective and retrospective clinical studies showed discrepancies in clinical outcomes, which might be related to differences in physicochemical properties. The aim of this work is to measure and compare the physicochemical properties of IS and three ISSs available in the market using innovative analytical procedures. The comprehensive elucidation of size, size distribution, morphology, and stability of these complex drugs revealed very significant differences between the products. This study serves to provide the basis to define critical quality attributes that may be linked to differences in clinical outcome and thus may contribute to an adequate regulatory approach for IS and its follow-on products.

Influence of combined iron supplementation and simulated hypoxia on the haematological module of the athlete biological passport

The integrity of the athlete biological passport (ABP) is underpinned by understanding normal fluctuations of its biomarkers to environmental or medical conditions, for example, altitude training or iron deficiency. The combined impact of altitude and iron supplementation on the ABP was evaluated in endurance-trained athletes (n = 34) undertaking 3 weeks of simulated live-high: train-low (14 h.d^-1 , 3000 m). Athletes received either oral, intravenous (IV) or placebo iron supplementation, commencing 2 weeks prior and continuing throughout hypoxic exposure. Venous blood was sampled twice prior, weekly during, and up to 6 weeks after altitude. Individual ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (%retic), and OFF score were calculated using the adaptive model and assessed at 99% and 99.9% specificity. Eleven athletes returned values outside of the calculated reference ranges at 99%, with 8 at 99.9%. The percentage of athletes exceeding the thresholds in each group was similar, but IV returned the most individual occurrences. A similar frequency of abnormalities occurred across the 3 biomarkers, with abnormal [Hb] and OFF score values arising mainly during-, and %retic values mainly post- altitude. Removing samples collected during altitude from the model resulted in 10 athletes returning abnormal values at 99% specificity, 2 of whom had not triggered the model previously. In summary, the abnormalities observed in response to iron supplementation and hypoxia were not systematic and mostly in line with expected physiological adaptations. They do not represent a uniform weakness in the ABP. Nevertheless, altitude training and iron supplementation should be carefully considered by experts evaluating abnormal ABP profiles.

Markers of oxidative/nitrosative stress and inflammation in lung tissue of rats exposed to different intravenous iron compounds

Iron deficiency anemia is a frequent complication in clinical conditions such as chronic kidney disease, chronic heart failure, inflammatory bowel disease, cancer, and excessive blood loss. Given the ability of iron to catalyze redox reactions, iron therapy can be associated with oxidative stress. The lung is uniquely susceptible to oxidative stress, and little is known about the effects of intravenous iron treatment in this organ. This study characterized changes in markers of oxidative/nitrosative stress and inflammation in the lung of non-iron deficient, non-anemic rats treated with five weekly doses (40 mg iron per kg body weight) of low molecular weight iron dextran (LMWID), iron sucrose (IS), ferric carboxymaltose (FCM), ferumoxytol (FMX), iron isomaltoside 1000 (IIM), or saline (control). Rats treated with LMWID, FMX, or IIM showed significant changes in most measures of oxidative/nitrosative stress, inflammation, and iron deposition compared to the saline-treated controls, with greatest changes in the LMWID treatment group. Increases in products of lipid peroxidation (thiobarbituric acid reactive substances) and protein nitrosation (nitrotyrosine) were consistent with increases in the activity of antioxidant enzymes (catalase, Cu,Zn-SOD, GPx), decreases in antioxidative capacity (reduced:oxidized GSH ratio), increased levels of transcription factors involved in the inflammatory pathway (NF-κB, HIF-1α), inflammatory cytokines (TNF-α, IL-6), adhesion molecules (VCAM-1), markers of macrophage infiltration (ED-1), and iron deposition (Prussian blue, ferritin). Since changes in measured parameters in FCM- or IS-treated rats were generally modest, the results suggest that FCM and IS have a low propensity to induce lung inflammation. The relevance of these findings to clinical safety profiles of the tested intravenous iron products requires further investigation.

Markers of iron status in chronic kidney disease

Anemia is one of the main comorbidities related to chronic kidney disease (CKD). Until the advent of erythropoiesis stimulating agents (ESA), endogenous erythropoietin deficiency has been thought to be the main culprit of anemia in CKD patients. The use of ESAs has shed new light on the physiology of CKD anemia, where iron homeostasis plays an increasingly important role. Disorders of iron homeostasis occurring in CKD turn the anemia management in those patients into a complex multifactorial therapeutic task, where ESA and Iron dose must be properly balanced to achieve the desired outcome without exposing the patients to the risk of serious adverse events. This review covers diagnostic markers traditionally used for quantifying iron status in CKD patients, such as serum ferritin and transferrin saturation, new ones, such as reticulocyte hemoglobin content and percent hypochromic red cells (HRC), as well as experimental ones, such as hepcidin and soluble transferrin receptor (sTfR). Each marker is presented in terms of their diagnostic performance, followed by biological and analytical variability data. Advantages and disadvantages of each marker are briefly discussed. Although serum ferritin and transferrin saturation are easily available, they exhibit large biological variability and require caution when used for diagnosing iron status in CKD patients. Reticulocyte hemoglobin content and the percentage of HRC are more powerful, but their widespread use is hampered by the issue of sample stability in storage. sTfR and hepcidin show promise, but require further investigation as well as the development of standardized, low-cost assay platforms.

The Use of Darbepoetin to Stimulate Erythropoiesis in the Treatment of Anemia of Chronic Kidney Disease in Dogs

Background

Darbepoetin alfa (darbepoetin) is an erythropoiesis‐stimulating agent used for the treatment of anemia secondary to chronic kidney disease (CKD) in dogs, but reports describing response are lacking.

Hypothesis/Objectives

To evaluate the effectiveness of darbepoetin in dogs with anemia secondary to CKD, dosing protocols, and adverse events.

Animals

Thirty‐three client‐owned dogs with naturally occurring CKD, including 26 with comorbidities.

Methods

Multi‐institutional retrospective study.

Results

The median starting dosage and highest dosage of darbepoetin administered were 0.5 and 0.8 μg/kg SC once weekly, respectively. Response to treatment was defined as achieving a packed cell volume (PCV) ≥30% or an increase in PCV ≥10%. Twenty‐eight of 33 dogs (85%) achieved a PCV ≥30% and 22 of 33 (67%) dogs achieved an increase in PCV ≥10%. Median time to achieve a PCV ≥30% was 29 days. A higher starting dosage was associated with achieving an increase in PCV ≥10% (P = .01). No dog sustained a response at a dosing interval >q21d. Potential adverse events included increased blood pressure requiring treatment (n = 12), seizures (n = 5), vomiting (n = 3), diarrhea (n = 3), and possible pure red cell aplasia (PRCA) (n = 2).

Conclusions and Clinical Importance

Darbepoetin, when combined with treatment of comorbidities, is an effective treatment for anemia secondary to CKD in dogs. A dosing interval >q21d was ineffective at maintaining a response to treatment. PRCA was a possible adverse event in 2 of 33 dogs (6%).

Effect of Intravenous Iron Supplementation on Iron Stores in Non-Anemic Iron-Deficient Patients with Hereditary Hemorrhagic Telangiectasia

In hereditary hemorrhagic telangiectasia (HHT), frequent episodes of nasal and gastrointestinal bleeding commonly lead to iron-deficiency with or without anemia. In the retrospective study presented here we assessed the iron stores, as determined by analysis of plasma ferritin, during oral and intravenous iron supplementation, respectively, in a population of iron-deficient non-anemic HHT patients who were inadequately iron-repleted by oral supplementation. A switch from oral to intravenous iron supplementation was associated with a significant increase in ferritin in this patient population.

Management of anemia in patients with diabetic kidney disease: A consensus statement

This consensus statement focuses on the window of opportunity, which exists while treating patients with diabetic kidney disease and anemia.

EDTA capped iron oxide nanoparticles magnetic micelles: drug delivery vehicle for treatment of chronic myeloid leukemia and T1–T2 dual contrast agent for magnetic resonance imaging

This study shows that multiple functionalities like drug delivery and T₁–T₂ dual modalities can be achieved by a proper surface architecture.

A cohort investigation of anaemia, treatment and the use of allogeneic blood transfusion in colorectal cancer surgery

Introduction

Preoperative identification and treatment of anaemia is advocated as part of Patient Blood Management due to the association of adverse outcome with the perioperative use of blood transfusion. This study aimed to establish the rate of anaemia identification, treatment and implications of this preoperative anaemia on ARBT use.

Methods

All patients who underwent elective surgery for colorectal cancer over 18 months at a single Tertiary Centre were reviewed. Electronic databases and patient casenotes were reviewed to yield required data.

Results

Complete data was available on 201 patients. 67% (n = 135) had haemoglobin tested at presentation. There was an inverse correlation between tumour size and initial haemoglobin (P < 0.01, Rs = −0.3). Initial haemoglobin levels were significantly lower in patients with right colonic tumours (P < 0.01). Patients who were anaemic preoperatively received a mean 0.91 units (95%CI 0–0.7) per patient which was significantly higher than non-anaemic patients (0.3 units [95%CI 0–1.3], P < 0.01). For every 1 g/dl preoperative haemoglobin increase, the likelihood of transfusion was reduced by approximately 40% (OR 0.57 [95%CI 0.458–0.708], P < 0.01). Laparoscopic surgery was associated with fewer anaemic patients transfused (P < 0.01).

Conclusion

Haemoglobin levels should be routinely checked at diagnosis of colorectal cancer, particularly those with large or right sided lesions. Early identification of anaemia allows initiation of treatment which may reduce transfusion risk even with modest haemoglobin rises. The correct treatment of this anaemia needs to be established.

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Exclusion of anaemia is underperformed during initial management of colorectal cancer.

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Anaemia is more frequently associated with larger diameter and right sided tumours.

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When identified, preoperative anaemia is undertreated.

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Reduction in severity of anaemia at surgery is associated with reduced transfusion requirements.

Managing hyperphosphatemia in patients with chronic kidney disease on dialysis with ferric citrate: latest evidence and clinical usefulness

Ferric citrate is a novel phosphate binder that allows the simultaneous treatment of hyperphosphatemia and iron deficiency in patients being treated for end-stage renal disease with hemodialysis (HD). Multiple clinical trials in HD patients have uniformly and consistently demonstrated the efficacy of the drug in controlling hyperphosphatemia with a good safety profile, leading the US Food and Drug Administration in 2014 to approve its use for that indication. A concurrent beneficial effect, while using ferric citrate as a phosphate binder, is its salutary effect in HD patients with iron deficiency being treated with an erythropoietin-stimulating agent (ESA) in restoring iron that becomes available for reversing chronic kidney disease (CKD)-related anemia. Ferric citrate has also been shown in several studies to diminish the need for intravenous iron treatment and to reduce the requirement for ESA. Ferric citrate is thus a preferred phosphate binder that helps resolve CKD-related mineral bone disease and iron-deficiency anemia.

Novel iron-containing phosphate binders and anemia treatment in CKD: oral iron intake revisited

Recent reports have shown that novel phosphate binders containing iron are not only efficacious for the treatment of hyperphosphatemia but also may reduce the need for erythropoiesis-stimulating agents and intravenous (IV) iron for anemia management in patients on maintenance hemodialysis (MHD). Possible healthcare cost savings, which have not been demonstrated in a long-term study, may be an additional advantage of using such multi-pronged treatment strategies for the control of both hyperphosphatemia and iron needs. It is currently assumed that oral iron supplementation is less efficient than the IV route in patients with chronic kidney disease (CKD). The unexpected efficacy of novel iron-containing phosphate binders, such as ferric citrate, in repleting insufficient iron stores and improving the anemia of CKD could change this view. Previous assumptions of self-controlled iron uptake by 'mucosal block' or hepcidin, or else by impaired intestinal iron absorption due to CKD-associated inflammation cannot be reconciled with recent observations of the effects of ferric citrate administration. Citrate in the intestinal lumen may partly contribute to the acceleration of iron absorption. Animal experiments and clinical studies have also shown that oral iron overload can cause excessive iron accumulation despite high hepcidin levels, which are not able to block iron absorption completely. However, like with IV iron agents, no long-term safety data exist with respect to the effects of iron-containing phosphate binders on 'hard' patient outcomes. Future randomized prospective studies in patients with CKD are necessary to establish the safety of oral iron-containing phosphate binders for the control of both hyperphosphatemia and renal anemia.

Switching patients with non-dialysis chronic kidney disease from oral iron to intravenous ferric carboxymaltose: effects on erythropoiesis-stimulating agent requirements, costs, hemoglobin and iron status

Background

Patients with non-dialysis-dependent chronic kidney disease (ND-CKD) often receive an erythropoiesis-stimulating agent (ESA) and oral iron treatment. This study evaluated whether a switch from oral iron to intravenous ferric carboxymaltose can reduce ESA requirements and improve iron status and hemoglobin in patients with ND-CKD.

Methods

This prospective, single arm and single-center study included adult patients with ND-CKD (creatinine clearance ≤40 mL/min), hemoglobin 11–12 g/dL and iron deficiency (ferritin <100 μg/L or transferrin saturation <20%), who were regularly treated with oral iron and ESA during 6 months prior to inclusion. Study patients received an intravenous ferric carboxymaltose dose of 1,000 mg iron, followed by a 6-months ESA/ ferric carboxymaltose maintenance regimen (target: hemoglobin 12 g/dL, transferrin saturation >20%). Outcome measures were ESA dose requirements during the observation period after initial ferric carboxymaltose treatment (primary endpoint); number of hospitalizations and transfusions, renal function before and after ferric carboxymaltose administration, number of adverse reactions (secondary endpoints). Hemoglobin, mean corpuscular volume, ferritin and transferrin saturation were measured monthly from baseline until end of study. Creatinine clearance, proteinuria, C-reactive protein, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase bimonthly from baseline until end of study.

Results

Thirty patients were enrolled (age 70.1±11.4 years; mean±SD). Mean ESA consumption was significantly reduced by 83.2±10.9% (from 41,839±3,668 IU/patient to 6,879±4,271 IU/patient; p<0.01). Hemoglobin increased by 0.7±0.3 g/dL, ferritin by 196.0±38.7 μg/L and transferrin saturation by 5.3±2.9% (month 6 vs. baseline; all p<0.01). No ferric carboxymaltose-related adverse events were reported and no patient withdrew or required transfusions during the study.

Conclusion

Among patients with ND-CKD and stable normal or borderline hemoglobin, switching from oral iron to intravenous ferric carboxymaltose was associated with significant improvements in hematological and iron parameters and a significant reduction in ESA dose requirements in this single-center pilot study.

Trial Registration

ClinicalTrials.gov NCT02232906

Is anemia a new cardiovascular risk factor?

Anemia is frequent in patients with cardiovascular disease and is often characterized as the fifth cardiovascular risk factor. It is considered to develop due to a complex interaction of iron deficiency, cytokine production and impaired renal function, although other factors, such as blood loss, may also contribute. Unfortunately, treatment of anemia in cardiovascular disease lacks clear targets and specific therapy is not defined. Treatment with erythropoietin-stimulating agents in combination with iron is the basic strategy but clear guidelines are not currently available. This review aims to clarify poorly investigated and defined issues concerning the relation of anemia and cardiovascular risk--in particular in patients with acute coronary syndromes and chronic heart failure--as well as the current therapeutic strategies in these clinical conditions.

Role of preoperative intravenous iron therapy to correct anemia before major surgery: study protocol for systematic review and meta-analysis

BACKGROUND

Preoperative anemia is a common and potentially serious hematological problem in elective surgery and increases the risk for perioperative red blood cell (RBC) transfusion. Transfusion is associated with postoperative morbidity and mortality. Preoperative intravenous (IV) iron therapy has been proposed as an intervention to reduce perioperative transfusion; however, studies are generally small, limited, and inconclusive.

METHODS/DESIGN

We propose performing a systematic review and meta-analysis. We will search MEDLINE, EMBASE, EBM Reviews, Cochrane-controlled trial registry, Scopus, registries of health technology assessment and clinical trials, Web of Science, ProQuest Dissertations and Theses, and conference proceedings in transfusion, hematology, and surgery. We will contact our study drug manufacturer for unpublished trials. Titles and abstracts will be identified and assessed by two reviewers for potential relevance. Eligible studies are: randomized or quasi-randomized clinical trials comparing preoperative administration of IV iron with placebo or standard of care to reduce perioperative blood transfusion in anemic patients undergoing major surgery. Screening, data extraction, and quality appraisal will be conducted independently by two authors. Data will be presented in evidence tables and in meta-analytic forest plots. Primary efficacy outcomes are change in hemoglobin concentration and proportion of patients requiring RBC transfusion. Secondary outcomes include number of units of blood or blood products transfused perioperatively, transfusion-related acute lung injury, neurologic complications, adverse events, postoperative infections, cardiopulmonary complications, intensive care unit (ICU) admission/readmission, length of hospital stay, acute kidney injury, and mortality. Dichotomous outcomes will be reported as pooled relative risks and 95% confidence intervals. Continuous outcomes will be reported using calculated weighted mean differences. Meta-regression will be performed to evaluate the impact of potential confounding variables on study effect estimates.

DISCUSSION

Reducing unnecessary RBC transfusions in perioperative medicine is a clinical priority. This involves the identification of patients at risk of receiving transfusions along with blood conservation strategies. Of potential pharmacological blood conservation strategies, IV iron is a compelling intervention to treat preoperative anemia; however, existing data are uncertain. We propose performing a systematic review and meta-analysis evaluating the efficacy and safety of IV iron administration to anemic patients undergoing major surgery to reduce transfusion and perioperative morbidity and mortality.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015016771.

Iron therapy for the treatment of iron deficiency in chronic heart failure: intravenous or oral?

This article considers the use and modality of iron therapy to treat iron deficiency in patients with heart failure, an aspect of care which has received relatively little attention compared with the wider topic of anaemia management. Iron deficiency affects up to 50% of heart failure patients, and is associated with poor quality of life, impaired exercise tolerance, and mortality independent of haematopoietic effects in this patient population. The European Society of Cardiology Guidelines for heart failure 2012 recommend a diagnostic work-up for iron deficiency in patients with suspected heart failure. Iron absorption from oral iron preparations is generally poor, with slow and often inefficient iron repletion; moreover, up to 60% of patients experience gastrointestinal side effects. These problems may be exacerbated in heart failure due to decreased gastrointestinal absorption and poor compliance due to pill burden. Evidence for clinical benefits using oral iron is lacking. I.v. iron sucrose has consistently been shown to improve exercise capacity, cardiac function, symptom severity, and quality of life. Similar findings were observed recently for i.v. ferric carboxymaltose in patients with systolic heart failure and impaired LVEF in the double-blind, placebo-controlled FAIR-HF and CONFIRM-HF trials. I.v. iron therapy may be better tolerated than oral iron, although confirmation in longer clinical trials is awaited. Routine diagnosis and management of iron deficiency in patients with symptomatic heart failure regardless of anaemia status is advisable, and, based on current evidence, prompt intervention using i.v. iron therapy should now be considered.

Hepcidin-25, mean corpuscular volume, and ferritin as predictors of response to oral iron supplementation in hemodialysis patients

The benefit of oral iron therapy (OIT) and factors predictive of OIT response are not established in hemodialysis (HD) patients with iron deficiency anemia (IDA). We examined the values of hepcidin-25, mean corpuscular volume (MCV), and ferritin as predictors of OIT response. Oral ferrous fumarate (50 mg/day, 8 weeks) was given to 51 HD patients with IDA (hemoglobin (Hb) < 12 g/dL, ferritin < 100 ng/mL) treated with an erythropoietin activator. Sixteen patients were responders (improvement of Hb (ΔHb) ≥ 2 g/dL) and 35 were non-responders (ΔHb < 2g/dL). Baseline Hb, MCV, serum hepcidin-25, ferritin, iron parameters, and C-reactive protein (CRP) before and ΔHb after OIT were compared between groups. Hepcidin-25, MCV, ferritin, and transferrin saturation were lower in the responders than in the non-responders. Hepcidin-25 positively correlated with ferritin. Hepcidin-25, MCV, and ferritin positively correlated with baseline Hb and negatively correlated with ΔHb. Despite normal CRP levels in all patients, CRP correlated positively with hepcidin-25 and ferritin. Stepwise multiple linear regression analysis and receiver operating characteristics curve analysis revealed that hepcidin-25, MCV, and ferritin could predict OIT response. We conclude that hepcidin-25, MCV, and ferritin could be useful markers of iron storage status and may help predict OIT response in HD patients.

Four weeks of IV iron supplementation reduces perceived fatigue and mood disturbance in distance runners

Purpose

To determine the effect of intravenous iron supplementation on performance, fatigue and overall mood in runners without clinical iron deficiency.

Methods

Fourteen distance runners with serum ferritin 30–100 µg·L⁻¹ were randomly assigned to receive three blinded injections of intravenous ferric-carboxymaltose (2 ml, 100 mg, IRON) or normal saline (PLACEBO) over four weeks (weeks 0, 2, 4). Athletes performed a 3,000 m time trial and 10×400 m monitored training session on consecutive days at week 0 and again following each injection. Hemoglobin mass (Hbmass) was assessed via carbon monoxide rebreathing at weeks 0 and 6. Fatigue and mood were determined bi-weekly until week 6 via Total Fatigue Score (TFS) and Total Mood Disturbance (TMD) using the Brief Fatigue Inventory and Brunel Mood Scale. Data were analyzed using magnitude-based inferences, based on the unequal variances t-statistic and Cohen's Effect sizes (ES).

Results

Serum ferritin increased in IRON only (Week 0: 62.8±21.9, Week 4: 128.1±46.6 µg·L⁻¹; p = 0.002) and remained elevated two weeks after the final injection (127.0±66.3 µg·L⁻¹, p = 0.01), without significant changes in Hbmass. Supplementation had a moderate effect on TMD of IRON (ES -0.77) with scores at week 6 lower than PLACEBO (ES -1.58, p = 0.02). Similarly, at week 6, TFS was significantly improved in IRON vs. PLACEBO (ES –1.54, p = 0.05). There were no significant improvements in 3,000 m time in either group (Week 0 vs. Week 4; Iron: 625.6±55.5 s vs. 625.4±52.7 s; PLACEBO: 624.8±47.2 s vs. 639.1±59.7 s); but IRON reduced their average time for the 10×400 m training session at week 2 (Week 0: 78.0±6.6 s, Week 2: 77.2±6.3; ES–0.20, p = 0.004).

Conclusion

During 6 weeks of training, intravenous iron supplementation improved perceived fatigue and mood of trained athletes with no clinical iron deficiency, without concurrent improvements in oxygen transport capacity or performance.

Comparison of two doses of elemental iron in the treatment of latent iron deficiency: efficacy, side effects and blinding capabilities

Adherence to iron supplementation can be compromised due to side effects, and these limit blinding in studies of iron deficiency. No studies have reported an efficacious iron dose that allows participants to remain blinded. This pilot study aimed to determine a ferrous sulfate dose that improves iron stores, while minimising side effects and enabling blinding. A double-blinded RCT was conducted in 32 women (18-35 years): 24 with latent iron deficiency (serum ferritin < 20 µg/L) and 8 iron sufficient controls. Participants with latent iron deficiency were randomised to 60 mg or 80 mg elemental iron or to placebo, for 16 weeks. The iron sufficient control group took placebo. Treatment groups (60 mg n = 7 and 80 mg n = 6) had significantly higher ferritin change scores than placebo groups (iron deficient n = 5 and iron sufficient n = 6), F(1, 23) = 8.46, p ≤ 0.01. Of the 24 who completed the trial, 10 participants (77%) on iron reported side effects, compared with 5 (45%) on placebo, but there were no differences in side effects (p = 0.29), or compliance (p = 0.60) between iron groups. Nine (69%) participants on iron, and 11 (56%) on placebo correctly guessed their treatment allocation. Both iron doses were equally effective in normalising ferritin levels. Although reported side-effects were similar for both groups, a majority of participants correctly guessed their treatment group.