Limitations of Serum Ferritin in Diagnosing Iron Deficiency in Inflammatory Conditions

Examining the impact of polyfluoroalkyl substance exposure on erythrocyte profiles and its related nutrients: Insights from a prospective study on young Taiwanese

Per- and polyfluoroalkyl substances (PFAS) constitute a group of synthetic chemicals extensively utilized across various commonplace products. PFAS are known to have various toxic effects on human health. The relationship between PFAS exposure and erythrocytes has been a subject of interest in epidemiological research, but so far, only limited cross-sectional studies have investigated. Additionally, the role of erythrocyte related nutrition indicators on PFAS-induced changes in erythrograms has not been explored. To fill these knowledge gaps, we launched a longitudinal study over a decade, tracking 502 adolescents and young adults aged 12 to 30 from the YOung TAiwanese Cohort (YOTA). Our analysis encompassed 11 types of plasma PFAS, as well as erythrograms and serum levels of ferritin, transferrin saturation, vitamin B12, and folate. Our examination unveiled positive associations between specific average levels of PFAS compounds, including linear perfluorooctanoic acid (PFOA), branched perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS), and transferrin saturation. Furthermore, linear PFOA and both linear and branched PFOS were negatively correlated with vitamin B12 levels. Specifically, we observed that the average linear PFOA demonstrated positive correlations with mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH), while average PFNA also exhibited positive associations with hemoglobin (Hb) and hematocrit (Hct) in a multiple linear regression model. Subsequent analysis revealed noteworthy interactions between vitamin B12 and PFNA, as well as folate and PFNA, in the context of their impact on Hb, Hct, and PFNA relationships. Additionally, an interaction with transferrin saturation was identified in the correlation between Hct and PFNA. These findings suggest a plausible link between PFAS exposure and erythrograms among young populations, underscoring the potential involvement of iron status, vitamin B12, and folate in this association. Further studies are imperative to elucidate the precise effects of PFAS on erythrocyte in human subjects.

Prognostic value of post-operative iron biomarkers in colorectal cancer: population-based patient cohort

BACKGROUND

Post-operative anaemia is linked to iron deficiency. We investigated the prognostic value of post-operative iron biomarkers in colorectal cancer (CRC).

METHODS

Ferritin, transferrin, iron, and transferrin saturation (TS%) were measured from blood collected at a single time-point post-surgery in 2769 CRC patients. Associations between iron biomarkers with cancer-specific survival (CSS) and overall survival (OS) were assessed using Cox regression with hazard ratios (HR), stratified by post-operative time of blood collection (<1-month/≥1-month).

RESULTS

After a median follow-up of 9.5 years, 52.6% of patients had died. For iron biomarkers assessed <1-month post-surgery, higher compared to normal TS% was associated with shorter CSS (HR [95% CI] = 2.36 [1.25-4.46]), and higher iron levels with better OS (upper vs. median tertile: HR [95% CI] = 0.79 [0.65-0.97]). When assessed ≥1-month post-surgery, elevated ferritin was associated with poor CSS (high vs. normal: HR [95% CI] = 1.44 [1.10-1.87]), and low TS% with worse CSS (low vs. normal: HR [95% CI] = 1.60 [1.24-2.06]). Similar but weaker associations were observed for OS.

CONCLUSION

Monitoring of serum ferritin and TS% beyond 1-month post-surgery may be relevant for risk stratification of patients with operable CRC. Future studies should validate our findings.

Prevalence, risk factors, and treatment of anemia in hospitalized older patients across geriatric and nephrological settings in Italy

Anemia is a common but often underdiagnosed and undertreated geriatric syndrome in hospitalized older patients. In this retrospective multicenter study, we aimed at characterizing the prevalence, risk factors, diagnostic and treatment approach to anemia in older patients admitted to acute care hospitals, focusing on differences between nephrology and geriatrics units. Prevalence and risk factors for anemia, diagnostic inertia (lack of iron, vitamin B12, and folate status assessment), replacement inertia (omitted treatment with iron, vitamin B12 or folic acid), and erythropoiesis-stimulating agents (ESA) inertia were explored. 1963 patients aged 82.7 (6.8) years were included in the study; 66.7% of the study population had anemia; among anemic patients, diagnostic inertia and replacement inertia were common with rates of 22-31% and 50-87%, respectively; omitted treatment with ESA affected 67.2% of patients and was more prevalent in geriatric units. In most cases, patients with ESA inertia were not routinely screened for iron tests. COPD, cancer, eGFR 45-60 ml/min were associated with increased tendency to ESA inertia. In conclusion, anemia had a high prevalence in older patients discharged from acute care units, but it is often underdiagnosed and undertreated.

Absolute and functional iron deficiency: Biomarkers, impact on immune system, and therapy

Iron is essential for numerous physiological processes and its deficiency often leads to anemia. Iron deficiency (ID) is a global problem, primarily affecting reproductive-age women and children, especially in developing countries. Diagnosis uses classical biomarkers like ferritin or transferrin saturation. Recent advancements include using soluble transferrin receptor (sTfR) or hepcidin for improved detection and classification of absolute and functional iron deficiencies, though mostly used in research. ID without anemia may present symptoms like asthenia and fatigue, even without relevant clinical consequences. ID impacts not only red-blood cells but also immune system cells, highlighting its importance in global health and immune-related comorbidities. Managing ID, requires addressing its cause and selecting appropriate iron supplementation. Various improved oral and intravenous products are available, but further research is needed to refine treatment strategies. This review updates on absolute and functional iron deficiencies, their relationships with the immune system and advancements in diagnosis and therapies.

The Diagnostic Performance of Serum Glycosylated Ferritin in Patients Undergoing Regular Blood Transfusion: An Indicator of Iron Overload to Initiate Iron Chelation Therapy

Background and objective Serum ferritin concentration and transferrin saturation are commonly employed to estimate body iron but are non-specific to iron overload. Glycosylated ferritin may be primarily elevated in cases of iron overload in patients undergoing regular blood transfusions. In this study, we aimed to estimate glycosylated ferritin and determine its cutoff values for iron overload in patients receiving blood transfusions regularly. We also endeavored to the examine correlation between serum ferritin and glycosylated ferritin in patients receiving regular blood transfusions. Methods We conducted a cross-sectional study involving 17 patients undergoing regular blood transfusions in the Department of Medical Oncology/Hematology, who had already received ≥10 transfusions without any iron chelation therapy or acute inflammation. All participants were evaluated based on a questionnaire to gather relevant medical details. Serum iron, ferritin, glycosylated ferritin, and unsaturated iron-binding capacity (UIBC) were estimated. Total iron-binding capacity (TIBC) and transferrin saturation were also calculated. Results Participants were divided into two groups based on transferrin saturation (≥50% as a reference for iron overload). The group with transferrin saturation ≥50% had significantly higher levels of serum ferritin, glycosylated ferritin, and iron, compared to the group with transferrin saturation <50%. Glycosylated ferritin showed a positive correlation with ferritin (rho=0.80) and transferrin saturation (rho=0.64), which was statistically significant. UIBC and TIBC showed a negative association with glycosylated ferritin. The correlation of glycosylated ferritin with units of blood transfusion (Spearman's rho=0.60) was found to be better than that of serum ferritin (Spearman's rho=0.52). Conclusions Based on our findings, glycosylated ferritin could be a potential marker for transfusion-related iron overload. The optimal cutoff value for iron overload using serum glycosylated ferritin level was >587.55 ng/mL. Further extensive studies with larger sample sizes will substantiate the role of glycosylated ferritin in predicting post-transfusion iron overload.

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.

Anemia, Iron Deficiency, and Cause-Specific Mortality: The Atherosclerosis Risk in Communities Study

INTRODUCTION

Anemia is a risk factor for all-cause mortality in older adults. Iron deficiency may also be associated with adverse outcomes, independent of its role in causing anemia. This study tested the hypotheses that anemia, and low ferritin among non-anemic participants, were associated with all-cause and cause-specific mortality in a community-based cohort of older adults.

METHODS

Fasting blood was obtained from 5,070 ARIC participants (median age: 75 years) in 2011-2013. Anemia was defined by hemoglobin concentrations <12 g/dL in women and <13 g/dL in men. We classified 4,020 non-anemic participants by quartiles of plasma ferritin, measured by the SomaScan proteomics platform. Cox proportional hazards regression was used. Mortality was ascertained via phone calls with proxies as part of twice-yearly cohort follow-up, surveillance of local hospital discharge indexes, state death records, and linkage to the National Death Index.

RESULTS

Of the total participants, 21% had anemia at baseline. Over a median of 7.5 years, there were 1,147 deaths, including 357 due to cardiovascular disease (CVD), 302 to cancer, and 132 to respiratory disease. Compared to those with normal hemoglobin, participants with anemia had a higher risk of all-cause mortality (hazard ratio 1.81 [95% CI: 1.60-2.06]), and mortality due to CVD (1.77 [1.41-2.22]), cancer (1.81 [1.41-2.33]), and respiratory disease (1.72 [1.18-2.52]) in demographics-adjusted models. In fully adjusted models, associations with all-cause mortality (1.37 [1.19-1.58]) and cause-specific mortality were attenuated. In non-anemic participants, lower ferritin levels were not associated with all-cause or cause-specific mortality, though associations were observed among participants with lesser evidence of inflammation (CRP below the median level of 1.9 mg/L) and for cancer mortality in men only.

CONCLUSION

Anemia is common among older adults and is associated with all-cause mortality, as well as mortality due to CVD, cancer, and respiratory disease. Our results do not provide evidence that iron deficiency, independent of anemia, is associated with mortality in this population.

No evidence of genetic causation between iron and infertility: a Mendelian randomization study

Background

Observational studies have explored the impact of iron homeostasis on infertility; however, establishing definitive causal relationships remains challenging. This study utilized a two-sample Mendelian randomization approach to investigate the potential causal relationship between iron status and infertility.

Materials and methods

Four indicators of iron status-serum iron, ferritin, transferrin saturation, and total iron binding capacity, were considered as exposure factors. Infertility was the outcome variable for both men and women. Robust causality was assessed using the primary inverse-variance-weighted method, complemented by three supplementary Mendelian randomization approaches. Sensitivity analyses were performed to enhance the precision and reliability of the results.

Results

No statistically significant associations were identified between the four indicators of iron status and infertility. These results remained consistent across multiple Mendelian randomization methodologies.

Conclusion

In conclusion, there is no evidence of a genetic causal relationship between iron status and infertility. Nevertheless, this does not preclude the possibility of a connection between iron status and infertility at different mechanistic levels.

Secondary Hemochromatosis Caused by Iron Overdose During Pregnancy and the Postpartum Period: A Case Report

Iron deficiency anemia is the most common cause of anemia in pregnancy. Therefore, iron administration is recommended for treatment. Iron deficiency anemia during pregnancy does not always result in microcytic anemia. Thus, iron may continue to be administered as diagnostic therapy, even in patients with normocytic anemia. In the present case, although the patient had normocytic anemia, repeated intravenous iron administration resulted in liver dysfunction due to secondary iron overload, which required intensive care. In pregnant women with perinatal hepatic dysfunction, iron overload secondary to iron therapy administered to correct anemia during pregnancy should be considered in the differential diagnosis.

Association of serum ferritin and all-cause mortality in AKI patients: a retrospective cohort study

Background

Serum ferritin (SF) is clinically found to be elevated in many disease conditions, and our research examines serum ferritin in patients with acute kidney injury (AKI) and its implication on the risk of short-term mortality in AKI.

Methods

Data were extracted from the Medical Information Mart for Intensive Care IV 2.2 (MIMIC-IV 2.2) database. Adult patients with AKI who had serum ferritin tested on the first day of ICU admission were included. The primary outcome was 28-day mortality. Kaplan-Meier survival curves and Cox proportional hazards models were used to test the relationship between SF and clinical outcomes. Subgroup analyses based on the Cox model were further conducted.

Results

Kaplan-Meier survival curves showed that a higher SF value was significantly associated with an enhanced risk of 28-day mortality, 90-day mortality, ICU mortality and hospital mortality (log-rank test: p < 0.001 for all clinical outcomes). In multivariate Cox regression analysis, high level of SF with mortality was significantly positive in all four outcome events (all p < 0.001). This result remains robust after adjusting for all variables. Subgroup analysis of SF with 28-day mortality based on Cox model-4 showed that high level of SF was associated with high risk of 28-day mortality in patients regardless of the presence or absence of sepsis (p for interaction = 0.730). Positive correlations of SF and 28-day mortality were confirmed in all other subgroups (p for interaction>0.05).

Conclusion

High level of SF is an independent prognostic predictor of 28-day mortality in patients with AKI.

Prevalence of Iron Deficiency Using 3 Definitions Among Women in the US and Canada

Importance

The prevalence of iron deficiency varies widely according to how it is defined.

Objective

To compare the prevalence of iron deficiency among women using 3 different definitions.

Design, Setting, and Participants

The cross-sectional Hemochromatosis and Iron Overload Screening Study (HEIRS; 2000-2006) evaluated the prevalence, determinants, and outcomes of hemochromatosis and other iron-related disorders. Multiethnic, primary care-based screening (2001-2003) was performed at 5 field centers (4 in the US and 1 in Canada). Volunteer women aged 25 years and older were recruited at primary care venues associated with the field centers. Data were analyzed from June to December 2023.

Main Outcomes and Measures

Measures included transferrin saturation, serum ferritin level, and self-reported age, pregnancy, and race and ethnicity. Three iron deficiency definitions were studied: (1) combined transferrin saturation less than 10% and serum ferritin less than 15 ng/mL (HEIRS), (2) serum ferritin less than 15 ng/mL (World Health Organization [WHO]), and (3) serum ferritin less than 25 ng/mL (a threshold for iron-deficient erythropoiesis [IDE]).

Results

Among 62 685 women (mean [SD] age, 49.58 [14.27] years), 1957 women (3.12%) had iron deficiency according to the HEIRS definition, 4659 women (7.43%) had iron deficiency according to the WHO definition, and 9611 women (15.33%) had iron deficiency according to the IDE definition. Among 40 381 women aged 25 to 54 years, 1801 women (4.46%) had iron deficiency according to HEIRS, 4267 women (10.57%) had iron deficiency according to WHO, and 8573 women (21.23%) had iron deficiency according to IDE. Prevalence rates of iron deficiency among 2039 women aged 25 to 44 years who reported pregnancy were 5.44% (111 women) according to HEIRS, 18.05% (368 women) according to WHO, and 36.10% (736 women) according to IDE. Iron deficiency prevalence by the 3 respective definitions increased significantly in each racial and ethnic group and was significantly higher among Black and Hispanic participants than Asian and White participants. The relative iron deficiency prevalence among the 62 685 women increased 2.4-fold (95% CI, 2.3-2.5; P < .001) using the WHO definition and increased 4.9-fold (95% CI, 4.7-5.2; P < .001) using the IDE definition.

Conclusions and Relevance

Three definitions of iron deficiency were associated with significantly different prevalence of iron deficiency in women, regardless of self-reported age, pregnancy, or race and ethnicity. Using higher serum ferritin thresholds to define iron deficiency could lead to diagnosis and treatment of more women with iron deficiency and greater reduction of related morbidity.

Intravenous iron and iron deficiency anemia in patients with gastrointestinal cancer: A systematic review

BACKGROUND

Iron deficiency anemia (IDA) is a prevalent hematological complication associated with gastrointestinal (GI) cancers due to an increased loss of iron and decreased iron absorption. The purpose of this systematic review is to evaluate the use of parenteral iron to treat IDA in patients with GI cancer.

METHODS

PubMed, Cochrane, EMBASE, CINHAL and Scopus were searched from January 1, 2010 to September 29, 2023 with no language restrictions. We excluded editorials, case reports, abstracts, conference papers, and poster presentations. Studies were included if they discussed IDA, GI neoplasms, use of iron supplementation (with or without erythropoietin-stimulating agents [ESAs]), defined anemia and had an adult patient population. We assessed the efficacy of parenteral iron in comparison to other iron supplementation methods when treating IDA in patients with GI cancer. The Cochrane Risk of Bias Tool 2 (RoB 2) and the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) assessment tools were used to assess the quality of the included studies. Moreover, the Cochrane Effective Practice and Organization data collection form was used to collect pertinent study information.

RESULTS

Our search yielded 3,969 studies across all databases. Twenty-one studies were included (6 randomized control trials; 15 non-randomized studies). Of the 15 studies evaluating hemoglobin (Hb) response, seven studies found an increase in Hb levels when patients were treated with IV iron. The 14 studies evaluating red blood cell (RBC) transfusion rates found conflicting differences in RBC transfusion needs when treated with IV iron. Studies analyzing health related outcomes typically found an increase in quality of life and decreased post-operative complications.

DISCUSSION

This review demonstrates improved outcomes of IDA in patients with GI cancer treated with IV iron instead of other iron supplementation methods. Timely diagnosis and appropriate IDA management can greatly improve quality of life in this patient population, especially if myelosuppressive chemotherapy is required.

Iron deficiency in patients with cancer: a prospective cross-sectional study

BACKGROUND

Despite the deleterious consequences of iron deficiency (ID) in patients with cancer, underdiagnosis is frequent. The CARENFER study aimed to assess the prevalence of ID using both serum ferritin concentration and transferrin coefficient saturation (iron-saturation of transferrin, TSAT) index, as well as ID anaemia in patients with cancer.

METHODS

This prospective cross-sectional study was conducted in 15 oncology units in France in 2019. All patients present in the medical unit during the 2-week study period, regardless of the type of tumour (solid or haematological) and treatment, were eligible. Serum ferritin concentration, TSAT index and haemoglobin level were determined. ID and ID-associated anaemia were defined according to European Society of Medical Oncology 2018 Guidelines: ID was defined either as ferritin <100 µg/L (absolute ID) or as ferritin ≥100 µg/L and TSAT <20% (functional ID).

RESULTS

A total of 1221 patients with different types of solid malignant tumours were analysed: median age 64 years; 89.4% under treatment for their cancer, mainly by chemotherapy (75.4%). Overall, ID was found in 57.9% (55.1-60.6) of patients. Among them, functional ID accounted for 64% of cases. ID anaemia was reported in 21.8% (19.6-24.2) of all patients with cancer. ID was highly prevalent in untreated (75/130, 57.4%) and non-anaemic (419/775, 54.1%) patients.

CONCLUSION

This study highlights the high prevalence of ID in patients with cancer, whether or not associated with anaemia or treatment. These results emphasise the need to a better detection and management of ID in cancer, thereby optimising overall patient care.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT03924271.

Effects of Oral Iron Supplementation on Blood Iron Status in Athletes: A Systematic Review, Meta-Analysis and Meta-Regression of Randomized Controlled Trials

BACKGROUND

Iron deficiency in athletes is initially treated with a nutritional intervention. If negative iron balance persists, oral iron supplementation (OIS) can be used. Despite the recent proposal for a refinement of treatment strategies for iron-deficient athletes, there is no general consensus regarding the actual efficiency, dosage, or optimal regimen of OIS.

OBJECTIVE

The aim of this meta-analysis was to evaluate to what extent OIS affects blood iron parameters and physical performance in healthy adult athletes.

METHODS

PubMed, Web of Science, PEDro, CINAHL, SPORTDiscus, and Cochrane were searched from inception to 2 November 2022. Articles were eligible if they satisfied the following criteria: recruited subjects were healthy, adult and physically active individuals, who used exclusively OIS, irrespective of sex and sports discipline.

EXCLUSION CRITERIA

simultaneous supplementation with iron and any other micronutrient(s), intravenous iron supplementation or recent exposure to altitude acclimatisation. The methodological quality of included studies was assessed with the PEDro scale, the completeness of intervention reporting with the TIDieR scale, while the GRADE scale was used for quality of evidence synthesis. The present study was prospectively registered in PROSPERO online registry (ID: CRD42022330230).

RESULTS

From 638 articles identified through the search, 13 studies (n = 449) were included in the quantitative synthesis. When compared to the control group, the results demonstrated that OIS increases serum ferritin (standardized mean difference (SMD) = 1.27, 95% CI 0.44-2.10, p = 0.006), whereas blood haemoglobin (SMD = 1.31, 95% CI - 0.29 to 2.93, p = 0.099), serum transferrin receptor concentration (SMD = - 0.74, 95% CI - 1.89 to 0.41, p = 0.133), and transferrin saturation (SMD = 0.69, 95% CI - 0.84 to 2.22, p = 0.330) remained unaltered. Following OIS, a trend of small positive effect on VO2max (SMD = 0.49, 95% CI - 0.09 to 1.07, p = 0.086) was observed in young healthy athletes. The quality of evidence for all outcomes ranged from moderate to low.

CONCLUSIONS

Increase in serum ferritin concentration after OIS was evident in subjects with initial pre-supplementation serum ferritin concentration ≤ 12 µg/l, while only minimal, if any effect, was observed in subjects with higher pre-supplementation serum ferritin concentration. The doses of OIS, that induced a beneficial effect on hematological parameters differed from 16 to 100 mg of elementary iron daily, over the period between 6 and 8 weeks. Shorter supplementation protocols have been shown to be ineffective.

Transferrin Saturation, Serum Ferritin, and C-Reactive Protein vs. Serum Ferritin for an optimal Iron Deficiency Diagnosis in Candidates for Bariatric Surgery

INTRODUCTION

Iron has different physiological processes and is regulated by hepcidin that is also an acute phase reactant, which increases with inflammation. Obesity produces a pro-inflammatory state, affecting directly the normal regulation of iron, causing ferritin (FER) deficiency. FER is used as the only indicator of the status of iron in patients with obesity, so the majority of them would be underdiagnosed, leading to a high prevalence of iron deficiency (ID) and anemia. The aim of this study is to evaluate the diagnostic tests: transferrin saturation (TS), FER, and C-reactive protein (CRP) vs. FER with the objective of analyzing the most accurate variable for the diagnosis of ID.

MATERIALS AND METHODS

We present a cross-sectional, analytical, and retrospective study, evaluating the diagnostic tests in 96 patients, to whom two methods were applied for the diagnosis of ID: method 1 (FER < 30 ng/mL) and method 2 divided into 2A (FER < 30 ng/mL), 2B (FER 30-100 ng/mL + CRP ≥ 5 mg/L), 2C (FER 100-300 ng/mL + CRP ≥ 5 mg/L + TS < 20%), and 2D (TS < 20%).

RESULTS

The prevalence of ID obtained using method 1 was 30.2% while 69.8% presented ID using total method 2, confirming an underdiagnosis of 39.6%.

CONCLUSION

The inflammatory state in patients with obesity must be considered in the diagnosis of ID. The use of TS, FER, and CRP has greater validity than the use of serum FER for the diagnosis of ID in patients with obesity.

Roxadustat and Oral Iron Absorption in Chinese Patients with Anemia of Chronic Kidney Disease: A Randomized, Open-Label, Phase 4 Study (ALTAI)

INTRODUCTION

Anemia of chronic kidney disease (CKD) has a high incidence and is associated with many disease conditions. Iron dysmetabolism is an important contributor to anemia in CKD patients.

METHODS

ALTAI, a randomized, active-controlled, phase 4 trial, investigated the efficacy of roxadustat versus recombinant human erythropoietin (rHuEPO) on gastrointestinal iron absorption in patients with anemia of CKD (stage 4/5). The primary endpoint was change from baseline to day 15 in gastrointestinal iron absorption (serum iron area under the concentration-time curve; AUC0-3h) following single-dose oral iron.

RESULTS

Twenty-five patients with a mean age of 55.1 years were randomized 1:1 to roxadustat (n = 13) or rHuEPO (n = 12). Baseline iron profiles were similar between treatment groups. Change from baseline to day 15 in serum iron AUC0-3h was not statistically significantly different between the roxadustat and rHuEPO groups. Mean (SD) change from baseline in serum iron AUC0-3h was 11.3 (28.2) g × 3 h/dl in the roxadustat group and - 0.3 (9.7) g × 3 h/dl in the rHuEPO group. Roxadustat treatment was associated with decreased hepcidin and also increased transferrin, soluble transferrin receptor, and total iron-binding capacity (TIBC), with nominal significance. The proportion of patients experiencing one or more adverse events was 38.5% when treated with roxadustat and 16.7% with rHuEPO.

CONCLUSIONS

The study showed no significant difference between roxadustat and rHuEPO in iron absorption but was underpowered because of recruitment challenges.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT04655027.

Unraveling the Role of Maternal Serum Ferritin Levels in Preterm Delivery: A Comprehensive Review

Preterm delivery remains a critical global health concern, with numerous adverse consequences for both neonate and healthcare systems. Understanding the relationship between maternal ferritin levels, as a marker of iron status, and the risk of preterm birth is the focal point of this comprehensive review. We provide insights into the multifaceted nature of this connection, highlighting factors that influence maternal ferritin levels, including dietary intake, genetic and physiological variations, comorbidities, and iron supplementation. While evidence suggests an association between low maternal ferritin levels and preterm birth, causality remains elusive, necessitating further research with robust study designs. The potential mechanisms linking maternal iron status to preterm birth, such as inflammation, infection, and oxidative stress, are explored, underscoring the need for in-depth investigations. This comprehensive review emphasizes the clinical importance of assessing and monitoring maternal ferritin levels in prenatal care and advocates for public health initiatives to raise awareness and provide targeted interventions, particularly in high-risk populations. As we strive to address these unanswered questions and embark on innovative research directions, the aim is to ultimately enhance our understanding of the complex relationship between maternal iron status and preterm birth, leading to improved maternal and child health outcomes.

Intravenous iron for critically ill children. Comparison of three dose regimens

BACKGROUND

Anemia is extremely common among patients admitted to pediatric intensive care. Alternative treatments to transfusions such as intravenous iron must be considered. There are no published data for a prospective intravenous (IV) iron study focused in the critically ill children. The objective is to examine the safety and efficacy of intravenous iron sucrose infusion to manage anemia in pediatric critical care. A secondary objective is to examine the effect of different dose regimens of iron sucrose (3, 5, and 7 mg/kg dose).

PROCEDURE

Prospective investigation of intravenous iron sucrose utilization at a tertiary pediatric intensive care unit between October 2017 and November 2022.

RESULTS

In all 115 patients received a total of 616 infusions of IV iron. Transferrin saturation index (TSI) was the most common altered iron deficiency biomarker (91.8%). After IV iron treatment, hemoglobin showed a significant increase within a 30-day follow-up (9.2 vs. 11.6 g/dL, p < .001). There was also a significant improvement in TSI and serum iron (p < .001). Iron deficit replacement was higher in the 7 mg/kg dose group (94%) compared to 85.9% in the 5 mg/kg regimen and 77.5% in the lower dose group (p = .008), requiring less doses and a shorter time. Very few mild adverse reactions were reported (1.3% of infusions), with no differences between groups. The most frequent adverse effect was gastrointestinal in three cases. There were no anaphylaxis-like or other serious/life-threatening adverse effects.

CONCLUSIONS

This is the first study to evaluate intravenous iron therapy in pediatric critical care, providing preliminary evidence of safety and efficacy of IV iron sucrose. The 7 mg/kg dose regimen showed higher iron deficit replacement in a shorter time, which could be beneficial in critically ill children.

Effect of Ziltivekimab on Determinants of Hemoglobin in Patients with CKD Stage 3-5: An Analysis of a Randomized Trial (RESCUE)

SIGNIFICANCE STATEMENT

Systemic inflammation in CKD can lead to anemia. Ziltivekimab, a fully human monoclonal antibody targeting the IL-6 ligand, has been shown to reduce systemic inflammation in patients with CKD. It has also been shown to increase serum albumin in patients on hemodialysis with inflammation and hyporesponsiveness to treatment with erythropoiesis-stimulating agents. This exploratory analysis of the RESCUE clinical trial found that among patients with CKD stage 3-5 and systemic inflammation, ziltivekimab treatment significantly increased hemoglobin (Hb) levels after 12 weeks compared with placebo. Ziltivekimab was also associated with significant increases in serum iron levels, total iron-binding capacity, and transferrin saturation. No major safety concerns were reported. Further clinical trials are warranted to study ziltivekimab's potential for anemia management in patients with CKD.

BACKGROUND

In the phase 2 RESCUE clinical trial, ziltivekimab, a fully human monoclonal antibody against the IL-6 ligand, significantly reduced the biomarkers of inflammation compared with placebo, in patients with CKD and systemic inflammation (high-sensitivity C-reactive protein ≥2 mg/L). The aim of this subanalysis of RESCUE trial data was to assess the effect of ziltivekimab on Hb and iron homeostasis in this patient population.

METHODS

This was an analysis of exploratory end points from the RESCUE trial ( NCT03926117 ), which included 264 adults with CKD stage 3-5 and high-sensitivity C-reactive protein ≥2 mg/L. Participants received placebo or subcutaneous ziltivekimab (7.5, 15, or 30 mg) (1:1:1:1) once every 4 weeks, up to 24 weeks. End points for this analysis were changes in Hb and biomarkers of iron homeostasis from baseline to week 12.

RESULTS

The trial was terminated early due to the coronavirus disease 2019 pandemic, and thus, data up to week 12 are presented. Hb levels significantly increased from baseline to week 12 with ziltivekimab 7.5, 15, and 30 mg (treatment differences versus placebo: +0.57 g/dl [95% confidence interval, 0.27 to 0.86], +1.05 g/dl [0.76 to 1.33], and +0.99 g/dl [0.70 to 1.28], respectively, all P < 0.001). Ziltivekimab was associated with significant increases in serum iron levels, total iron-binding capacity, and transferrin saturation from baseline to week 12 ( P < 0.05 versus placebo for all doses and comparisons). Cases of sustained thrombocytopenia, sustained neutropenia, anemia, and iron deficiency anemia were infrequent and similar across all groups.

CONCLUSIONS

Anti-inflammatory therapy with ziltivekimab improved the markers of anemia and iron homeostasis in people with stage 3-5 CKD and systemic inflammation, suggesting a possible role in anemia management.

Low Serum Hepcidin Levels in Patients with Ulcerative Colitis - Implications for Treatment of Co-existent Iron-Deficiency Anemia

Ulcerative colitis (UC) is often associated with anemia. Hepcidin, the central regulator of iron homeostasis, is known to be induced by inflammation and suppressed by anemia. It is not clear how hepcidin is affected in those with UC, when both inflammation and anemia may co-exist.Such knowledge may hold implications for treatment. Hematological and iron-related parameters, C-reactive protein (CRP), growth differentiation factor 15 (GDF-15) and erythroferrone (ERFE) (erythroid regulators of hepcidin) levels were estimated in blood from those with UC and in control subjects. Values for hematological and iron-related parameters showed evidence of iron-deficiency and resultant anemia, in patients with UC. The presence of UC was significantly associated with inflammation. Serum levels of ERFE, but not of GDF-15, were significantly higher in patients with UC than in control patients, while hepcidin levels were significantly lower. Serum hepcidin concentrations in patients with UC correlated positively with serum iron, ferritin and GDF-15, and negatively with serum ERFE. The iron status and serum hepcidin levels in UC patients with co-existent anemia were significantly lower and serum ERFE values significantly higher than in those with UC without anemia. The effect of anemia on hepcidin predominated over that of inflammation in patients with UC, resulting in suppressed hepcidin levels. This effect is possibly mediated through erythroferrone. We suggest that a serum hepcidin-guided approach may be useful to guide use of oral iron supplements to treat co-existent iron-deficiency anemia in patients with UC and other chronic inflammatory diseases.

The IRONy in Athletic Performance

Iron is an essential micronutrient for athletes, intricately linked to their performance, by regulating cellular respiration and metabolism. Impaired iron levels in the body can significantly hinder athletic performance. The increased demand for iron due to exercise, coupled with potential dietary iron insufficiencies, particularly among endurance athletes, amplifies the risk of iron deficiency. Moreover, prolonged exercise can impact iron absorption, utilization, storage, and overall iron concentrations in an athlete. On the contrary, iron overload may initially lead to enhanced performance; however, chronic excess iron intake or underlying genetic conditions can lead to detrimental health consequences and may negatively impact athletic performance. Excess iron induces oxidative damage, not only compromising muscle function and recovery, but also affecting various tissues and organs in the body. This narrative review delineates the complex relationship between exercise and iron metabolism, and its profound effects on athletic performance. The article also provides guidance on managing iron intake through dietary adjustments, oral iron supplementation for performance enhancement in cases of deficiency, and strategies for addressing iron overload in athletes. Current research is focused on augmenting iron absorption by standardizing the route of administration while minimizing side effects. Additionally, there is ongoing work to identify inhibitors and activators that affect iron absorption, aiming to optimize the body's iron levels from dietary sources, supplements, and chelators. In summary, by refining the athletic diet, considering the timing and dosage of iron supplements for deficiency, and implementing chelation therapies for iron overload, we can effectively enhance athletic performance and overall well-being.

New Perspectives on Circulating Ferritin: Its Role in Health and Disease

The diagnosis of iron disturbances usually includes the evaluation of serum parameters. Serum iron is assumed to be entirely bound to transferrin, and transferrin saturation-the ratio between the serum iron concentration and serum transferrin-usually reflects iron availability. Additionally, serum ferritin is commonly used as a surrogate of tissue iron levels. Low serum ferritin values are interpreted as a sign of iron deficiency, and high values are the main indicator of pathological iron overload. However, in situations of inflammation, serum ferritin levels may be very high, independently of tissue iron levels. This presents a particularly puzzling challenge for the clinician evaluating the overall iron status of the patient in the presence of an inflammatory condition. The increase in serum ferritin during inflammation is one of the enigmas regarding iron metabolism. Neither the origin, the mechanism of release, nor the effects of serum ferritin are known. The use of serum ferritin as a biomarker of disease has been rising, and it has become increasingly diverse, but whether or not it contributes to controlling the disease or host pathology, and how it would do it, are important, open questions. These will be discussed here, where we spotlight circulating ferritin and revise the recent clinical and preclinical data regarding its role in health and disease.

Accuracy of reticulocyte hemoglobin for diagnosing iron deficiency in former very preterm infants: a population-based cohort study

Background

Serum ferritin (SF) is commonly used to diagnose iron deficiency (ID) but has limitations. Reticulocyte hemoglobin (Ret-He) is being increasingly used for ID diagnosis. This study aimed to assess accuracy of Ret-He for ID diagnosis in former very preterm infants (VPI) at 4-6 months corrected age (CA).

Methods

A retrospective population-based cohort study was conducted on all live VPI born between 23 and 30 weeks of gestational age (GA) in Nova Scotia from 2012 to 2018. Infants underwent SF and Ret-He testing at 4-6 months CA. ID was defined using two definitions. The first defined ID as SF < 20 mcg/L at both 4- and 6-months CA, and the second as SF < 30 mcg at at both 4- and 6-months CA. The accuracy of Ret-He for identifying ID was assessed using the area under the receiver operating characteristic curve (AUC).

Results

ID was present in 39.7% (62) of 156 infants in the first definition and 59.6% (93) in the second at 4-6 months CA. The AUC of Ret-He for ID diagnosis was 0.64 (p = 0.002) in the first definition and 0.59 (p = 0.04) in the second. The optimal cut-off was 29.4pg in the first and 29.7 in the second definition. The sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) at the 29.4 pg cut-off were 50.0%, 78.7%, 60.8%, and 70.5% for definition 1 and 44.1%, 74.6%, 71.9%, and 47.5% at the 29.7pg cut-off for definition 2.

Conclusion

Ret-He had low diagnostic accuracy for ID diagnosis in former VPI. Caution is advised when using Ret-He alone for ID diagnosis. Further research is needed to establish optimal approaches for identifying ID in VPI.

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.

Serum iron levels in tuberculosis patients and household contacts and its association with natural resistance-associated macrophage protein 1 polymorphism and expression

BACKGROUND

Iron deficiency can impair immune function, increasing tuberculosis (TB) susceptibility and severity. The research aimed to investigate iron deficiency anemia in TB patients and household contacts and its association with natural resistance-associated macrophage protein 1 (NRAMP1) polymorphism and expression.

METHODS

The levels of iron, ferritin, and transferrin were measured in the serum by ELISA (Enzyme-Linked Immunosorbent Assay). NRAMP1 polymorphisms were determined by polymerase chain reaction (PCR) and sequencing. NRAMP1 gene expression was measured by real-time PCR. Interferon-gamma release assay (IGRA) checked on household contacts to screen household contacts with positive IGRA as the control.

RESULTS

This study involved 35 TB cases and 35 TB contacts. The results showed that the serum Fe levels were found to be lower in the TB case group (median 149.6 μmol/L) than in the positive IGRA household contacts group (median 628.53 μmol/L) with a p-value <0.001. Meanwhile, ferritin levels in TB cases tended to be higher, in contrast to transferrin, which was found to tend to be lower in TB cases than household contacts but did not show a significant difference. This study found no association between the polymorphism of exon 15 D543 and active TB. However, NRAMP1 gene expression was lower in TB cases than in positive IGRA household contacts (p = 0.011). Besides, there was a positive correlation between NRAMP1 gene expression and serum Fe levels (r = 0.367, p = 0.006). TB was associated with decreased NRAMP1 gene expression (OR 0.086 95% CI 0.02-0.366, p = 0.001). Besides, TB was associated with low Fe levels (OR 0.533 95% CI 0.453-0.629, p < 0.001).

CONCLUSION

Comparing the TB case to the household contacts group, decreased serum Fe levels were discovered in the TB case group. This study also shows a correlation of NRAMP1 gene expression to Fe levels in TB patients and household contacts and describes that TB may lead to decreased Fe levels by downregulating NRAMP1 expression.

Fibroblast growth-factor 23 and vitamin D are associated with iron deficiency and anemia in children with chronic kidney disease

BACKGROUND

This cross-sectional study investigates the association of fibroblast growth-factor 23 (FGF23) and other bone mineral parameters with iron status and anemia in pediatric chronic kidney disease (CKD).

METHODS

Serum calcium, phosphorus, 25-hydroxyvitamin D (25(OH)D), intact parathormone, c-terminal FGF23, a-Klotho, iron (Fe), ferritin, unsaturated iron-binding capacity, and hemoglobin (Hb) were measured in 53 patients from 5 to 19 years old with GFR < 60 mL/min/1.73 m2. Transferrin saturation (TSAT) was calculated.

RESULTS

Absolute (ferritin ≤ 100 ng/mL, TSAT ≤ 20%) and functional iron deficiency (ferritin > 100 ng/mL, TSAT ≤ 20%) were observed in 32% and 7.5% of patients, respectively. In CKD stages 3-4 (36 patients), lnFGF23 and 25(OH)D were correlated with Fe (rs =  - 0.418, p = 0.012 and rs = 0.467, p = 0.005) and TSAT (rs =  - 0.357, p = 0.035 and rs = 0.487, p = 0.003) but not to ferritin. In this patient group, lnFGF23 and 25(OH)D were correlated with Hb z-score (rs =  - 0.649, p < 0.001 and rs = 0.358, p = 0.035). No correlation was detected between lnKlotho and iron parameters. In CKD stages 3-4, in multivariate backward logistic regression analysis, including bone mineral parameters, CKD stage, patient age, and daily alphacalcidol dose as covariates, lnFGF23 and 25(OH)D were associated with low TSΑΤ (15 patients) (OR 6.348, 95% CI 1.106-36.419, and OR 0.619, 95% CI 0.429-0.894, respectively); lnFGF23 was associated with low Hb (10 patients) (OR 5.747, 95% CI 1.270-26.005); while the association between 25(OH)D and low Hb did not reach statistical significance (OR 0.818, 95% CI 0.637-1.050).

CONCLUSIONS

In pediatric CKD stages 3-4, iron deficiency and anemia are associated with increased FGF23, independently of Klotho. Vitamin D deficiency might contribute to iron deficiency in this population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Reticulocyte Hemoglobin as a Screening Test for Iron Deficiency Anemia: A New Cut-Off

Introduction: Latent iron deficiency (LID), in which iron stores in the body are depleted without incidental anemia, poses a key diagnostic challenge. Reticulocyte hemoglobin content (Ret-Hb) is directly correlated with the functionally available iron for heme synthesis in erythroblasts. Consequently, Ret-Hb has been proposed as an efficient iron status marker. Aim: To assess the importance of Ret-Hb in detecting latent iron deficiency as well as its use in screening for iron deficiency anemia. Materials and Methods: A study involving 108 individuals was conducted at Najran University Hospital, 64 of whom had iron deficiency anemia (IDA) and 44 of whom had normal hemoglobin levels. All patients were subjected to complete blood count (CBC), reticulocyte percentage, Ret-Hb, serum iron, total iron binding capacity (TIBC), and serum ferritin measurements. Results: A significant decrease in Ret-Hb level was observed in IDA patients compared to non-anemic individuals, with a cut-off value of 21.2 pg (a value below which indicates IDA). Conclusion: The measurement of Ret-Hb, in addition to CBC parameters and indices, provides an accessible predictive marker for both iron deficiency (ID) and IDA. Lowering the Ret-Hb cut-off could better allow for its use as a screening parameter for IDA.

Iron Metabolism in Cardiovascular Disease: Physiology, Mechanisms, and Therapeutic Targets

The cardiovascular system requires iron to maintain its high energy demands and metabolic activity. Iron plays a critical role in oxygen transport and storage, mitochondrial function, and enzyme activity. However, excess iron is also cardiotoxic due to its ability to catalyze the formation of reactive oxygen species and promote oxidative damage. While mammalian cells have several redundant iron import mechanisms, they are equipped with a single iron-exporting protein, which makes the cardiovascular system particularly sensitive to iron overload. As a result, iron levels are tightly regulated at many levels to maintain homeostasis. Iron dysregulation ranges from iron deficiency to iron overload and is seen in many types of cardiovascular disease, including heart failure, myocardial infarction, anthracycline-induced cardiotoxicity, and Friedreich's ataxia. Recently, the use of intravenous iron therapy has been advocated in patients with heart failure and certain criteria for iron deficiency. Here, we provide an overview of systemic and cellular iron homeostasis in the context of cardiovascular physiology, iron deficiency, and iron overload in cardiovascular disease, current therapeutic strategies, and future perspectives.

How to diagnose iron deficiency in chronic disease: A review of current methods and potential marker for the outcome

Iron deficiency (ID) is the most common nutritional disorder worldwide. It is often observed in patients with chronic diseases, such as heart failure (HF), chronic kidney disease (CKD), inflammatory bowel disease (IBD) and cancer. ID is associated with poor clinical outcome, including poor performance, reduced quality of life, as well as increased hospitalization and mortality. The aim of this review is to provide an overview about the role of ID in chronic diseases (HF, CKD, IBD, cancer) regarding their current definitions and clinical relevance; diagnostic accuracy of iron parameters in chronic inflammatory conditions and its potential as prognostic markers. Due to different definitions and guideline recommendations of ID, various laboratory parameters for ID diagnostic exist and there is no general consensus about the definition of ID and its treatment. Still, a general trend can be observed across all investigated indications of this review (HF, CKD, IBD, cancer) that serum ferritin and transferrin saturation (TSAT) are the two parameters mentioned most often and emphasized in all guidelines to define ID and guide treatment. The most commonly used threshold values for the diagnosis of ID are TSAT of < 20% and serum ferritin of < 100-300 µg/L. Noteworthy, both TSAT and particularly ferritin are frequently applied, but both may vary due to inflammatory conditions. Studies showed that TSAT is less affected by inflammatory processes and may therefore be more accurate and reliable than serum ferritin, particularly in conditions with elevated inflammatory state. A low iron status and particularly a low TSAT value was associated with a poor outcome in all investigated indications, with the strongest evidence in HF patients. Routine surveillance of iron status in these groups of patients with chronic conditions is advisable to detect ID early. Depending on the inflammatory state, TSAT < 20% may be the more accurate diagnostic marker of ID than ferritin. Moreover, TSAT may also be the more reliable estimate for the prognosis, particularly in HF.

Defining ferritin clinical decision limits to improve diagnosis and treatment of iron deficiency: A modified Delphi study

BACKGROUND

Iron deficiency is highly prevalent worldwide and is an issue of health inequity. Despite its high prevalence, uncertainty on the clinical applicability and evidence-base of iron-related lab test cut-offs remains. In particular, current ferritin decision limits for the diagnosis of iron deficiency may not be clinically appropriate nor scientifically grounded.

METHODS

A modified Delphi study was conducted with various clinical experts who manage iron deficiency across Canada. Statements about ferritin decision limits were generated by a steering committee, then distributed to the expert panel to vote on agreement with the aim of achieving consensus and acquiring feedback on the presented statements. Consensus was reached after two rounds, which was defined as 70% of experts rating their agreement for a statement as 5 or higher on a Likert scale from 1 to 7.

RESULTS

Twenty-six clinical experts across 10 different specialties took part in the study. Consensus was achieved on 28 ferritin decision limit statements in various populations (including patients with multiple comorbid conditions, pediatric patients, and pregnant patients). For example, there was consensus that a ferritin <30 μg/L rules in iron deficiency in all adult patients (age ≥ 18 years) and warrants iron replacement therapy.

CONCLUSION

Consensus statements generated through this study corresponded with current evidence-based literature and guidelines. These statements provide clarity to facilitate clinical decisions around the appropriate detection and management of iron deficiency.

Preoperative ferritin and hemoglobin levels are lower in patients with a history of COVID-19 but blood loss and transfusion requirements are not increased

INTRODUCTION

A history of COVID-19 (Coronavirus Disease 2019), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have an impact on hemoglobin and ferritin levels predisposing patients to increased blood transfusion requirements following total joint arthroplasty (TJA). The current study compares ferritin levels, hemoglobin levels, and transfusion rates between SARS-CoV-2 IgG positive and SARS-CoV-2 IgG negative TJA patients.

MATERIALS AND METHODS

Preoperative ferritin levels, pre- and postoperative hemoglobin levels, postoperative change in hemoglobin, and transfusion rates of 385 consecutive SARS-CoV-2 IgG positive patients undergoing TJA were compared to those of 5156 consecutive SARS-CoV-2 IgG negative patients undergoing TJA.

RESULTS

Preoperative hemoglobin levels were significantly lower in SARS-CoV-2 IgG positive patients [13.3 g/dL (range 8.9-17.7 g/dL)] compared to 13.5 g/dl (7.3-18.3 g/dL; p value 0.03). Ferritin levels were significantly lower in SARS-CoV-2 IgG positive patients (mean of 106.1 ng/ml (2.1-871.3.3 ng/ml) vs. 123.7 ng/ml (1.4-1985 ng/ml) (p value 0.02)). Hemoglobin on postoperative day (POD) one, after four-six weeks, and transfusion rates did not differ between the two groups.

CONCLUSION

Although preoperative hemoglobin and ferritin levels are lower in SARS-CoV2 IgG positive patients, there was no difference in hemoglobin on POD one, recovery of hemoglobin levels at four-six weeks postoperatively, and transfusion rates after surgery. Routine ferritin testing prior to TJA is not recommended in SARS-CoV-2 IgG positive patients.

Associations between serum soluble transferrin receptor and the prevalence of cancers

Background

As increasing experimental evidence suggests that iron metabolism play crucial roles in cancer and non-cancer conditions, there is a lack of data on serum soluble transferrin receptor (sTfR), a promising marker representing unmet cellular iron demands, between cancer risk from epidemiological studies. Here, we aimed to evaluate the predictive value of sTfR and cancer prevalence.

Materials and methods

We analyzed on 5,480 adult participants from 2015 to 2018 National Health and Nutrition Examination Survey (NHANES). Spearman correlation analysis was performed to investigate the correlations between sTfR and other characteristics. To identify the associations between sTfR and the prevalence of cancers, stratified multivariable logistic regression models, subgroup and sensitivity analyses were also performed.

Results

In tertile analyses, participants in the highest level of sTfR were significantly associated with increased prevalence of total cancers [odds ratio (OR) = 1.53, 95% confidence interval (CI): 1.15-2.02] as compared with those at the lowest tertile. Each unit increment in ln-transformed sTfR concentration was shown to be associated with 39% increased risks of total cancers. Similar associations were found in males rather than females. Further subgroup and sensitivity analyses indicated that, in continuous and tertile analyses, sTfR was more closely associated with male- and female-specific cancers of prostate and testis (2.35: 1.03-5.40; 2.03: 1.00-4.09; respectively), and breast, cervix, ovary and uterus (1.92: 1.11-3.35; 1.66: 1.02-2.69; respectively).

Conclusions

Our findings suggested that elevated level of sTfR was associated with the prevalence of cancers, especially in sex-specific cancers. In order to better determine them, further research in humans will be required.

Malnutrition in elderly patients with type 2 diabetes mellitus in a Nigerian tertiary hospital: A cross-sectional study

Introduction

The global population of the elderly with type 2 diabetes mellitus (T2DM) is growing due to improvement in DM care and increased life expectancy. Malnutrition is a recognized complication of DM especially in the elderly. However, despite the impact of malnutrition on the overall outcome of the elderly with DM, it has not received adequate attention.

Aim

To determine the prevalence of malnutrition and associated factors in the elderly with T2DM.

Methods

This was a cross-sectional study that involved 96 elderly with T2DM and 96 age and sex matched elderly without T2DM as controls. Malnutrition was assessed using mini-nutritional assessment-short form (MNA-SF), hypoalbuminemia and body mass index (BMI). The factors associated with some malnutrition indices were determined.

Results

The mean age of T2DM and non-T2DM groups were 66.73 ± 5.18 years and 66.78 ± 5.25 years respectively. The observed malnutrition indices among elderly with T2DM and controls were hypoalbuminemia (79.2% vs 25.0%; P ≤0.001); overweight and obesity (58.3% vs 24.0%); and underweight (16.7% vs 4.2%). According to MNA-SF, malnutrition (7.3% vs 0%) and at risk of malnutrition (42.7% vs 16.7%) were significantly more prevalent among elderly with T2DM compared to controls (P ≤0.001). On logistic regression, the significant predictors of malnutrition were male gender (AOR:2.70; CI:1.11-6.55; P = 0.028) and albuminuria (AOR:3.14; CI:1.18-8.35; P = 0.022) and poor glycemic control (AOR:7.05; CI:2.01-24.71; P = 0.002).

Conclusion

Malnutrition is highly prevalent in elderly with T2DM. Poor glycemic control, albuminuria and male gender were significant predictors of malnutrition in this study. Nutritional assessment should be included in the routine DM care especially among the elderly.

Changes in obesity and iron deficiency between 4 and 9 years of age. Longitudinal study of childhood obesity (ELOIN)

BACKGROUND

Recent studies revealed that children who are overweight have a higher risk of iron deficiency, although the etiology of this relationship remains unclear. The aim of the study was to evaluate the association between changes in obesity status between 4 and 9 years of age and iron deficiency.

SUBJECTS

This population-based cohort study included 1347 children from the ELOIN study, conducted in Madrid, Spain. Follow-up with physical examinations and a computer-assisted telephone interview were carried out at 4, 6 and 9 years of age, and a blood test was performed at 9 years.

METHODS

Changes in obesity were estimated based on body mass index and waist circumference, according to the persistence or variation in obesity rates at 4, 6 and 9 years and were classified as follows: (1) Stable without obesity; (2) Remitting obesity at 9 years; (3) Incident obesity or relapse at 9 years; and (4) Stable with obesity. Iron deficiency was defined as transferrin saturation value below 16%. Odds ratios (ORs) for iron deficiency were estimated according to obesity status using logistic regression and adjusted for confounding variables, including C-reactive protein (CRP).

RESULTS

The prevalence of iron deficiency in the stable general obesity (GO) and abdominal obesity (AO) groups was 38.2% and 41.2%, versus 23.6% and 23.4% in the stable without obesity groups, respectively. The ORs for iron deficiency were 1.85 (95% CI: 1.03-3.32) in the stable GO group and 2.34 (95% CI: 1.29-4.24) in the stable AO group. This association disappeared when CRP was included in the analysis.

CONCLUSIONS

An extended state of obesity during the first stages of life is associated with iron deficiency, and this association may be mediated by CRP. Prevention and early detection of obesity in children should be a priority to avoid a double burden of malnutrition.

Chronic Fatigue Syndrome in Patients with Deteriorated Iron Metabolism

Fatigue is a common, non-specific symptom that often impairs patients’ quality of life. Even though fatigue may be the first symptom of many serious diseases, it is often underestimated due to its non-specific nature. Iron metabolism disorders are a prominent example of conditions where fatigue is a leading symptom. Whether it is an iron deficiency or overload, tiredness is one of the most common features. Despite significant progress in diagnosing and treating iron pathologies, the approach to chronic fatigue syndrome in such patients is not precisely determined. Our study aims to present the current state of knowledge on fatigue in patients with deteriorated iron metabolism.

Multiple Indicators of Undernutrition, Infection, and Inflammation in Lactating Women Are Associated with Maternal Iron Status and Infant Anthropometry in Panama: The MINDI Cohort

Maternal infections, nutrient deficiencies, and inflammation (MINDI) co-exist in lactating indigenous women in Panama, but their impact on maternal iron status and infant growth is unknown. For this secondary analysis of cross-sectional data of lactating mothers from our MINDI cohort, we investigated associations of MINDI variables with maternal anemia, elevated serum transferrin receptor (sTfR), low serum iron, hepcidin, ferritin, and infant weight-for-age (WAZ), length-for-age (LAZ), and head-circumference-for-age (HCAZ) Z-scores in 99 mother-infant dyads. A bootstrapping resampling procedure preselected covariates for inclusion in multivariable regressions models from chronic maternal infections and nutritional status [folate, vitamins A, D, retinol-binding protein (RBP), insulin-growth factor-1 (IGF-1)] and inflammation [C-reactive protein (CRP), cytokines, platelet indices] indicators. Anemia was prevalent (53.5%) but underestimated due to widespread low plasma volume (<2.2 L, 79.9%) and was associated with indicators of malnutrition [lower IGF-1, body mass index (BMI), vitamin D, and intake of green/leafy vegetables], but not inflammation. Higher CRP was associated with lower serum iron, and higher hepcidin and ferritin, whereas maternal platelets were associated with lower HCAZ (β = −0.22), WAZ (β = −0.17), and LAZ (β = −0.17). Higher LAZ was also associated with maternal serum vitamin D (β = 0.23), whereas maternal iron supplementation lowered LAZ (β = −0.22). Assessment of iron status in this MINDI cohort is complex and supplementation strategies must consider consequences for both the mother and the infant.

Individual and environmental determinants of serum ferritin levels: A structural equation model

BACKGROUND AND OBJECTIVES

Serum ferritin levels are increasingly being used to assess iron stores. Considerable variation in ferritin levels within and between individuals has been observed, but our current understanding of factors that explain this variation is far from complete. We aim to combine multiple potential determinants in an integrative model, and investigate their relative importance and potential interactions.

METHODS

We use ferritin measurements collected by Sanquin Blood Bank on both prospective (N = 59 596) and active blood donors (N = 78 318) to fit a structural equation model with three latent constructs (individual characteristics, donation history, and environmental factors). Parameters were estimated separately by sex and donor status.

RESULTS

The model explained 25% of ferritin variance in prospective donors, and 40% in active donors. Individual characteristics and donation history were the most important determinants of ferritin levels in active donors. The association between environmental factors and ferritin was smaller but still substantial; higher exposure to air pollution was associated with higher ferritin levels, and this association was considerably stronger for active blood donors than for prospective donors.

DISCUSSION

In active donors, individual characteristics explain 20% (17%) of ferritin variation, donation history explains 14% (25%) and environmental factors explain 5% (4%) for women (men). Our model presents known ferritin determinants in a broader perspective, allowing for comparison with other determinants as well as between new and active donors, or between men and women.

Iron homeostasis in heart transplant recipients randomized to ferric derisomaltose or placebo

INTRODUCTION

The randomized IronIC trial evaluated the effect of intravenous ferric derisomaltose on physical capacity in iron-deficient, maintenance heart transplant (HTx) recipients. Iron deficiency was defined as in heart failure with high cut-points for ferritin to compensate for inflammation. However, intravenous iron did not improve physical capacity except in patients with ferritin <30 μg/L. We aimed to explore determinants of iron status in the 102 IronIC participants to better define iron deficiency in the HTx population.

METHODS

We assessed key governors of iron homeostasis, such as hepcidin, soluble transferrin receptor (sTfR), and interleukin-6 (IL-6). We also measured growth factors and inflammatory markers with relevance for iron metabolism. The results were compared to those of 21 healthy controls.

RESULTS

Hepcidin did not differ between HTx recipients and controls, even though markers of inflammation were modestly elevated. However, HTx recipients with ferritin <30 μg/L or sTfR above the reference range had significantly reduced hepcidin levels suggestive of true iron deficiency. In these patients, intravenous iron improved peak oxygen uptake. Hepcidin correlated positively with ferritin and negatively with sTfR.

CONCLUSION

HTx recipients with iron deficiency as defined in heart failure do not have elevated hepcidin levels, although inflammatory markers are modestly increased. The high ferritin cut-offs used in heart failure may not be suitable to define iron deficiency in the HTx population. We suggest that hepcidin and sTfR should be measured to identify patients with true iron deficiency, who might benefit from treatment with intravenous iron.

Novel Phenotyping for Acute Heart Failure—Unsupervised Machine Learning-Based Approach

Acute heart failure (AHF) is a life-threatening, heterogeneous disease requiring urgent diagnosis and treatment. The clinical severity and medical procedures differ according to a complex interplay between the deterioration cause, underlying cardiac substrate, and comorbidities. This study aimed to analyze the natural phenotypic heterogeneity of the AHF population and evaluate the possibilities offered by clustering (unsupervised machine-learning technique) in a medical data assessment. We evaluated data from 381 AHF patients. Sixty-three clinical and biochemical features were assessed at the admission of the patients and were included in the analysis after the preprocessing. The K-medoids algorithm was implemented to create the clusters, and optimization, based on the Davies-Bouldin index, was used. The clustering was performed while blinded to the outcome. The outcome associations were evaluated using the Kaplan-Meier curves and Cox proportional-hazards regressions. The algorithm distinguished six clusters that differed significantly in 58 variables concerning i.e., etiology, clinical status, comorbidities, laboratory parameters and lifestyle factors. The clusters differed in terms of the one-year mortality (p = 0.002). Using the clustering techniques, we extracted six phenotypes from AHF patients with distinct clinical characteristics and outcomes. Our results can be valuable for future trial constructions and customized treatment.

Is Iron Deficiency Anemia still Becoming Community Health Problem in Urban Area?

Background: Iron deficiency anemia is one of the common public health problems that found in various countries, including Indonesia. The incidence of iron deficiency anemia does not only occur in rural areas but also in urban areas. Iron deficiency that occurs in adolescent girls with or without anemia has a negative impact on immune function, growth and physical and mental development. Purpose: To determine the incidence of anemia in adolescent girls in urban areas. Patients and methods: This study was an observational study with a cross sectional design. The research subjects were 52 young women aged 15-25 years living in the city of Semarang, Central Java. The subject will be taken a blood sample to check the complete blood profile and iron status, namely serum ferritin, serum iron, and serum TIBC (total iron binding capacity). Research data analysis was carried out using a computer program. Results: The prevalence of iron deficiency anemia among female adolescents in urban areas in this study was 13.4% while adolescent girls who experienced iron deficiency without anemia were 13.4%. Conclusion: Iron deficiency anemia can occur in urban areas with a prevalence > 5%.  

Acute chest syndrome and COVID‐19 in hydroxyurea naïve sickle cell disease patient in a low resource setting

Acute chest syndrome (ACS) is a severe complication of sickle cell disease (SCD) and one of the leading causes of mortality in SCD patients. The management of ACS is challenging and requires prompt intervention to halt clinical deterioration. With the outbreak of the Coronavirus Disease 2019 (COVID‐19) pandemic, which also primarily results in acute respiratory illness, the clinical picture and treatment outcome in SCD patients with ACS remain unknown. We present a case of a 30‐year‐old male who came in with features of painful vaso‐occlusive episode and haemolysis that later evolved to acute chest syndrome. Chest X‐ray showed pneumonic changes and mild bilateral pleural effusion, and nasal Reverse Transcription‐Polymerase Chain Reaction (RT‐PCR) for COVID‐19 test came out positive. He was managed supportively with simple transfusion, antibiotics, dexamethasone and oxygen support with a good clinical outcome. Presenting with non‐specific symptoms and similar respiratory symptoms and signs, the clinical picture of COVID‐19 can prove difficult to discern from that of ACS due to other causes. This report emphasizes a need for a higher index of suspicion whenever a SCD patient presents with symptoms of acute respiratory distress.

Therapeutic potential of induced iron depletion using iron chelators in Covid-19

Ferritin, which includes twenty-four light and heavy chains in varying proportions in different tissues, is primarily responsible for maintaining the body's iron metabolism. Its normal value is between 10 and 200 ngmL^-1 in men and between 30 and 300 ngmL^-1 in women. Iron is delivered to the tissue via them, and they act as immunomodulators, signaling molecules, and inflammatory markers. When ferritin level exceeds 1000 µgL^-1, the patient is categorized as having hyperferritinemia. Iron chelators such as deferiprone, deferirox, and deferoxamine are currently FDA approved to treat iron overload. The inflammation cascade and poor prognosis of COVID-19 may be attributed to high ferritin levels. Critically ill patients can benefit from deferasirox, an iron chelator administered orally at 20-40 mgkg^-1 once daily, as well as intravenous deferoxamine at 1000 mg initially followed by 500 mg every 4 to 12 h. It can be combined with monoclonal antibodies, antioxidants, corticosteroids, and lactoferrin to make iron chelation therapy effective for COVID-19 victims. In this article, we analyze the antiviral and antifibrotic activity of iron chelators, thereby promoting iron depletion therapy as a potentially innovative treatment strategy for COVID-19.

A Bioinformatics-Assisted Review on Iron Metabolism and Immune System to Identify Potential Biomarkers of Exercise Stress-Induced Immunosuppression

The immune function is closely related to iron (Fe) homeostasis and allostasis. The aim of this bioinformatics-assisted review was twofold; (i) to update the current knowledge of Fe metabolism and its relationship to the immune system, and (ii) to perform a prediction analysis of regulatory network hubs that might serve as potential biomarkers during stress-induced immunosuppression. Several literature and bioinformatics databases/repositories were utilized to review Fe metabolism and complement the molecular description of prioritized proteins. The Search Tool for the Retrieval of Interacting Genes (STRING) was used to build a protein-protein interactions network for subsequent network topology analysis. Importantly, Fe is a sensitive double-edged sword where two extremes of its nutritional status may have harmful effects on innate and adaptive immunity. We identified clearly connected important hubs that belong to two clusters: (i) presentation of peptide antigens to the immune system with the involvement of redox reactions of Fe, heme, and Fe trafficking/transport; and (ii) ubiquitination, endocytosis, and degradation processes of proteins related to Fe metabolism in immune cells (e.g., macrophages). The identified potential biomarkers were in agreement with the current experimental evidence, are included in several immunological/biomarkers databases, and/or are emerging genetic markers for different stressful conditions. Although further validation is warranted, this hybrid method (human-machine collaboration) to extract meaningful biological applications using available data in literature and bioinformatics tools should be highlighted.

CLINICAL SIGNIFICANCE AND CORRELATION ANALYSIS OF SERUM FERRITIN IN PATIENTS WITH HEPATIC ALVEOLAR ECHINOCOCCOSIS

The serum ferritin (SF) levels of patients with hepatic alveolar echinococcosis (HAE) were compared to the laboratory reference value, and the correlation between SF and associated parameters in patients with HAE was assessed. Hematological and imaging data of 245 patients with HAE were collected. Patients were classified into the LSF group (SF ≤ 204 ng/ml) or HSF group (SF > 204 ng/ml) according to the level of SF. There was no significant difference in the serum iron level between groups (P > 0.05). Significant differences in unsaturated iron-binding capacity (UIBC), liver function, blood coagulation, lipid, blood cell count, and lesion characteristics were observed (P < 0.05). Correlation analysis showed that SF was related to UIBC, γ-glutamyl transferase, total bilirubin (TBIL), direct bilirubin (DBIL), fibrinogen (FIB), neutrophil count, and maximal lesion diameter (all absolute rs ≥ 0.4). The correlation coefficient between SF and UIBC showed the highest absolute value (rs = -0.556, P < 0.001). Single-factor linear regression analysis showed that TBIL and DBIL showed the R2 values were 0.221 and 0.220, and the R2 values of UIBC, FIB, and maximal lesion diameter were 0.157, 0.174, and 0.167, respectively, and those of the remaining indicators were <0.1. Multi-factor binary logistic regression analysis showed that UIBC (P < 0.001, OR = 0.909), FIB (P = 0.020, OR = 1.662), hemoglobin (HGB) (P = 0.002, OR = 1.029), and maximal lesion diameter (P = 0.002, OR = 1.146) were significant factors influencing SF abnormalities. SF levels in some patients with HAE were higher than the laboratory reference value. Correlation and regression analysis of SF suggested that the UIBC, FIB, HGB, and maximal lesion diameter were related to SF and affected the SF level. These results may be helpful for the diagnosis and severity assessment of HAE in the future.

Iron Deficiency in Cystic Fibrosis: A Cross-Sectional Single-Centre Study in a Referral Adult Centre

Iron deficiency (ID) diagnosis in cystic fibrosis (CF) is challenging because of frequent systemic inflammation. We aimed to determine the prevalence and risk factors of ID in adult patients with CF. We conducted a single-centre prospective study in a referral centre. ID was defined by transferrin saturation ≤16% or ferritin ≤20 (women) or 30 (men) μg/L, or ≤100 μg/L in the case of systemic inflammation. Apparent exacerbation was an exclusion criterion. We included 165 patients (78 women), mean age—31.1 ± 8.9 years. ID prevalence was 44.2%. ID was significantly associated with female gender (58.9% vs. 38%), lower age (29.4 ± 8.5 vs. 32.5 ± 9.1), lower body mass index (20.5 ± 2.2 vs. 21.3 ± 2.5), and Pseudomonas aeruginosa colonization (70.8% vs. 55.1%). Diabetes mellitus, antiacid drug use and low pulmonary function were more frequent in patients with ID with no statistical significance. The use of CFTR correctors was not associated with ID. In the multivariate analysis, ID was associated with female gender (OR 2.64, CI95% 1.31−5.31), age < 30 years (OR 2.30, CI95% 1.16−4.56), and P. aeruginosa (OR 2.09, CI95% 1.04−4.19).

Iron Deficiency in Patients with Inflammatory Bowel Diseases: A Prospective Multicenter Cross-Sectional Study

BACKGROUND

Iron deficiency (ID) is a frequent condition in patients with inflammatory bowel disease (IBD).

AIM

Our aim was to investigate the prevalence of ID in patients with IBD.

METHODS

This was a prospective multicenter cross-sectional study conducted in 21 gastroenterology departments in France between January and March 2020. All adult patients with confirmed IBD who were admitted to the hospital were eligible for inclusion. ID was defined as ferritinemia ≤ 100 μg/L in patients with signs of inflammation (C-reactive protein (CRP) ≥ 5 mg/L) or ferritinemia < 30 μg/L in the absence of inflammation.

RESULTS

In total, 1036 IBD (685 Crohn's disease and 351 ulcerative colitis) patients (52.1% women) with a mean age of 41.8 ± 15.5 years were recruited. Approximately half of the patients (504, 51.1%) were in disease remission at the time of enrollment. Systematic monitoring of iron status was performed in 12/21 (57%) participating centers, including measurements of ferritin (12/12, 100%), hemoglobin (11/12, 92%), transferrin saturation (TSAT) (6/12, 50.0%), and serum iron (5/12, 42%). About one-fifth of the patients had been treated with intravenous iron (218, 21.0%), whereas only a small percentage received oral iron (36, 3.5%). ID occurred in 97 patients (23.7% CI 95% 19.8-28.1). Patients with moderate/severe IBD activity (OR: 3.66; CI 95% 24.4-61.2; p = 0.007) or concomitant anemia (OR: 3.66; CI 95% 1.97-6.78; p < 0.001) had an increased likelihood of having ID.

CONCLUSION

Patients with moderate/severe IBD activity or concomitant anemia are at increased risk of ID. Early detection and management of ID in patients with IBD is recommended.

Iron Deficiency and Incident Infections among Community-Dwelling Adults Age 70 Years and Older: Results from the DO-HEALTH Study

OBJECTIVES

To assess if baseline iron deficiency, with or without anemia, is associated with incident infections over 3 years among community-dwelling older adults.

DESIGN

Prospective secondary analysis of DO-HEALTH, a 3-year randomized, double-blind controlled trial.

SETTING AND PARTICIPANTS

2157 community-dwelling adults age 70+ from 5 European countries with good cognitive function and mobility and no major health events in the 5 years prior to enrollment Measurements: Incident infections, their severity and type were recorded every 3 months throughout the 3-year follow-up. Iron deficiency was defined as soluble transferrin receptor (sTfR) levels > 28.1 nmol/l and anemia as hemoglobin levels < 120 g/l for women and 130 g/l for men. We applied negative binomial mixed effects regression models with random effects for countries, and controlling for treatment allocation, age, sex, body mass index, polypharmacy, number of comorbidities, smoking status, living situation, alcohol intake, frailty status, and physical activity levels. A pre-defined stratified analysis was performed to explore if the associations between iron deficiency and infections were consistent by baseline anemia status.

RESULTS

In total, 2141 participants were included in the analyses (mean age 74.9 years, 61.5% of women, 26.8% with iron deficiency). Across all participants, baseline iron deficiency was not associated with incident overall infections, but was associated with a 63% greater rate of incident severe infections requiring hospitalization (incidence rate ratio [IRR] 1.63, 95% Confidence Interval [CI] 1.11-2.41, p=0.01). This association was more pronounced among the 2000 participants who did not have anemia at baseline (IRR=1.80, 95% CI 1.20-2.69, p=0.005).

CONCLUSION

Based on this prospective study among generally healthy European community-dwelling older adults, iron deficiency was not associated with the incidence rate of overall infections but may increase the incidence of severe infections. Intervention studies are needed to prove the causality of this observation.

Iron Deficiency in Heart Failure: Mechanisms and Pathophysiology

Iron is an essential micronutrient for a myriad of physiological processes in the body beyond erythropoiesis. Iron deficiency (ID) is a common comorbidity in patients with heart failure (HF), with a prevalence reaching up to 59% even in non-anaemic patients. ID impairs exercise capacity, reduces the quality of life, increases hospitalisation rate and mortality risk regardless of anaemia. Intravenously correcting ID has emerged as a promising treatment in HF as it has been shown to alleviate symptoms, improve quality of life and exercise capacity and reduce hospitalisations. However, the pathophysiology of ID in HF remains poorly characterised. Recognition of ID in HF triggered more research with the aim to explain how correcting ID improves HF status as well as the underlying causes of ID in the first place. In the past few years, significant progress has been made in understanding iron homeostasis by characterising the role of the iron-regulating hormone hepcidin, the effects of ID on skeletal and cardiac myocytes, kidneys and the immune system. In this review, we summarise the current knowledge and recent advances in the pathophysiology of ID in heart failure, the deleterious systemic and cellular consequences of ID.