Disorders of Iron Metabolism: New Diagnostic and Treatment Approaches to Iron Deficiency

ESPEN practical short micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. The importance of MNs in common pathologies is recognized by recent research, with deficiencies significantly impacting the outcome.

OBJECTIVE

This short version of the guideline aims to provide practical recommendations for clinical practice.

METHODS

An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL for the initial guideline. The search focused on physiological data, historical evidence (for papers published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations.

RESULTS

The limited number of interventional trials prevented meta-analysis and led to a low level of evidence for most recommendations. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90 % of votes. Altogether the guideline proposes 3 general recommendations and specific recommendations for the 26 MNs. Monitoring and management strategies are proposed.

CONCLUSION

This short version of the MN guideline should facilitate handling of the MNs in at-risk diseases, whilst offering practical advice on MN provision and monitoring during nutritional support.

Perspectives on Iron Deficiency as a Cause of Human Disease in Global Public Health

Iron (Fe) is a necessary trace element in numerous pathways of human metabolism. Therefore, Fe deficiency is capable of causing multiple health problems. Apart from the well-known microcytic anemia, lack of Fe can cause severe psychomotor disorders in children, pregnant women, and adults in general. Iron deficiency is a global health issue, mainly caused by dietary deficiency but aggravated by inflammatory conditions. The challenges related to this deficiency need to be addressed on national and international levels. This review aims to summarize briefly the disease burden caused by Fe deficiency in the context of global public health and aspires to offer some hands-on guidelines.

Management of nutritional iron deficiency anemia for young children in the emergency department

BACKGROUND

Guidelines for young children with nutritional iron deficiency anemia (IDA) presenting to the emergency department (ED) are lacking, leading to variability in care. We aimed to standardize management of these patients through the development and implementation of an evidence-based algorithm using quality improvement methodology.

PROCEDURE

Baseline data of the target population (n = 42; 60% male; median age 22.5 months, median hemoglobin 5.3 g/dl) identified variability across four key measures of clinical management: laboratory evaluation, therapy choice, therapy administration, and patient disposition. Literature review and consensus from pediatric hematology providers informed a draft algorithm that was refined in an iterative multidisciplinary process. From September 2020 to June 2021, we aimed to increase IDA management per the algorithm by ≥20% relative to baseline for the four key outcome measures using sequential Plan-Do-Study-Act (PDSA) cycles. Process measures focusing on provider communication/documentation and balancing measures involving efficiency and therapy-related adverse events were assessed concurrently.

RESULTS

Thirty-five patients were evaluated among four PDSA cycles and shared similar characteristics as the baseline population. Improvements of ≥20% above baseline adherence levels or 100% adherence were achieved for all outcome measure across four PDSA cycles. Adherence to recommended laboratory evaluation improved from 43 (baseline) to 71%, therapy choice from 78 to 100%, therapy administration from 50 to 83%, and disposition from 85 to 100%. ED length of stay remained stable.

CONCLUSIONS

Implementation of a standardized algorithm for young children with nutritional IDA in the ED increased adherence to evidence-based patient care.

The Role of Chosen Essential Elements (Zn, Cu, Se, Fe, Mn) in Food for Special Medical Purposes (FSMPs) Dedicated to Oncology Patients-Critical Review: State-of-the-Art

The scoping review aimed to characterise the role of selected essential elements (Zn, Cu, Se, Fe, Mn) in food for special medical purposes (FSMPs) aimed at oncology patients. The scope review was conducted using Scopus, Google Scholar, and Web of Science to find published references on this subject. Data from the reviewed literature were related to the physiological functions of the element in the body, and the effects of deficiencies and excesses, referring to the latest ESPEN and EFSA guidelines, among others. Important dietary indices/parameters based on the literature review are provided for each element. On the basis of the literature, data on the level of elements in patients with cancer were collected. The content of these elements in 100 mL of FSMPs was read from the manufacturers' declarations. The literature has been provided on the importance of each element in cancer. Our findings show that the essential elements (Zn, Cu, Se, Fe, and Mn) of FSMPs for cancer patients are not adequately treated. We suggest solutions to ensure the safe use of FSMPs in oncology patients.

Evaluation of genotoxicity of SUNACTIVE Zn-P240 in vitro and in vivo

We evaluated the potential genotoxic effects of the nutrient supplement SUNACTIVE Zn-P240 in vitro and in vivo. Genotoxicity tests were performed at the Korea Testing and Research Institute, a GLP certification institution. A bacterial reverse mutation test was performed using the pre-incubation method, while the in vitro chromosome aberration test was performed using a cultured Chinese hamster lung cell line in the presence or absence of metabolic activation. The in vivo micronucleus test was performed using ICR mice. The bacterial reverse mutation test revealed that SUNACTIVE Zn-P240 did not induce genetic mutations at the tested doses in Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and Escherichia coli (WP2uvrA) tester strains. Meanwhile, the results of the in vitro chromosomal aberration and in vivo micronucleus tests revealed that SUNACTIVE Zn-P240 did not induce chromosomal aberrations. These results suggest that SUNACTIVE Zn-P240 did not exhibit mutagenic or clastogenic properties in vitro and in vivo.

Cognitive control inhibition networks in adulthood are impaired by early iron deficiency in infancy

Iron deficiency, a common form of micronutrient deficiency, primarily affects children and women. The principal cause of iron deficiency is undernutrition in low-income countries and malnutrition in middle to upper income regions. Iron is a key element for myelin production, neuronal metabolism, and dopamine functions. Iron deficiency in early life can alter brain development and exert long-lasting effects. Control inhibition is an executive function that involves several brain regions, including the prefrontal cortex and caudate and sub-thalamic nuclei. Dopamine is the prevalent neurotransmitter underlying cognitive inhibition. We followed cohort study participants who had iron deficiency anemia in infancy as well non-anemic controls. At 22 years of age, the participants were subjected to functional magnetic resonance imaging (fMRI) to evaluate the correlation between functional connectivity and performance on an inhibitory cognitive task (Go/No-Go). We hypothesized that former iron deficient anemic (FIDA) participants demonstrate less strength in functional connectivity compared with controls (C). There were not significant group differences in the behavioral results in terms of accuracy and response time. A continuous covariate interaction analysis of functional connectivity and the Go/No-Go scores demonstrated significant differences between the FIDA and C groups. The FIDA participants demonstrated less strength in connectivity in brain regions related to control inhibition, including the medial temporal lobe, impairment in the integration of the default mode network (indicating decreased attention and alertness), and an increase in connectivity in posterior brain areas, all of which suggest slower circuitry maturation. The results support the hypothesis that FIDA young adults show differences in the connectivity of networks related to executive functions. These differences could increase their vulnerability to develop cognitive dysfunctions or mental disorders in adulthood.

ESPEN micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. Recent research has shown the importance of MNs in common pathologies, with significant deficiencies impacting the outcome.

OBJECTIVE

This guideline aims to provide information for daily clinical nutrition practice regarding assessment of MN status, monitoring, and prescription. It proposes a consensus terminology, since many words are used imprecisely, resulting in confusion. This is particularly true for the words "deficiency", "repletion", "complement", and "supplement".

METHODS

The expert group attempted to apply the 2015 standard operating procedures (SOP) for ESPEN which focuses on disease. However, this approach could not be applied due to the multiple diseases requiring clinical nutrition resulting in one text for each MN, rather than for diseases. An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL. The search focused on physiological data, historical evidence (published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations.

RESULTS

There was a limited number of interventional trials, preventing meta-analysis and leading to a low level of evidence. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90% of votes. Altogether the guideline proposes sets of recommendations for 26 MNs, resulting in 170 single recommendations. Critical MNs were identified with deficiencies being present in numerous acute and chronic diseases. Monitoring and management strategies are proposed.

CONCLUSION

This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.

A novel [1,2,4]triazolo[1,5-a]pyrimidine derivative as a fluorescence probe for specific detection of Fe3+ ions and application in cell imaging

The detection of metal ions is of particular importance for monitoring environmental pollution and life metabolic activities. However, it is still a challenge to achieve Fe³⁺ detection with specific sensitivity and rapid response, especially in the presence of chelating agents for Fe³⁺ ions. Herein, a novel fluorescence probe for Fe³⁺, i.e., amide derivative of [1,2,4]triazolo[1,5-a] pyrimidine (TP, Id), was synthesized, featuring specific Fe³⁺ selectivity, rapid quenching (5 s), low limit of detection (0.82 μM), good permeability and low cytotoxicity. More importantly, Id can be used to identify and detect Fe³⁺ in the presence of existing strong chelating agents (e.g., EDTA) for Fe³⁺ ions. The results show that the as-synthesized fluorescence probe is particularly suitable as a bioimaging reagent to monitor intracellular Fe³⁺ in living HeLa cells. Furthermore, we proposed the binding mode for Id with Fe³⁺ ions and the light-emitting mechanism through high-resolution mass spectra and density function theory calculations, respectively. An Id-based test paper can be used to rapidly identify Fe³⁺. These results are expected to improve the development of new sensitive and specific fluorescent sensors for Fe³⁺.

Impact of in-hospital intravenous iron supplementation on red blood cell transfusions: experience from an Internal Medicine Unit

BACKGROUND

Pharmacological treatment of iron deficiency anaemia can reduce red blood cell (RBC) transfusions. Intravenous iron provides a more effective and quicker correction of iron deficiency anaemia than oral iron, and third-generation high-dose intravenous iron formulations allow the complete correction of iron deficiency with just one or two drug infusions, thus facilitating iron supplementation therapy and reducing transfusion requirement.

MATERIAL AND METHODS

In an observational, retrospective study we compared RBC transfusion requirement during hospitalisation and within 3 months of hospital discharge in 88 patients with iron deficiency anaemia treated with high-dose ferric carboxymaltose and in 85 patients treated with ferric gluconate while hospitalised in the Internal Medicine unit of our Institution.

RESULTS

Ferric carboxymaltose reduced the number of RBC units given to each transfused patient during hospitalisation (1.81±0.84 vs 2.39±1.49, p=0.011). At hospital discharge, fewer ferric carboxymaltose patients were prescribed home therapy with iron. No differences between treatment groups were observed in the proportion of patients or the number of RBC units transfused within 3 months of discharge. At one month from discharge, however, only 2 ferric carboxymaltose patients had been transfused compared with 7 ferric gluconate patients (p=0.078). Patients transfused post-discharge were more likely to have an underlying malignancy and/or higher serum creatinine concentrations.

DISCUSSION

Treatment with ferric carboxymaltose reduced the number of RBC units per transfused patient. Larger studies are required to define risk factors associated with post-discharge transfusion requirement and to establish if home therapy with iron will reduce subsequent transfusions in patients treated with ferric carboxymaltose.

Decreased Iron Intake Parallels Rising Iron Deficiency Anemia and Related Mortality Rates in the US Population

BACKGROUND

Prevalence of iron deficiency anemia and its related mortality rate are on the rise in the United States and causes are unclear.

OBJECTIVES

The aim was to examine trends and causes of Fe deficiency anemia prevalence and Fe deficiency-related mortality rates in the total US population.

METHODS

Changes in daily dietary Fe intake, serum iron concentration, hemoglobin, red cell distribution width (RDW), and mean corpuscular volume (MCV) obtained from the laboratory files of NHANES, Fe deficiency anemia-related mortality rates from the CDC, and iron concentrations of US food products from the USDA between 1999 and 2018 were analyzed.

RESULTS

Of food items with revised concentrations in USDA Nutrient Database for Standard Reference [SR28 (2015)], 62.4% had lower Fe concentrations than in SR11 (1999). There was a 15.3% reduction in beef (relatively higher in heme iron) and a 21.5% increase in chicken meat consumption in the American diet between 1999 and 2018. Dietary iron intake decreased by ∼6.6% and ∼9.5% for male and female adults, respectively. Increases of prevalence of estimated anemia in the United States ranged from 10.5% to 106% depending on age and sex. Age-adjusted mortality rates with iron deficiency anemia as the underlying cause of death increased from ∼0.04 to ∼0.08 deaths per 100,000 people, whereas all other anemias as the underlying causes of death decreased by ≥25%. Mean RDW and serum folate concentrations increased, whereas hemoglobin, serum iron concentrations, and MCV, parameters traditionally associated with Fe deficiency anemia, decreased during this period.

CONCLUSIONS

Increased iron deficiency anemia and related mortality rates in the US population between 1999 and 2018 were likely related to the decline in dietary iron intake resulting from an Fe concentration decline in US food products and a shift in dietary patterns.

The Top 100 Cited Papers in the Field of Iron Deficiency in Humans: A Bibliometric Study

Worldwide, iron deficiency is a common form of micronutrient deficiency with a high individual and societal cost. There are considerable knowledge and practice gaps in the diagnosis and treatment of iron deficiency. Bibliometric analysis examines the published body of knowledge of a subject in an objective fashion. The Web of Science Core Collection was searched to retrieve the 100 most cited papers on the topic of iron deficiency, and the key metrics of each paper were extracted. A keyword study was performed using VOSviewer 1.6.10 software, which provided a visual mapping of the network of keyword cooccurrences. The papers were published between 1964 and 2017 and were cited an average of 636 times. They were contributed by authors from 119 different countries/regions, with the largest contributing country being the United States. 29 institutions contributed at least 6 publications each, and 4 researchers authored or coauthored at least 5 papers. Keyword analysis suggests that the most cited topics could be grouped into 4 categories: (1) epidemiologic research of the global burden of iron deficiency, (2) clinical aspects of iron deficiency anemia, (3) iron metabolism, and (4) the impact of iron deficiency on children. Identification of the most impactful studies in the field of iron deficiency may be helpful to practitioners interested in improving their knowledge base. Compared to bibliometric studies performed on other topics, the medical literature of iron deficiency is mature, as evidenced by the high citation rate of the top 100 papers. Despite the high worldwide prevalence of iron deficiency, the top cited papers are dominated by a relatively small number of countries and institutions. Interestingly, however, the most cited authors in this study do not overlap with the most cited institutions.

UVA-Triggered Drug Release and Photo-Protection of Skin

Light has attracted special attention as a stimulus for triggered drug delivery systems (DDS) due to its intrinsic features of being spatially and temporally tunable. Ultraviolet A (UVA) radiation has recently been used as a source of external light stimuli to control the release of drugs using a "switch on- switch off" procedure. This review discusses the promising potential of UVA radiation as the light source of choice for photo-controlled drug release from a range of photo-responsive and photolabile nanostructures via photo-isomerization, photo-cleavage, photo-crosslinking, and photo-induced rearrangement. In addition to its clinical use, we will also provide here an overview of the recent UVA-responsive drug release approaches that are developed for phototherapy and skin photoprotection.

Iron Deficiency Anemia in Children Residing in High and Low-Income Countries: Risk Factors, Prevention, Diagnosis and Therapy

Iron deficiency and iron-deficiency anemia (IDA) affects approximately two billion people worldwide, and most of them reside in low- and middle-income countries. In these nations, additional causes of anemia include parasitic infections like malaria, other nutritional deficiencies, chronic diseases, hemoglobinopathies, and lead poisoning. Maternal anemia in resource-poor nations is associated with low birth weight, increased perinatal mortality, and decreased work productivity. Maintaining a normal iron balance in these settings is challenging, as iron-rich foods with good bioavailability are of animal origin and either expensive and/or available in short supply. Apart from infrequent consumption of meat, inadequate vitamin C intake, and diets rich in inhibitors of iron absorption are additional important risk factors for IDA in low-income countries. In-home iron fortification of complementary foods with micronutrient powders has been shown to effectively reduce the risk of iron deficiency and IDA in infants and young children in developing countries but is associated with unfavorable changes in gut flora and induction of intestinal inflammation that may lead to diarrhea and hospitalization. In developed countries, iron deficiency is the only frequent micronutrient deficiency. In the industrialized world, IDA is more common in infants beyond the sixth month of life, in adolescent females with heavy menstrual bleeding, in women of childbearing age and older people. Other special at-risk populations for IDA in developed countries are regular blood donors, endurance athletes, and vegetarians. Several medicinal ferrous or ferric oral iron products exist, and their use is not associated with harmful effects on the overall incidence of infectious illnesses in sideropenic and/or anemic subjects. However, further research is needed to clarify the risks and benefits of supplemental iron for children exposed to parasitic infections in low-income countries, and for children genetically predisposed to iron overload.

Barriers to and Facilitators of Iron Therapy in Children with Iron Deficiency Anemia

OBJECTIVE

To characterize barriers to and facilitators of successful iron therapy in young children with iron deficiency anemia (IDA) from an in-depth parental perspective.

STUDY DESIGN

Prospective, mixed methods study of children age 9 months to 4 years with a diagnosis of nutritional IDA by clinical history and laboratory criteria and their parents. Clinical data were obtained from the electronic health record. Semistructured interviews focused on knowledge of IDA, clinical effects, experience with iron therapies, and motivation were conducted with the parent who identified as the child's primary caregiver.

RESULTS

Twenty patient-parent dyads completed the study; 80% (n = 16) identified as Hispanic/Latino (white). Patients' median age was 23 months (50% male); median initial hemoglobin concentration was 8.2 g/dL and duration of oral iron therapy was 3 months. Parents' median age was 29 years (85% female); 8 interviews (40%) were conducted in Spanish. Barriers included difficulty in administering oral iron owing to side effects and poor taste. Facilitators included provision of specific instructions; support from healthcare providers and additional caregivers at home; motivation to benefit child's health, which was strengthened by strong emotional reactions (ie, stress, anxiety) to therapy and follow-up; and an appreciation of child's improvement with successful completion of therapy.

CONCLUSIONS

Our findings support the need for interventions designed to promote oral iron adherence in children with IDA. Rather than focusing on knowledge content related to IDA, interventions should aim to increase parental motivation by emphasizing the health benefits of adhering to iron therapy and avoiding more invasive interventions.

H2 O2 induces oxidative stress damage through the BMP-6/SMAD/hepcidin axis

Age-related macular degeneration (AMD) is one of the leading causes of blindness in elderly individuals worldwide. Oxidative stress injury to retinal pigment epithelial (RPE) cells plays a major role in the pathogenesis of AMD. The purpose of this study was to observe the correlation between Hepcidin and neovascular age-related macular degeneration (nAMD) and to further observe whether oxidative stress can inhibit Hepcidin expression through relevant signaling pathways to produce oxidative damage. We compared the concentrations of Hepcidin in the aqueous humor of nAMD patients and a control group and found that the concentration of Hepcidin was lower in nAMD patients. Through PCR and western blotting, we observed that H₂ O₂ can significantly inhibit the expression of Bone morphogenetic protein-6 (BMP-6) and Hepcidin and increase the intracellular iron concentration in RPE cells, while BMP-6 can reverse the inhibition of Hepcidin and the increase in iron concentration caused by H₂ O₂ . In addition, alterations in smad1 and smad5 expression were examined, and pretreatment with BMP-6 was demonstrated to reduce H₂ O₂ -induced activation of smad1 and smad5. The effects of BMP-6 were attenuated by smad1 and smad5 siRNA, further verifying that oxidative stress inhibits the expression of Hepcidin by inhibiting activation of the BMP/SMAD signaling pathway. To some extent, this study verified that oxidative stress injury plays a role in nAMD by affecting the level of hepcidin, which lays a foundation for exploring new methods to treat nAMD.

A novel fluorescent probe based on isocoumarin for Hg2+ and Fe3+ ions and its application in live-cell imaging

Synthesis of the 2-amino-4-phenyl-6- (isocoumarin-3-yl) -3-cyanopyridine (APICP) containing both isocoumarin and pyridine ring in its structure was carried out, and this compound was characterized by ATR-FTIR, ¹H NMR, and ¹³C NMR spectral techniques. A fluorescence sensor determining Hg²⁺ and Fe³⁺ ions in DMSO/HEPES buffer solution (9/1 v/v, 5 μM, pH 7.0) was developed using the synthesized compound, and the detection limits of the sensor with exquisite selectivity were calculated as 8.12 nM and 5.51 nM for Hg²⁺ and Fe³⁺ ions, respectively. Jobs plot method was used to determine the stoichiometry of APICP-Hg²⁺/Fe³⁺ complexes as 2:1 and FT-IR and ESI-MS methods confirmed the results. Besides, cell growth inhibitory potentials of the sensor over HepG2 cells and in vivo fluorescent cell imaging experiments were conducted. Findings revealed the relatively low cytotoxic effects of the synthesized sensor (IC₅₀: 0.541 ± 0.039 mM), and it could be utilized as an intracellular imaging agent for the determination of Fe³⁺ and Hg²⁺ ions in biological systems.