THE DIAGNOSIS OF IRON DEFICIENCY ANEMIA

Serum iron and ferritin levels in female patients with gingivitis and periodontitis

AIM

The aim of the study was to compare serum ferritin and iron levels and periodontal status in pre- and post-menopausal female patients.

MATERIALS AND METHODS

A total of 108 systemically healthy patients were included in the study, 63 patients in the pre-menopause group and 45 patients in the post-menopause group. The periodontal diagnosis was made according to the new periodontal disease classification of the American Academy of Periodontology and the European Federation of Periodontology Serum Iron (μg/dL) and Serum Ferritin (ng/mL) values were analysed in patients divided into groups according to menopausal status and periodontal status.

RESULT

The mean ferritin in pre-menopausal women (34.96 ± 27.87 ng/mL) was lower than the mean ferritin in post-menopausal women (64.24 ± 36.05 ng/mL), and this difference was found to be statistically significant (P<0.001). There was no statistically significant difference between the averages of iron and ferritin according to periodontal diagnosis in pre-menopausal women (P = 0.200 and P = 0.858). A statistically significant difference was found between serum ferritin averages according to periodontal diagnosis in post-menopausal women (P < 0.001). Serum ferritin at % Interdental bone loss = 0 in Post-M was 33.93 ± 8.65 ng/mL; 47.51 ± 16.17 ng/mL in Stage 1 periodontitis; 72.66 ± 18.12 ng/mL in Stage 2 periodontitis; It was found to be 87.4 ± 47.1 ng/mL in Stage 3-4 periodontitis.

CONCLUSION

Serum ferritin values might vary depending on the presence or severity of periodontitis in post-menopausal women.

Dietary fatty acids and flight-training influence the expression of the eicosanoid hormone prostacyclin in songbirds

Diet shifts can alter tissue fatty acid composition in birds, which is subsequently related to metabolic patterns. Eicosanoids, short-lived fatty acid-derived hormones, have been proposed to mediate these relationships but neither baseline concentrations nor the responses to diet and exercise have been measured in songbirds. We quantified a stable derivative of the vasodilatory eicosanoid prostacyclin in the plasma of male European Starlings (Sturnus vulgaris, N = 25) fed semisynthetic diets with either high (PUFA) or low (MUFA) amounts of n6 fatty acid precursors to prostacyclin. Plasma samples were taken from each bird before, immediately after, and two days following a 15-day flight-training regimen that a subset of birds (N = 17) underwent. We found elevated prostacyclin levels in flight-trained birds fed the PUFA diet compared to those fed the MUFA diet and a positive relationship between prostacyclin and body condition, indexed by fat score. Prostacyclin concentrations also significantly decreased at the final time point. These results are consistent with the proposed influences of precursor availability (i.e., dietary fatty acids) and regulatory feedback associated with exercise (i.e., fuel supply and inflammation), and suggest that prostacyclin may be an important mediator of dietary influence on songbird physiology.

Effect of Needling at Selected Acupuncture Points (GB39, BL17, LR13) on Hemoglobin Levels in Anemia: a Randomized Placebo Controlled Study

Iron deficiency anemia (IDA) is an important public health issue in India. This study was performed to determine the impact of acupuncture at the GB39, BL17, and LR13 points on hemoglobin levels, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and red cell distribution width (RDW) in people with IDA. One hundred women with IDA were randomly allocated to the acupuncture group (AG) or placebo control group (PCG). For 30 minutes per day, daily for 2 weeks, the AG received acupuncture at GB39, BL17, and LR13, while the PCG received needling at non-acupuncture points. Outcomes were assessed before and after the intervention. We found a significant increase (p < 0.001) in hemoglobin level (AG 10.39-11.38 g/dl, effect size 0.785; PCG 10.58-10.40 g/dl, effect size 0.191), MCH (AG 25.69-27.50 fl, effect size 0.418; PCG 27.43-27.23 fl, effect size 0.058), and RDW (AG 15.12-16.41 fl, effect size 0.626; PCG 14.91-14.94 fl, effect size 0.017) in the AG compared to the PCG. Results suggest that needling at the GB39, BL17, and LR13 acupuncture points is more effective in treating people with IDA than needling at non-acupuncture points.

Childhood Anemia and Risk for Acute Respiratory Infection, Gastroenteritis, and Urinary Tract Infection: A Systematic Review

Objective Children younger than 5 years, particularly children below 2 years, are among the most vulnerable groups for developing anemia and infections. This review is intended to assess the association between anemia and childhood acute respiratory infections (ARTIs), acute gastroenteritis (AGE), and urinary tract infections (UTIs).

Methods PubMed was searched for published articles from January 2000 to August 2021 in English using the following terms: anemia and acute respiratory tract infections in children; anemia and UTIs in children; anemia and AGE in children. The data extraction were conducted by two investigators using the same methodology. Using descriptive statistics, the data from different sources were synthesized, including medians and ranges.

Results A total of 426 articles and 27 original articles and 1 systematic review were included. Iron deficiency anemia is common among children between 6 months and 3 years of age. This age group can be considered a highly susceptible age for contraction of ARTI and AGE. Children below 5 years suffer five to six episodes of acute ARTI per year on average, and pneumonia accounts for the highest number of deaths, which is around 1.1 million each year. When considered, the odds ratio of anemia to increase the susceptibility of contracting lower ARTI would range from 2 to 5.7. Also, anemic children were 10 times more susceptible to developing acute recurrent ARTI and 4 times more susceptible to contracting pneumonia. Respiratory syncytial virus is the commonest viral etiology. Anemia would increase the risk of diarrhea by 2.9-fold in toddlers, while mild anemia, moderate anemia, and severe anemia would increase the susceptibility to contract AGE by 1.6, 1.6, and 8.9 times, respectively. Rotavirus is the commonest etiology. Some studies observed a protective effect of mild to moderate iron-deficient anemia from respiratory infections.

Conclusion Infectious disease imposes a heavy burden on the health sector in a country. The highest susceptibility for infections and the development of anemia would be due to inadequate nutrition supplementation to meet the demand during rapid body growth. Therefore, based on the available evidence, one can take the necessary steps to reduce the infectious disease burden by correcting the anemia status in children.

Effects of Dietary Supplementation with Iron in Breeding Pigeons on the Blood Iron Status, Tissue Iron Content, and Full Expression of Iron-Containing Enzymes of Squabs

This study was aimed at investigating the effects of diet iron levels on the blood iron status, tissue iron content, mRNA levels, and the activity of iron-containing enzymes in different tissues of squabs. A total of 120 pairs of healthy Silver Feather King parental pigeons with similar average body weight and egg production were randomly divided into 5 groups with 8 replicates and 3 pairs of pigeons per replicate. The five groups of breeding pigeons were fed an iron-unsupplemented basal diet and basal diet supplemented with 75, 150, 300, and 600 mg iron/kg, respectively. The diets were fed in the form of granular feed based on corn, soybean meal, wheat, and sorghum. A broken line model was used for regression analysis. The results showed that plasma iron (PI), serum ferritin, iron contents in crop milk and liver, liver catalase (CAT) activity, and heart succinate dehydrogenase (SDH) activity were affected by iron levels (P < 0.05). And PI, serum ferritin, iron content in crop milk, and heart SDH activity increased quadratically (P < 0.05), but the iron content and CAT activity in the liver decreased quadratically (P < 0.005) as dietary iron level increased. According to the broken-line model of serum ferritin fitting (P < 0.002), the optimal dietary iron level of breeding pigeons was estimated to be 193 mg/kg. In conclusion, serum ferritin is a sensitive index to evaluate the iron requirement of the breeding pigeon with two squabs, and the recommended iron supplemental level is 193 mg/kg.

Influences of Vitamin D and Iron Status on Skeletal Muscle Health: A Narrative Review

There is conflicting evidence of the roles vitamin D and iron have in isolation and combined in relation to muscle health. The purpose of this narrative review was to examine the current literature on the roles that vitamin D and iron have on skeletal muscle mass, strength, and function and how these nutrients are associated with skeletal muscle health in specific populations. Secondary purposes include exploring if low vitamin D and iron status are interrelated with skeletal muscle health and chronic inflammation and reviewing the influence of animal-source foods rich in these nutrients on health and performance. PubMed, Scopus, SPORT Discus, EMBAE, MEDLINE, and Google Scholar databases were searched to determine eligible studies. There was a positive effect of vitamin D on muscle mass, particularly in older adults. There was a positive effect of iron on aerobic and anaerobic performance. Studies reported mixed results for both vitamin D and iron on muscle strength and function. While vitamin D and iron deficiency commonly occur in combination, few studies examined effects on skeletal muscle health and inflammation. Isolated nutrients such as iron and vitamin D may have positive outcomes; however, nutrients within food sources may be most effective in improving skeletal muscle health.

The Purified Siderophore from Streptomyces tricolor HM10 Accelerates Recovery from Iron-Deficiency-Induced Anemia in Rats

Iron-deficiency-induced anemia is associated with poor neurological development, including decreased learning ability, altered motor functions, and numerous pathologies. Siderophores are iron chelators with low molecular weight secreted by microorganisms. The proposed catechol-type pathway was identified based on whole-genome sequences and bioinformatics tools. The intended pathway consists of five genes involved in the biosynthesis process. Therefore, the isolated catechol-type siderophore (Sid) from Streptomyces tricolor HM10 was evaluated through an anemia-induced rat model to study its potential to accelerate recovery from anemia. Rats were subjected to an iron-deficient diet (IDD) for 42 days. Anemic rats (ARs) were then divided into six groups, and normal rats (NRs) fed a standard diet (SD) were used as a positive control group. For the recovery experiment, ARs were treated as a group I; fed an IDD (AR), group II; fed an SD (AR + SD), group III, and IV, fed an SD with an intraperitoneal injection of 1 μg Sid Kg^-1 (AR + SD + Sid1) and 5 μg Sid Kg^-1 (AR + SD + Sid5) twice per week. Group V and VI were fed an iron-enriched diet (IED) with an intraperitoneal injection of 1 μg Sid Kg^-1 (AR + IED + Sid1) and 5 μg Sid Kg^-1 (AR + IED + Sid5) twice per week, respectively. Weight gain, food intake, food efficiency ratio, organ weight, liver iron concentration (LIC) and plasma (PIC), and hematological parameters were investigated. The results showed that ~50-60 mg Sid L^-1 medium could be producible, providing ~25-30 mg L^-1 purified Sid under optimal conditions. Remarkably, the AR group fed an SD with 5 μg Sid Kg^-1 showed the highest weight gain. The highest feed efficiency was observed in the AR + SD + Sid5 group, which did not significantly differ from the SD group. Liver, kidneys, and spleen weight indicated that diet and Sid concentration were related to weight recovery in a dose-dependent manner. Liver iron concentration (LIC) in the AR + IED + Sid1 and AR + IED + Sid5 groups was considerably higher than in the AR + SD + Sid1 AR + SD + Sid5 groups or the AR + SD group compared to the AR group. All hematological parameters in the treated groups were significantly closely attenuated to SD groups after 28 days, confirming the efficiency of the anemia recovery treatments. Significant increases were obtained in the AR + SD + Sid5 and AR + IED + Sid5 groups on day 14 and day 28 compared to the values for the AR + SD + Sid1 and AR + IED + Sid1 groups. The transferrin saturation % (TSAT) and ferritin concentration (FC) were significantly increased with time progression in the treated groups associatively with PIC. In comparison, the highest significant increases were noticed in ARs fed IEDs with 5 μg Kg^-1 Sid on days 14 and 28. In conclusion, this study indicated that Sid derived from S. tricolor HM10 could be a practical and feasible iron-nutritive fortifier when treating iron-deficiency-induced anemia (IDA). Further investigation focusing on its mechanism and kinetics is needed.

Influence of iron manipulation on hypoxic pulmonary vasoconstriction and pulmonary reactivity during ascent and acclimatization to 5050 m

KEY POINTS

Iron acts as a cofactor in the stabilization of the hypoxic-inducible factor family, and plays an influential role in the modulation of hypoxic pulmonary vasoconstriction. It is uncertain whether iron regulation is altered in lowlanders during either (1) ascent to high altitude, or (2) following partial acclimatization, when compared to high-altitude adapted Sherpa. During ascent to 5050 m, the rise in pulmonary artery systolic pressure (PASP) was blunted in Sherpa, compared to lowlanders; however, upon arrival to 5050 m, PASP levels were comparable in both groups, but the reduction in iron bioavailability was more prevalent in lowlanders compared to Sherpa. Following partial acclimatization to 5050 m, there were differential influences of iron status manipulation (via iron infusion or chelation) at rest and during exercise between lowlanders and Sherpa on the pulmonary vasculature.

ABSTRACT

To examine the adaptational role of iron bioavailability on the pulmonary vascular responses to acute and chronic hypobaric hypoxia, the haematological and cardiopulmonary profile of lowlanders and Sherpa were determined during: (1) a 9-day ascent to 5050 m (20 lowlanders; 12 Sherpa), and (2) following partial acclimatization (11 ± 4 days) to 5050 m (18 lowlanders; 20 Sherpa), where both groups received an i.v. infusion of either iron (iron (iii)-hydroxide sucrose) or an iron chelator (desferrioxamine). During ascent, there were reductions in iron status in both lowlanders and Sherpa; however, Sherpa appeared to demonstrate a more efficient capacity to mobilize stored iron, compared to lowlanders, when expressed as a Δhepcidin per unit change in either body iron or the soluble transferrin receptor index, between 3400-5050 m (P = 0.016 and P = 0.029, respectively). The rise in pulmonary artery systolic pressure (PASP) was blunted in Sherpa, compared to lowlanders during ascent; however, PASP was comparable in both groups upon arrival to 5050 m. Following partial acclimatization, despite Sherpa demonstrating a blunted hypoxic ventilatory response and greater resting hypoxaemia, they had similar hypoxic pulmonary vasoconstriction when compared to lowlanders at rest. Iron-infusion attenuated PASP in both groups at rest (P = 0.005), while chelation did not exaggerate PASP in either group at rest or during exaggerated hypoxaemia ( P I O 2  = 67 mmHg). During exercise at 25% peak wattage, PASP was only consistently elevated in Sherpa, which persisted following both iron infusion or chelation. These findings provide new evidence on the complex interplay of iron regulation on pulmonary vascular regulation during acclimatization and adaptation to high altitude.

Prevalence and Risk Factors for Iron Deficiency in Adults With Cystic Fibrosis

BACKGROUND

Iron deficiency is common in cystic fibrosis (CF), but previous prevalence studies often reported results confounded by acute exacerbations. This single-center retrospective study aimed to identify the prevalence of iron deficiency in a stable adult CF population, identify the risk factors associated with iron deficiency, and compare common laboratory indicators of iron status.

METHODS

Medical charts of 105 patients aged 18-67 were reviewed to determine the prevalence of anemia. Of these patients, a subgroup of 67 were included in analyses of iron deficiency, defined as serum ferritin < 12 ng/mL and/or percent transferrin saturation (TSAT) < 16%. Data on sex, age, body mass index, anemia status, vitamin deficiencies, presence of comorbidities, colonization with Pseudomonas aeruginosa, and use of acid blockers and CF transmembrane conductance regulator modulators were collected to evaluate relationship of iron deficiency with these clinical factors. κ agreements between serum iron, ferritin, transferrin, and TSAT were compared.

RESULTS

In this stable CF population, the prevalence of iron deficiency was 41.8% (n = 67), and the prevalence of anemia was 33.3% (n = 105). Iron deficiency was associated with presence of anemia (P < .001), vitamin A deficiency (P = .012), and moderate (P = .047) and severe lung disease (P = .045) compared with mild lung disease. Transferrin agreed poorly with other iron status indicators.

CONCLUSION

Iron deficiency is common in CF, although prevalence rates can vary widely depending on the laboratory parameters used. CF centers should consider routine screening for iron deficiency.

Maltobionic acid accelerates recovery from iron deficiency-induced anemia in rats

In experiments 1 and 2, effect of ingestion of maltobionic acid calcium salt (MBCa) on recovery of rats from a latent iron deficiency and from iron deficiency anemia was examined, respectively. After grouping rats into control and iron-deficiency groups, a latent iron deficiency or iron-deficiency anemia was induced in the latter group. And recovery from these states by MBCa containing diets (0%, 3%, and 6% MBCa in diet, classified into MBCa-0, MBCa-3, and MBCa-6 groups) was compared for convalescence period in light of iron sufficient control group. In experiment 1, MBCa ingestion significantly increased the iron concentration in the serum and liver, and promoted recovery from a latent iron deficiency. In experiment 2, hemoglobin and hematocrit levels increased significantly with MBCa intake, and recovery from iron-deficiency anemia was promoted. MBCa effectively promoted the recovery of rats from a subclinical iron deficiency and iron-deficiency anemia.Abbreviations: ANOVA: analysis of variance; DMT1: divalent metal transporter 1; EDTA-2Na: disodium salt of ethylenediaminetetraacetic acid; Fpn: feroportin; Hb: hemoglobin; Ht: hematocrit; ICP-OES: inductivity coupled plasma optical emission spectrometer; MBCa: maltobionic acid calcium salt; nitroso-PSAP: 2-nitroso-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol; SE: standard error; SI: serum-iron concentration; TSAT: transferrin saturation; TIBC: total iron-binding capacity; UIBC: unsaturated iron-binding capacity.

EFFECTS OF MODEST IRON LOADING ON IRON INDICES IN HEALTHY INDIVIDUALS

Intravenous (iv) iron administration is typically indicated in individuals who have iron deficiency refractory to oral iron. However, in certain chronic disease states, it may be beneficial to administer iv iron to individuals who are not strictly iron deficient. The purpose of this study was to define a dose-response relationship between clinical indices of iron status and modest loading with iv iron in healthy, iron-replete participants. This was a double-blind, controlled study involving 18 male participants. Participants were block randomised 2:1 to the iron and saline (control) groups. Participants in the iron group received 250 mg of iv iron, once a month for six months, provided that their ferritin remained < 300 µg/L and their transferrin saturation remained < 45%. Otherwise they received a saline infusion, as did the control participants. Iron indices were measured monthly during the study. The pulmonary vascular response to sustained hypoxia and total hemoglobin mass were measured before, at three months (hemoglobin mass only) and at six months, as variables that may be affected by iron loading. Serum ferritin was robustly elevated by iv iron by 0.21 µg/L/mg of iron delivered (95% CI: 0.15-0.26 µg/L/mg), but the effects on all other iron indices did not reach statistical significance. The pulmonary vascular response to sustained hypoxia was significantly suppressed by iron loading at six months, but the hemoglobin mass was unaffected. We conclude that the robust effect on ferritin provides a quantitative measure for the degree of iron loading in iron-replete individuals.

Biomarkers of Nutrition for Development (BOND)-Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation.

Professor Clement Alfred Finch: hematologist, humanist, and mentor for many (July 4, 1915 - June 28, 2010)

Clement Alfred Finch was a physician, researcher and educator who helped advance the scientific basis and practices of diagnosis and treatment of anemia since the time when little was known about the disease. He was born in New York, USA and graduated from medical school in 1941. He had a 60-year tenure at the University of Washington and published extensively (more than 300 scholarly articles and close to 30 key reviews). He was instrumental in collaborating with key Thai hematologists, particularly at the premier Siriraj Medical School. His contribution on iron metabolization in the bloodstream has been a corner stone of hematology. It included seminal research which led to the widespread supplementation with iron in diets by women to avoid iron deficiency anemia.

Celiac Disease in Children with Moderate-to-Severe Iron-deficiency Anemia

Objective

To evaluate the proportion of children with moderate to severe iron-deficiency anemia who have associated celiac disease.

Methods

This cross-sectional analytical study was conducted among children aged 1 to 12 years of age with moderate-to-severe iron deficiency anemia and control children without anemia.Serum IgA-tissue trans-glutaminase levels were assessed in both cases and controls. All children with positive celiac serology underwent upper gastrointestinal endoscopy and duodenal biopsy; biopsy finding of Marsh grade 3 was considered positive for celiac disease.

Results

There were 152 anemic children and 152 controls with mean (SD) hemoglobinof 7.7 (1.8) and 12.2 (0.74) g/dL, respectively. 16 (10.5%) cases and 3 (2%) control patients had positive serology for celiac disease [OR (95% CI) 5.33 (1.52-18.67), P=0.007]. Six (3.9%) children with iron-deficiency anemia and none of the controls had biopsy features diagnostic of celiac disease.

Conclusion

In the Northern Indian tertiary-care hospital outpatient setting, Celiac disease was associated with 4% of children presenting with moderate-to-severe anemia.

Current understanding of iron homeostasis

Iron is an essential trace element, but it is also toxic in excess, and thus mammals have developed elegant mechanisms for keeping both cellular and whole-body iron concentrations within the optimal physiologic range. In the diet, iron is either sequestered within heme or in various nonheme forms. Although the absorption of heme iron is poorly understood, nonheme iron is transported across the apical membrane of the intestinal enterocyte by divalent metal-ion transporter 1 (DMT1) and is exported into the circulation via ferroportin 1 (FPN1). Newly absorbed iron binds to plasma transferrin and is distributed around the body to sites of utilization with the erythroid marrow having particularly high iron requirements. Iron-loaded transferrin binds to transferrin receptor 1 on the surface of most body cells, and after endocytosis of the complex, iron enters the cytoplasm via DMT1 in the endosomal membrane. This iron can be used for metabolic functions, stored within cytosolic ferritin, or exported from the cell via FPN1. Cellular iron concentrations are modulated by the iron regulatory proteins (IRPs) IRP1 and IRP2. At the whole-body level, dietary iron absorption and iron export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin. When tissue iron demands are high, hepcidin concentrations are low and vice versa. Too little or too much iron can have important clinical consequences. Most iron deficiency reflects an inadequate supply of iron in the diet, whereas iron excess is usually associated with hereditary disorders. These disorders include various forms of hemochromatosis, which are characterized by inadequate hepcidin production and, thus, increased dietary iron intake, and iron-loading anemias whereby both increased iron absorption and transfusion therapy contribute to the iron overload. Despite major recent advances, much remains to be learned about iron physiology and pathophysiology.

Determination of Dietary Iron Requirements by Full Expression of Iron-Containing Enzymes in Various Tissues of Broilers

BACKGROUND

The current dietary iron requirement (80 mg/kg) of broilers is mainly based on growth, hemoglobin concentration, or hematocrit data obtained in a few early studies; however, expressions of iron-containing enzymes might be more sensitive novel criteria to evaluate dietary iron requirements.

OBJECTIVE

The objective of this study was to determine dietary iron requirements of broilers for the full expression of succinate dehydrogenase (SDH), catalase, and cytochrome c oxidase (COX) in various tissues.

METHODS

A total of 336 1-d-old Arbor Acres male chicks were randomly assigned to 1 of 7 treatments with 6 replicates and fed a basal corn and soybean-meal diet (control, containing 67 mg Fe/kg) and the basal diet supplemented with 20, 40, 60, 80, 100, or 120 mg Fe/kg from FeSO₄ ⋅ 7H₂O for 21 d. Regression analysis was performed to estimate the optimal dietary iron concentration with the use of broken-line or quadratic models.

RESULTS

SDH activity in the liver and heart, COX and catalase activity in the liver, Sdh mRNA levels in the liver, and Cox mRNA levels in the liver and heart of broilers were affected (P < 0.027) by supplemental iron concentration, and increased quadratically (P < 0.004) as dietary iron concentration increased. Dietary iron requirements estimated on the basis of fitted broken-line or quadratic-curve models (P < 0.005) of the above indexes were 97-136 mg/kg.

CONCLUSIONS

SDH activity in the liver and heart, COX and catalase activity in the liver, Sdh mRNA levels in the liver, and Cox mRNA levels in the liver and heart are, to our knowledge, new and sensitive criteria to evaluate the dietary iron requirements of broilers, and the dietary iron requirements would be 97-136 mg/kg to support the full expression of the above iron-containing enzymes in various tissues of broiler chicks from 1 to 21 d of age, which are higher than the current NRC iron requirement.

The reproductive ecology of iron in women

Reproductive ecology focuses on the sensitivity of human reproduction to environmental variation. While reproductive ecology has historically focused on the relationship between energy status and reproductive outcomes, iron status is equally critical to women's reproductive health, given the wide-ranging detrimental effects of iron-deficiency anemia on maternal and infant well-being. This review interprets the vast literature on iron status and women's reproduction through an evolutionary framework. First, it will critique the evidence for iron deficiency caused by blood loss during menstruation, reinterpreting the available data as ecological variation in menses within and between populations of women. Second, it will highlight the scant but growing evidence that iron status is implicated in fertility, a relationship that has deep evolutionary roots. Third, this review proposes a new hypothesis for the transfer of iron from mother to infant via pregnancy and breastfeeding: reproductive iron withholding. In this hypothesis, mothers transfer iron to infants in a manner that helps infants avoid iron-mediated infection and oxidative stress, but trades off with potential risk of maternal and infant iron deficiency. Finally, this review explores two main factors that can modify the relationship between iron status and the gestation-lactation cycle: (1) the relationship between long-term reproductive effort (parity) and iron status and (2) supplementation schemes before and during pregnancy. The review concludes by suggesting continued research into iron homeostasis in women using evolutionary, ecological, and biocultural frameworks.

A cross-sectional study of the prevalence and associations of iron deficiency in a cohort of patients with chronic obstructive pulmonary disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Iron deficiency, with or without anaemia, is associated with other chronic conditions, such as congestive heart failure, where it predicts a worse outcome. However, the prevalence of iron deficiency in COPD is unknown. This observational study aimed to determine the prevalence of iron deficiency in COPD and associations with differences in clinical phenotype.

SETTING

University hospital outpatient clinic.

PARTICIPANTS

113 adult patients (65% male) with COPD diagnosed according to GOLD criteria (forced expiratory volume in 1 s (FEV1): forced vital capacity (FVC) ratio <0·70 and FEV1 <80% predicted); with age-matched and sex-matched control group consisting of 57 healthy individuals.

MAIN OUTCOME MEASURES

Prevalence of iron deficiency, defined as: any one or more of (1) soluble transferrin receptor >28.1 nmol/L; (2) transferrin saturation <16% and (3) ferritin <12 µg/L. Severity of hypoxaemia, including resting peripheral arterial oxygen saturation (SpO2) and nocturnal oximetry; C reactive protein (CRP); FEV1; self-reported exacerbation rate and Shuttle Walk Test performance.

RESULTS

Iron deficiency was more common in patients with COPD (18%) compared with controls (5%). In the COPD cohort, CRP was higher in patients with iron deficiency (median 10.5 vs 4.0 mg/L, p<0.001), who were also more hypoxaemic than their iron-replete counterparts (median resting SpO2 92% vs 95%, p<0.001), but haemoglobin concentration did not differ. Patients with iron deficiency had more self-reported exacerbations and a trend towards worse exercise tolerance.

CONCLUSIONS

Non-anaemic iron deficiency is common in COPD and appears to be driven by inflammation. Iron deficiency associates with hypoxaemia, an excess of exacerbations and, possibly, worse exercise tolerance, all markers of poor prognosis. Given that it has been shown to be beneficial in other chronic diseases, intravenous iron therapy should be explored as a novel therapeutic option in COPD.

Iron homeostasis during cystic fibrosis pulmonary exacerbation

BACKGROUND

Hypoferremia is a marker of disease severity in cystic fibrosis (CF). The effect of systemic antibiotics on iron homeostasis during CF pulmonary exacerbation (CFPE) is unknown. Our central hypotheses were that, by the completion of treatment, serum iron would increase, serum concentrations of interleukin-6 (IL-6) and hepcidin-25, two mediators of hypoferremia, would decrease, and sputum iron would decrease.

METHODS

Blood and sputum samples were collected from 12 subjects with moderate-to-severe CF (median percentage-predicted forced expiratory volume in 1 second (FEV(1) %) = 29%; median weight = 56 kg) within 24 hours of starting and completing a course of systemic antibiotics.

RESULTS

After treatment, subjects showed median FEV(1) % and body weight improvements of 4.5% and 2.0 kg, respectively (p < 0.05). Median serum iron rose by 2.4 μmol/L (p < 0.05), but 75% of patients remained hypoferremic. Median serum IL-6 and hepcidin-25 levels fell by 12.1 pg/mL and 37.5 ng/mL, respectively (p < 0.05). Median serum erythropoietin (EPO) and hemoglobin levels were unaffected by treatment. We observed a trend toward lower sputum iron content after treatment.

CONCLUSIONS

Hypoferremia is a salient characteristic of CFPE that improves with waning inflammation. Despite antibiotic treatment, many patients remain hypoferremic and anemic because of ineffective erythropoiesis.

Rethinking iron regulation and assessment in iron deficiency, anemia of chronic disease, and obesity: introducing hepcidin

Adequate iron availability is essential to human development and overall health. Iron is a key component of oxygen-carrying proteins, has a pivotal role in cellular metabolism, and is essential to cell growth and differentiation. Inadequate dietary iron intake, chronic and acute inflammatory conditions, and obesity are each associated with alterations in iron homeostasis. Tight regulation of iron is necessary because iron is highly toxic and human beings can only excrete small amounts through sweat, skin and enterocyte sloughing, and fecal and menstrual blood loss. Hepcidin, a small peptide hormone produced mainly by the liver, acts as the key regulator of systemic iron homeostasis. Hepcidin controls movement of iron into plasma by regulating the activity of the sole known iron exporter ferroportin-1. Downregulation of the ferroportin-1 exporter results in sequestration of iron within intestinal enterocytes, hepatocytes, and iron-storing macrophages reducing iron bioavailability. Hepcidin expression is increased by higher body iron levels and inflammation and decreased by anemia and hypoxia. Importantly, existing data illustrate that hepcidin may play a significant role in the development of several iron-related disorders, including the anemia of chronic disease and the iron dysregulation observed in obesity. Therefore, the purpose of this article is to discuss iron regulation, with specific emphasis on systemic regulation by hepcidin, and examine the role of hepcidin within several disease states, including iron deficiency, anemia of chronic disease, and obesity. The relationship between obesity and iron depletion and the clinical assessment of iron status will also be reviewed.

Diagnosing anemia in inflammatory bowel disease: beyond the established markers

The main types of anemia in inflammatory bowel disease (IBD) are iron deficiency anemia (IDA) and anemia of inflammatory etiology, or anemia of chronic disease (ACD). In the management of IBD patients with anemia it is essential for the physician to diagnose the type of anemia in order to decide in an evidence-based manner for the appropriate treatment. However, the assessment of iron status in IBD in many cases is rather difficult due to coexistent inflammation. For this assessment several indices and markers have been suggested. Ferritin, seems to play a central role in the definition and diagnosis of anemia in IBD and transferrin, transferrin saturation (Tsat), and soluble transferrin receptors are also valuable markers. All these biochemical markers have several limitations because they are not consistently reliable indices, since they are influenced by factors other than changes in iron balance. In this review, in addition to them, we discuss the newer alternative markers for iron status that may be useful when serum ferritin and Tsat are not sufficient. The iron metabolism regulators, hepcidin and prohepcidin, are still under investigation in IBD. Erythrocytes parameters like the red cell distribution width (RDW) and the percentage of hypochromic red cells as well as reticulocyte parameters such as hemoglobin concentration of reticulocytes, red blood cell size factor and reticulocyte distribution width could be useful markers for the evaluation of anemia in IBD.

Case studies: iron

Iron biomarkers were developed to define the size of iron stores and the adequacy of the iron supply required to meet functional needs. Approximately 80% of the iron delivered to tissues through the circulating plasma pool will be incorporated into hemoglobin. Consequently, with the exception of serum ferritin, iron biomarkers are measures of iron sufficiency for erythrocyte production. They have proven to be very valuable in the determination of the cause of anemia in the clinical setting in which additional information about factors that affect the patient's health is available. However, all current biomarkers are affected by factors other than iron status, which limit their utility for the determination of the prevalence of iron deficiency in some populations, particularly in populations who live in developing countries. Furthermore, relations between iron status and functional outcomes such as neonatal and infant mortality; motor, cognitive, and emotional development in infants; and severe morbidity from malaria in young children are inadequately characterized. There is a need to identify and standardize biomarkers that have the highest predictive value for specific functional outcomes in each setting. The most appropriate biomarkers may vary with the setting and be influenced by age, sex, gestational stage of pregnancy, and environmental factors such as repeated or chronic infections. There is also an urgent need for improved technology to permit the use of specific biomarkers in field studies in resource-poor regions. Finally, more research is required to define the potential role of hepcidin and non-transferrin-bound iron assays.

[Review of haematology and biochemistry parameters to identify iron deficiency]

INTRODUCTION

There has been a continuous improvement in the methods to detect iron deficiency, a common condition in children, in the last decades or so, but it is still difficult to establish which parameters should be included in a diagnostic panel for iron deficiency and iron deficiency anaemia. The objectives of this study were to evaluate the diagnostic efficiency of commonly used haematological and biochemical markers, as well as the reticulocyte haemoglobin content (CHr) in the diagnosis of iron deficiency with or without anaemia.

STUDY DESIGN

A descriptive cross-sectional study was carried out on an urban population of both sexes aged 6 months to 14 years. A complete blood cell count with CHr was obtained. Biochemical markers of iron metabolism, transferrin saturation, serum iron, ferritin and total iron binding capacity were also measured.

RESULTS

Samples were obtained for 237 children. A multiple stepwise logistic regression analysis identified CHr and iron serum as the only parameters independently associated to iron deficiency (P<0.05). CHr was the strongest predictor of iron deficiency and iron deficiency anaemia.

CONCLUSIONS

Our study indicates that the measurement of CHr may be a reliable method to assess deficiencies in tissue iron supply. CHr together with a complete blood count may provide an alternative to the traditional biochemical panel for the diagnosis of iron deficiency in children.

Absorption and side-effects after peroral administration of sustained release iron tablets. Ferro-Retard compared with Ferronicum and Duroferon Duretter

Study I. In 13 iron deficient patients the absorption from 100 mg ferrous sulphate (Ferro-Retard) after 3 and 5 hours was comparable to the absorption from 176 mg ferrous gluconate in rapidly disintegrating tablets (Ferronicum). Study II. (a) The serum iron elevation in 14 blood donors with normal Hb after administration of ferrous sulphate (100 mg Fe2+) in Ferro-Retard or Duroferon Duretter seemed to be equal when tested on the 4th day after donation of 450 ml blood. (b) The iron absorption, measured by the elevation of serum iron 5 and 8 hours after administration of sustained release tablets, proved to be better on the 11th and especially on the 16th day than on the 4th day after donation. Study III (side-effects). In a study on 113 subjects the total number of complaints was unusually high both before and after administration of placebo, rapidly disintegrating and sustained release ferrous sulphate tablets. The selection of participants and other methodological factors have probably been of importance. Hence, comparisons between different studies of side-effects should always be carried out with caution.

Intravenous Iron Therapy: A Summary of Treatment Options and Review of Guidelines

Iron replacement for iron-deficiency anemia has historically been accomplished with the use of oral iron therapy. Although oral iron is appropriate for most iron-deficiency anemia patients, many patients do not respond to or may be intolerant of oral iron, or may experience bleeding of sufficient magnitude to require higher iron doses than that achievable with oral iron. Intravenous iron therapy is a useful option for these latter patients. Three intravenous iron products are recommended: low-molecular weight iron dextran (INFeD), ferric gluconate (Ferrlecit), and iron sucrose (Venofer). These intravenous iron products have superior safety profiles compared to high-molecular weight iron dextran. The Food and Drug Administration's approval of erythropoietic-stimulating agents to treat certain types of anemia has increased usage of intravenous iron for functional iron deficiency. This review summarizes the current status of intravenous iron products and discusses their advantages and disadvantages in treating both absolute and functional iron deficiency.

Benefits and risks of iron therapy for chronic anaemias

Iron is used widely for the treatment of anaemias with iron-restricted erythropoiesis. This intervention can be both beneficial and detrimental depending on the type of the underlying process. While in iron deficiency anaemia (IDA), the most frequent anaemia in the world, iron is the therapy of choice, this intervention can be harmful in the anaemia of chronic disease or anaemia associated with renal failure, the most common anaemias in hospitalized adult patients in Western countries. Iron is able to negatively affect cell-mediated immune effector mechanisms directed against invading microorganisms and tumour cells while at the same time, as an essential nutrient, it can stimulate the proliferation of these unwanted cells. In addition, iron catalyses the formation of toxic radicals leading to tissue damage or the promotion of cardiovascular events. Thus, it is essential to correctly diagnose the precise cause of anaemia and to consider the benefits and hazards of targeted iron therapy.

Iron supplement use and iron status among US adults: results from the third National Health and Nutrition Examination Survey

BACKGROUND

Patients with hemochromatosis are instructed to avoid taking supplemental iron. Whether supplemental iron intakes lead to higher iron status among healthy persons remains less clear.

OBJECTIVE

The objective was to ascertain whether supplemental iron intakes are associated with increases in iron transport (transferrin saturation) and stores (serum ferritin) among US adults aged > or = 19 y.

DESIGN

We analyzed data for 5948 adults from whom a fasting serum sample was collected during the third National Health and Nutrition Examination Survey. We used multivariable linear regression and analysis of variance to assess the association of supplemental iron intake with iron transport and stores among men (aged 19-30 y or > 30 y) and women (nonpregnant premenopausal or postmenopausal); multiple comparison tests were also performed.

RESULTS

Healthy adults who took supplements containing average daily amounts of iron at < or = 3 times the recommended dietary allowance (RDA) did not have significantly higher iron transport or stores than did those who did not take supplements. In younger men, the intake of > 32 mg Fe/d (> 4x RDA) was associated with mean transport iron concentrations that were significantly higher than those in persons who took 0 to < or = 24 mg Fe/d. In older men, the intake of > 32 mg Fe/d (> 4x RDA) was associated with mean iron stores that were significantly higher than those in persons who took 0 to < or = 24 mg Fe/d; a similar result was observed in postmenopausal women, but it was of borderline statistical significance.

CONCLUSION

Supplement users should be made aware of the amount of iron necessary to satisfy dietary requirements and informed of the possible influence that excess iron intake can have on body iron stores and health.

Iron metabolism in the hemoglobin-deficit mouse: correlation of diferric transferrin with hepcidin expression

The iron requirements of the erythroid compartment modulate the expression of hepcidin in the liver, which in turn alters intestinal iron absorption and iron release from the reticuloendothelial system. We have taken advantage of an inherited anemia of the mouse (hemoglobin deficit, or hbd) to gain insights into the factors regulating hepcidin expression. hbd mice showed a significant anemia but, surprisingly, their iron absorption was not increased as it was in wild-type animals made anemic to a similar degree by dietary iron depletion. In wild-type mice hepatic hepcidin levels were decreased but in hbd animals a significant and unexpected increase was observed. The level of absorption was appropriate for the expression of hepcidin in each case, but in hbd mice did not reflect the degree of anemia. However, this apparent inappropriate regulation of hepcidin correlated with increased transferrin saturation and levels of diferric transferrin in the plasma, which in turn resulted from the reduced capacity of hbd animals to effectively use transferrin-bound iron. These data strengthen the proposal that diferric transferrin is a key indicator of body iron requirements.

Soluble transferrin receptor and zinc protoporphyrin--competitors or efficient partners?

OBJECTIVES

Soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZPP) are both parameters of iron deficient erythropoiesis (IDE), the sTfR measurement is commonly regarded to be the more sensitive test. sTfR also reflects erythropoietic activity, it is increased in enhanced erythropoiesis.

METHODS

We investigated the diagnostic accuracy of sTfR in assessment of iron deficiency (ID) and compared it with ZPP. The study was performed on 174 subjects, in which ID has been precisely staged.

RESULTS

Individuals without ID and patients with storage iron depletion only, had normal sTfR values. Patients classified as IDE and patients with iron deficiency anemia had significantly increased sTfR. There was a good correlation between sTfR and hemoglobin (r = -0.86; P < 0.0001) and between sTfR and ZPP (r = 0.86; P < 0.0001). When diagnosing ID, ZPP was the more sensitive test. In mildly developed IDE associated with ZPP-ratios between 40 and 70 micromol/mol heme, the sTfR concentration was elevated in only 25% of the cases. Reliably elevated sTfR values were observed only in more advanced IDE, associated with ZPP > 70 mumol/mol heme.

CONCLUSIONS

ZPP is not inferior to sTfR when diagnosing IDE. Given the good correlation between sTfR and ZPP and because ZPP is uninfluenced by the erythropoietic activity, sTfR and ZPP are not competitors, rather efficient partners in diagnosing anemias. By measuring ZPP and sTfR simultaneously, the diagnostic uncertainty inherent in each of them individually can be eliminated. In particular, the simultaneous determination of ZPP and sTfR enhances the diagnostic power of sTfR in assessment of the erythropoietic activity.

Anemia of chronic disease: pathophysiology and laboratory diagnosis

Classic iron deficiency (ID) does not represent a challenge for the laboratory and physicians. The anemia that accompanies infection, inflammation, and cancer, commonly termed anemia of chronic disease (ACD), features apparently normal or increased iron stores. However, 20% of these patients have iron-restricted erythropoiesis (functional ID), an imbalance between the iron requirements of the erythroid marrow and the actual iron supply. Functional ID leads to a reduction in red cell hemoglobiniza-tion, causing hypochromic microcytic anemia. The diagnosis of functional ID in real time is based on measuring the hemoglobin content of reticulocytes. An examination of the biochemical markers of iron metabolism demonstrates weaknesses in the diagnosis of functional ID. We developed a diagnostic plot for the assessment of iron status in ACD and the detection of advancing ID in patients with ID, ACD, and the combined state of functional ID and ACD. The plot indicates the correlation between a marker of the iron supply for erythropoiesis (ie, the ratio of the soluble transferrin receptor value to the logarithm of the ferritin value) and the reticulocyte hemoglobin content and functions as a marker of iron demand. The diagnostic plot shows good selectivity for assessing the iron status of disease-specific anemias such as classic ID, end-stage renal failure, cancer-related anemia, and the anemia of infection and inflammation. The therapeutic implications of the diagnostic plot are to differentiate patients who should be administered oral iron supplements, recombinant human erythropoietin (r-HuEPO), or a combination of r-HuEPO and iron. The response of erythropoiesis to r-HuEPO depends on the iron supply and the proliferation of erythropoiesis. The lack of an increase or a decrease in reticulocyte hemoglobin levels indicates a nonresponder to r-HuEPO or functional ID.