Using Reticulocyte Hemoglobin Equivalent as a Marker for Iron Deficiency and Responsiveness to Iron Therapy.

OBJECTIVE: To assess the accuracy of a simplified approach for the diagnosis of iron deficiency anemia (IDA) based on the complete blood cell count (CBC) and reticulocyte analysis. PATIENTS AND METHODS: Five hundred fifty-six consecutive, nonselected patients referred for diagnosis and/or treatment of anemia were included in this diagnostic study to compare the performance of reticulocyte hemoglobin equivalent (RET-He) versus traditional biochemical markers for diagnosis and treatment of IDA. Complete blood count, serum ferritin, iron, and transferrin saturation were performed as clinically indicated. Reticulocyte hemoglobin equivalent was measured with a Sysmex XN-450 analyzer on the residual CBC sample. The study period was from September 20, 2017, through and including November 15, 2018. RESULTS: Patients (N=556) were studied at baseline, of whom 150 were subsequently treated with intravenous iron. Receiver operating characteristic analysis yielded an RET-He cut-off of 30.7 pg to identify IDA (area under curve, 0.733; 95% CI, 0.692 to 0.775), with 68.2% sensitivity and 69.7% specificity. Patients (n=240) were seen at follow-up, with 57 treated and 183 not treated with intravenous iron. Responsiveness was defined as a hemoglobin increase of ≥1.0 g: a combination of RET-He <28.5 pg and hemoglobin value <10.3 g/dL had 84% sensitivity and 78% specificity as response predictor (area under the curve, 0.749; 95% CI, 0.622 to 0.875). CONCLUSION: Data from CBC and RET-He can identify patients with IDA, determine need for and responsiveness to intravenous iron, and reduce time for therapeutic decisions. Limitations of this study are uncontrolled design, its single-site and retrospective nature, and that it requires prospective validation.

In vitro and in vivo DFO-chelatable labile iron release profiles among commercially available intravenous iron nanoparticle formulations.

Intravenous (IV) iron formulations are complex colloidal suspensions of iron oxide nanoparticles. Small changes in formulation can allow more labile iron to be released after injection causing toxicity. Thus, bioequivalence (BE) evaluation of generic IV iron formulations remains challenging. We evaluated labile iron release in vitro and in vivo using a high performance liquid chromatography chelatable iron assay to develop a relational model to support BE. In vitro labile iron release and in vivo labile iron pharmacokinetics were evaluated for Venofer®, Ferrlecit®, generic sodium ferric gluconate complex, InFeD®, Feraheme® and a pre-clinical formulation GE121333. Labile iron release profiles were studied in vitro in 150 mM saline and a biorelevant matrix (rat serum) at 0.952 mgFe/mL. In vivo plasma labile iron concentration-time profiles (t0-240 min) were studied in rats after a 40 mgFe/kg IV dose. In vitro labile iron release in saline was significantly higher compared to rat serum, especially with InFeD®. An in vitro release constant (iKr) was calculated which correlated well with maximal plasma concentrations in the in vivo rat PK model (R2 = 0.711). These data suggest an in vitro to in vivo correlation model of labile iron release kinetics could be applied to BE. Other generic IV iron formulations need to be studied to validate this model.

In vivo study of the effect of lactoferrin on iron metabolism and bioavailability from different iron chemical species for formula milk fortification.

Iron fortification in infant formulas is a common practice for providing iron to newborns in order to avoid its deficiency (anemia). Depending on the physicochemical species used, its bioavailability might be insufficient to meet iron requirements. In this vein, the influence of Lactoferrin (Lf) presence on iron bioavailability in 2-week-old wistar rats fed with formula milk fortified with 57 Fe(III)2 -Lf or 57 Fe(II)SO4 (in presence of Lf) using quantitative speciation (by HPLC-ICP-MS) and Isotope Pattern Deconvolution (IPD) is studied here. Results obtained were compared among fortifiers and also with the maternal group. In RBCs, iron was mainly bound to hemoglobin in all the assayed groups in the same extent. Regarding serum samples, several iron-proteins were observed (such as transferrin and albumin). In both samples, iron content in the fractions studied was similar in all groups compared and exogenous 57 Fe incorporation of intaked iron was always above 50%, showing no significative differences between physicochemical forms but related to the dose administered. Regarding iron stores (liver) the group fed with formula milk fortified with the higher dose of 57 FeSO4 in presence of Lf presented the highest values of total iron even superior than those found in the maternal group, and also the highest exogenous (57 Fe) incorporation. In conclusion, it was proved that iron fortification is required to ensure proper iron levels in all body compartments. No significative differences were observed between different physicochemical species when iron is administered at low doses. However, higher iron doses lead to a greater incorporation in all the iron-proteins studied.

Comparative Efficacy and Safety of Phosphate Binders in Hyperphosphatemia Patients With Chronic Kidney Disease.

BACKGROUND: In this study, we coordinated a network meta-analysis to establish the efficacy and safety of different agents used in the treatment of hyperphosphatemia patients with chronic kidney disease. METHODS: PubMed, CNKI, and Embase were systematically searched to retrieve relevant studies. Outcomes were presented by mean differences, odds ratios, and corresponding 95% credible intervals for continuous outcomes and binary outcomes, respectively. Each therapy was ranked according to the value of surface under the cumulative ranking curve. Consistencies between direct and indirect comparisons were assessed with a node-splitting plot. RESULTS: In terms of efficacy end points (including levels of serum phosphate, serum calcium, serum intact parathyroid hormone, and serum calcium × phosphorus product), all 7 kinds of agents outperformed or performed at least equally to placebo, with iron-based phosphate-binding agents being potentially the most effective. As for safety end points (including mortality, adverse events, and all-cause discontinuation), almost all agents were equivalent in term of mortality and all-cause discontinuation except in the comparison between iron-based phosphate-binding agents and placebo. Meanwhile, iron-based phosphate-binding agents colestilan and nicotinic acid performed poorly compared with placebo in terms of adverse events. Furthermore, iron-based phosphate-binding agents were potentially the safest agents followed sequentially by calcium-based phosphate-binding agents and placebo. CONCLUSION: Iron-based phosphate-binding agents were the preferable agents when considering efficacy and safety simultaneously.

Toxicity Studies of Ethyl Maltol and Iron Complexes in Mice.

Ethyl maltol and iron complexes are products of ethyl maltol and the iron found in the cooking pots used to prepare the Chinese dish, hot-pot. Because their safety is undocumented, the toxicity study of ethyl maltol and iron complexes was conducted in male and female Kunming (KM) mice. The animal study was designed based on the preliminary study conducted to determine the median lethal dose (LD50). The doses used in the study were 0, 1/81, 1/27, 1/9, and 1/3 of the LD50 (mg kg body weight (BW)-1 day-1) dissolved in the water. The oral LD50 of the ethyl maltol and iron complexes was determined to be 743.88 mg kg BW-1 in mice. The ethyl maltol and iron complexes targeted the endocrine organs including the liver and kidneys following the 90 D oral exposure. Based on the haematological data, the lowest-observed-adverse-effect level (LOAEL) of the ethyl maltol and iron complexes was determined to be 1/81 LD50 (9.18 mg kg BW-1 day-1) in both male and female mice. Therefore, we suggest that alternative strategies for preparing the hot-pot, including the use of non-Fe-based cookware, need to be developed and encouraged to avoid the formation of the potentially toxic complexes.

The biomedical piglet: establishing reference intervals for haematology and clinical chemistry parameters of two age groups with and without iron supplementation.

BACKGROUND: The similarities between swine and humans in physiological and genomic patterns, and the great correlation in size and anatomy, make pigs extremely useful in preclinical studies. New-born piglets can represent a model for congenital and genetic diseases in new-born children. It is known that piglets may have significant differences in clinicopathological results compared to adult pigs. Therefore, adult laboratory reference intervals cannot be applied to piglets. The aim of this study was to compare haematological and chemical variables in piglets of two ages and determinate age-related reference intervals for commercial hybrid young pigs. Blood samples were collected under general anaesthesia from 130 animals divided into five- (P5) and 30- (P30) day-old piglets. Only P30 animals were treated with parenteral iron after birth. Samples were analysed using automated haematology (ADVIA 2120) and chemistry analysers, and age-related reference intervals were calculated. RESULTS: Significant higher values of RBC, Hb and HCT were observed in P30 animals when compared to P5, with an opposite trend for MCV. These results were associated with a reduction of the RBC regeneration process and the thrombopoietic response. The TSAT and TIBC were significantly higher in P30 compared to P5; however, piglets remained iron deficient compared to adult reference intervals reported previously. CONCLUSIONS: In conclusion, this paper emphasises the high variability occurring in clinicopathological variables between new-born and 30-day-old pigs, and between piglets and adult pigs. This study provides valuable reference data for piglets at precise ages and could be used in the future as historical control improving the Reduction in animal experiments, as suggested by the 3Rs principle.

An association of transferrin gene polymorphism and serum transferrin levels with age-related macular degeneration.

Age-related macular degeneration (AMD) is a degenerative disease of the eye, triggered by the damage of the macular cells. In the Western world it is the most frequent cause of blindness in the elderly. Oxidative stress is proved to play a key role in AMD pathogenesis and since iron accumulation has been found in AMD maculas, it may accelerate the oxidative processes in this tissue. In the present work we investigated the association between four polymorphisms of the transferrin gene (rs8177178; rs8177179; rs4481157; rs1130459) and AMD in dependence on the transferrin protein and iron serum levels. We employed PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism) for genotype determination, ELISA assay for serum transferrin evaluation and colorimetric assay for measurement of iron concentration in the serum. We found that advanced age and AMD family history may be independent risk factors for AMD (1.02, p < 0.05 and 8.88, p < 0.001, respectively). At the rs4481157 site The GG genotype of the rs4481157 polymorphism decreased the risk of dry AMD (OR 0.50; p < 0.05), while the GA increased this risk (OR 1.07; p < 0.05). Moreover, the GA genotype of this polymorphism decreased the risk of progression to the wet form (OR 0.63; p < 0.05). The analysis of the gene-environment interactions showed that the rs4481157 polymorphism modulates the AMD risk among obese (BMI above 30) individuals. In the former smokers group we observed a moderate association between rs4481157 polymorphism and AMD risk while this association in current smokers was stronger. We found also that the serum level of transferrin was higher in the AMD group (p < 0.001) than in the control, but the total serum iron levels did not differ between both groups. We found that the serum transferrin was associated with the rs8177178 (p < 0.001) and rs4481157 (p < 0.01) polymorphisms, and the common variant (GG) of both sites was related to a lower level of transferrin. Presented data may contribute to the involvement of iron homeostasis in AMD risk.

Peripapillary retinal nerve fiber layer thickness in children with iron deficiency anemia.

PURPOSE: To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness in children with iron deficiency anemia (IDA) in comparison with healthy controls and to investigate the correlation between peripapillary RNFL thicknesses and the hematologic parameters in these subjects. METHODS: Forty eyes of 40 children with a diagnosis of IDA (anemic group) and 40 eyes of 40 age- and sex-matched healthy children (control group) were enrolled in this study. Peripapillary RNFL thickness measurements were performed using Cirrus HD optical coherence tomography (OCT). RESULTS: Mean age of each group was 11.3±2.7 years. Average RNFL and RNFLs of superior and inferior quadrants were significantly thinner in the anemic group than in the control group (p=0.006, p=0.005, and p=0.005, respectively). In addition, average peripapillary RNFL thickness and RNFL thicknesses of superior, inferior, and temporal quadrants were correlated with hemoglobin levels (r1=0.734, p1<0.001, r2=0.456, p2=0.005, r3=0.598, p3<0.001, r4=0.349, p4=0.037, respectively) in anemic group. CONCLUSIONS. We found that children with IDA had different peripapillary RNFL profile measured by Cirrus HD spectral-domain OCT. We caution ophthalmologists when they measure RNFL thickness in children to diagnose glaucoma or other neuro-ophthalmic disorders.

Iron deficiency anaemia in pregnancy and postpartum: pathophysiology and effect of oral versus intravenous iron therapy.

Nutritional iron-deficiency anaemia (IDA) is the most common disorder in the world, affecting more than two billion people. The World Health Organization's global database on anaemia has estimated a prevalence of 14% based on a regression-based analysis. Recent data show that the prevalence of IDA in pregnant women in industrialized countries is 17.4% while the incidence of IDA in developing countries increases significantly up to 56%. Although oral iron supplementation is widely used for the treatment of IDA, not all patients respond adequately to oral iron therapy. This is due to several factors including the side effects of oral iron which lead to poor compliance and lack of efficacy. The side effects, predominantly gastrointestinal discomfort, occur in a large cohort of patients taking oral iron preparations. Previously, the use of intravenous iron had been associated with undesirable and sometimes serious side effects and therefore was underutilised. However, in recent years, new type II and III iron complexes have been developed, which offer better compliance and toleration as well as high efficacy with a good safety profile. In summary, intravenous iron can be used safely for a rapid repletion of iron stores and correction of anaemia during and after pregnancy.

Evidence that stainable bone marrow iron following parenteral iron therapy does not correlate with serum iron studies and may not represent readily available storage iron.

We recently reported that parenteral iron therapy is associated with a characteristic pattern of iron staining on bone marrow aspirate smears. We now present clinical information from 6 patients who received parenteral iron and, at one or more points in follow-up, were found to have low or borderline low serum ferritin levels and/or serum iron levels, even though marrow aspirate smears revealed abundant stainable iron in the pattern characteristic of prior parenteral iron therapy. We conclude that stainable iron seen in this pattern does not correlate with serum iron studies and may not represent functionally available storage iron. This pattern of iron staining should not be used as evidence to withhold further iron therapy in patients who otherwise continue to have features of iron deficiency anemia.

Serum hepcidin is significantly associated with iron absorption from food and supplemental sources in healthy young women.

BACKGROUND: Hepcidin is a key regulator of iron homeostasis, but to date no studies have examined the effect of hepcidin on iron absorption in humans. OBJECTIVE: Our objective was to assess relations between both serum hepcidin and serum prohepcidin with nonheme-iron absorption in the presence and absence of food with the use of dual stable-iron-isotope techniques. DESIGN: The study group included 18 healthy nonpregnant women. Women received in random order a supplemental iron source (7.6 mg FeSO4 providing 0.9 mg 58Fe as FeSO4) and 6.8 mg 57Fe ferrous sulfate tracer administered with a nonheme food source [orange-fleshed sweet potato (OFSP): 1.4 mg native Fe]. Iron absorption was determined by analyzing blood samples taken 14 d after dosing with the use of magnetic sector thermal ionization mass spectrometry. Serum hepcidin was assessed by a new competitive serum enzyme-linked immunosorbent assay (ELISA) specific for the refolded, mature 25-amino acid form, and serum prohepcidin was assessed by an ELISA specific for amino acids 28-47 of the hepcidin prohormone. RESULTS: In these women, iron absorption averaged 14.71 +/- 10.7% from the supplemental iron compared with 3.63 +/- 6.5% from the OFSP. Absorption of nonheme iron assessed in the presence (P = 0.038) and absence (P = 0.0296) of food was significantly associated with serum hepcidin but was not significantly related to serum prohepcidin. CONCLUSION: Serum hepcidin, but not prohepcidin, was inversely associated with iron absorption from supplemental and food-based nonheme-iron sources in iron-replete healthy women.

Prevalence of iron deficiency in children 6-24 months in Lagos.

BACKGROUND: Iron deficiency is the commonest cause of nutritional anaemia in children worldwide particularly in developing countries. Infants and toddlers are prone to developing iron deficiency anaemia (IDA). This study was carried out to determine the prevalence of IDA and some factors associated with it in this group of children. STUDY DESIGN: Haemoglobin concentration and mean corpuscular volume (MCV) estimations carried out in 282 apparently well children aged 6-24 months. Estimations of serum iron (SI), total iron binding capacity (TIBC), serum ferritin (SF) and transferrin saturation (TS) were also determined in children with anaemia (Hb concentration < 11.0 g/dl). Information on current diet was also obtained using a diet record. RESULTS: Two hundred and twenty three (79.1%) children had anaemia. The mean Hb concentrations of all the age groups were less than 11.0 g/dl. Forty (14.9%) children had IDA (defined as aneamia plus 2 or more of the following--MCV < 70fl, Ts < 10% or SF < 10 microg/dL). The mean age of children with IDA (8.96 +/- 2.54 months) was statistically lower than for those without the condition 10.94 +/- 4.55 months (p = 0.016). Inclusion of vegetables and animal protein less than three times a week in the diet were both significantly associated with IDA. CONCLUSION: The prevalence of IDA in this study is high especially before the age of 12 months and an average weekly intake less than 3 times a week or iron rich foods like animal protein and vegetables was significantly associated with IDA. Emphasis should be on the inclusion of iron rich foods in the diet following exclusive breastfeeding to reduce the prevalence of IDA in these children.

Iron deficient and manganese supplemented diets alter metals and transporters in the developing rat brain.

Manganese (Mn) neurotoxicity in adults can result in psychological and neurological disturbances similar to Parkinson's disease, including extrapyramidal motor system defects and altered behaviors. Iron (Fe) deficiency is one of the most prevalent nutritional disorders in the world, affecting approximately 2 billion people, especially pregnant and lactating women, infants, toddlers, and adolescents. Fe deficiency can enhance brain Mn accumulation even in the absence of excess Mn in the environment or the diet. To assess the neurochemical interactions of dietary Fe deficiency and excess Mn during development, neonatal rats were exposed to either a control diet, a low-Fe diet (ID), or a low-Fe diet supplemented with Mn (IDMn) via maternal milk during the lactation period (postnatal days [PN] 4-21). In PN21 pups, both the ID and IDMn diets produced changes in blood parameters characteristic of Fe deficiency: decreased hemoglobin (Hb) and plasma Fe, increased plasma transferrin (Tf), and total iron binding capacity (TIBC). Treated ID and IDMn dams also had decreased Hb throughout lactation and ID dams had decreased plasma Fe and increased Tf and TIBC on PN21. Both ID and IDMn pups had decreased Fe and increased copper brain levels; in addition, IDMn pups also had increased brain levels of several other essential metals including Mn, chromium, zinc, cobalt, aluminum, molybdenum, and vanadium. Concurrent with altered concentrations of metals in the brain, transport proteins divalent metal transporter-1 and transferrin receptor were increased. No significant changes were determined for the neurotransmitters gamma aminobutyric acid and glutamate. The results of this study confirm that there is homeostatic relationship among several essential metals in the brain and not simply between Fe and Mn.

The effect of repeated blood donations on the iron status of Iranian blood donors attending the Iranian blood transfusion organization.

OBJECTIVE: Blood donation leads to substantial iron loss, as about 0.5 mg iron is lost per each milliliter of blood donated. If not compensated for efficiently, the iron loss may eventually lead to anemia, though non-anemic iron deficiency per se may be problematic. The aim of this study was to evaluate the effects of blood donation, and its frequency over a year's time, on iron status of Iranian male blood donors attended blood transfusion stations of the Iranian Blood Transfusion Organization (IBTO). DESIGN AND SETTING: A cross-sectional, descriptive, and analytic study was conducted. 91 male volunteer blood donors aged from 20 to 50 years attending three IBTO stations located in central areas of Tehran, and 63 apparently healthy controls that were matched for age, gender, monthly income, height, and weight, were included in the study. Blood donors were divided into 4 groups according to the frequency of blood donation per year; i.e. 1, 2, 3, and 4 with 20, 30, 26, and 15 persons in each group, respectively. Just before blood donation, 10 mL venous blood sample was taken and divided into heparinized and non-heparinized tubes for determination of hemoglobin (Hb), hematocrit (Hct), serum iron (SI), total iron binding capacity (TIBC), ferritin, transferrin saturation (TS), and mean corpuscular hemoglobin concentration (MCHC). Dietary assessment was also done using 3 different questionnaires; i.e. general health, food frequency, and 24hr recall. RESULTS: The levels of Hb, Hct, and iron status indices were all significantly lower in the subjects than in controls and a gradual but significant decrease in iron status indices in each time of blood donation was found. Serum ferritin showed significant correlations with age (r = 0.33, p < 0.001) and body-mass index (BMI) (r = 0.26, p = 0.03) only in the control group. Frequency of blood donation per year was also inversely correlated with Hb (r = -0.67, p < 0.001), Hct (r = -0.65, p < 0.001), MCHC (r = -0.56, p < 0.001), serum ferritin (r = -0.38, p < 0.001), SI (r = -0.62, p < 0.001), and TS (r = -0.61, p < 0.001), but was directly correlated with TIBC (r = 0.56, p < 0.001). Interestingly in blood donors, but not in healthy controls, serum ferritin levels showed weak but statistically significant correlations with daily intake of iron (r = 0.17, p < 0.05) and energy (r = 0.20, p = 0.03). CONCLUSION: Though repeated blood donations might diminish iron status, it could be safe to donate 2-3 U/year without an appreciable incidence of iron deficiency, provided that the pre-donation Hb and ferritin values are >/= 14.7 g/dL and 58.9 mug/L, respectively. The male volunteers with Hb >/= 14.2 g/dL and serum ferritin >/= 57.2 mug/L could donate 1-2 U/year and those with Hb >/= 13.1 g/dL and serum ferritin >/= 35.3 mug/L could donate just once a year. Volunteers who undergo (repeated) blood donation should receive special nutritional care, especially in terms of iron and energy.

Iron absorption by healthy women is not associated with either serum or urinary prohepcidin.

BACKGROUND: Although hepcidin is proposed as a regulator of iron absorption, this has not been assessed in humans. OBJECTIVE: Our objective was to assess the relation between serum or urinary prohepcidin and iron absorption in healthy premenopausal women. DESIGN: The subjects were 28 healthy women aged 22-51 y with normal hemoglobin concentrations (120-152 g/L). Absorption of 0.5 mg Fe with 0.2 microCi 59Fe tracer, both as FeSO4, was measured by whole-body scintillation counting 13 d after oral administration. Fasting blood and urine samples were collected the day of and 16 wk after the absorption measurement. Serum and urinary prohepcidin concentrations were measured by an enzyme-linked immunosorbent assay by using an antibody against amino acid residues 28-47 of the proregion. RESULTS: Mean (+/-SD) iron absorption was 36 +/- 19% (range: 4-81%), and serum ferritin (geometric x) was 27 microg/L (range: 4-122 microg/L), as commonly observed in healthy premenopausal women. Serum prohepcidin was 196 microg/L (range: 99-376 microg/L) and, in contrast with urinary prohepcidin, was relatively consistent for the women between 0 and 16 wk. Serum prohepcidin correlated directly with serum ferritin (R2 = 0.28, P < 0.01) but was unrelated to 59Fe absorption, in contrast to serum ferritin (R2 = 0.33, P < 0.01). CONCLUSIONS: Serum prohepcidin concentrations were relatively stable within subjects and correlated with serum ferritin. However, unlike serum ferritin, neither serum nor urinary prohepcidin concentrations were related to iron absorption in healthy women.

The utility of biological monitoring for manganese in ferroalloy smelter workers in South Africa.

Five hundred and nine workers at a manganese (Mn) smelting works comprising eight production facilities and 67 external controls were studied cross-sectionally. Exposure measures from personal sampling included inhalable dust, cumulative exposure indices (CEI) and average intensity (INT = CEI/years exposed) calculated for the current job at the smelter and also across all jobs held by subjects. Biological exposure was measured by Mn in the blood (MnB) and urine (MnU) and biological effect was measured by serum prolactin. Average lifetime exposure intensity across all jobs ranged from near 0 (0.06 microg/m3) for unexposed external referents to 5 mg/m3. Atmospheric exposures and MnB and MnU distributions were consistent with published data for both unexposed and smelter workers. Associations between biological exposures and groups defined by atmospheric exposures in the current job were substantial for MnB, less so for MnU and absent for serum prolactin. Random sampling of MnB measurements representative of a group of workers with more than 1-2 years of service in the same job and notionally homogenous exposure conditions could serve as a cross-sectional predictor of atmospheric Mn exposure in the current job, as well as for surveillance of Mn exposure trends over time. Correlations at the individual level were only modest for MnB (33% of the variance in log atmospheric Mn intensity in the current job was explained by log MnB), much worse for MnU (only 7%). However, a receiver operating characteristic (ROC) analysis was performed which showed that it is possible to use a MnB cut-off of 10 microg/l (the 95th percentile in the unexposed) to good effect as a screening tool to discriminate between individual exposures exceeding and falling below a relatively strict atmospheric Mn exposure threshold at the ACGIH threshold limit value (TLV) of 0.2 mg/m3. MnU has no utility as a measure of biological exposure nor does serum prolactin as a measure of biological effect.

Serum ferritin levels and other indicators of organic iron as risk factors or markers in coronary artery disease.

BACKGROUND: Several international studies have discussed whether serum ferritin is a risk marker in coronary heart disease. The objective of this study was to evaluate the importance of serum ferritin levels and other indicators of organic iron as possible risk factors or markers in coronary artery disease. Secondly, the classical factors were studied in order to identify possible associations with organic iron markers. METHODS AND RESULTS: In a medical institution, 1263 patients underwent cinecoronary arteriography from December 1997 to May 1998. A sample of 400 patients was separated, at random, to establish a comparative clinical study between two groups: group A, comprising 200 individuals with coronary atherosclerosis and group B, comprising 200 patients without coronary atherosclerosis, as confirmed by cinecoronary arteriography. From group A, 182 patients (130 males) and from group B, 157 (96 females) did not show any exclusion criteria and were considered eligible. All women were in the postmenopausal period. The blood samples were collected by a biologist, between 8.30 and 9.0 a.m., after a 12-hour fast and a 36-hour non-smoking period. In order to analyze all results, univariate analysis, the logistic regression technique and the interactive forward stepwise method were used in order to optimize the model and to predict the chances of coronary atherosclerosis. The results of the logistic regression with all the variables analyzed showed that male gender, age, smoking, triglycerides/VLDL interaction, increased serum LDL-C levels and decreased serum HDL-C levels are important to predict the chances of coronary atherogenesis. CONCLUSION: Serum levels of ferritin and of other organic iron indicators--transferrin saturation, total iron-binding capacity, hemoglobin and hematocrit--were neither risk factors nor risk markers for coronary atherosclerosis. Paradoxically, serum iron levels were higher in the group without atherosclerosis. In this study, variables classically considered as risk factors were similar to those in the literature.

Effects of ascorbic acid on interactions between ciprofloxacin and ferrous sulphate, sodium ferrous citrate or ferric pyrophosphate, in mice.

The absorption of ciprofloxacin has been reported to be impaired by concomitant administration of ferrous sulphate. The effects of sodium ferrous citrate and ferric pyrophosphate, which have been used as extensively as ferrous sulphate, on the absorption of ciprofloxacin were compared with that of ferrous sulphate. The effects of ascorbic acid on the interactions between ciprofloxacin and each iron compound were studied in mice. Mice were treated orally with ciprofloxacin (50 mg kg(-1)) alone, the iron compound (ferrous sulphate, sodium ferrous citrate or ferric pyrophosphate; 50 mg elemental iron kg(-1)) alone, ciprofloxacin with each iron compound or ciprofloxacin in combination with each iron compound and ascorbic acid (250 mg kg(-1)). The maximum serum concentration of ciprofloxacin was significantly (P < 0.01) reduced from 1.15+/-0.11 microg mL(-1) (ciprofloxacin alone) to 0.17+/-0.01, 0.27+/-0.01 or 0.28+/-0.02 microg mL(-1), respectively, when ferrous sulphate, sodium ferrous citrate or ferric pyrophosphate was administered along with ciprofloxacin. The addition of ascorbic acid did not affect the inhibitory effects of each iron compound on the absorption of ciprofloxacin. Ciprofloxacin did not affect the variation of serum iron levels after administration of each iron compound. The addition of ascorbic acid significantly (P < 0.01) enhanced the increase in serum iron concentration after administration of sodium ferrous citrate, showing an increase from 270+/-6 microg dL(-1) to 463+/-11 microg dL(-1) compared with an increase from 248+/-8 microg dL(-1) to 394+/-18 microg dL(-1) after administration of sodium ferrous citrate alone. Ascorbic acid also caused a significant (P < 0.01) increase in serum iron concentration from 261+/-16 microg dL(-1) to 360+/-12 microg dL(-1) after administration of ferric pyrophosphate, although it did not affect the levels after ferrous sulphate administration. The results suggest that sodium ferrous citrate and ferric pyrophosphate should not be administered with ciprofloxacin (as for ferrous sulphate) and that sodium ferrous citrate is converted to the ferric form more easily than ferrous sulphate. This difference in convertibility might contribute to a clinical difference between sodium ferrous citrate and ferrous sulphate.

Comparison of the toxicities of two iron formulations in a swine model.

OBJECTIVE: To describe the histopathologic and pharmacokinetic differences of acute iron poisoning between chewable multivitamins with iron and solid iron tablets in a swine model. METHODS: This was a prospective, randomized, unblinded toxicity study of iron poisoning of two iron formulations in male Yorkshire pigs. Eight swine were randomized to receive 60 mg/kg of iron in either solid iron tablets or chewable multivitamins with iron. Serum iron, arterial blood gases, and episodes of vomiting were recorded over a ten-hour period. Routine histologic evaluations of the esophagus, stomach, small intestine, large intestine, and liver were performed immediately after the study period. Pharmacokinetic analyses of area under the concentration-time curve (AUC), time to peak concentration, and peak serum iron concentration were performed. RESULTS: There was no significant difference between the serum iron levels except at three and four hours. There was a significant higher AUC in the chewable group compared with the solid group. Pathologic evaluation identified severe esophageal inflammation and focal erosion in the solid iron tablet group in two of the four animals, compared with no focal erosions and minimal esophageal inflammation in the chewable group. No significant change was identified in the liver, small intestine, or large intestine in either group. CONCLUSIONS: These results demonstrate increased local gastrointestinal toxicity following a large ingestion of solid iron tablets in a swine model, compared with chewable multivitamins with iron. Higher serum iron levels were identified in the animals that received chewable multivitamins with iron.

Clinical biochemistry, haematology and body weight in piglets.

Reference ranges for clinical biochemical parameters commonly investigated in pigs were determined in one- (day 1), 21- and 35-day old piglets. The mean and standard deviation were also estimated for body weight, and haematological and clinical biochemical parameters at these ages. The piglets were divided into 2 investigation groups according to whether they had a haemoglobin concentration < or = 80 g/l ("anaemic group") or > 80 g/l ("normal group") on days 14, 21 and 28. The "anaemic group" was compared to the "normal group" on days 21 and 35. Many of the clinical biochemical parameters varied according to age. Some of the enzymes had high average values and wide reference ranges in piglets, especially on day 1, compared to the reference ranges for sows given in the literature. The reference ranges for some of the metabolic parameters were broader on day 1 than later in the preweaning period. The reference ranges for albumin, total iron-binding capacity and serum iron were, however, lower and more narrow on day 1. On days 21 and 35, relatively high values for phosphorus must be considered "normal" compared to the figures given in the literature for adult pigs. The other minerals seemed to be quite unaffected of age, but some were affected by anaemia. The anaemic piglets had lower average serum iron but higher total iron-binding capacity than the "normal" piglets on days 21 and 35. However, variation between piglets gave wide reference ranges, indicating that these parameters will only have limited usefulness in detecting iron deficiency anaemia in piglets. The electrolytes seemed also to be affected by the existence of anaemia. The body weight and leukocyte counts were significantly lower in the "anaemic group" than the "normal group" on day 35, while the greatest differences in clinical biochemical parameters between the groups were found on day 21, when the piglets in the "anaemic group" were most severely anaemic. Although these piglets suffered from severe iron-deficiency anaemia, only a few clinical biochemical parameters were affected, and the differences between groups were mostly small.