Many algorithms have been developed in the past few decades to estimate nonheme iron absorption from the diet based on single meal absorption studies. Yet single meal studies exaggerate the effect of diet and other factors on absorption. Here, we propose a new algorithm based on complete diets for estimating nonheme iron absorption.
View Article and Find Full Text PDFThe existence of multiple inherited disorders of iron metabolism suggests genetic contributions to iron deficiency. We previously performed a genome-wide association study of iron-related single nucleotide polymorphisms (SNPs) using DNA from white men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study with serum ferritin (SF) ≤ 12 µg/L (cases) and controls (SF >100 µg/L in men, SF >50 µg/L in women). We report a follow-up study of white, African-American, Hispanic, and Asian HEIRS participants, analyzed for association between SNPs and eight iron-related outcomes.
View Article and Find Full Text PDFThe existence of multiple inherited disorders of iron metabolism in man, rodents and other vertebrates suggests genetic contributions to iron deficiency. To identify new genomic locations associated with iron deficiency, a genome-wide association study (GWAS) was performed using DNA collected from white men aged≥25 y and women≥50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study with serum ferritin (SF)≤12 µg/L (cases) and iron replete controls (SF>100 µg/L in men, SF>50 µg/L in women). Regression analysis was used to examine the association between case-control status (336 cases, 343 controls) and quantitative serum iron measures and 331,060 single nucleotide polymorphism (SNP) genotypes, with replication analyses performed in a sample of 71 cases and 161 controls from a population of white male and female veterans screened at a US Veterans Affairs (VA) medical center.
View Article and Find Full Text PDFBackground: A new index to determine body iron promises a simpler approach to monitoring iron deficiency (ID) prevalence.
Objective: Our objective was to compare ID defined as body iron <0 mg/kg and calculated from the log ratio of transferrin receptor to ferritin (the body iron model) to ID defined as >/=2 of 3 abnormal concentrations in ferritin, transferrin saturation, or erythrocyte protoporphyrin (the ferritin model).
Design: We used measures of iron status and inflammation from 486 children aged 1-2 y, 848 children aged 3-5 y, and 3742 nonpregnant females aged 12-49 y from the National Health and Nutrition Examination Survey 2003-2006.
Background: Soluble transferrin receptor (sTfR) assays are currently not standardized. This hinders data comparison between studies and also affects the use of a recently proposed model to estimate body iron.
Methods: We evaluated the analytical performance of a fully automated sTfR immunoturbidimetric assay (Roche Diagnostics) and compared it with two ELISA assays (Ramco Laboratories and an in-house ELISA assay used in the body iron model).
The nature of the enhancing effect of muscle tissue on nonheme iron absorption in humans is unclear but thought to be related to muscle proteins. We conducted radioiron absorption studies to compare iron absorption from proteins isolated from beef and chicken muscle with that from freeze-dried beef and chicken muscle and from egg albumin. All meals contained an equivalent amount of protein as part of a semisynthetic liquid formula.
View Article and Find Full Text PDFThe UK Food Standards Agency convened a group of expert scientists to review current research investigating diet and carriers of genetic mutations associated with hereditary haemochromatosis. The workshop concluded that individuals who are heterozygous for the C282Y mutation of the HFE gene do not appear to respond abnormally to dietary Fe and therefore do not need to change their diet to prevent accumulation of body Fe.
View Article and Find Full Text PDFIt is widely recognized that the intake of animal foods is the most important dietary determinant of the iron status of a population. The primary reason is the high bioavailability of heme iron, but it is also known from radiolabeled single-meal feeding studies in humans that muscle tissue facilitates absorption of nonheme iron. In the present study, we examined the effect of meat intake on nonheme iron absorption from a whole diet.
View Article and Find Full Text PDFThe best treatment option for patients with relapsed or high-grade follicular lymphoma (FL) is unknown. In spite of major advances in the therapy for FL, disease-free survival remains short, and median time to progression is just over a year. Autologous stem cell transplantation in patients with relapsed FL is safe and appears to improve disease-free survival.
View Article and Find Full Text PDFThe quantitative assessment of body iron based on measurements of the serum ferritin and transferrin receptor was used to examine iron status in 800 Bolivian mothers and one of their children younger than 5 years. The survey included populations living at altitudes between 156 to 3750 m. Body iron stores in the mothers averaged 3.
View Article and Find Full Text PDFAnaemia is typically the first clue to iron deficiency, but an isolated haemoglobin measurement has both low specificity and low sensitivity. The latter can be improved by including measures of iron-deficient erythropoiesis such as the transferrin iron saturation, mean corpuscular haemoglobin concentration, erythrocyte zinc protoporphyrin, percentage of hypochromic erythrocytes or reticulocyte haemoglobin concentration. However, the changes in these measurements with iron deficiency are indistinguishable from those seen in patients with the anaemia of chronic disease.
View Article and Find Full Text PDFSeveral reports have defined nonfamilial thrombotic thrombocytopenic purpura (TTP) as an autoimmune disorder caused by antibodies to von Willebrand's factor-cleaving protease (vWF-CP). This raises the possibility that rituximab, a monoclonal antibody against CD20 present in B-lymphoid cells, may have utility in the treatment of TTP. We report five consecutively treated patients with relapsed TTP who responded rapidly to immune suppression by rituximab at our institution.
View Article and Find Full Text PDFIn the past seven years numerous genes that influence iron homeostasis have been discovered. Dr. Beutler provides a brief overview of these genes, genes that encode HFE, DMT-1, ferroportin, transferrin receptor 2, hephaestin, and hepcidin to lay the groundwork for a discussion of the various clinical forms of iron storage disease and how they differ from one another.
View Article and Find Full Text PDFBackground: Fish sauce is consumed daily by a large proportion of the Vietnamese population and could therefore be a potentially useful food vehicle for iron-fortification programs.
Objective: We evaluated the efficacy of iron-fortified fish sauce in improving the iron status of anemic women.
Design: In a randomized, double-masked study of 152 anemic (hemoglobin concentration of 81-119 g/L) women, a meal based on noodles or rice was served 6 d/wk with 10 mL fish sauce containing either 10 mg Fe as NaFeEDTA (iron-fortified group) or no added iron (control group).
Background: Phytic acid in cereal-based and legume-based complementary foods inhibits iron absorption. Low iron absorption from cereal porridges contributes to the high prevalence of iron deficiency in infants from developing countries.
Objective: The objective was to measure the influence of phytic acid degradation on iron absorption from cereal porridges.
Current initiatives to reduce the high prevalence of nutritional iron deficiency have highlighted the need for reliable epidemiologic methods to assess iron status. The present report describes a method for estimating body iron based on the ratio of the serum transferrin receptor to serum ferritin. Analysis showed a single normal distribution of body iron stores in US men aged 20 to 65 years (mean +/- 1 SD, 9.
View Article and Find Full Text PDFFortification of cereal flours may be a useful public health strategy to combat iron deficiency. Cereal flours that are used shortly after production (e.g.
View Article and Find Full Text PDFThe aim of the present study was to compare Fe absorption from industrially-manufactured and home-cooked cereal foods. Fe absorption was measured using the radiolabelled Fe extrinsic tag technique in thirty-nine adult human subjects from cereal porridges manufactured by extrusion cooking or roller-drying, and from the same cereal flours after home cooking to produce pancakes, chappattis or bread. One series of cereal porridges was amylase-treated in addition before roller-drying.
View Article and Find Full Text PDFSevere aplastic anemia can be treated with either bone marrow transplantation (BMT) or immunosuppressive therapy (IST). A retrospective review of patients with severe aplastic anemia treated with both of these modalities was conducted. Fifteen BMT and 16 IST patients were available for analysis, and follow-up of 22 and 15 years was available for the BMT and IST groups, respectively.
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