Soluble Transferrin Receptor Concentrations Research Articles

Serum soluble transferrin receptor concentrations in US preschool children and non‐pregnant women of childbearing age from the National Health and Nutrition Examination Survey 2003–2008

Serum soluble transferrin receptor (sTfR) is elevated during increased cellular iron demands and erythropoiesis. It is recommended as a sensitive and accurate measure of iron deficiency in populations. The lack of assay standardization and of representative data on the distribution of sTfR in at‐risk populations limits its use. Using data from NHANES 2003–2008, we examined the distribution of sTfR and developed assay‐specific cutoff values for defining elevated sTfR in two US populations groups: children 1–5 y (n=2042) and non‐pregnant women 12–49 y (n=5656). On average, children had higher geometric mean sTfR concentrations (4.20 mg/L; CI: 4.15–4.26) than non‐pregnant women (3.42 mg/L; CI: 3.37–3.48) (p<0.001). Among children, those aged 1–2 y (compared to those aged 3–5 y), boys (compared to girls), and non‐Hispanic black [NHB] children (compared to non‐Hispanic white [NHW] and Mexican‐American [MA] children) had higher sTfR concentrations. Among non‐pregnant women, adolescents (12–19 y) had higher sTfR concentrations than adults aged 20–34 y but not compared to adults aged 35–49 y; NHB women (compared to NHW and MA women) and multiparous women (compared to nulliparous women) had higher sTfR concentrations. The derived cutoff values (95th percentile in a defined healthy reference population) for elevated sTfR in the US were 5.74 mg/L for children 1–5 y and 4.94 mg/L for non‐pregnant women 12–49 y.

The Effects of 8 Weeks of Endurance Running on Hepcidin Concentrations, Inflammatory Parameters, and Iron Status in Female Runners

Exercise-associated iron deficiency is a common disorder in endurance athletes. The authors investigated the effects of long-term endurance exercise on hepcidin concentrations, inflammatory parameters, and iron status in moderately trained female long-distance runners. Eighteen runners were assigned to either an interval- or a continuous-training exercise group. The physical training consisted of two 3-week progressive overload periods, each followed by a week's recovery, and concluded with a 10- or 21-km competitive run. Samples were taken 6 times during the 8-wk training program, first at baseline (BPre), then after the first and second 3-wk training loads (TPost1, TPost2), after each recovery week (Recovery1 and Recovery2), and poststudy (BPost). Soluble transferrin receptor (sTfR) concentrations were increased in Recovery2 and BPost compared with BPre (p=.02), hemoglobin decreased in TPost1 and TPost2 (p<.001), and red blood cells decreased in TPost2 (p=.01). Hepcidin decreased with time in TPost1 and in BPost compared with BPre (p<.001) and increased in TPost2 compared with TPost1 (p<.001). No differences over time were found for high-sensitivity C-reactive protein. The main findings of the current study indicate that serum hepcidin and sTfR were affected after 8 weeks of endurance running in women. No positive relation was found with inflammation.

Hepcidin expression in patients with acute leukaemia

Hepcidin plays a central role in iron homeostasis, which is regulated by iron stores, the rate of erythropoiesis, inflammation, and hypoxia. Aberrant expression of hepcidin was found in many diseases, however, there is scant information on hepcidin expression in acute leukemia (AL). 32 patients with AL which diagnosis according to FAB criteria were studied. Serum hepcidin levels, erythropoietin (EPO), interleukin-6 (IL-6), hematological parameters, intracellular and extracellular iron store were evaluated. Hepcidin was elevated significantly with increased iron storage in patients at onset of AL when erythropoiesis was depressed by blast cells, then decreased significantly with AL remission, while soluble transferrin receptor (sTfR) concentration was elevated. Negative correlations were found between serum hepcidin and erythropoietic markers including RBC, Hb, Ret and sTfR. Positive correlations were shown between hepcidin and ferritin, between hepcidin and ratio of sideroblasts, as well as between hepcidin and IL-6. Hepcidin production was regulated by iron stores, inflammation and erythropoietic activity in AL patients. Erythropoietic activity may play the main role among the regulators of hepcidin expresssion.

Hepatic iron stores are increased as assessed by magnetic resonance imaging in a Chinese population with altered glucose homeostasis

Emerging scientific evidence has disclosed a correlation between iron metabolism and type 2 diabetes (T2D). The objective of this study was to test the hypothesis that body iron stores are higher in a Chinese population with altered glucose homeostasis. Serum iron, ferritin, and soluble transferrin receptor concentrations were measured in 298 subjects, including 70 subjects with normal glucose tolerance (NGT group), 60 subjects with prediabetes (prediabetes group), and 168 subjects with T2D (T2D group). Hepatic iron stores in 88 subjects were assessed by using a magnetic resonance imaging (MRI) T2* gradient-recalled-echo technique. A general linear model ANOVA was performed for comparisons between groups after adjustment for age and BMI. Stepwise multiple linear regression analysis was used to identify factors associated with the MRI-estimated hepatic iron concentration (M-HIC). Mean (±SD) M-HIC and R2* values in the prediabetes and T2D groups were significantly higher than in the NGT group (M-HIC: 40.6 ± 8.6 and 39.3 ± 10.7 μmol/g compared with 27.8 ± 9.1 μmol/g; R2* values: 47.9 ± 11.9 and 47.3 ± 11.5 s(-1) compared with 34.9 ± 7.0 s(-1); all P < 0.01). No significant difference was shown in M-HIC and R2* values between prediabetes and T2D groups. The M-HIC independently contributed to 43.3% of the glycated hemoglobin variance after adjustment for main clinical indexes (P < 0.001). The proportions of subjects with mild hepatic iron overload in the NGT, prediabetes, and T2D groups were 12.5%, 70.6%, and 63.6%, respectively. To our knowledge, our findings provide novel evidence to support the hypothesis of a mild iron overload in patients with prediabetes and T2D. A cohort study concerned with the effect of the attenuation of excess iron on glucose metabolism in a prediabetic population is warranted.

Relationship of the Availability of Micronutrient Powder with Iron Status and Hemoglobin among Women and Children in the Kakuma Refugee Camp, Kenya

Micronutrient powder is a potential strategy to improve iron status and reduce anemia in refugee populations. To evaluate the effect of the availability of home fortification with a micronutrient powder containing 2.5 mg of sodium iron ethylenediaminetetraacetate (NaFeEDTA) on iron status and hemoglobin in women and children in the Kakuma Refugee Camp in northwest Kenya. Hemoglobin and soluble transferrin receptor were measured in 410 children 6 to 59 months of age and 458 women of childbearing age at baseline (just before micronutrient powder was distributed, along with the regular food ration) and at midline (6 months) and endline (13 months)follow-up visits. At the baseline, midline, and endline visits, respectively, the mean (+/- SE) hemoglobin concentration in women was 121.4 +/- 0.8, 120.8 +/- 0.9, and 120.6 +/- 1.0 g/L (p = .42); the prevalence of anemia (hemoglobin < 120 g/L) was 42.6%, 41.3%, and 41.7% (p = .92); and the mean soluble transferrin receptor concentration was 24.1 +/- 0.5, 20.7 +/- 0.7, and 20.8 +/- 0.7 nmol/L (p = .0006). In children, the mean hemoglobin concentration was 105.7 +/- 0.6, 109.0 30322 1.5, and 105.5 +/- 0.3 g/L (p = .95), respectively; the prevalence of anemia (hemoglobin < 110 g/L) was 55.5%, 52.3%, and 59.8% (p = .26); and the mean soluble transferrin receptor concentration was 36.1 +/- 0.7, 29.5 +/- 1.9, and 28.4 +/- 3.2 nmol/L (p = .02), in models that were adjusted for age using least squares means regression. In children and in women of childbearing age, the availability of micronutrient powder was associated with a small improvement in iron status but no significant change in hemoglobin in this refugee camp setting.

Analysis of CD177 neutrophil expression in β-thalassemia patients

Ineffective erythropoiesis plays a well established role in the pathophysiology of disease expression in β-thalassemia major and intermedia. CD177 expression was investigated in different clinical conditions. The study aimed to analyze neutrophil expression of CD177 in β-thalassemia patients and its correlation with serum soluble transferrin receptor (s-TfR) concentration as a marker for the extent of erythropoiesis and hence disease severity in these patients. Flow cytometric analysis of neutrophil CD177 expression and enzyme immunoassay measurement of serum s-TfR concentration were assessed in 45 β-thalassemia patients of whom 36 had β-thalassemia major and nine had β-thalassemia intermedia. They were also assessed in 21 age- and gender-matched control children. Neutrophil mean fluorescence intensity ratio (MFIR) of CD177 expression was significantly higher in patients than in controls (p < 0.001). There was highly significant increase in serum s-TfR concentration in β-thalassemia patients than in controls (p < 0.001). There was a highly significant positive correlation between MFIR of CD177 expression and serum s-TfR concentration in β-thalassemia patients (r = 0.59, p < 0.001). Elevated CD177 expression is not only a specific feature of polycythemia rubra vera (PV) but may be also an indicator of increased erythropoietic activity in thalassemia syndromes.

Assessment of iron status in US pregnant women from the National Health and Nutrition Examination Survey (NHANES), 1999–2006

Total body iron calculated from serum ferritin and soluble transferrin receptor concentrations allows for the evaluation of the full range of iron status. We described the distribution of total body iron and the prevalence of iron deficiency (ID) on the basis of total body iron in US pregnant women. We examined data from the National Health and Nutrition Examination Survey (NHANES) in 1999-2006 for 1171 pregnant women. ID prevalence (±SE) in US pregnant women, which was defined as total body iron <0 mg/kg, was 18.0 ± 1.4%. Pregnant women in the first trimester had a higher mean total body iron than did pregnant women in the second or third trimesters. ID prevalence in pregnant women increased significantly with each trimester (6.9 ± 2.2%, 14.3 ± 2.1%, and 29.5 ± 2.7% in the first, second, and third trimesters, respectively). Pregnant women with parity ≥2 had the lowest mean total body iron and the highest prevalence of ID compared with values for pregnant women with parity of 0 or 1. The ID prevalence in non-Hispanic white pregnant women was significantly lower than in Mexican American or non-Hispanic black pregnant women. The mean total body iron and the prevalence of ID did not differ by educational level or by family income. To our knowledge, these are the first data on total body iron distributions for a representative sample of US pregnant women. Low total body iron is more prevalent in pregnant women in the second or third trimesters, in Mexican American pregnant women, in non-Hispanic black pregnant women, and in women with parity ≥2.

Role of androgen-mediated enhancement of erythropoiesis in the increased body iron stores of patients with polycystic ovary syndrome

To determine whether androgen excess contributes to the increased body iron stores of polycystic ovary syndrome (PCOS) by stimulating erythropoietic activity, by measuring serum soluble transferrin receptor (sTfR) concentrations and its ratio to ferritin levels in patients with PCOS, as surrogate markers of erythropoietic activity and of the appropriateness of cellular iron demands for the total body iron contents, respectively. Case-control study. Academic hospital. One hundred-four patients with PCOS and 100 controls without androgen excess. Blood sampling and oral glucose tolerance test. Serum sTfR and ferritin concentrations, as well as indexes of androgen excess, inflammation, obesity, and insulin and glucose metabolism. Serum ferritin levels increased in women presenting with PCOS, obesity, and/or abnormal glucose tolerance, but these disorders did not influence sTfR concentrations. The sTfR/ferritin ratio decreased with obesity and abnormal glucose tolerance, and its logarithm correlated inversely with body mass index, free T, and C-reactive protein levels and directly with the insulin sensitivity and disposition indexes. A stepwise multiple regression analysis indicated that the changes in the insulin sensitivity index explained 7% of the variability of the logarithm of sTfR/ferritin ratio. Increased serum ferritin levels in patients with PCOS are associated with a reduction in insulin sensitivity but do not result from a putative enhancement of erythropoiesis by androgen excess.

Weight status and iron deficiency among urban Malian women of reproductive age

The present study investigated the association between weight status and Fe deficiency (ID) among urban Malian women of reproductive age. Height, weight, serum ferritin (SF), soluble transferrin receptor (sTfR) and C-reactive protein (CRP) concentrations were measured in sixty apparently healthy women aged 15-49 years old in Bamako, Mali. Prevalences of overweight and obese were 19 and 9%, respectively. SF was non-significantly different between overweight (84μg/l) and normal-weight women (52μg/l). The prevalence of ID (SF<12μg/l) was 9% in the overweight group and no true ID (sTfR>8·3mg/l) cases were recorded in the overweight and obese groups. The prevalence OR of ID (SF<12μg/l) in the overweight group was NS (OR=0·3; P=0·363). Conversely, the chronic energy deficiency group was at a significantly higher risk of ID than the normal-weight group, adjusting or not for CRP (OR=7·7; 95% CI 1·49, 39·96; P=0·015). The lack of association between overweight and ID in the present study could be due to the fact that the excess of body fat of the women might not be critical to induce chronic inflammation related to reduced Fe absorption. Future research based on a larger convenience sample should be designed to further investigate associations between overweight, obesity and ID in developing countries.

Gold kiwifruit consumed with an iron-fortified breakfast cereal meal improves iron status in women with low iron stores: a 16-week randomised controlled trial

Ascorbic acid, and more recently, the carotenoids lutein and zeaxanthin have been shown to enhance Fe absorption. However, it is not clear whether Fe status improves when foods high in ascorbic acid and carotenoids are consumed with Fe-fortified meals. The present study aimed to investigate whether consuming high v. low ascorbic acid-, lutein- and zeaxanthin-rich fruit (gold kiwifruit v. banana) with Fe-fortified breakfast cereal and milk improved Fe status in women with low Fe stores. Healthy women aged 18-44 years (n 89) with low Fe stores (serum ferritin≤25μg/l and Hb≥115g/l) were randomly stratified to receive Fe-fortified breakfast cereal (16mg Fe as ferrous sulfate), milk and either two gold kiwifruit or one banana (164mg v. not detectable ascorbic acid; 526 v. 22·90μg lutein and zeaxanthin, respectively) at breakfast every day for 16 weeks. Biomarkers of Fe status and dietary intake were assessed at baseline and end in the final sample (n 69). Median serum ferritin increased significantly in the kiwifruit group (n 33) compared with the banana group (n 36), with 10·0 (25th, 75th percentiles 3·0, 17·5) v. 1·0 (25th, 75th percentiles -2·8, 6·5) μg/l (P<0·001). Median soluble transferrin receptor concentrations decreased significantly in the kiwifruit group compared with the banana group, with -0·5 (25th, 75th percentiles -0·7, -0·1) v. 0·0 (25th, 75th percentiles -0·3, 0·4) mg/l (P=0·001). Consumption of an Fe-fortified breakfast cereal with kiwifruit compared with banana improved Fe status. Addition of an ascorbic acid-, lutein- and zeaxanthin-rich fruit to a breakfast cereal fortified with ferrous sulfate is a feasible approach to improve Fe status in women with low Fe stores.

Randomized, double-blind, placebo-controlled trial of an iron-fortified food product in female soldiers during military training: relations between iron status, serum hepcidin, and inflammation

Iron status degrades in female soldiers during military training. Inflammation-mediated up-regulation of hepcidin, a key mediator of iron homeostasis, may be a contributing factor. We measured the efficacy of an iron-fortified food product for maintaining iron status in female soldiers during basic combat training (BCT) and examined relations between iron status, serum hepcidin concentrations, and inflammation. A randomized, double-blind, placebo-controlled trial was conducted. Volunteers received an iron-fortified food product (total dose = 56 mg Fe/d) or a placebo twice daily during the 9-wk BCT course. Iron-status indicators, serum hepcidin concentrations, and markers of inflammation were measured pre- and post-BCT. BCT affected iron status; serum ferritin concentrations decreased (P < or = 0.05), and concentrations of soluble transferrin receptor (sTfR) and hemoglobin and the red cell distribution width increased (P < or = 0.05). Consumption of the iron-fortified food product attenuated declines in iron status in iron-deficient anemic soldiers; a group-by-time interaction was observed for hemoglobin and sTfR concentrations (P < or = 0.05). Serum hepcidin concentrations were not affected by BCT; however, hepcidin concentrations were lower in iron-deficient anemic soldiers than in those with normal iron status (P < or = 0.05) and were positively associated with serum ferritin (P < or = 0.05) and C-reactive protein (P < or = 0.05) concentrations pre- and post-BCT. Twice-daily consumption of an iron-fortified food product improved iron status in iron-deficient anemic soldiers but not in iron-normal or iron-deficient nonanemic soldiers. Serum hepcidin concentrations were not affected by training but were associated with iron status and inflammation pre- and post-BCT. This trial was registered at clinicaltrials.gov as NCT01100905.

Deficiência de ferro no idoso

Anemia is a common problem in the elderly and is associated with significant morbidity and mortality. More than 10% of all individuals above the age of 65 have anemia. Because an increasing proportion of the world's population is aged 65 and older, it is inevitable that the prevalence of anemia will increase in the future. Thus, early diagnosis of anemia is important to prevent the condition from worsening, to slow disease progression, and improve outcomes in patients. The WHO definition of anemia (hemoglobin concentration <12 g/dL, in women and <13 g/dL, in men) is most often used in epidemiologic studies of older adults. Among older adults with anemia approximately one-third have evidence of iron, folate, and/or vitamin B12 deficiency, another third have renal insufficiency and/or chronic inflammation, and the remaining third have anemia that is unexplained. Anemia due to iron deficiency (IDA) is microcytic and hypochromic. Low serum ferritin levels, high total iron-binding capacity, low transferrin saturation, high concentrations of soluble transferrin receptor, and absent bone marrow iron stores accompany IDA. Iron deficiency in the elderly usually occurs as a result of chronic gastrointestinal blood loss caused by gastritis, ulcers, colon cancer, or angiodysplasia. Gastrointestinal tract abnormalities can be identified in the majority of patients with IDA. In some cases, inadequate intake or inadequate absorption of iron may contribute to the anemia. However, in all cases blood loss should be investigated and excluded before assuming that iron deficiency is due to other causes. Treatment includes stopping blood loss and replacing iron.

Total Hemoglobin Mass, Iron Status, and Endurance Capacity in Elite Field Hockey Players

The aims of this study were as follows: To evaluate total hemoglobin mass (tHbmass) in international field hockey players; to examine the correlation between tHbmass and maximum oxygen uptake (VO2max); and to assess influences of iron status on tHbmass and on VO2max. The players of the German women's (N = 17, aged 24.8 +/- 3.0 [21-31] years) and men's (N = 17, aged 24.2 +/- 2.9 [19-32] years) national field hockey team were investigated. tHbmass was measured by an optimized carbon monoxide rebreathing method. The following parameters were measured in venous blood: Hemoglobin concentration (Hbconc), hematocrit (Hct), number and percentage of reticulocytes, reticulocyte hemoglobin content, serum iron, serum ferritin, serum transferrin, unsaturated iron-binding capacity, and serum soluble transferrin receptor concentration. VO2max was determined in a treadmill test. tHbmass (women: 10.6 +/- 1.1 g/kg; men: 12.5 +/- 0.9 g/kg) correlated to VO2max (women: 46.6 +/- 2.9 mL/min/kg; men: 55.8 +/- 4.0 mL/min/kg) in women (r = 0.56, p < 0.05) and in men (r = 0.57, p < 0.05), whereas Hbconc and Hct did not. The investigated parameters of iron status showed no association to tHbmass or to VO2max. In conclusion, tHbmass can be used as an indicator for endurance capacity in elite field hockey players, whereas Hbconc may not. tHbmass or VO2max were not influenced by the actual iron status of the investigated athletes.

Association of increased maternal ferritin levels with gestational diabetes and intra-uterine growth retardation

The objectives of the present study were to determine whether or not increased serum ferritin in women with premature labour is associated with gestational diabetes mellitus (GDM) and intra-uterine growth retardation (IUGR) and, if so, whether or not such increased levels reflect excess maternal iron stores, and have an effect on neonatal iron status and outcome. This prospective, single-hospital, observational study involved 63 mothers and their 90 preterm neonates. Full blood counts as well as serum ferritin, soluble transferrin receptor (sTfR) and erythropoietin concentrations were compared across the three study groups based on maternal ferritin levels at the time of delivery. Perinatal history, neonatal morbidity and early outcomes were also assessed. High maternal ferritin levels were significantly associated with higher rates of GDM and IUGR. However, there was no correlation between maternal ferritin and sTfR levels or between maternal and neonatal iron status. Elevated maternal ferritin is not a reflection of excess iron stores, but is related to an increased risk of GDM or IUGR. Also, maternal ferritin levels are not associated with either neonatal iron status or neonatal outcomes.

Decreased serum prohepcidin concentration in patients with polycythemia vera

Iron deficiency is a common complication in patients with polycythemia vera (PV). Hepcidin is a principal regulator of iron homeostasis. The aim of our study was to assess prohepcidin, a hepcidin precursor, and other iron status parameters in the serum of PV patients. The study was performed in 60 patients (F/M 26/34) aged 38~84 (66+/-10) years. The control group consisted of 20 healthy volunteers, age and sex matched. The following parameters were determined in blood serum samples: prohepcidin concentration, iron content, unsaturated iron binding capacity (UIBC), total iron binding capacity (TIBC), transferrin saturation (TfS), and concentrations of ferritin and soluble transferrin receptor (sTfR). All PV patients showed significantly lower levels of prohepcidin, higher levels of sTfR and TIBC compared to the control group. 40% of the patients from the study group showed concentrations of ferritin below the normal range and significantly lower levels of serum iron and TfS, and significantly higher levels of sTfR, UIBC and TIBC in comparison with the rest of the study group. In this group of patients, prohepcidin concentrations were significantly lower than those in other patients. The results indicate that PV patients suffer from iron metabolism disorders. The decreased serum level of prohepcidin in PV patients may be a result of iron deficiency.

Improved method for assessing iron stores in the bone marrow

Background:Bone marrow iron microscopy has been the “gold standard” method of assessing iron deficiency. However, the commonly used method of grading marrow iron remains highly subjective.Aim:To improve the bone marrow...

Hepcidin and Iron Deficiency in Pre-Kidney Transplant Patients

Hepcidin is a hormone that regulates the intestinal absorption of iron and its release from the reticuloendothelium. The objective of this study was to determine the use of hepcidin for kidney disease patients with a diagnosis of iron deficiency pretransplantation by evaluating the soluble transferrin receptor (sRTfR-F) index as a marker for iron deficiency. This transverse study of 164 pretransplant patients determined hematometry and conventional markers related to iron metabolism, as well as soluble transferrin receptor (sTfR), its index (sTfR-F), and serum hepcidin concentrations. The following markers of inflammation (MIF) were also assessed C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and soluble TNF-alpha receptor (s-TNF-alphaR). Among the studied patients, 11.4% showed an absolute iron deficiency with ferritin concentrations < 100 ng/mL, a mean hepcidin value of 120.7 +/- 38.5 ng/mL, and a mean sTfR-F value of 1.03 +/- 0.3; 18.2% of patients displayed a ferritin > 800 ng/mL with mean hepcidin and sTfR-F values of 147.5 +/- 36.6 ng/mL and 0.54 +/- 0.2, respectively. Iron deficiency was not observed in the other patients when considering the conventional markers: ferritin > 100 ng/mL and transferrin saturation (ST) > 20%. However, this study showed that determination of hepcidin concentrations together with M/F improved the identification of iron deficiency in pretransplant patients by 21.6%.

Circulating soluble transferrin receptor concentration decreases after exercise-induced improvement of insulin sensitivity in obese individuals

Circulating soluble transferrin receptor (sTfR) has been recently found to be associated negatively with insulin sensitivity. To evaluate circulating sTfR concentration after changing insulin sensitivity in obese individuals. Circulating sTfR concentration was evaluated after diet-induced weight loss in obese women (diet (D) group, n=8); after diet-induced weight loss plus resistance training (D+RT group, n=11); and after follow-up without weight loss (control (C) group, n=7). After 16 weeks, insulin sensitivity (HOMA (Homeostasis Model Assessment) value) significantly improved in parallel to weight loss (-7.3%) and reduced total fat mass (evaluated using magnetic resonance imaging) in the D group. Thigh muscle mass decreased significantly (P=0.03). Serum sTfR concentration did not change significantly. In the D+RT group, weight loss (-8.7%) and improvement of insulin sensitivity were of similar magnitude. Thigh muscle mass was preserved (P=0.8). Serum sTfR concentration decreased significantly (P=0.001). Interestingly, higher the thigh muscle volume after weight loss, higher the decrease in circulating sTfR concentration. We also found that higher the increases in leg force at week 16, higher the decrease in circulating sTfR concentration in all individuals as a whole. No significant changes were observed in insulin sensitivity, sTfR concentration or thigh muscle mass in the C group. These findings suggest a long-term regulation of serum sTfR concentration by exercise-induced improvement of insulin sensitivity in obese individuals.

Dietary practices and nutritional status of 0–24-month-old children from Brazilian Amazonia

To assess the nutritional status and dietary practices of 0-24-month-old children living in Brazilian Amazonia. Cross-sectional study. Information on children's dietary intakes was obtained from diet history data. Weight and length were measured for anthropometric evaluation. Fe status was assessed using fasting venous blood samples; Hb, serum ferritin and soluble transferrin receptor concentrations were measured. The towns of Assis Brasil and Acrelândia in the state of Acre, north-west Brazil. A total of sixty-nine randomly selected 0-24-month-old children. Of these children, 40.3 % were anaemic, 63.1 % were Fe-deficient, 28.1 % had Fe-deficiency anaemia and 11.6 % were stunted. Breast-feeding was initiated by 97.1 % of mothers, followed by early feeding with complementary foods. The dietary pattern reflected a high intake of carbohydrate-rich foods and cow's milk, with irregular intakes of fruit, vegetables and meat. All infants and 92.3 % of toddlers were at risk of inadequate Fe intakes. Fe from animal foods contributed on average 0.5 % and 14.3 % to total dietary Fe intake among infants and toddlers, respectively. Poor nutritional status and inadequate feeding practices in this study population reinforce the importance of exclusive breast-feeding during the first 6 months of life. Greater emphasis is required to improve the bioavailability of dietary Fe during complementary feeding practices.

Iron deficiency anemia: diagnosis and management

Iron deficiency anemia (IDA) still remains universally problematic worldwide. The primary focus of this review is to critique articles published over the past 18 months that describe strategies for the diagnosis and management of this prevalent condition. The medical community continues to lack consensus when identifying the optimal approach for the diagnosis and management of IDA. Current diagnostic recommendations revolve around the validity and practicality of current biomarkers such as soluble transferrin-receptor concentrations and others, and cause-based diagnostics that potentially include endoscopy. Management of IDA is based on supplementation combined with effective etiological treatment. Advances in oral and parenteral low-molecular-weight iron preparations has expanded and improved treatment modalities for IDA. Since the introduction of low versus high-molecular-weight intravenous iron administration, there have been fewer serious adverse events associated with parenteral iron preparations. Best practice guidelines for diagnosing and managing IDA should include the design of an algorithm that is inclusive of multiple biomarkers and cause-based diagnostics, which will provide direction in managing IDA, and distinguish between IDA from the anemia of chronic disease.