Despite the established utility of serum transferrin receptor (sTfR), serum ferritin, and the sTfR/log ferritin ratio (TfR-F Index) in the diagnosis of iron deficiency (ID) anemia, the numeric values of these parameters, which are indicative of subclinical ID, remain to be clearly defined. In this study, 65 apparently healthy nonanemic adults (22 men and 43 women) were treated with 3 months of oral iron supplementation to evaluate its effect on parameters reflecting iron status and to determine the prevalence of subclinical iron deficiency in apparently healthy adults. Significant supplementation-induced changes were observed in sTfR, ferritin, and TfR-F Index values in women, whereas in men, none of the studied parameters showed any significant change. Iron-deficient erythropoiesis (IDE) was not observed in men, but was found in 17 women (40%). Although individuals with a compromised iron status may be represented in substantial numbers in conventional reference populations, they can be readily identified using sTfR, ferritin, and TfR-F Index determinations. © 1998 by The American Society of Hematology.

Objective-Obesity is associated with endothelial dysfunction that may contribute to the development of atherosclerosis.We studied whether weight reduction improves endothelial function in overweight individuals. Methods and Results-Flow-mediated endothelium-dependent vasodilation of the brachial artery was measured in 67 adults (age: 46Ϯ7 years, body mass index: 35.2Ϯ5.4 kg/m 2 ) before and after a 6-week weight reduction program induced by very-low-calorie diet (daily energy: 580 kcal/2.3 MJ). Caloric restriction reduced body weight from 101Ϯ18 to 90Ϯ17 kg. Flow-mediated vasodilation increased from 5.5%Ϯ3.7 to 8.8%Ϯ3.7% (PϽ0.0001). Nitrate-mediated vasodilation was not significantly affected. The improvement in flow-mediated dilation was associated with the reduction in plasma glucose concentration (Pϭ0.0003). This relationship was independent of changes in weight, serum lipids, oxidized LDL, C-reactive protein, adiponectin, blood pressure, and insulin. Key Words: endothelium Ⅲ obesity Ⅲ risk factors Ⅲ glucose Ⅲ weight reduction T he vascular endothelium plays an important role in the regulation of arterial tone, thrombosis, and inflammation. Endothelial dysfunction may predispose arteries to the development of atherosclerotic lesions and is pathophysiologically linked to acute cardiovascular syndromes. 1 A common condition associated with endothelial dysfunction is obesity. Endothelial-dependent vascular responses to both agoniststimulated 2,3 and flow-mediated vasodilation 4 have been shown to be blunted in obese individuals. The mechanisms of obesity-induced endothelial dysfunction may be multifactorial, because excess adipose tissue induces several metabolic changes that may interfere with normal endothelial function. These may include dyslipidemia, elevated blood pressure, increased inflammation, oxidative stress, and changes in glucose metabolism. 5 Although weight reduction is known to reduce several of these risk factors for endothelial dysfunction, it is inadequately known whether endothelial function can be improved by reducing weight. We hypothesized that weight loss induced by very-low-calorie diet would enhance flow-mediated endothelium-dependent vasodilation in overweight adults. To gain insight for possible mechanisms of weight-loss-mediated changes in flow-mediated dilation, we also measured changes in several potential biochemical determinants of endothelial function. Conclusions-Weight Methods SubjectsWe recruited overweight (body mass index Ͼ27kg/m 2 ) men and women from an occupational health service clinic. The exclusion criteria included diabetes, pregnancy, gout, gall stone disease, alcohol/drug abuse, liver/kidney disorder, psychiatric disorder, and use of cholesterol lowering medication.Of the 74 subjects enrolled, 47 women and 20 men completed the 6-week program (9.5% dropout rate). Sixteen women were postmenopausal (2 using hormone replacement therapy), 19 subjects had treatment for hypertension, and there were 7 smokers and 13 ex-smokers. Most participants (65%) were sedentary, engag...

The results of this study elucidate the roles of sTfR and the TfR-F Index in the differential diagnosis between IDA and ACD and provide direct evidence that these parameters are useful in detecting FID, irrespective of the concurrent iron storage status.

Long-term iron overload is detected in at least 14% of children after therapy for acute lymphoblastic leukemia. Serum sTfR is an inappropriate marker for liver iron overload, whereas ferritin seems to be the most useful serologic marker for it.

Results:The intra-and between-assay imprecision (CV) for the holoTC RIA were 4 -7% and 6 -8%, respectively. A 95% central reference interval for serum holoTC was 37-171 pmol/L. All participants (n ‫؍‬ 16) with probable Cbl deficiency, 86% of those with possible, and 30% of those with potential Cbl deficiency had holoTC below the reference limit (<37 pmol/L). The holoTC correlated

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During the last few years the measurement of serum-soluble transferrin receptor (sTfR) has been introduced as a tool to detect iron deficiency and as an analyte to differentiate between anemia caused by iron deficiency (IDA) and that caused by chronic disease (ACD). Commercially available methods have emerged to make diagnostics by sTfR more readily accessible. We documented the analytical performance of a newly introduced IDeATM sTfR immunoenzymometric assay (IEMA) by Orion Diagnostica. We also evaluated its clinical performance in 98 consecutive anemic patients, with information derived from bone marrow aspirate samples as the reference for iron status. The clinical usefulness of two other commercially available sTfR assays was assessed for comparison. The analytical performance and clinical applicability of the IDeA were sufficient to support reliable clinical work. We conclude that IDA and iron deficiency in the presence of inflammatory states can be differentiated efficiently from ACD with this new commercial test to measure sTfR.

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