Leucocyte function in iron-deficiency anemia.

Production of hydrogenperoxide and myeloperoxidase-mediated iodination, by leucocytes was studied in normal subjects and subjects suffering from iron-deficiency anemia. The leucocytes obtained from severe cases of iron-deficiency anemia showed decreased myeloperoxidase-mediated iodination. Defective myeloperoxidase-mediated iodination can explain the basis for the leucocyte microbicidal defect in iron deficiency anemia.     

Impaired phenylalanine-tyrosine conversion in patients with iron-deficiency anemia studied by a L-(2H5)phenylalanine-loading test

Ten patients with manifest iron deficiency and without documented relationship to phenylketonuria patients were orally loaded with 25 mg/kg of L-(2H5)phenylalanine. Before loading, the fasting phenylalanine-tyrosine plasma ratio was determined and after loading, the concentrations of labeled and nonlabeled phenylalanine and tyrosine were determined in five consecutive plasma samples. With respect to the fasting phenylalanine-tyrosine ratio and to the post-load ratios of labeled phenylalanine over labeled tyrosine, the iron-deficient patients showed data intermediate between those of normals and heterozygotes for phenylketonuria. Compared to a 100% in vivo activity of phenylalanine hydroxylase in normals and a circa 37% activity in heterozygotes for classic phenylketonuria, iron-deficient patients with an average hemoglobin of 8.6 +/- 1 g/dl showed an activity of circa 56%. After normalization of their iron status, four patients were subjected again to the L-(2H5)phenylalanine-loading test. For three of these individuals, test results shifted into the range of normal.     

Effects of fungicides on thyroid function, metabolism, and thermoregulation in cotton rats

Among the myriad of recent studies on endocrine-disrupting chemicals, relatively few involve thyroid disruption, and most of these address exposure/disruption during embryonic life. Of those involving adult vertebrates, the endpoints examined are thyroid measurements. Even though thyroid disruption could potentially interfere with energy metabolism and thermoregulation such that over-winter survival might be compromised, the possible energetic consequences of these thyroid perturbations have not been investigated. We assessed thyroid function and measured resting metabolic rates of cotton rats chronically exposed to the fungicides vinclozolin or mancozeb. In addition, we measured norepinephrine-induced nonshivering thermogenesis and cold-induced thermogenesis and then cold-acclimated the mancozeb animals. Although thyroid hormone concentrations generally decreased, this was compensated for by an increase in thyroxine turnover (vinclozolin study only) such that thyroxine utilization rate was not different. In addition, there was no difference between the treated and control animals in any of the metabolic parameters measured. It is concluded that wild rodents exposed to these compounds are not energetically compromised.     

Using ferritin levels to determine iron-deficiency anemia in pregnancy

BACKGROUND: Standard obstetrical practice has included iron therapy for patients with anemia without requiring the determination of iron deficiency. However, the proportion of pregnant women with anemia who have such a deficiency may be relatively modest. We instituted a practice protocol using serum ferritin levels to determine the proportion of women undergoing prenatal care who had both anemia and iron deficiency. METHODS: We evaluated consecutive women entering prenatal care. Those with anemia (hemoglobin level <11 mg/dL) underwent testing for serum ferritin level and other hematologic variables. RESULTS: A total of 182 patients entered prenatal care. Hemoglobin data were available for 173 (95%). Thirty-eight (22%) had anemia (hemoglobin level <11 mg/dL); 1 of those women was excluded from the study. Using a ferritin level of 12 mg per dL as the cutoff for iron deficiency, 54% (20) of the 37 remaining patients with anemia had an iron deficiency, and 46% (17) had anemia not related to such a deficiency. Use of hematologic indices provided on complete blood count were not useful in predicting iron deficiency based on serum ferritin levels. CONCLUSIONS: In our population of prenatal patients with anemia, only approximately half had an iron deficiency. Diagnostic and therapeutic approaches to screening for anemia in pregnancy should be reconsidered and further evaluated.     

婴儿期营养性缺铁性贫血的现状分析

目的 调查婴儿缺铁性贫血现状.方法 对2006年7月～9月住院的716例婴儿开展贫血的临床表现、血液分析的结果、入院原发疾病的记录以及对于患儿喂养史、既往史及家族史的问卷式调查.结果 缺铁性贫血患儿检出率占同期住院婴儿的16.34%(117/716),其中轻度贫血88例(75.21%),中度贫血28例(23.93%),重度1例(0.85%).7～9月龄的婴儿缺铁性贫血检出率较高与喂养不当有关(χ2=10.7874,P＜0.005).结论 加强母婴保健,指导科学喂养是防治婴儿营养性缺铁性贫血的关键.     

健康促进改善缺铁性贫血的研究

缺铁性贫血(IDA)是目前我国急待解决的重要营养问题之一。江苏育龄妇女贫血患病率较高,个别地区育龄妇女贫血患病率高达65.8%[1],主要是铁缺乏引起[2,3]。2003年中国疾病预防控制中心食物强化办公室(FFO)在江苏南京、徐州、常州采用健康促进的方法开展了“应用铁强化酱油预防和     

Prevention and treatment of iron-deficiency anemia: new focuses and perspectives

The authors briefly describe the epidemiology of anemia, the goals established by the United Nations to combat the problem worldwide, and the difficulties encountered in applying proven effective strategies in public health services to prevent and cure anemia in pregnant women and children, both of which are prime high-risk groups. They analyze recent research aimed at four objectives related to prevention and cure: improving treatment efficacy; increasing effectiveness; reducing costs; and decreasing unwanted side effects. The study indicates that ongoing research could improve prospects for treatment through public health services.     

高原地区儿童缺铁性贫血及相关因素研究

了解高原地区0~6岁儿童的贫血状况及其影响因素,为制定贫血防治措施提供依据.方法 采用分层随机整群抽样的方法,抽取高原地区甘南藏族自治州4个县1 512名0~6岁儿童测定血红蛋白、问卷调查儿童饮食行为和家长营养知识.结果 不同年龄、家庭所在地、主要抚养人文化程度、主要抚养人职业、家庭人均收入儿童贫血患病率差异均有统计学意义(x2值分别为12.83,39.48,27.05,44.26,32.45,P值均<0.05).不同性别、民族儿童贫血患病率差异无统计学意义.0~6岁儿童贫血患病率为67.0%;1岁以下婴幼儿患病率最高,随着年龄增长患病率下降.农村儿童贫血患病率为74.0%,高于城市儿童的58.6%(x2=39.48,P<0.05).混合喂养和人工喂养的0~6月龄婴儿贫血患病率(73.1%,75.0%)高于纯母乳喂养的婴儿(48.9%)(x2=6.78,P<0.05).挑食可导致儿童贫血患病率高发.结论 针对高原地区儿童家长开展健康教育,合理调整饮食结构,纠正挑食等不良饮食习惯,可以降低儿童贫血发生率.     

Premature conclusions in the diagnosis of iron-deficiency anemia: cause and effect

Case records of patients with iron-deficiency anemia were audited using a computer-based algorithm. In 24 of 35 cases, the diagnostic conclusion seemed unjustified and characteristic of premature closure, one of four recurring errors in diagnostic reasoning described previously. Premature closure appeared to originate from subjects at all levels of training, to be easily and unquestioningly accepted by other physicians, and to inappropriately condition diagnostic and therapeutic decisions. Heuristics and biases described by Tversky and Kahneman are considered as contributory factors and patient care and teaching implications are discussed.     

Defining iron-deficiency anemia in public health terms: a time for reflection

This paper provides a historical context for this meeting, which aimed to examine critically the way we have defined iron-deficiency anemia as a public health problem. The terms and concepts used to define the problem are reviewed first, followed by estimates of the global prevalence of the problem from 1985 to 2000. It is argued that recent estimates are not credible and that we must redefine the problem in terms that are important, measurable and addressable. This meeting was designed to take first steps toward that goal, namely, to identify the causal factors (e.g., iron deficiency vs. iron-deficiency anemia vs. severe anemia from any cause) that link iron-deficiency anemia to important health outcomes and to estimate the magnitude of their effects in public health terms.     

Risk factors for iron-deficiency anemia in children and adolescents with intestinal helminthic infections]

OBJECTIVE: To investigate risk factors for iron-deficiency anemia in children and adolescents (7 to 17 years of age) with intestinal helminthic infections. METHODS: A cross-sectional study was carried out with 1 709 children and adolescents living in Jequié, a town in the state of Bahia, Brazil, who had mild to moderate infection by Schistosoma mansoni, Ascaris lumbricoides, Trichuris trichiura, or hookworms. We obtained data concerning hemoglobin levels (using a portable hemoglobinometer), dietary habits (24-hour dietary recall), parasitic infections (Kato-Katz method), sanitary conditions (water supply, sewage connection, garbage collection), housing conditions (type of construction, number of persons per room), income, and amount of schooling of the parents or guardians. The risk factors for anemia were studied based on a hierarchical model of causality. RESULTS: The prevalence of parasitic infection was 74.8% for T. trichiura, 63.0% for A. lumbricoides, 55.5% for S. mansoni, and 15.7% for hookworms. Among the children and adolescents studied 32.2% were anemic. After adjustment for confounding variables, the results of the multivariate analysis showed that the following variables were significantly associated with anemia: per capita family income below US$ 27 (equal to one fourth of the Brazilian minimum wage), male sex, age of 7 to 9 years, and inadequate intake of bioavailable iron. CONCLUSIONS: The initiatives to control anemia in the group at greatest risk, as identified in this study, should seek to increase the consumption of iron-rich foods, boost the bioavailability of the iron ingested, and improve socioenvironmental conditions.     

The developmental and probabilistic nature of the functional consequences of iron-deficiency anemia in children

It is often assumed that the psychometric tools currently available measure accurately the effects of iron-deficiency anemia (IDA) on cognition in young children and that such effects are rooted in cerebral changes. It is also assumed that snapshots of development within a clinical trial can document such effects. I challenge these assumptions on the basis of four considerations. The first is that there are multiple biological, physical and social-psychological factors that reorient the trajectory of different psychobiological domains in early life after intense and prolonged stress. Further, psychobiological development changes are not necessarily caused by brain changes; there are other mechanisms that also affect development (e.g., biomechanics). A second consideration focuses on intraindividual, interindividual and intergroup differences concerning the nature of the effect of IDA and the response to iron treatment. Individual and group factors can moderate the effects of IDA; for example, different stages of iron deficiency involve different systemic changes, which in turn affect different psychobiological domains. The third consideration is that differences in the time of measurement of an intervention within a randomized trial could lead to detecting effects in different domains or effects of different intensity within the same domain. Finally, developmental assessments with the traditional developmental scales during the first 18 mo of life yield equivocal findings. Snapshots of development will overlook the course of effects of a nutrition intervention over time. Repeated measures over time within the same domain are considered particularly useful to draw the course of development.