铁过量与疾病

铁是人体所必需的微量元素，是几乎所有生物细胞正常生长所必需。严重的铁缺乏，其危害是显而易见的。但机体内铁代谢的失衡，身体内储存铁过多对机体的损害作用亦应引起重视。本文就机体内铁储存过多与某些疾病之间的关系作一综述。     

Hepcidin与铁代谢

铁元素是人体含量最多的必需微量元素，具有广泛的生理学和病理学作用。由于机体缺乏主动的铁排泄机制，肠道铁吸收的调控便成为维持机体铁稳态的关键。因此，深入研究机体铁代谢的精密调控变得更加重要。Hepcidin是一种肝脏合成的具有抗菌功能的多肽，是控制小肠铁吸收以及调节机体铁稳态的铁调节激素。肝脏Hepcidin基因高表达可能是许多贫血包括炎症和慢性疾病性贫血的根本原因，而Hepcidin表达障碍可能是许多铁超负荷类疾病的起因。全面研究Hepcidin与机体铁稳态的关系对铁代谢相关疾病的预防、诊断以及治疗可能具有十分重要的理论意义和应用价值。     

铁代谢障碍对机体功能的影响

机体通过一套严格的机制维持体内铁的平衡。任何环节出现异常都可导致铁代谢障碍，从而引起一系列病变如缺铁性贫血、血色病、铁中毒乃至恶性肿瘤等。本文从铁代谢障碍方面来综述近年来有关铁代谢的研究。     

037 Hepcidin与铁代谢

铁元素是人体含量最多的必需微量元素,具有广泛的生理学和病理学作用.由于机体缺乏主动的铁排泄机制,肠道铁吸收的调控便成为维持机体铁稳态的关键.因此,深入研究机体铁代谢的精密调控变得更加重要.Hepcidin是一种肝脏合成的具有抗菌功能的多肽,是控制小肠铁吸收以及调节机体铁稳态的铁调节激素.肝脏Hepcidin基因高表达可能是许多贫血包括炎症和慢性疾病性贫血的根本原因,而Hepcidin表达障碍可能是许多铁超负荷类疾病的起因.全面研究Hepcidin与机体铁稳态的关系对铁代谢相关疾病的预防、诊断以及治疗可能具有十分重要的理论意义和应用价值.     

运动与铁代谢

运动训练会导致铁代谢发生紊乱,从而使运动员发生缺铁性贫血。运动导致缺铁的原因可能在于吸收下降、摄入不足、丢失增加、溶血以及机体应激等方面。而铁缺乏时会导致运动能力的下降。在运动实践中铁的补充对防治铁缺乏具有一定的效果,但补铁更应该建立在一个有效的临床指导基础上。     

铁与人体健康

从生物化学和生理功能两方面分析讨论铁在机体内的分布、吸收、代谢以及铁负荷的多少对健康的影响。结果表明 :科学地把握铁的摄入量将促进人体的健康。     

013 铁负荷与人体健康

铁负荷指身体内的铁含量增加，伴有或不伴有器官的损害。遗传因素、后天获得性因素、膳食因素等可促使机体发生铁负荷。机体铁负荷会引起肝脏疾病、糖尿病、心脑血管疾病等多种疾病的发生。铁负荷带来的机体损害日益受到人们的重视。本文综述了铁负荷的发生、铁负荷与慢性病的研究进展及铁负荷的治疗。     

铁缺乏症的研究新进展

铁缺乏症（ＩＤＤ）是最见的营养缺乏性疾病之一，加强防治是儿童保健的重要课题。本文对ＩＤＤ的流行病学、母婴代谢关系、诊断及防治方法的研究现状和进展作了全面综述。     

铁负荷与人体健康

铁负荷指身体内的铁含量增加,伴有或不伴有器官的损害。遗传因素、后天获得性因素、膳食因素等可促使机体发生铁负荷。机体铁负荷会引起肝脏疾病、糖尿病、心脑血管疾病等多种疾病的发生。铁负荷带来的机体损害日益受到人们的重视。本文综述了铁负荷的发生、铁负荷与慢性病的研究进展及铁负荷的治疗。     

Food iron absorption in iron deficiency

The absorption of food iron in relation to the diet was studied in 10 phlebotomized normal young male subjects during 3 to 5 months. The iron absorption was calculated from the net increase of the hemoglobin mass. There was pronounced individual variation in the mean dietary absorption ranging between 1.9 and 5.0 mg. There was no correlation between the amount of iron absorbed and the amount of iron ingested. There was no apparent influence of a high or a low intake of animal products, cereals, vegetables, tea, or alcohol on the individual absorption values. A negative correlation between the iron absorption and the total amount of fecal dry substance was observed. This might be ascribed to an influence of dietary fibers on the absorption of food iron.     

Measurement of iron absorption from meals contaminated with iron

A method is described to measure in vitro the extent of isotopic exchange between the native nonheme food iron and added inorganic reduction to radioiron tracer. The food is digested with pepsin and trypsin in the presence of radioiron. The exchangeability of food iron is calculated from the specific activity in the food and in an extract of bathophenantroline in isoamyl alcohol obtained after digesting this food. The precision and accuracy of the method is illustrated by two kinds of studies, those in which different amounts of contamination iron are added to a meal and those evaluating contamination iron in natural meals. The present method will make it possible to measure validly iron absorption from meals contaminated with unknown amounts of iron of unknown exchangeability with the extrinsic radioiron tracer.     

Correct assessment of iron depletion and iron deficiency anemia

OBJECTIVE: Iron deficiency anemia is caused by decreased production of red blood cells (RBCs) and is characterized by a reduction in either the hematocrit (Ht) or the concentration of hemoglobin (Hb). It is detected by blood iron status measures that are below population reference standards and also below the "usual or normal" levels for an individual. In some medicine practices, usually only hemoglobin and hematocrit are routinely measured with a full blood count, without measuring the indicators of iron status. Biochemical measures that are collected on single occasion are difficult to interpret in individuals, and normal ranges of hemoglobin and hematocrit do not necessarily confirm an iron deficiency condition, because they decrease only when severe iron depletion is present and are often unreliable or misleading. Thus, iron-depleted individuals can quickly develop iron deficiency if not detected early. METHODS: Information from hematological laboratory tests records on female patients at reproductive ages were collected and analysed. RESULTS: In this study, measurement of general test for anemia in some individuals revealed normal levels of RBCs count, Hb, Ht, mean corpuscular volume (MCV), mean cell hemoglobin concentration (MCHC), and cell morphology, whereas the levels of parameters of iron depletion and iron deficiency anemia such as serum iron and ferritin showed reduced values. The results indicate that individuals who are ordered cell blood count (CBC) measures alone without examining the indicators of iron status (Group C vs Group D) may not be correctly assessed with a definitive diagnosis and categorized as normal individuals. But in fact, they are susceptible to iron depletion and could develop iron deficiency anemia. CONCLUSIONS: In evaluation of iron deficiency status it is important that total CBC test be accompanied by the other tests of iron status to pinpoint true iron deficiency. Otherwise, many cases may be missed out and misdiagnosed as normal individuals.     

孕母铁缺乏对新生儿铁水平的影响

目的:通过对孕母及新生儿铁相关指标的追踪调查探讨孕母铁缺乏对新生儿铁水平的影响。方法:全程追踪81例孕母,分别于孕早、中、晚期及分娩时测定血液中血红蛋白(Hb)、网织红细胞(Ret)、网织红细胞成熟指数(RMI)、血清铁(SI)、血清铁蛋白(SF)和血清转铁蛋白受体(sTfR)。结果:孕母孕早期各组间SF和SI的差异有统计学意义(P<0.05,P<0.01)。孕中期及孕晚期各组间SF的差异有统计学意义(P<0.05,P<0.01)。全程缺铁性贫血(IDA)组、中晚孕期IDA组与全程正常组组间比较及孕中晚期不同铁水平组间比较SI及SF的差异均有统计学意义(P<0.01,P<0.05)。结论:孕母不同孕期、不同程度铁缺乏对新生儿脐血铁水平有影响,孕母轻度铁缺乏会影响新生儿铁贮备,孕母缺铁越早对新生儿铁贮备的影响越大。     

Determining iron bio-availability with a constant heme iron value

Iron deficiency is the most common and widespread nutritional disorder in the world. Consuming foods rich in dietary iron (high in both content and availability) is an effective way to alleviate iron deficiency. Iron from animal foods is more bio-available than iron from plant sources. This is due to the heme iron content in animal foods. According to the Monsen model, an average of 40% of total iron in meat, fish and poultry is in the heme form. Although the Monsen model can provide a generally good estimate of the heme iron content in animal products, recent research has suggested that the constant 40% value of heme iron is either an under- or over-estimation, depending on the source of the food. During this study a review was performed on the heme iron content of meat, fish and poultry, and comparisons are made with reference to the Monsen model. The aim of this study was to investigate whether using the constant 40% value for heme iron is adequate in describing the bio-availability of total iron in a particular food.     

Women with low iron stores absorb iron from soybeans

BACKGROUND: Worldwide, 30% of the population, a greater proportion of whom are women and children, is iron deficient. Soybeans are a major source of nonheme iron in many human diets, but information on iron bioavailability is still conflicting. Because much of soybean iron is in ferritin [distinct from the poorly bioavailable iron in cereals resulting from interactions between calcium, Fe(III), phytate, and proteins in the meal], soybeans provide a target for manipulating seed iron composition to achieve increased iron bioavailability. OBJECTIVE: The aim was to reevaluate soybean iron bioavailability. DESIGN: Eighteen women, most with marginal iron deficiency, consumed meals with intrinsically labeled ((55)Fe) soybeans (hydroponically grown and nonnodulating) as soup (n = 11) or muffins (n = 7) and a reference dose of (59)Fe as ferrous sulfate in ascorbate solution. The radioactivity in red cells was measured 14 and 28 d later. RESULTS: The mean (55)Fe absorption from either soup or muffins was 27% and that from the reference dose was 61%. (55)Fe was distributed approximately equally between protein (49.3 +/- 3.0%) and phytate, a contrast with nodulating soybeans likely caused by a high phosphate content in the growth medium. There was an expected inverse correlation (r = -0.793, P < 0.001) between red cell radioactivity and serum ferritin concentration. CONCLUSIONS: These results show that soybeans appear to be a good source of nutritional iron in marginally iron-deficient individuals. More study is needed on the effect of plant nodulation on the form of soybean iron, aimed at enhancing bioavailability to combat iron deficiency in at-risk populations.