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。     

缺铁与铁过剩生物学作用

叙述人体必需微量元素铁，铁缺乏或过剩均可导致疾病的发生和生理变化     

孕妇微量元素铁与贫血的关系分析

目的探讨孕妇微量元素铁与贫血的关系,为孕期保健提供可靠的依据。方法应用原子吸收光谱仪对642名孕妇进行血液微量元素铁测定,并对血红蛋白(Hb)含量进行检测,分析两者的关系。结果 54.21%的孕妇存在微量元素铁的缺乏,34.58%的孕妇存在血红蛋白缺乏,贫血发生率与微量元素铁缺乏呈明显正相关。结论随着孕周的增加,缺铁性贫血孕妇比例升高,需采取综合措施,适当补充铁剂。     

微量元素铁与人体健康

铁(Fe)是人体必需微量元素,在人体中分布很广,几乎所有组织都含有铁,是人体发育的“建筑材料”。作者从多个方面对铁与人体健康的研究进行综述。     

6—18月婴幼儿全血微量元素铁缺乏对智能发育的影晌

目的：探讨全血微量元素铁缺乏对6-18月婴幼儿智能发育的影响。方法：选取儿童保健门诊174名微量元素铁缺乏的6—18月婴幼儿为病例组，同时参考120名微量元素铁正常组为对照组，使用盖塞尔发展诊断量表评估婴幼儿智能发育情况。结果：微量元素铁缺乏对6—18月婴幼儿智能各项能区发育有影响，病例组与对照组比较有显著差异。结论：微量元素铁缺乏可影响婴幼儿智能发育。     

绝经前期女性在不同工作环境中体内微量元素铁的变化

目的:探讨在不同工作环境中体内微量元素铁的变化。方法:采用调查问卷的方法对3组不同环境的4 500名绝经前期妇女进行调查和血标本收集。结果:在相同的工种且不同的环境中体内微量元素铁的丢失情况不同。结论:不同工作环境中,体内微量元素铁的丢失情况不同。应对不同工作环境的绝经前期妇女采取铁元素的补充,以防止微量元素铁过度丢失所引起机体贫血的发生和发展。     

反复呼吸道感染小儿血中锌 铁的变化和临床意义

目的:探讨小儿反复呼吸道感染与血清中微量元素锌、铁含量的关系。方法:采用电感耦合等离子发射光谱仪测定患儿血清中微量元素锌、铁与健康儿童作为对照组进行比较。结果:反复呼吸道感染患儿血清中微量元素锌、铁的含量明显低于健康儿童(P0.05)。结论:小儿反复呼吸道感染与血清中微量元素缺乏密切相关,应及时调整患儿体内微量元素的平衡,提高患儿的抗感染能力。     

绝经前期女性在不同工作环境中体内微量元素铁的变化

目的探讨在不同工作环境中体内微量元素铁的变化.方法采用调查问卷的方法对3组不同环境的4500名绝经前期妇女进行调查和血标本收集.结果在相同的工种且不同的环境中体内微量元素铁的丢失情况不同.结论不同工作环境中,体内微量元素铁的丢失情况不同.应对不同工作环境的绝经前期妇女采取铁元素的补充,以防止微量元素铁过度丢失所引起机体贫血的发生和发展.     

铁螯合剂治疗妇科肿瘤的研究

研究证明,增加外源性的铁元素可以防止细胞凋亡,而铁螯合剂可以抑制妇科肿瘤癌细胞生长。探讨微量元素铁在妇科肿瘤发生中的作用机制及铁螯合剂在治疗妇科肿瘤方面的作用,以期尽早将研究成果推广至临床妇科肿瘤的治疗领域。     

绝经铁多心脏病

世间一切事物都有其两面性,就以“铁”元素对人体作用而言,正是如此。以往人们只知道铁是人体生命活动尤其是造血不可缺少的微量元素,而近年又发现铁对人体也有不良作用,甚至被宣布为“比胆固醇更危险的有害因素”。     

Iron Metabolism in Man

Iron metabolism in man is a highly regulated process designed to provide iron for erythropoiesis, mitochondrial energy production, electron transport, and cell proliferation. The mechanisms of iron handling also protect cells from the deleterious effects of free iron, which can produce oxidative damage of membranes, proteins, and lipids. Over the past decade, several important molecules involved in iron homeostasis have been discovered, and their function has expanded our understanding of iron trafficking under normal and pathological conditions. Physiologic iron metabolism is strongly influenced by inflammation, which clinically leads to anemia. Although hepcidin, a small circulating peptide produced by the liver, has been found to be the key regulator of iron trafficking, molecular pathways of iron sensing that control iron metabolism and hepcidin production are still incompletely understood. With this review, we provide an overview of the current understanding of iron metabolism, the recently discovered regulators of iron trafficking, and a focus on the effects of inflammation on the process.     

Iron Sucrose Versus Oral Iron Therapy in Pregnancy Anemia

Background:

Iron deficiency anemia (IDA) is the most common medical problem in pregnancy. Parenteral iron is a useful treatment, although iron dextran use decreased due to anaphylaxis. Iron sucrose is a newer agent that has overcome the shortcomings of iron dextran.

Objective:

The aim of this study was to compare the efficacy and tolerance of intravenous iron sucrose (IVIS) therapy with oral iron (OI) therapy in pregnant women with IDA and to study the factors influencing treatment.

Materials and Methods:

This prospective, randomized clinical trial included pregnant women between 14 and 36 weeks with established IDA who were treated with IVIS or OI (ferrous fumarate). All patients were monitored for laboratory response and adverse effects. Independent sample-t test, Chi square test and ANOVA were used for statistical analysis. P < 0.05 was considered significant.

Results:

Although hemoglobin increased in both the groups, increase in the reticulocyte count and percentage increase in hemoglobin was significantly higher in the IVIS group than in the OI group (23.62% vs. 14.11%). Serum ferritin was significantly higher in the IVIS group than in the OI group (P = 0.000). The IVIS group had no major side-effects. Compliance was good with OI, although 23% had gastrointestinal side-effects. Patient weight, gestation at diagnosis, initial hemoglobin and ferritin levels did not influence the response to treatment.

Conclusion:

IVIS is safe and effective in the treatment of IDA during pregnancy. Iron stores increased better with IVIS compared with OI.     

Iron Deprivation in Cancer––Potential Therapeutic Implications

Iron is essential for normal cellular function. It participates in a wide variety of cellular processes, including cellular respiration, DNA synthesis, and macromolecule biosynthesis. Iron is required for cell growth and proliferation, and changes in intracellular iron availability can have significant effects on cell cycle regulation, cellular metabolism, and cell division. Perhaps not surprisingly then, neoplastic cells have been found to have higher iron requirements than normal, non-malignant cells. Iron depletion through chelation has been explored as a possible therapeutic intervention in a variety of cancers. Here, we will review iron homeostasis in non-malignant and malignant cells, the widespread effects of iron depletion on the cell, the various iron chelators that have been explored in the treatment of cancer, and the tumor types that have been most commonly studied in the context of iron chelation.     

Factors affecting iron absorption and the role of fortification in enhancing iron levels

Iron is an important micronutrient required for a number of biological processes including oxygen transport, cellular respiration, the synthesis of nucleic acids and the activity of key enzymes. The World Health Organization has recognised iron deficiency as the most common nutritional deficiency globally and as a major determinant of anaemia. Iron deficiency anaemia affects 40% of all children between the ages of 6 and 59 months, 37% of mothers who are pregnant and 30% of women between the ages of 15 and 49 years worldwide. Dietary iron exists in two main forms known as haem iron and non-haem iron. Haem iron is obtained from animal sources such as meat and shows higher bioavailability than non-haem iron, which can be obtained from both plant and animal sources. Different components in food can enhance or inhibit iron absorption from the diet. Components such as meat proteins and organic acids increase iron absorption, while phytate, calcium and polyphenols reduce iron absorption. Iron levels in the body are tightly regulated since both iron overload and iron deficiency can exert harmful effects on human health. Iron is stored mainly as haemoglobin and as iron bound to proteins such as ferritin and hemosiderin. Iron deficiency affects individuals at increased risk due to factors such as age, pregnancy, menstruation and various diseases. Different solutions for iron deficiency are applied at individual and community levels. Iron supplements and intravenous iron can be used to treat individuals with iron deficiency, while various types of iron-fortified foods and biofortified crops can be employed for larger communities. Foods such as rice, flour and biscuits have been used to prepare fortified iron products. However, it is important to ensure the fortification process does not exert significant negative effects on organoleptic properties and the shelf life of the food product.     

Effects of Iron Intake on Iron Stores in Elderly Men and Women: Longitudinal and Cross-Sectional Results

Objective: For middle aged and elderly subjects there is a concern that increased iron intake, especially heme iron associated with consumption of red meat, leads to increased iron stores resulting in disturbed glucose homeostasis and risk for cardiovascular disease and certain types of cancer. The aim of this study was to investigate the influence of heme, non-heme and iron supplementation on iron stores in healthy elderly men and women.

Method: We conducted a 10 year longitudinal study (48 men and 77 women) and a one year cross-sectional study (165 men and 226 women) in healthy elderly men and women enrolled in the New Mexico Aging Process Study. Iron stores were estimated by serum ferritin concentrations and iron intake was determined by three-day food records in the longitudinal study and by a food frequency questionnaire in the cross-sectional study.

Results: We found no association between heme iron intake and iron stores in either the longitudinal or cross sectional study. In the cross-sectional study we found in women, but not in men, that age and supplemental iron intake were significantly and positively associated with increased iron stores.

Conclusion: Iron stores in elderly men are thought to reach steady state levels where iron absorption is adjusted to a level just sufficient to cover basal iron losses. In elderly women, we speculate that not enough time has elapsed for postmenopausal women to reach steady state levels of iron stores resulting in increases in iron absorption with age. Another factor is that use of hormone replacement therapy could further delay some women in reaching steady state iron levels due to continued menstrual blood losses.     

Intestinal Iron Homeostasis and Colon Tumorigenesis

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.     

Out of Balance—Systemic Iron Homeostasis in Iron-Related Disorders

Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism.     

Iron Deficiency in Heart Failure: A Practical Guide

Iron is an element necessary for cells due to its capacity of transporting oxygen and electrons. One of the important co-morbidities in heart failure is iron deficiency. Iron has relevant biological functions, for example, the formation of haemoglobin, myoglobin and numerous enzymatic groups. The prevalence of iron deficiency increases with the severity of heart failure. For a long time, the influence of iron deficiency was underestimated especially in terms of worsening of cardiovascular diseases and of developing anaemia. In recent years, studies with intravenous iron agents in patients with iron deficiency and cardiovascular diseases indicated new insights in the improvement of therapy. Experimental studies support the understanding of iron metabolism. Many physicians remain doubtful of the use of intravenous iron due to reports of side effects. The aim of this review is to describe iron metabolism in humans, to highlight the influence of iron deficiency on the course and symptoms of heart failure, discuss diagnostic tools of iron deficiency and provide guidance on the use of intravenous iron.     

Identification,Prevention and Treatment of Iron Deficiency during the First 1000 Days

Iron deficiency is a global problem across the life course, but infants and their mothers are especially vulnerable to both the development and the consequences of iron deficiency. Maternal iron deficiency during pregnancy can predispose offspring to the development of iron deficiency during infancy, with potentially lifelong sequelae. This review explores iron status throughout these “first 1000 days” from pregnancy through two years of age, covering the role of iron and the epidemiology of iron deficiency, as well as its consequences, identification, interventions and remaining research gaps.     

铁与慢性肝损伤

铁代谢异常对慢性肝损伤的影响日益为人们所关注，铁负荷过度通过活性氧中间体导致脂质过氧化损伤，及影响T细胞和枯否细胞的功能从而导致肝细胞损伤。铁与肝炎病毒具有协同毒性作用。铁会影响慢性肝炎患者对干扰素的应答。铁负荷可促发酒精性肝损伤。铁和高胰岛素血症在非酒精性脂肪肝的发病机制中具有协同作用。遗传性血色病系HFE基因突变导致铁过量从肠粘膜细胞转移入门脉循环，以致过量的铁质在肝内沉积从而导致肝纤维化、肝硬化发生。