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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The target organ failures associated with uremia are most often considered to be caused by processes other than uremia per se. Heart disease, for example, is considered the product of hypertension, lipid abnormalities, and so forth, rather then the uremic state. Erythropoietin deficiency, blood loss, and iron deficiency are believed to cause anemia, rather than the uremic state. Malnutrition is believed to be the product of poor nutrient intake and perhaps nutrient losses, rather than uremia per se. This article reviews evidence suggesting that anemia and malnutrition share a common cause; the acute-phase inflammatory process that is a normal host-defense mechanism. Given the high prevalence of heart disease among patients with end-stage renal disease (ESRD), data indicating activation of the acute-phase process in patients with kidney failure, and emerging evidence that the process has a significant role in the risk for cardiovascular disease among patients without kidney failure, there is a strong likelihood that heart disease will share with anemia and malnutrition the acute-phase state as a contributing cause. Thus, instead of disconnected target organ failures, each with different antecedent causes, we see emerging the likelihood of a unifying pathobiology for uremia. The antecedents of morbidity and mortality appear as a web of organ failures connected by a common pathobiology. Whereas each failure likely has contributing causes other than the acute-phase state, they probably share the state as a causative, contributing, or exacerbating factor.
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PMID:Acute-phase inflammatory process contributes to malnutrition, anemia, and possibly other abnormalities in dialysis patients. 989 76

Iron supplementation has become an integral part of the management of patients receiving epoetin therapy, and clinicians have found it necessary to learn how and when to use it to the best advantage. Three routes of administration for iron are available: oral, intramuscular, and intravenous. Oral iron has the advantage of being simple and cheap, but it is limited by side-effects, poor compliance, poor absorption, and low efficacy. Intravenous iron is the best means of guaranteeing delivery of readily available iron to the bone marrow, but it requires greater clinical supervision. The i.v. iron preparations vary widely in their degradation kinetics, bioavailability, side-effect profiles, and maximum dose for single administration. Iron dextran is hampered by a small but significant risk of anaphylaxis, whereas all i.v. iron preparations can induce "free iron" reactions if the circulating plasma transferrin is overloaded. Intravenous iron may be given in advance of epoetin therapy, as concomitant treatment to prevent the development of iron deficiency, as treatment of absolute or functional iron deficiency, or as adjuvant therapy to enhance the response to epoetin in iron-replete patients. Markers of iron status that may indicate a need for i.v. iron include a serum ferritin of less than 100 microg/liter, a transferrin saturation of less than 20%, and a percentage of hypochromic red cells more than 10%. Various regimens are available for giving i.v. iron: low-dose administration of 20 to 60 mg every dialysis session in hemodialysis patients, medium-dose administration of 100 to 400 mg, and high-dose administration of 500 to 1000 mg. Iron sodium gluconate can only be given as a low-dose regimen because of toxicity, whereas the only preparation suitable for high-dose administration is iron dextran. Although concerns have been raised regarding iron overload and long-term toxicity with i.v. iron therapy in terms of increased risk of infections, cardiovascular disease, and malignancy, there is little evidence to substantiate this in patients receiving epoetin. Care should be taken, however, to prevent the serum ferritin rising above 800 to 1000 microg/liter and the transferrin saturation above 50%. Provided this is done, the benefits of i.v. iron almost certainly outweigh the risks in terms of optimizing the response to epoetin therapy.
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PMID:Strategies for iron supplementation: oral versus intravenous. 1008 88

Anemia is a prevalent condition with a variety of underlying causes. Once the etiology has been established, many forms of anemia can be easily managed by the family physician. Iron deficiency, the most common form of anemia, may be treated orally or, rarely, parenterally. Vitamin B12 deficiency has traditionally been treated with intramuscular injections, although oral and intranasal preparations are also available. The treatment of folate deficiency is straightforward, relying on oral supplements. Folic acid supplementation is also recommended for women of child-bearing age to reduce their risk of neural tube defects. Current research focuses on folate's role in reducing the risk of premature cardiovascular disease.
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PMID:Ambulatory management of common forms of anemia. 1019 99

Anemia is a frequent finding, particularly in the elderly population, and usually indicative of a serious disease. The main causes of preoperative anemia are acute or chronic hemorrhage, iron deficiency, renal insufficiency, inflammatory and neoplastic diseases. A preexisting mild anemia may be enhanced or unmasked by surgically induced bleeding or repeated diagnostic phlebotomies, and by a postoperative erythropoietic dysfunction caused by the surgical trauma, irrespective of any hemorrhage. Low hemoglobin values are associated with a distinct increase of mortality and morbidity, both in the normal population and perioperatively and in the critically ill patients. The anemia-associated risk is exacerbated by preexisting cardiovascular disease, important intraoperative blood loss and advanced age. In contradiction to established therapeutical concepts, the administration of allogeneic blood beyond hemoglobin levels of 8-10 g/dl has not been found to decrease perioperative or intensive care morbidity or mortality. Rather, in addition to the inherent long-term risks of transfusions, a liberal transfusion strategy seems to increase the incidence of postoperative complications. Thus, current transfusion guidelines tend to be interpreted in an increasingly restrictive manner. Depending on the urgency of the clinical situation, the primary goal should be to diagnose and treat the underlying disease, rather than to focus on the symptom anemia. Time permitting, the patient's cardiovascular and pulmonary status should be optimized preoperatively. Furthermore, iron should be substituted to treat and prevent deficiency. Recombinant human erythropoietin has successfully been used to treat anemia of chronic renal failure and chronic disease, as well as in the perioperative and intensive care setting, and to support the efficiency of autologous programs.
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PMID:[Perioperative anemia]. 1125 80

In Europe, iron deficiency is considered to be one of the main nutritional deficiency disorders affecting large fractions of the population, particularly such physiological groups as children, menstruating women and pregnant women. Some factors such as type of contraception in women, blood donation or minor pathological blood loss (haemorrhoids, gynaecological bleeding...) considerably increase the difficulty of covering iron needs. Moreover, women, especially adolescents consuming low-energy diets, vegetarians and vegans are at high risk of iron deficiency. Although there is no evidence that an absence of iron stores has any adverse consequences, it does indicate that iron nutrition is borderline, since any further reduction in body iron is associated with a decrease in the level of functional compounds such as haemoglobin. The prevalence of iron-deficient anaemia has slightly decreased in infants and menstruating women. Some positive factors may have contributed to reducing the prevalence of iron-deficiency anaemia in some groups of population: the use of iron-fortified formulas and iron-fortified cereals; the use of oral contraceptives and increased enrichment of iron in several countries; and the use of iron supplements during pregnancy in some European countries. It is possible to prevent and control iron deficiency by counseling individuals and families about sound iron nutrition during infancy and beyond, and about iron supplementation during pregnancy, by screening persons on the basis of their risk for iron deficiency, and by treating and following up persons with presumptive iron deficiency. This may help to reduce manifestations of iron deficiency and thus improve public health. Evidence linking iron status with risk of cardiovascular disease or cancer is unconvincing and does not justify changes in food fortification or medical practice, particularly because the benefits of assuring adequate iron intake during growth and development are well established. But stronger evidence is needed before rejecting the hypothesis that greater iron stores increase the incidence of CVD or cancer. At present, currently available data do not support radical changes in dietary recommendations. They include all means for increasing the content of dietary factors enhancing iron absorption or reducing the content of factors inhibiting iron absorption. Increased knowledge and increased information about factors may be important tools in the prevention of iron deficiency in Europe.
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PMID:Iron deficiency in Europe. 1168 48

End-stage renal disease (ESRD) is characterized by a high mortality rate, derived largely from cardiovascular disease (CVD). In patients with ESRD, high levels of pro-inflammatory cytokines and increased oxidative stress are common features that may contribute to malnutrition, anaemia, recombinant human erythropoietin (rHuEPO) resistance, and atherosclerosis. Inflammation predicts poor outcome in ESRD. It is multifactorial in cause and, while it may reflect the underlying CVD, the acute-phase response may also contribute to both oxidative stress and progressive vascular injury. In patients with ESRD, the acute-phase response may be influenced by a number of factors unrelated to dialysis and perhaps by the dialysis procedure itself. Inflammation and the acute-phase response interact with the haematopoietic system at several levels resulting in reduced erythropoiesis, accelerated destruction of erythrocytes, and blunting of the reactive increase in erythropoietin in response to reduced haemoglobin levels. In patients with ESRD, rHuEPO resistance has been linked with inflammation, the latter of which is often associated with a state of functional iron deficiency. Patients with ESRD are thought to have a reduced capacity to handle oxidative stress. There is recent evidence that a relationship may exist between inflammation and oxidative stress and treatment of anaemia with rHuEPO. However, iron may also generate oxidative stress. Controlled trials are needed before evidence-based recommendations for the management of inflammation-induced anaemia and resistance to rHuEPO can be defined.
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PMID:Anaemia, rHuEPO resistance, and cardiovascular disease in end-stage renal failure; links to inflammation and oxidative stress. 1209 5

Iron deficiency is the most common disorder of iron metabolism worldwide, but there is concern that iron accumulation resulting from enhanced iron absorption may also be a cause of morbidity. In patients with genetic haemochromatosis the clinical manifestations of iron overload are well-known. In northern Europe 90% of such patients are homozygous for the C282Y mutation of the HFE gene and this genotype is found in 1 in 200 of the population. Heterozygosity for C282Y occurs in 15% of the population and 25% carry another mutation, H63D. Population studies have revealed (i) the serum transferrin saturation is strongly influenced by HFE genotype, being lowest in subjects lacking mutations and highest in those homozygous for C282Y; (ii) most subjects homozygous for C282Y accumulate iron but do not present with the clinical manifestations of iron overload. Testing for HFE mutations in clinics for diabetes, liver disease and cardiovascular disease has shown that homozygosity for C282Y is not commonly found. Heterozygosity for either C282Y or H63D does not appear to be a risk factor for these common conditions.
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PMID:HFE Mutations as risk factors in disease. 1240 9

Recent epidemiologic studies show that iron deficiency occurs in the vast majority of patients with chronic kidney disease (CKD). In patients with CKD, increased iron losses and, to a lesser extent, poor oral absorption, can lead to iron-deficiency anemia. Correction of iron-deficiency anemia is preferable by the oral route, however, data on oral iron use are limited in this population. In CKD patients, parenteral iron administered with recombinant human erythropoietin (rHuEpo), is the best potential option for the correction of anemia. Nondextran iron preparations are preferable because of a reduced incidence of serious adverse events. Parenteral iron in CKD patients may not be entirely innocuous and, although commonly used, have not received Food and Drug Administration approval for use in this patient population. Exposure to intravenous (IV) iron may lead to oxidative stress, renal injury, infection, cardiovascular disease, and osteomalacia. Studies are needed to confirm the existence and magnitude of these complications. The current data suggest that the overall risk-benefit ratio favors use of IV iron when compared with untreated or partially treated iron-deficiency anemia.
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PMID:Issues related to iron replacement in chronic kidney disease. 1243 92

End-stage renal disease (ESRD) is characterized by a high mortality rate, which is mainly caused by cardiovascular disease. In patients with ESRD, high levels of pro-inflammatory cytokines and increased oxidative stress are common features and may contribute to the development of malnutrition, anaemia, resistance to recombinant human erythropoietin (epoetin) and atherosclerosis. The onset of inflammation is multi-factorial and is a predictor of poor outcome in ESRD. Although the inflammation may reflect the underlying cardiovascular disease, the acute-phase response may also contribute to both oxidative stress and progressive vascular injury. The acute-phase response in these patients may be influenced by a number of factors, and possibly the dialysis procedure itself. Inflammation and the acute-phase response interact with the haematopoietic system at several levels, resulting in reduced erythropoiesis, accelerated destruction of erythrocytes and blunting of the reactive increase in erythropoietin in response to reduced haemoglobin levels. In patients with ESRD, epoetin resistance has been linked with inflammation, which is often associated with a state of functional iron deficiency. Patients with ESRD are thought to have a reduced capacity in their control of oxidative stress and there is evidence that suggests that a relationship may exist between inflammation, oxidative stress and the treatment of anaemia with epoetin. Controlled trials are needed before evidence-based recommendations for the management of inflammation-induced anaemia and resistance to epoetin can be defined.
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PMID:Anaemia and inflammation: what are the implications for the nephrologist? 1460 95

Anemia is a common feature of chronic renal dysfunction and is associated with significant morbidity and mortality. Although acquired insufficiency of erythropoietin is virtually universal, iron deficiency is also a common contributor to the development of anemia. Iron replacement, in particular via the intravenous route, has become commonplace and results in improved hematocrits either on its own or in association with an erythropoiesis stimulating agent. However, intravenous iron is not without its potential complications. These include acute allergic reactions, iron overload, potentially accelerated cardiovascular disease and risk of infection. It is the purpose of this review to critically evaluate the available clinical and experimental evidence linking iron supplementation therapy with these complications.
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PMID:Intravenous iron therapy in renal failure: friend and foe? 1537 9


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