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

The treatment efficacy of erythropoietin (EPO) in end-stage renal disease (ESRD) can be limited by deficiencies of iron, folate, or vitamin B12, by hyperparathyroidism, or by aluminum intoxication. Since EPO costs are significant, this study attempted to determine the cost-effectiveness of performing a panel of screening tests for anemia before starting EPO. Anemia screening was performed prospectively in 48 new-onset ESRD patients at the Ralph H. Johnson Veterans Affairs Medical Center before EPO treatment was started. Serum iron, transferrin, folate, vitamin B12, parathyroid hormone, and aluminum levels were determined, and transferrin saturation (Tfsat) was calculated at the first dialysis session. At presentation for dialysis, the mean hematocrit was 0.264 +/- 0.036 and the mean blood urea nitrogen was 32 +/- 2 mmol/L. Eighteen patients (37.5%) had a serum iron level lower than 7 micromol/L, suggesting iron deficiency. Twenty-five patients (52%) had Tfsat less than 0.20, consistent with overt iron deficiency. No patient was found to be vitamin B12 deficient, to be aluminum intoxicated, or to have significant hyperparathyroidism. One patient had folate deficiency. A cost-effectiveness analysis was performed assuming that (1) EPO would be given at an average starting dose of 6,000 U/wk at a cost of $14/2,000 U of EPO; (2) that without screening 1 month would elapse before a poor response was identified; and (3) that the failure to treat aluminum intoxication and hyperparathyroidism or to replete iron, vitamin B12, or folate deficiency would significantly impair the response to EPO. The Tfsat screen had a cost-effectiveness ratio of 0.2019, saving approximately $5.00 in EPO use for each dollar of test administration. All other screens had cost-effectiveness ratios greater than 1.0, indicating that their testing costs exceeded dollar savings in EPO use. In conclusion, iron deficiency is common in anemic patients starting dialysis, but other causes of anemia are not. It is imperative that current clinical practices be influenced by cost-effectiveness considerations. Given the cost of laboratory screens, and the relative ineffectiveness of the other screens examined here to identify factors known to impair the response to EPO, anemia screening before initiating EPO therapy should be limited to tests to identify iron deficiency.
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PMID:A cost-effectiveness analysis of anemia screening before erythropoietin in patients with end-stage renal disease. 915 97

Cadmium, lead, mercury, and aluminum are toxic metals that may interact metabolically with nutritionally essential metals. Iron deficiency increases absorption of cadmium, lead, and aluminum. Lead interacts with calcium in the nervous system to impair cognitive development. Cadmium and aluminum interact with calcium in the skeletal system to produce osteodystrophies. Lead replaces zinc on heme enzymes and cadmium replaces zinc on metallothionein. Selenium protects from mercury and methylmercury toxicity. Aluminum interacts with calcium in bone and kidneys, resulting in aluminum osteodystrophy. Calcium deficiency along with low dietary magnesium may contribute to aluminum-induced degenerative nervous disease.
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PMID:Toxic and essential metal interactions. 924 Sep 18

The influence of angiotensin-converting enzyme inhibitors (ACEIs) on recombinant human erythropoietin (rhEPO) maintenance doses in hemodialysis patients was studied. One hundred and eight chronic hemodialysis patients (55 males and 53 females, mean age 61.2+/-12.6 years) were investigated. The rhEPO maintenance doses in the ACEI-treated group (n = 49) were 101.7+/-51.7 U/kg/week and in the nontreated group (n = 59) 79.2+/-37.8 U/kg/week (p < 0.05). No difference was observed in hematocrit between the ACEI-treated and nontreated groups. In stepwise regression analysis, the parameters associated with increased rhEPO maintenance doses were female gender, ACEI administration, low total iron binding capacity, and low serum free carnitine levels. In conclusion, ACEI administration might reduce the response to rhEPO. In hemodialysis patients who need high-dose rhEPO to maintain the target hematocrit in the absence of iron deficiency, hyperparathyroidism, infection, malignancy, malnutrition, and aluminum toxicity, ACEI administration should be considered.
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PMID:Angiotensin-converting enzyme inhibitors are associated with the need for increased recombinant human erythropoietin maintenance doses in hemodialysis patients. Risks of Cardiac Disease in Dialysis Patients Study Group. 934 82

Estimation of red cell ferritin (RCFer) may give a good indication of iron supply to the erythron and it may therefore be clinically useful for the detection of functional iron deficiency. In a cross-sectional study of hemodialysis patients on erythropoietin (EPO) therapy and regular oral iron we have compared the RCFer levels with conventional indicators of iron status. The patients studied, 19 female, 48 male, mean age 62 +/- 3.6 years (range 20-83 years) were characterized by the following mean parameters: aluminum 1.24 +/- 0.12 mumol/L, PTH 115.7 +/- 39 pg/mL, vitamin B12 626 +/- 71.2 ng/L, serum folate 18.8 +/- 2.2 micrograms/L, and hemoglobin 9.8 +/- 0.3 g/dL (range 7.3-12.4). The median serum ferritin (SF), RCFer, total iron binding capacity (TIBC), transferrin saturation (TS), and serum iron were 68 micrograms/L, 14.1 ag ferritin/red cell, 57 mumol/L, 20% and 11.5 mumol/L, respectively. Eleven patients had a reduced RCFer (< 7 ag ferritin/red cell), 5 had a SF of < 15 micrograms/L and 22 a TS of < 16%. The occurrence of functional iron deficiency was suggested by the presence of 10 subjects with reduced RCFer despite normal SF levels (15-240 micrograms/L). Four patients with reduced SF showed acceptable levels of RCFer, suggesting that some patients may maintain an adequate iron supply despite diminished iron stores. Despite oral iron therapy, a significant number of patients (63%) on regular hemodialysis remain relatively iron deficient with a serum ferritin of less than 100 micrograms/L. It has previously been proposed that oral iron provides adequate supplementation during increased demand caused by EPO stimulation. The present study has demonstrated overt iron deficiency in five subjects and suggests functional iron deficiency in a further seven (22% of total patients). We therefore conclude that oral iron therapy cannot maximize the response to EPO.
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PMID:Red cell ferritin, a marker of iron deficiency in hemodialysis patients. 941 34

The present study was designed to investigate the impact of aluminum toxicity on the response to recombinant human erythropoietin (rHuEPO) therapy in hemodialysis patients, when iron deficiency has been corrected or excluded. We studied 39 patients on regular hemodialysis (20 males and 19 females; mean age 58.8 years), who were under maintenance rHuEPO treatment for at least 6 months, and who had stable hematocrit levels for more than 3 months. All patients had adequate iron stores and availability with serum ferritin > 100 micrograms and iron saturation > 25%. They were classified into two groups: 19 poor responders, who required subcutaneous rHuEPO doses > 100 U/kg/week and failed to achieve the target hematocrit level of 30%, and 20 good responders, who needed doses of < or = 100 U/kg/week to maintain the target level. Serum aluminum levels including basal (Albasal) and 44 h after desferrioxamine (DFO) infusion (Alpost-DFO), intact parathyroid hormone, and inflammatory and hemolytic indices were examined in both groups. The results showed that the mean weekly rHuEPO doses were significantly lower and the mean hematocrit levels higher in the good responders than in the poor responders. Although the poor responders had markedly higher mean Albasal and Alpost-DFO levels, no differences were observed in the other parameters between the two groups. Furthermore, the poor responders significantly had the greater increment in the serum aluminum levels after DFO infusion (delta Al = Alpost-DFO-Albasal). The mean corpuscular volume had a strong inverse correlation with delta Al in the poor response group (r = -0.711, p < 0.001). We concluded that the post-DFO rise of serum aluminum can be used as a means of estimating tissue stores. Subclinical aluminum toxicity may exhibit an inhibitory effect on erythropoietic response to rHuEPO therapy.
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PMID:Recombinant human erythropoietin resistance in iron-replete hemodialysis patients: role of aluminum toxicity. 948 32

Anemia is the most common hematologic abnormality in patients with chronic renal failure. The reasons for anemia in chronic renal failure are many and include erythropoietin and iron deficiencies, inflammation, infection, aluminum toxicity, and hyperparathyroidism. Iron deficiency alone affects more than 50% of patients on dialysis, and the estimated iron loss for these patients is 1.5 to 3 grams per year. The use of erythropoietin has also uncovered iron deficiency in a multitude of patients. Iron and erythropoietin supplementation has often restored normal or near-normal levels of hematocrit in these patients and has therefore improved some of the symptoms classically connected with chronic renal failure, such as fatigue, cold intolerance, and mental sluggishness, among others. Resistance to erythropoietin is frequently observed in the maintenance care for dialysis patients, and the most common reason is iron deficiency. It is important to understand the physiology of renal anemia, erythropoiesis and iron metabolism in order to avoid mistakes and misconceptions in the management of iron in chronic dialysis patients. In this article, we review several mistakes, misconceptions, practices, and guidelines in iron supplementation therapy. We also review the physiology of anemia in renal disease and the importance of erythropoietin and iron in causing anemia and discuss recent Dialysis Outcomes Quality Initiative (DOQI) guidelines on the topic.
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PMID:The use of iron in patients on chronic dialysis: mistake and misconceptions. 956 79

A longitudinal study on iron nutritional status was carried out among 45 preterm, healthy infants 4-12 months of age from low-income families in Sao Paulo State, Brazil. The aim of the study was to determine whether cooking food in iron pots has the potential to prevent anemia in premature infants. 22 infants were randomly assigned to receive food cooked in iron pots, while food for the 23 controls was prepared in aluminum pots. Mothers of infants in both groups were instructed to administer 2 mg of ferrous sulfate starting at 15 days of age. At study onset, when infants were 4 months of age, there were no differences between these two groups in hematologic parameters. By 12 months of age, the children fed food from in iron pots had significantly more favorable hematologic values than control children. These differences included mean hemoglobin (116 vs. 103 g/L), hematocrit (0.35 vs. 0.31), mean corpuscular volume (72.1 vs. 62.7 fL), free erythrocyte protoporphyrin (0.78 vs. 1.46 mol/L), and median serum ferritin (5 vs. 0 g/L). There were no significant differences between groups in serum iron concentration, total iron-binding capacity, or transferrin saturation. Iron deficiency anemia (hemoglobin of 110 g/L or less) was found in 8 infants (36.4%) in the group fed food cooked in iron pots and 17 infants (73.9%) fed food prepared in aluminum pots. Although these findings indicate that the iron added to foods cooked in iron pots is bioavailable, the amount obtained through this process is insufficient to replenish depleted iron stores during the first year of life. This intervention merits consideration, however, as an adjunct to programs aimed at preventing iron deficiency in premature infants.
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PMID:Iron nutritional status is improved in Brazilian preterm infants fed food cooked in iron pots. 956 93

Iron deficiency is an important factor for high erythropoietin (EPO) requirements. Some studies have shown a decrease in recombinant human erythropoietin (rHuEPO) dosage with correction of iron deficiency. This is a 2 year prospective study of 58 chronic hemodialysis (HD) patients in whom iron deficiency was corrected with intravenous iron therapy. Patients were stratified into two groups: Group 1 with 25 patients (EPO < 70 U/kg per HD), and Group 2 with 33 patients (EPO > 70 U/kg per HD). For Groups 1 and 2, respectively, differences in mean age (56.5 vs 64.1 years), rHuEPO dose (30.1 vs 148.7 U/kg per HD), and hematocrit concentration (36.5% vs 32.7%) were statistically significant (p < 0.05). Although iron saturation was 45% compared with 41.3% for Groups 1 and 2, respectively, serum parathyroid hormone, aluminum, and urea reduction ratio were similar for both. These data suggest that some patients continue to require a high rHuEPO dose in spite of adequate iron repletion. Further investigation into factors causing EPO resistance is important to decrease rHuEPO requirements and improve cost effectiveness.
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PMID:Erythropoietin (EPO) requirements remain high in EPO resistant patients after iron repletion. 980 3

We defined erythropoietin (EPO) resistance by the ratio of the weekly EPO dose to hematocrit (Hct), yielding a continuously distributed variable (EPO/Hct). EPO resistance is usually attributed to iron or vitamin deficiency, hyperparathyroidism, aluminum toxicity, or inflammation. Activation of the acute-phase response, assessed by the level of the acute-phase C-reactive protein (CRP), correlates strongly with hypoalbuminemia and mortality in both hemodialysis (HD) and peritoneal dialysis (PD) patients. In this cross-sectional study of 92 HD and 36 PD patients, we examined the contribution of parathyroid hormone (PTH) levels, iron indices, aluminum levels, nutritional parameters (normalized protein catabolic rate [PCRn]), dialysis adequacy (Kt/V), and CRP to EPO/Hct. Albumin level serves as a measure of both nutrition and inflammation and was used as another independent variable. Serum albumin level (deltaR2 = 0.129; P < 0.001) and age (deltaR2 = 0.040; P = 0.040) were the best predictors of EPO/Hct in HD patients, and serum albumin (deltaR2 = 0.205; P = 0.002) and ferritin levels (deltaR2 = 0.132; P = 0.015) in PD patients. When albumin was excluded from the analysis, the best predictors of EPO/Hct were CRP (deltaR2 = 0.105; P = 0.003) and ferritin levels (deltaR2 = 0.051; P = 0.023) in HD patients and CRP level (deltaR2 = 0.141; P = 0.024) in PD patients. When both albumin and CRP were excluded from analysis in HD patients, low transferrin levels predicted high EPO/Hct (deltaR2 = 0.070; P = 0.011). EPO/Hct was independent of PTH and aluminum levels, PCRn, and Kt/V. High EPO/Hct occurred in the context of high ferritin and low transferrin levels, the pattern expected in the acute-phase response, not in iron deficiency. In well-dialyzed patients who were iron replete, the acute-phase response was the most important predictor of EPO resistance.
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PMID:Acute-phase response predicts erythropoietin resistance in hemodialysis and peritoneal dialysis patients. 991 69

Aluminum, a trivalent cation unable to undergo redox reactions, has been linked to many diseases such as dialysis dementia and microcytic anemia without iron deficiency. It has also been implicated in Alzheimer's disease although this is controversial. Because cell death due to oxidative injury is suspected to be a contributory factor in many neurological diseases and aluminum neurotoxicity, glioma (C-6) and neuroblastoma (NBP2) cells were utilized to assess early changes in oxidative parameters consequent to a 48-h exposure to aluminum sulfate. A 500-microM concentration of this salt produced a significant increase in reactive oxygen species (ROS) production and a significant decrease in glutathione (GSH) content in glioma cells. However, the same concentration of the aluminum salt did not lead to any significant changes in the neuroblastoma cells. Mitochondrial respiratory activity in glioma cells was also found to be significantly higher in the aluminum treated cells. As judged by morin-metal complex formation, aluminum can enter glioma cells much more readily than neuroblastoma cells. Thus, it is possible that the cerebral target following an acute exposure to aluminum may be glial rather than neuronal.
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PMID:Aluminum-induced oxidative events in cell lines: glioma are more responsive than neuroblastoma. 1038 Nov 87


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