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

Inflammation is one of the major causes of resistance to erythropoietin (EPO) treatment. In the present study, the relationship between serum C-reactive protein (s-CRP) and the dose of recombinant human EPO required to maintain hemoglobin levels at approximately 12 g/dL was analyzed in 30 hemodialysis patients. The weekly EPO dose in patients with s-CRP > or = 20 mg/L was, on average, 80% higher than in patients with s-CRP less than 20 mg/L. The EPO doses and s-CRP were both inversely correlated to the levels of serum albumin and serum iron, suggesting that the principal mechanism by which inflammatory cytokines inhibit erythropoiesis is coupled to iron metabolism, ie, functional iron deficiency. Our results demonstrate the usefulness of s-CRP as a predictor of resistance to EPO treatment.
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PMID:High C-reactive protein is a strong predictor of resistance to erythropoietin in hemodialysis patients. 910 46

Anemia in chronic renal failure is predominantly caused by diminished erythropoietin synthesis by diseased kidneys. While iron deficiency is often stated as a cause of anemia in chronic renal failure prior to end-stage renal disease, its relative contribution is debated. It is speculated that rather than frank 'iron deficiency', many patients with chronic renal failure may indeed have impaired utilization of iron. We analyzed 139 consecutive patients with chronic renal failure starting maintenance hemodialysis to determine the relationship between hematocrit, measures of renal function (blood urea nitrogen and serum creatinine concentration), and measures of iron availability (serum transferrin saturation, serum iron level and serum ferritin). The 139 study subjects (60 men, 79 women) comprised 116 blacks (83%), 15 hispanics (11%), and 8 whites (6%) of a mean age 56 +/- 15 years. Only 23 (17%) of 139 subjects had positive hemoccult stool test for blood. Their mean hematocrit was 24 +/- 4.5%, mean blood urea nitrogen concentration was 121 +/- 38, mean serum creatinine concentration was 12.6 +/- 5.2 mg/dl, mean serum transferrin saturation was 22 +/- 14%, mean serum ferritin level was 235 +/- 194 U/l, mean serum iron level was 55 +/- 40 U/l, and mean total iron binding capacity was 254 +/- 93%. Multiple regression analysis with hematocrit as the outcome variable, and blood urea nitrogen level, serum creatinine concentration, serum albumin concentration, serum transferrin saturation, and serum ferritin level as the independent variables, showed an inverse correlation between hematocrit and serum creatinine concentration (p = 0.002). We conclude that in patients with chronic renal failure starting uremia therapy, anemia does not correlate with any of the commonly measured indices of body iron stores. We infer that impaired utilization of iron may be a significant factor in the anemia of chronic renal failure.
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PMID:Relative contributions of body iron status and uremia severity to anemia in patients with advanced chronic renal failure. 937 26

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

Data for iron-status indices in continuous ambulatory peritoneal dialysis patients are limited. The reliability of commonly used indices for the diagnosis of iron-deficiency anemia in peritoneal dialysis patients is still unknown. To study diagnostic values of iron-status indices, including serum ferritin, transferrin saturation, reticulocyte hemoglobin content, and bone marrow-stainable iron, 21 stable anemic peritoneal dialysis patients who have been treated with erythropoietin and oral iron supplementation for more than 3 months were enrolled in this study. The mean age was 51.4 +/- 2.9 years; dialysis duration, 28.7 +/- 5.1 months; initial hemoglobin, 8.4 +/- 0.2 g/dL; erythropoietin dosage, 71 +/- 2 micro/kg/wk; serum albumin, 3.5 +/- 0.1 g/dL; intact parathyroid hormone (PTH), 233 +/- 44 ng/mL; serum ferritin, 643 +/- 135 ng/mL; transferrin saturation, 33.93% +/- 3.9%; and reticulocyte hemoglobin content, 31.6 +/- 4 pg. Bone marrow aspiration was performed in all patients to determine marrow iron content and exclude hematological disorders. All patients were treated with 1, 000 mg of intravenous ferric saccharate infusion in two divided doses more than 1 week apart. Patients who responded to the iron infusion within 3 months by increasing serum hemoglobin of greater than 1 gm/dL more than baseline were defined as being functional iron deficient before the intravenous iron infusion. Serum ferritin, transferrin saturation, and reticulocyte hemoglobin content were followed serially after iron infusion. Fifteen patients (71.4%) responded to the iron administration, indicating iron deficiency. Nine of 13 (69%) patients with the presence of bone marrow-stainable iron still responded to intravenous iron supplementation, suggesting functional iron deficiency. Absence of bone marrow-stainable iron was not a sensitive marker for the diagnosis of iron deficiency, 25% sensitivity. No single value of iron-status indices that can definitely exclude iron-deficiency anemia in peritoneal dialysis patients was found. Therefore, failure to increase hemoglobin concentration after intravenous iron administration should be shown before excluding iron-deficiency anemia as a cause of poor erythropoietic response to erythropoietin therapy.
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PMID:Indices of iron status in continuous ambulatory peritoneal dialysis patients. 1040 Oct 35

In most chronic disease conditions, the systemic inflammatory response and its mediators play an essential pathogenic role. Protein calorie malnutrition, a prominent feature of end-stage renal disease (ESRD), also develops, largely as a consequence of the systemic inflammatory response. ESRD (uremia), dialysis, systemic metabolic acidosis, and infections activate the systemic inflammatory response. Elevations in C-reactive protein and depressions of serum albumin below 4 g/dL are found in more than 50% of ESRD patients undergoing dialysis. In many patients receiving dialysis, the impact of this acute-phase response on measures of iron metabolism limits the ability to diagnose iron deficiency. Furthermore, there are risks to iron administration, although data linking iron overload to risk of infection in dialysis patients is suggestive, not definitive. It seems reasonable to hypothesize that the greatest risk of iron administration is in patents who are already infected, and the greater risk would be to raise the serum iron level and transferrin saturation precipitously. The total-dose infusion method, which provides all iron required to correct deficiency in 1 dose, is more likely to produce side effects and rapidly raise serum iron levels and transferrin saturation. The use of low-dose intravenous iron supplementation (10 to 20 mg per dialysis treatment or 100 mg every second week) avoids iron overtreatment and should reduce adverse events. In ESRD patients receiving dialysis, the importance of the systemic inflammatory response in the development of protein calorie malnutrition, the impact of the acute-phase response on iron nutriture, and the response to erythropoietin therapy must be considered to achieve an understanding of the altered responses to nutritional therapy in this setting.
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PMID:The systemic inflammatory response and its impact on iron nutriture in end-stage renal disease. 1051 74

The prevalence of anemia increases with age and is frequently multifactorial. We postulated that malnutrition contributes to anemia in the elderly and is underdiagnosed. Our objective was to analyze the prevalence of anemia and its association with nutritional status in a hospitalized geriatric population. Included in this retrospective cohort study were 186 consecutive patients admitted in 1997 to a geriatric unit of a university hospital. We compared hematological and chemical blood tests routinely performed upon admission in patients with anemia (hemoglobin <120 g/l) and without anemia (hemoglobin > or = 120 g/l). Using these admission parameters, we defined a multiparameter score of malnutrition by low lymphocyte counts, decreased values of albumin, cholesterol, transferrin, cholinesterase, and zinc, iron deficiency by low transferrin saturation and normal C-reactive protein, and inflammation by increased C-reactive protein and high transferrin saturation. Of the 186 patients, 82 (44%) met the criteria for anemia on admission. In univariate analysis, patients with anemia differed significantly from patients with normal hemoglobin exhibiting lower serum values of albumin, iron, transferrin, cholesterol, cholinesterase, zinc, transferrin saturation, and lymphocyte count and higher C-reactive protein levels. Using a multiparameter score, anemia correlated significantly with parameters of malnutrition (P=0.0001) but not with iron deficiency (P=0.5) or with inflammation (P=0.08). In a multivariate logistic regression model, anemia was significantly associated with serum albumin (RR: 1.138; 95% CI: 1.056-1.227; P=0.0007), cholinesterase (RR: 1.387; 95% CI 1.122-1.714; P=0.0025), and transferrin saturation (RR: 1.05; 95% CI: 1.012-1.09; P=0.009). We conclude that malnutrition may play an important etiologic role in anemia in the elderly.
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PMID:Anemia: an indicator for malnutrition in the elderly. 1144 33

An analysis of the relationship between intermediate outcomes and duration of dialysis therapy in hemodialysis patients was performed by linking Health Care Financing Administration (HCFA) Core Indicators data with data obtained from HCFA form 2728 at the initiation of dialysis therapy. Patients who recently initiated hemodialysis therapy were less likely to meet Dialysis Outcomes Quality Initiative guidelines than patients with a longer duration of dialysis therapy. For both urea reduction ratio and Kt/V, odds ratios for adequate dialysis were approximately 0.20 for a duration of dialysis therapy less than 0.5 years and 0.42 to 0.63 for a duration of dialysis therapy of 0.5 to 1.0 years compared with a duration of dialysis therapy of 2.0 years or greater. For patients with a duration of dialysis therapy less than 0.5 years (compared with >/=2.0 years), the odds ratio for a hematocrit less than 28% was approximately 3.0, that for a hematocrit 33% or greater was approximately 0.6, and that for a serum albumin level of 3.5 g/dL or greater (bromcresol green method) or 3.2 g/dL or greater (bromcresol purple method) was approximately 0.4. There was a direct relationship between glomerular filtration rate at the initiation of dialysis therapy and both serum albumin and hematocrit values. Patients administered recombinant human erythropoietin (rHuEPO) predialysis were more likely to have greater hematocrits. There also was a direct relationship between hematocrit and serum albumin level. Therefore, several actionable items in regard to attentive overall medical care can result in an improvement in the percentage of patients newly started on hemodialysis therapy who meet intermediate outcomes, including the administration of rHuEPO predialysis, correction of iron deficiency, and timely placement of a permanent dialysis access.
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PMID:Duration of dialysis and its relationship to dialysis adequacy, anemia management, and serum albumin level. 1157 85

Several recently published reports have advanced our understanding of the epidemiology of anemia associated with chronic renal insufficiency. Anemia is commonly observed among subjects with chronic renal insufficiency. In comparison with subjects with preserved renal function, a significant decrease in hemoglobin could be detected in subjects with more modest degrees of renal insufficiency than was previously realized. Some of this undoubtedly reflects a decrease in renal production of erythropoietin, but these subjects may also suffer concomitant 'anemia of chronic disease'. Anemia is more likely not only among those with worse renal insufficiency, but also among black subjects, those with relative iron deficiency and those with lower serum albumin. Compared with those with preserved renal function, a significant decrease in hemoglobin could be detected in men at higher estimated creatinine clearance levels than in women; and at any given creatinine clearance, the decrease in hemoglobin is greater in men than in women. In the US, 800000 adults were estimated to suffer chronic renal insufficiency associated anemia, defined as hemoglobin level below 11 g/dl. As detailed in the present review, several methodological issues should be kept in mind when interpreting the literature. Further studies are needed to define the clinical implications of this common condition and to determine the most appropriate therapeutic response.
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PMID:Epidemiology of anemia associated with chronic renal insufficiency. 1198 Dec 65

An increasing number of reports documenting resistance to human recombinant erythropoietin (rHuEPO) therapy are challenging the concept that erythropoietin deficiency is the main cause of the anaemia of chronic kidney disease (CKD). In an attempt to establish whether other factors play a more predominant role in the anaemia of CKD, 988 patients receiving dialysis were assessed for a wide range of variables. Data were collected on haematocrit (Hct) levels, rHuEPO dose, dry weight, serum ferritin, transferrin saturation, serum albumin, serum aluminium, serum parathyroid hormone intact, eKt/V for urea, gender, dose of i.v. iron administered, time in hospital, and use of i.v. vancomycin. Hyporesponsiveness to rHuEPO was defined as patients requiring >500 IU/kg/week or failing to achieve Hct levels of >30%. Ninety-two (9.2%) of the 988 patients met the above criteria for hyporesponsiveness to rHuEPO. In 21 of these patients, Hct concentrations remained <30% at 6-month follow-up. There were known haematological causes of refractoriness to rHuEPO in nine of these patients. During extended follow-up, probable causes of hyporesponsiveness were discovered in all but two of the remaining 13 patients. Of 62 dialysis patients who received rHuEPO at doses >500 IU/kg/week, 45 (73%) had Hct concentrations of 33-42%. These patients were responding to the higher doses of rHuEPO with no obvious adverse effects. Lower values of serum ferritin, transferrin saturation, and eKt/V, or higher levels of parathyroid hormone or serum aluminium were not associated with higher rHuEPO dose requirements. These results suggest that erythropoietin deficiency is still the main cause of the anaemia of CKD. Erythropoietin replacement therapy can correct the anaemia in almost all iron replete patients providing enough hormone is given, functional iron deficiency is avoided, aluminium levels and parathyroid toxicities are controlled and that no de novo haematological condition that affects erythropoiesis or red blood cell survival develops. Consideration should be given to modifying the definition of rHuEPO hyporesponsiveness. The US Hct target of 33-36% for haemodialysis patients is narrow and the European target of Hct >33% may be significantly more practical and physiologically relevant.
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PMID:Is it time for a paradigm shift? Is erythropoietin deficiency still the main cause of renal anaemia? 1209 99

In a longitudinal follow-up study the effect of pharmaceutical supplementation of nutrients (folate, vitamin B12, B6, B1, C, iron and proteins) was established in 25 psychogeriatric patients (subject group). A reference group of 30 apparently healthy elderly subjects was used for comparison and statistical evaluation. At the time of hospitalization percentages concerning the incidence of decreased serum concentrations reflecting an inappropriate nutrient state in the subject group amounted to 28% for vitamin B12, 20% for folate, 36% for iron, 12% for transferrin and 56% for albumin concentrations. Increased plasma concentrations of homocysteine combined with decreased folate concentrations were found in 16% of the psychogeriatric patients. If compared with the initial results at admission, after three weeks of nutrient supplementation the vitamin B12 and folate serum concentrations were increased. Results for serum iron concentrations remained below the reference range interval in 5 of the 25 subjects reflecting iron deficiency. Initially decreased serum transferrin concentrations did not return to the reference range. Serum albumin levels still further decreased after admission to the hospital, resulting after three weeks in albumin concentrations below the reference range for 68% of the subjects. It is concluded that supplementation of folate and vitamin B12 lowered homocysteine plasma concentrations successfully. Supplementation of protein nutrients is not appropriate in order to restore disturbances of protein metabolism. Persisting low concentrations of proteins in serum are indicative of irreversible decreased synthesis.
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PMID:Effect of nutrient supplementation on serum homocysteine, iron and proteins in psychogeriatric patients. 1259 73


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