Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To demonstrate whether L-carnitine treatment could further improve the anemia in dialyzed patients under recombinant human erythropoietin (r-HuEPO) therapy, leading to a reduction in r-HuEPO requirements, L-carnitine (1 g intravenously after every dialysis session) was administered for 6 months to a group of 13 patients; the results were compared with data from a placebo control group (N = 11). Globular osmotic fragility and endogenous EPO secretion were also evaluated. L-Carnitine treatment promoted a 38.1% reduction in r-HuEPO requirements in the active group (102.2 +/- 52.6 U/kg/wk v 63.3 +/- 37.8 U/kg/wk; P < 0.02), with globular osmotic fragility and endogenous EPO levels remaining unchanged and thus not accounting for carnitine effect on anemia. In the active group, seven patients decreased r-HuEPO needs (responders), while six did not (nonresponders). Compared with nonresponders, responders showed higher mean values at time 0 for r-HuEPO requirements and endogenous plasma EPO levels, although not statistically significant. It is concluded that L-carnitine deficiency might promote EPO resistance in dialyzed patients, which is corrected by L-carnitine supplementation, ultimately reducing r-HuEPO requirements.
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PMID:L-carnitine effects on anemia in hemodialyzed patients treated with erythropoietin. 1046 27

Severe iron deficiency was induced in rats by rearing nursing dams and their offspring on a diet comprising all the requisite nutrients and trace metals except iron. The iron deficient 5-week-old rats exhibited a severe anemia and a drastic decrease in iron content of the hepatic tissue and of the mitochondrial fraction. Cytochromes c + c1 and b were moderately but significantly reduced. A large increase in liver concentration was observed in iron-deficient animals; whereas there was no modification in total lipid, cholesterol, phospholipid and fatty acid composition of the mitochondrial membrane. Mitochondria from iron-deficient rats presented a partial uncoupling of the oxidative phosphorylation process. This functional derangement was completely reversed by the presence of either bovine serum albumin or L-carnitine plus ATP. This behaviour suggested that endogenous long-chain fatty acids could be primarily involved in the onset of mitochondrial dysfunction. The hepatic energy state of the liver appeared dramatically decreased under the pathological condition of severe iron-deficiency anemia. The possibility of a direct link between the partial loss of coupled functions observed in isolated mitochondria and the heavy energy deficit detected in the liver is discussed.
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PMID:Dietary iron deficiency in the rat. I. Abnormalities in energy metabolism of the hepatic tissue. 794 4

The relationship between serum carnitine levels and erythrocyte osmotic fragility was investigated in 26 chronic hemodialysis patients (10 males and 16 females, mean age: 57.3 +/- 13.5 years). Serum total-carnitine (TC), free-carnitine (FC) and acyl-carnitine (AC) levels were determined by a spectrophotometric method. Erythrocyte osmotic fragility was measured with a coil planet centrifuge. Serum TC levels were 39.9 +/- 13.4 mumol/l (mean +/- SD), FC levels were 21.8 +/- 7.8 mumol/l and AC levels were 18.0 +/- 9.6 mumol/l. The mean hemolysis end point (HEP) was 67.4 +/- 5.4 mOsM, the hemolysis maximum point (HMP) was 86.3 +/- 5.4 mOsM and the hemolysis start point (HSP) was 101.2 +/- 4.4 mOsM. Each hemolysis point in hemodialysis patients was elevated in comparison with the normal range. There were no significant differences in hemolysis points between a recombinant human erythropoietin (rhEPO)-treated group and nontreated group. HEP correlated with serum TC (r = -0.56, p < 0.01) and AC levels (r = -0.58, p < 0.01). HMP correlated with serum TC (r = -0.42, p < 0.05) and FC levels (r = -0.41, p < 0.05). Dose requirement of rhEPO maintaining target hematocrit correlated with serum TC (r = 0.54, p < 0.05) and FC levels (r = 0.50, p < 0.05). These data support that low serum carnitine levels accelerate erythrocyte osmotic fragility. Carnitine may contribute to the metabolism of erythrocyte membrane and have an impact on the efficacy of rhEPO in correcting renal anemia.
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PMID:Correlation between serum carnitine levels and erythrocyte osmotic fragility in hemodialysis patients. 873 Apr 24

The effect of propionyl L-carnitine on skeletal muscle metabolism in chronic renal failure. Carnitine deficiency, resulting in defective oxidative ATP synthesis, has been implicated in the myopathy of chronic renal failure. Using 31P magnetic resonance spectroscopy we examined calf muscle metabolism in 10 dialysed patients before and after 8 weeks of propionyl L-carnitine (PLC) 2 g.p.o. daily. Resting phosphocreatine/ATP (4.41 +/- 0.20 [SEM]) decreased to normal control levels on PLC (3.98 +/- 0.14; controls 4.00 +/- 0.06). In contrast, there was no effect of PLC on aerobic and anaerobic metabolism of muscle during or following 2-10 min exercise. The maximal calculated oxidative capacity (Qmax) remained below normal (28 +/- 3 mM/min before and 24 +/- 3 mM/min after PLC; controls 49 +/- 3 mM/min). Qmax correlated positively with hemoglobin concentration ([Hb]) after PLC (p < 0.03). Oxidative capacity assessed by phosphocreatine recovery T significantly improved with PLC administration (0.93 +/- 0.1 to 0.74 +/- 0.08 min) in those patients (n = 6) with [Hb] > 10 g/dl. [Hb] was rate limiting to oxidative metabolism in recovery from exercise but only following treatment with PLC. Patients with anemia or those subjects who use relatively more non-oxidatively synthesized ATP during exercise, do not respond to PLC. Oxidative metabolism did not normalize on PLC suggesting that anemia and carnitine deficiency are not the only causes of mitochondrial dysfunction in renal failure.
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PMID:The effect of propionyl L-carnitine on skeletal muscle metabolism in renal failure. 920 67

Carnitine supplementation in hemodialyzed patients was studied in a double-blinded, randomized, controlled trial in order to elucidate the effect of intravenous carnitine on renal anemia in patients treated with recombinant human erythropoietin (rHuEPO). Twenty stable hemodialysis (HD) patients received intravenous L-carnitine after each dialysis session in a dosage of 5 (N = 15) and 25 (N = 5) mg/kg, respectively, together with intravenous iron saccharate (20 mg/HD session) for four months and without iron for a further four months. Twenty patients received placebo instead of carnitine with an identical iron regimen. After a run-in phase of six months with a stable rHuEPO requirement, the rHuEPO dose was adjusted monthly when necessary to maintain target hemoglobin levels. At study entry (T0), plasma and red blood cell carnitine levels did not correlate significantly with the rHuEPO requirement. However, plasma free and total carnitine levels showed a significant negative correlation with erythrocyte survival time at T0. After four months of coadministration of intravenous iron and L-carnitine (T4), the rHuEPO requirement decreased in 8 of 19 evaluable HD patients. In these responders, the weekly rHuEPO dose was decreased significantly by 36.9+/-23.3% (183.7+/-131.7 at T0 vs. 126.6+/-127.9 U/kg/week at T4, P < 0.001). The rHuEPO requirement, however, was unchanged when all carnitine-treated patients were compared between T0 and T4 (T0: 172.0+/-118.0 vs. T4: 152.3+/-118.8 U/kg/week, P = 0.07, NS), but the erythropoietin resistance index decreased significantly in this group (T0: 16.0+/-11.0 vs. T4: 13.6+/-10.5 U/kg/week/g of hemoglobin, P < 0.02). The erythrocyte survival time was measured in five HD patients treated with iron and carnitine at T0 and T4. Two out of these patients were carnitine responders and showed an increase of erythrocyte survival time of 15 and 20%, respectively. After the withdrawal of iron supplementation, the rHuEPO requirement increased comparably in both L-carnitine- and placebo-treated patients during four more months. According to our data, L-carnitine, in addition to iron supplementation, may have an effect on erythropoietin resistance and erythrocyte survival time in HD patients. More than half of our patients, however, showed no benefit. Further studies to identify those HD patients who might have a benefit of carnitine supplementation, as well as studies concerning the optimal dosage, duration, and way of administration of carnitine supplementation and its mechanism of action, are required.
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PMID:Anemia and carnitine supplementation in hemodialyzed patients. 1008 93

Adjuvant therapy may allow patients being treated with epoetin to derive greater clinical benefits. Iron supplementation is currently the most widely used form of adjuvant therapy; intravenous (i.v.) iron is required by the majority of haemodialysis patients receiving epoetin. Measurement of hypochromic red blood cells is the most direct way of assessing iron supply to the bone marrow. During the correction phase, a dose of i.v. iron equivalent to 50 mg/day is recommended, with the total dose not exceeding 3 g. When subclinical vitamin C deficiency is suspected, ascorbic acid may be given orally (1-1.5 g/week) or i.v. (300 mg three times weekly at the end of dialysis). The active vitamin D metabolites alfacalcidol and calcitriol may, under some circumstances, improve anaemia and reduce epoetin dosage requirements. Vitamin B6 requirements are increased during epoetin therapy, and supplementation at a dose of 100-150 mg/week is recommended. Supplementation of vitamin B12 is optional. Folic acid is supplemented routinely in haemodialysis patients, though evidence that it increases the efficacy of epoetin is limited. Low doses (2-3 mg/week) should normally be sufficient to maintain optimal folic acid stores in epoetin-treated patients, although higher doses are necessary for patients with hyperhomocysteinaemia. L-Carnitine supplementation may be appropriate in some patients with anaemia of chronic renal failure (CRF) unresponsive to, or requiring large doses of, epoetin. Androgens potentially could reduce epoetin costs in countries with limited resources, but should only be used in men older than 50 years with a remnant kidney. Recent animal studies indicate that the combination of epoetin and insulin-like growth factor 1 might be beneficial in CRF patients. High doses of angiotensin-converting enzyme (ACE) inhibitors should be reserved for dialysis patients who have hypertension that cannot be controlled by other agents, or who require an ACE inhibitor for treatment of heart failure.
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PMID:Is there a role for adjuvant therapy in patients being treated with epoetin? 1057 78

Anaemia is a common problem in patients with renal failure, whether or not they are on dialysis. There is a continuum of declining renal function. In addition, the creatinine clearance at which dialysis is initiated varies widely between institutions and between studies. The term 'progressive renal insufficiency' is therefore preferable to 'pre-dialysis'. The adverse effects of renal anaemia on left ventricular mass become apparent early in the course of progressive renal insufficiency; 75% of patients starting dialysis already have left ventricular hypertrophy (LVH). Correction of anaemia in patients with progressive renal insufficiency has been shown to improve physical function and anaemia-related symptoms, but no controlled studies have yet been conducted to determine its effects on LVH. Although one animal study generated some concern that epoetin may exacerbate a decline in renal function, there is no evidence from human studies for any such effect. Treatment of anaemia with epoetin in anaemic patients with progressive renal insufficiency is therefore recommended, provided blood pressure is controlled. To date, however, there are insufficient data to determine whether normalization of haemoglobin is advisable in this patient group. Detection and correction of iron deficiency is important to achieve the full benefits of epoetin, though recommendations cannot yet be made regarding the optimum route and timing of iron supplementation in patients with progressive renal insufficiency. In these patients the role of other adjuvant therapies, such as L-carnitine, vitamin B6, vitamin B12 and folic acid, also requires further investigation.
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PMID:How should anaemia be managed in pre-dialysis patients? 1033 70

Excess morbidity and mortality among long-term hemodialysis patients because of infectious complications is partly caused by an impairment of cellular immune defense. We hypothesized this impairment is related to an abnormal carnitine metabolism also present in these patients. In a double-blind, randomized, placebo-controlled trial, we investigated the effect of L-carnitine on phagocytic function and viability of blood leukocytes in 17 patients undergoing maintenance hemodialysis. After an observation period of 1 month, the patients received either 10 mg/kg of L-carnitine or placebo intravenously at the end of each hemodialysis session over a period of 4 months. Leukocyte oxidative metabolism was measured by means of luminol-enhanced chemiluminescence and superoxide generation after stimulation with Staphylococcus aureus or phorbol myristate acetate. Killing capacity and phagocytosis of radiolabeled staphylococci were determined. A lactate dehydrogenase (LDH) release test was applied to assess cell viability. We were unable to show an effect of L-carnitine on phagocytic function and viability in vivo. Several clinical parameters were observed during the trial. No statistically significant differences concerning dialysis-related morbidity, anemia, or reduction of blood urea nitrogen and creatinine levels were detected. Additionally, we tested the effect of L-carnitine on phagocytic function after in vitro incubation of blood leukocytes, which also showed no changes. LDH release was decreased, indicating an improved viability of these cells. The latter results were found after in vitro incubation of cells, but could not be confirmed in vivo. In summary, we could not show beneficial effects of L-carnitine administration in hemodialysis patients for the dosage and duration of treatment stated, either on phagocytic function and viability or on the clinical and biochemical parameters observed.
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PMID:Effects of L-carnitine on leukocyte function and viability in hemodialysis patients: A double-blind randomized trial. 1051 49

Anemia is a serious problem in hemodialysis patients, the main cause of which is erythropoietin deficiency. After the discovery of recombinant human erythropoietin (rHuEpo) at the end of the last decade, the hematological profile of hemodialysis patients improved significantly but at considerable expense. The deformability of red blood cells (RBC) influences their microcirculation and tissue oxygen delivery along with their life span. We investigated the deformabilty of RBCs in 15 hemodialysis patients before and after three months on L-carnitine supplementation (30 mg/Kg body wt/dialysis session). We excluded from the study all patients who received blood transfusions three months before or during the study, patients who had hemorrhagic episodes, those with hyperparathyroidism or infections, and any who required surgical intervention during the study. The serum iron, folic acid and vitamin B-12 levels were kept normal during the duration of the study. The erythropoietin dose taken before the beginning of L-cartnitine supplementation was not changed. The deformability of RBCs before and after dialysis, prior to and following three months on L-carnitine was determined and compared to the deformability of RBCs from a control group. Hematocrit levels were measured before entry into the study and every month for three months. We found that the deformability of RBCs before the dialysis session was significantly greater than that found in the control group (t-test, p < 0.00001), and that there was a further increase after the end of the dialysis session. Three months following L-carnitine supplementation, we found a significant reduction of RBCs deformability (paired t-test, p < 0.004), and a significant increase in the hematocrit (ANOVA, p < 0.0001). We concluded that abnormalities in the deformability of RBCs improved after L-carnitine and that this was responsible for the increase in the hematocrit. This may allow a substantial reduction in rHuEpo dose.
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PMID:Effect of L-carnitine supplementation on red blood cells deformability in hemodialysis patients. 1071 83

The use of recombinant human erythropoietin (rhEPO) has greatly facilitated the treatment of anemia in children with chronic renal failure, but is expensive. Several reports on adult patients have shown that supplementation with L-carnitine can decrease the requirement for rhEPO. The objective of this study was to investigate the effect of oral supplementation with L-carnitine on the rhEPO requirement in children on dialysis. We investigated 16 children on dialysis (11 hemodialysis, 5 peritoneal dialysis) with a median age of 10.2 years. All children were stable on rhEPO treatment at least 3 months before study entrance. After obtaining baseline data, all children were supplemented with L-carnitine 20 mg/kg/day. Data were collected for 26 weeks. Follow-up was completed for 12 patients (8 hemodialysis, 4 peritoneal dialysis). At baseline free carnitine (32+/-18 micromol/l) and total carnitine levels (54+/-37 micromol/l) were normal. At the end of the study free carnitine levels had increased to 97+/-56 micromol/l (P<0.05) and total carnitine levels to 163+/-90 micromol/l (P<0.05). There was no significant change in rhEPO requirement. Hemoglobin level or hematocrit did not change significantly during the study. In conclusion we could not demonstrate a beneficial effect of supplementation with L-carnitine on rhEPO requirement in children on dialysis.
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PMID:Oral L-carnitine does not decrease erythropoietin requirement in pediatric dialysis. 1109 4


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