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Query: UMLS:C0035078 (renal failure)
 31,970 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

End-stage renal failure (ESRF) is associated with a higher risk of cardiovascular disease (CVD) than predicted by the major risk factors. We investigate the hypothesis that metalloproteins such as transferrin and ceruloplasmin and the inflammatory response are associated with CVD risk in this population. In this cross-sectional study of 81 subjects stable on haemodialysis (HD), 43 with CVD and/or peripheral vascular disease (PAD) were compared to 38 subjects without clinical evidence of CVD/PAD. Serum concentrations of metalloproteins and acute phase reactants were compared by univariate analysis and logistic regression modelling. Body mass index, gender ratios, prevalence of diabetes, iron status, and homocysteine concentrations did not differ significantly between the groups. Those with CVD were older (P< 0.001) and had been on dialysis for longer (P = 0.004). CVD subjects had significantly higher concentrations of ceruloplasmin (325 vs 284 mg/L, P = 0.011), copper (18.2 vs 15.7 micromol/L, P = 0.002), and C-reactive protein (CRP) (median 9.0 vs 3.8 mg/L, P = 0.002). Transferrin iron binding capacity tended to be higher in the CVD group (P = 0.088). CVD risk for subjects with serum concentrations in the upper tertile was increased 9.4-fold (CI 2.8-31.0) for copper, 4.2-fold (CI 1.5-12.2) for ceruloplasmin, 3.9-fold (CI 1.3-12.1) for transferrin iron binding capacity, and 2.3-fold (CI 0.9-6.1) for CRP. In multivariate logistic regression models, age (P = 0.001) and time on dialysis (P = 0.002) were the strongest risk factors for CVD. After adjustment for age and time on dialysis, transferrin iron binding capacity (P = 0.013) and copper (P = 0.019) continued to be associated with CVD risk but ceruloplasmin (P = 0.065) and CRP (P = 0.634) were not. Total cholesterol was associated with a lower risk of CVD (ie protective), presumably due to cholesterol-lowering therapy in high-risk patients. In conclusion, copper and transferrin iron binding capacity may be associated with CVD risk in HD subjects.
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PMID:Are metalloproteins and acute phase reactants associated with cardiovascular disease in end-stage renal failure? 1094 71

In contrast to proteins and lipids, oxidative damage to DNA has not been well studied in patients undergoing hemodialysis (HD). We hypothesized that phagocytes are activated after blood-membrane contact during HD, and oxidants from metabolic activation can damage leukocyte DNA. To test this hypothesis, the 8-hydroxy-2'-deoxyguanosine (8-OHdG) content of leukocyte DNA was measured by high-performance liquid chromatography electrochemical detection method in 35 age- and sex-matched healthy subjects, 22 undialyzed patients with advanced renal failure, and 109 HD patients to assess the relation between oxidative DNA damage and complement-activating membranes, blood antioxidants, and iron status. Dialysis membranes were classified into complement-activating (cellulose; n = 55) and non-complement-activating (polymethylmethacrylate [PMMA]; n = 35; polysulfone [PS]; n = 19) membranes. We found increased oxidative stress in undialyzed and HD patients based on a decrease in plasma levels of ascorbate and alpha-tocopherol adjusted for blood lipid (alpha-tocopherol/lipid), serum albumin, and reduced glutathione levels in whole blood and an increase in oxidized glutathione levels in whole blood compared with controls (P < 0.001). The greatest 8-OHdG level in leukocyte DNA was in HD patients, followed by undialyzed patients and healthy controls (P < 0.001), and was significantly greater in HD patients using cellulose membranes than those using PMMA or PS membranes (P < 0.001). 8-OHdG levels correlated with plasma alpha-tocopherol/lipid (r = -0.314; P < 0.005), serum iron (r = 0. 446; P < 0.001), and transferrin saturation values (r = 0.202; P < 0.05) in the analysis of all HD patients. In a 6-week crossover study, 8-OHdG levels significantly decreased after the switch from cellulose to synthetic membranes for 2 weeks and increased after the shift from synthetic to cellulose membranes (P < 0.05). Iron metabolism indices and plasma alpha-tocopherol/lipid values did not change significantly in the study period. We conclude that 8-OHdG content in leukocyte DNA is a biomarker of oxidant-induced DNA damage in HD patients. Oxidative DNA damage is a consequence of uremia, further augmented by complement-activating membranes.
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PMID:8-hydroxy-2'-deoxyguanosine of leukocyte DNA as a marker of oxidative stress in chronic hemodialysis patients. 1105 49

The copper-binding protein ceruloplasmin oxidizes ferrous iron to ferric iron, an action that is critical for the binding of iron to transferrin in plasma. Ceruloplasmin, in common with ferritin and transferrin, is an acute-phase protein that is altered by inflammation. We sought to identify interrelationships between the copper and iron systems by measuring copper, ceruloplasmin, ferroxidase, ferritin, transferrin, iron, and iron-binding capacity in a group of hemodialysis patients. We looked for evidence of inflammation and free-radical injury by assaying for protein carbonyl groups, protein pyrrolation, di-tyrosine, and advanced oxidation protein products. Our findings were compatible with an active inflammatory state that affected both iron and copper metabolism. Transferrin levels were low, whereas ceruloplasmin levels were elevated compared to normal. Copper concentration was increased proportional to ceruloplasmin. Several variables including ceruloplasmin and transferrin were observed to correlate significantly with the level of pyrrolated protein. The data suggest that posttranslational modification of circulating proteins may affect their structural, enzymatic, and ligand-binding properties. Abnormalities in copper metabolism and their influence on iron handling in renal failure are complex and will require additional study before their importance can be defined.
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PMID:Relationships between the copper and iron systems in hemodialysis patients and variables affecting these systems. 1109 67

Mortality is markedly elevated in patients with end-stage renal disease. The leading cause of death is cardiovascular disease. Lipoprotein levels are only slightly elevated in dialysis patients, and cardiovascular risk is inversely correlated with serum cholesterol, suggesting that a process other than hyperlipidemia plays a role in the incidence of cardiovascular disease. Hypoalbuminemia, ascribed to malnutrition, has been one of the most powerful risk factors that predict all-cause and cardiovascular mortality in dialysis patients. The presence of inflammation, as evidenced by increased levels of specific cytokines (interleukin-6 and tumor necrosis factor alpha) or acute-phase proteins (C-reactive protein and serum amyloid A), however, has been found to be associated with vascular disease in the general population as well as in dialysis patients. The process of inflammation, also called the acute-phase response, additionally causes loss of muscle mass and changes in plasma composition-decreases in serum albumin, prealbumin, and transferrin levels, also associated with malnutrition. Inflammation alters lipoprotein structure and function as well as endothelial structure and function to favor atherogenesis and increases the concentration of atherogenic proteins in serum, such as fibrinogen and lipoprotein (a). Inflammation in dialysis patients is episodic. The causes are likely to be multifactorial and include vascular access infection, less-than-sterile dialysate, dialysate back leak, and nonbiocompatible membranes in addition to clinically apparent infection. In addition, proinflammatory compounds, such as advanced glycation end products, accumulate in renal failure, and defense mechanisms against oxidative injury are reduced, contributing to inflammation and to its effect on the vascular endothelium.
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PMID:The microinflammatory state in uremia: causes and potential consequences. 1142 86

The mortality among end-stage renal failure (ESRF) patients undergoing renal replacement therapy (RRT) remains high. An important proportion of these patients die shortly after the initiation of RRT. The present study aims to determine the best predictors for the early mortality in a group of 140 ESRF patients who initiated RRT between october 96 and december 99. The mean age of the study group was 61 +/- 13 years, and the mean follow-up time was 20 +/- 12 months. Diabetic nephropathy was the most prevalent etiology of renal failure (30%). The following data, collected immediately before the initiation of RRT, were included as independent variables: demographic and clinical characteristics, including the nutritional status established by the Subjective Global Assessment (SGA), follow-up time in the predialysis clinic (less or longer than 3 months), EPO therapy, vascular access, renal function (creatinine and urea clearances, and Kt/V urea), hematological and biochemical data including serum albumin, bicarbonate, transferrin, PTH and C-Reactive protein, as well as the protein catabolic rate and the percent of lean body mass normalized for ideal body weight, calculated from the 24 h total urine excretion of nitrogen and creatinine. The Cox proportional hazard regression model, stratified for an age over or less than 65 year, was utilized to determine the best predictors for the mortality during the study period. Sixty percent of patients had at least one comorbid condition, and 35% had cardiovascular diseases. Mild-moderate or severe malnutrition was observed in 48% of patients. The creatinine clearance and Kt/V urea before the initiation of RRT were: 9.50 +/- 2.64 ml/min/1.73 m2 and 1.47 +/- 0.44, respectively. Forty-one patients died during the study period (annual death rate: 17%). The best predictor of mortality was the nutritional status assessed by the SGA (OR: 2.32, IC 95% 1.54-3.48, p < 0.0001). In a second analysis in which the SGA was removed from the model, the previous history of cardiovascular diseases (OR: 2.07, CI 95%: 1.06-4.06, p = 0.032), and the percent of lean body mass/ideal weight (OR: 0.96; IC 95%: 0.93-0.99; p = 0.042), proved to be the best predictor of mortality. In conclusion, nutritional indices prior to the initiation of RRT, and the previous history of cardiovascular diseases were the best predictors of the early mortality in this unselected population on dialysis. Because nutritional status appeared to be a marker of the severity of the comorbid conditions, a better control of the number and severity of these comorbid conditions may be the best way for reducing the mortality in patients on RRT.
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PMID:[Predictors of early death during dialysis]. 1147 8

Ketoacids (KA) and recombinant human erythropoietin (rHuEPO) may each, on their own, influence the metabolic status of patients with chronic renal failure (CRF). A long-term prospective randomized study was designed to monitor the metabolic and nutritional status and progression of CRF using three therapeutic protocols: (A) low-protein diet (LPD) with 0.6 g of protein and 35 kcal/kg/day, with recombinant human erythropoietin (rHuEPO) at a dose of 40 U kg/week and keto acids (KA) 100 mg/kg/day, (Group I), (B) LPD and rHuEPO (Group II), and (C) LPD only (Group III). A total of 105 patients (50M/55F), aged 26-78 years, CCr 22-36 ml/min, were monitored at the beginning, and at every 6 months for 3 years in the above three study groups. Group I comprised 35 patients, Group II 38 patients and Group III 32 patients. During follow-up, a significantly smaller decrease in GFR (CCr, Cin) and in I/SCr, and an increase in serum albumin, transferrin, leucine, body mass, index and HDL-cholesterol were found in Group I (all p < 0.01). In addition, significant decreases were also seen in proteinuria, renal fractional leucine excretion and serum triglycerides level (p < 0.01). Co-administration of LPD, rHuEPO and KA thus constitutes an effective alternative to conservative management of CRF, delaying in follow-up period progression of renal failure and correction of metabolic parameters.
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PMID:Effects of low-protein diet supplemented with ketoacids and erythropoietin in chronic renal failure: a long-term metabolic study. 1180 7

This study focuses on the extent of oxidative DNA damage in peripheral blood leukocytes of chronic peritoneal dialysis (CPD) patients. 8-Hydroxy 2'-deoxyguanosine (8-OHdG) contents in peripheral leukocyte DNA were measured by an HPLC-electrochemical detection method in 24 age- and sex-matched healthy subjects, 22 nondialyzed patients with advanced renal failure, and 42 CPD patients. Mean 8-OHdG content was the highest in CPD patients, followed by the nondialyzed patients, and then by the healthy subjects (19.4 versus 11.9 versus 8.3/10(6) dG; ANOVA P < 0.001). In nondialyzed subjects, peripheral leukocyte 8-OHdG contents inversely correlated with renal creatinine clearance (r = -0.772; P < 0.001). Deficiency of blood antioxidants in CPD and nondialyzed patients was expressed by the lower plasma levels of ascorbate, cholesterol-standardized alpha-tocopherol and whole-blood reduced glutathione, and the higher levels of whole-blood oxidized glutathione as compared with healthy subjects (ANOVA P < 0.05). Mean serum ferritin and iron levels and transferrin saturation were higher in the CPD patients than those in the nondialyzed patients and controls (ANOVA P < 0.05). Flow cytometric analyses of intracellular reactive oxygen species production of peripheral leukocytes showed that spontaneous production by granulocytes, as well as phorbol-12-myristate-13-acetate (PMA)-induced production by granulocytes, lymphocytes and monocytes, were the highest from CPD patients, followed by nondialyzed patients, and then by the healthy subjects (ANOVA P < 0.05). Forward stepwise multiple regression disclosed that uremia, PD treatment, spontaneous and PMA-induced reactive oxygen species production in leukocytes, and serum iron were the independent determinants of peripheral leukocyte 8-OHdG content (R(2) = 0.769; P < 0.001). In conclusion, profound increased 8-OHdG levels in peripheral leukocyte DNA occur in the course of chronic renal failure, gradually increase with its progression, and are further exacerbated by PD treatment.
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PMID:Increased oxidative damage to peripheral blood leukocyte DNA in chronic peritoneal dialysis patients. 1196 Oct 20

Serum albumin, transferrin, and prealbumin levels decrease as glomerular filtration rate (GFR) declines, even prior to the start of dialysis. The levels of these serum proteins are also associated with creatinine levels and lean body mass. Lean body mass also decreases with advancing renal failure. While all of these measures are regarded as reflections of nutritional status, each are strongly associated with any of several indicators of inflammation: positive acute-phase proteins or the cytokines that regulate their synthesis rate, in both longitudinal and cross-sectional studies. Inflammation in turn is associated with comorbid conditions, cardiovascular disease, chronic infections, age, and vascular access type. Additionally, dialysis patients are subjected to oxidative stress and exposure of blood to foreign antigens in the dialysis process that also potentially contribute to inflammation. In otherwise healthy individuals reduced protein and calorie intake does not cause hypoalbuminemia since albumin fractional catabolic rate (FCR) and resting energy expenditure (REE) normally decrease in response. The simultaneous occurrence of decreased protein intake and inflammation prevent these homeostatic compensations to reduced nitrogen and energy intake from occurring, resulting in decreasing albumin, transferrin, and prealbumin levels and loss of muscle mass. Nutritional intake may also be challenged as a result of renal failure associated with anorexia, gastroparesis, and socioeconomic factors, which may all cause nutritional intake to be sufficiently marginal so that the combined effects of inflammation and decrease protein intake are expressed as decreased visceral and somatic protein stores.
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PMID:Serum albumin concentration in dialysis patients: why does it remain resistant to therapy? 1453 80

In patients with renal anemia, iron therapy can be administered intermittently or regularly at a low dose. We performed a randomized clinical trial in pediatric patients with end-stage renal failure on hemodialysis and absolute or functional iron deficiency. The study group received maintenance iron therapy according to the ferritin serum levels and the control group received intermittent 10-weekly doses. Success was defined as stabilization of ferritin levels between 100 and 800 microg/l and transferrin saturation (TSAT) between 20% and 50%, in addition to an increase in the hemoglobin level. The major reason for exclusion was iron overload. The study group received 6 mg/kg per month of parenteral iron [95% confidence interval (CI) 3.3-8.8] and the control group 14.4 mg/kg per month (95% CI 12-16.8) ( P<0.001). After 4 months of treatment, ferritin levels increased to 66 microg/l (95% CI 69-200) in the study group and to 334 microg/l (95% CI 145-522) in the control group ( P=0.009). Maintenance therapy and intermittent weekly doses were successful in 73% and 38%, respectively. After 3 months of treatment, hemoglobin levels increased to 10 g/dl, with no difference between the groups. However, in the control group the increase in hemoglobin levels was unsustained, and 3 patients needed transfusion. Patients in the control group had a higher risk of iron overload than patients in the study group (70% vs. 19%). Thus, the regimen based on assessment of serum ferritin levels was more efficient than the intermittent regimen because it increased and maintained the hemoglobin levels with lower iron doses and a lower risk of iron overload.
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PMID:Intermittent versus maintenance iron therapy in children on hemodialysis: a randomized study. 1463 60

Cardiovascular disease is common in patients with chronic kidney disease (CKD). As renal function fails, many patients become progressively malnourished, as evidenced by reduced levels of albumin, prealbumin, and transferrin. Malnourished patients have increased levels of C reactive protein (CRP), interleukin-6 (IL-6), and concomitant cardiovascular disease when they reach end stage. Many diseases that cause CKD, diabetes, and hypertension are also associated with cardiovascular disease. Thus the direct effect of renal failure per se directly contributing to the inflammation-malnutrition-atherosclerosis paradigm is not completely established in early stages of CKD. Some aspects of progressive renal failure, however, cause changes in plasma composition and endothelial structure and function that favor vascular injury. As renal function fails, hepatic apo A-I synthesis decreases and HDL levels fall. HDL is an important antioxidant and defends the endothelium from the effects of cytokines. Inflammation causes further structural and functional abnormalities in HDL. Apolipoprotein C III (apo C III), a competitive inhibitor of lipoprotein lipase is increased in CKD. Serum triglyceride levels increase as a result of accumulation of intermediate-density lipoprotein (IDL) comprising VLDL and chylomicron remnants. These impede vascular relaxation and are associated with cardiovascular disease. Activation of the renin angiotensin axis is a component of many renal diseases and adaptation to loss of renal mass. Angiotensin II (AngII) activates NADPH oxidases, leading to production of the superoxide anion and decreased availability of nitric oxide (NO), further impairing vascular function. H(2)O(2), produced as a consequence of superoxide dismutation, stimulates vascular cell proliferation and hypertrophy. Leukocyte-derived myeloperoxidase functions as an "NO Oxidase" in the inflamed vasculature and contributes to decreased NO bioavailability and compromised vascular reactivity. The changes in lipoprotein composition and structure as well as AngII-mediated alterations in endothelial function amplify the effect of subsequent inflammatory events.
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PMID:The role of oxidative stress-altered lipoprotein structure and function and microinflammation on cardiovascular risk in patients with minor renal dysfunction. 1497 55


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