Protein intake does not depend on the dose of dialysis delivered--provided Kt/V is adequate

BACKGROUND: A link between malnutrition and the dialysis dose has been recentlypostulated on the basis of the direct relationship between Kt/Vand nPCR and an increase in dialysis therapy has been also proposedin malnourished patients or when nPCR is less than 1 g/kg b.w.,but the clinical meaning of such a relationship is unclear. DESIGN: Both dietary protein intake and nPCR were simultaneously determinedin a selected population of 35 well-dialysed patients (Kt/V>0.8)and were related to the delivered dialysis dose. RESULTS: No relationship was found between measured Kt/V (1.10 ±0.20) and dietary protein intake (PI, 0.98 ± 0.20 g/kg)and similarly no relationship was evident between the dialysisdose and nPCR (0.99 ± 0.20 g/kg). Although the mean nPCRvalue was similar to that of protein intake, nPCR exceeded proteinintake when PI was less than 1 g/kg b.w. CONCLUSION: Our results demonstrate that if the dialysis dose is adequate,protein intake is a dialysis—independent or patient—dependentvariable. They also show that at least 0.9 to 1.0 g proteinper kg b.w are required to maintain nitrogen balance even inwell-dialysed patients.     

Effect of predialysis eating on measurement of urea reduction ratio and Kt/V

Physicians utilize the measurement of the urea reduction ratio (URR) and Kt/V as surrogates for the adequacy of hemodialysis, as well as to follow the course of patients longitudinally. These measurements are affected by the duration of a dialysis treatment, the type and size of the dialyzer membrane used during the treatment, the blood flow rate during the treatment, and the adequacy of vascular access. We, and others, have noted that eating during dialysis can be associated with decreases in URR and Kt/V. However, there have been no previous studies that have examined the effects of eating before dialysis on these variables. This study examined the effects of eating one-third of a daily diet 2 hours before dialysis as opposed to fasting for a minimum of 3 hours before dialysis on the measured URR and Kt/V as obtained routinely in our dialysis unit. Sixty seven patients gave informed consent for the study, and 42 completed the protocol. No differences were found in URR or Kt/V when dialysis was performed 2 hours after eating compared with performing dialysis after at least a 3-hour fast in the group as a whole or in subgroup analyses of men, women, patients with diabetes, patients in different age groups, or patients who dialyzed on different shifts. Unlike intradialytic food ingestion, moderate predialysis food intake does not affect the measurement of dialysis adequacy as determined by URR and Kt/V.     

Influence of parenteral iron therapy and oral vitamin E supplementation on neutrophil respiratory burst in chronic hemodialysis patients

BACKGROUND: Bioincompatibility of hemodialysis (HD) membranes is responsible for neutrophil activation leading to oxidative stress, which can be further increased by intravenous (IV) iron (Fe) administration. The aim of our study was to monitor neutrophil respiratory burst during HD and to find out whether this process is influenced by IV Fe and oral vitamin E administration. METHODS: Within four HD sessions, blood samples were taken from seven chronic HD patients at time 0 (before HD), 60, 70, and 130 min of HD session. Neutrophil respiratory burst was assessed by luminol-enhanced chemiluminescence (CL). Plasma advanced oxidation protein products (AOPP) concentration was measured spectrophotometrically. During the second and the fourth HD, 62.5 mg of sodium ferric gluconate was applied IV in the 65th minute of HD. Before the last two HD, the patients were given orally 200 mg of vitamin E daily for 7 days. Patient's results were compared with healthy controls. RESULTS: Predialysis CL is higher in patients than in controls (1,926 +/- 436 vs. 1,083 +/- 325 RLU, p<.01). CL decreases in the 60th min of HD (1,926 +/- 436 vs. 1,220 +/- 599 RLU, p<.05); thereafter, it remains stable. After Fe application, CL increases at time 130 compared with CL at time 60 (1,303 +/- 269 vs. 877 +/- 292 RLU, p<.05). AOPP concentration is higher in patients than in controls (137.5 +/- 42.7 vs. 88.9 +/- 24.8 micromol/L, p<.01) and remains unaffected by vitamin E supplementation. After vitamin E intake, predialysis CL remains significantly higher than in controls, and changes in CL during HD are minimal despite Fe administration. CONCLUSION: HD patients' neutrophils generate more oxygen radicals than in healthy individuals. This production decreases during HD and then increases after IV Fe administration. Short-term vitamin E administration attenuates this fluctuation of neutrophil oxidative metabolism, without affecting the total degree of oxidative stress.     

Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement

Nephrol Dial     

Effect of oral vitamin E and C therapy on calcineurin inhibitor levels in heart transplant recipients.

BACKGROUND: A recent prospective trial demonstrated that oral vitamins C and E retard the early progression of transplant-associated coronary arteriosclerosis; as a result, a number of centers have added these agents to their maintenance regimens. This study reviewed the impact of vitamin E and C supplementation on calcineurin inhibitor trough concentrations. METHODS: A retrospective chart review of the first 29 heart transplant patients prescribed anti-oxidant agents was performed. Twenty-two patients taking cyclosporin A (CsA) and 7 patients taking tacrolimus were prescribed vitamin C (500 mg twice a day) and vitamin E (400 IU twice a day). Serum chemistries and drug levels were measured before and after vitamin therapy was initiated. RESULTS: The baseline CsA trough concentration (mean +/- SD) was 137 +/- 39 ng/ml and it declined to 99 +/- 54 ng/ml (p = 0.007) after anti-oxidant therapy was initiated. The average percentage decrease in the CsA trough concentration was 30%. No significant changes were seen in the patients taking tacrolimus. CONCLUSIONS: These data demonstrate that supplementation with the anti-oxidant agents vitamin C and vitamin E decreases CsA concentrations but does not appear to effect tacrolimus concentrations. Although more detailed pharmacokinetic analysis is necessary to clarify the exact mechanism of this interaction, physicians who take care of transplant recipients should be aware that more frequent CsA concentration monitoring is warranted after initiating these anti-oxidant agents.     

Effect of mycophenolate mofetil on erythropoiesis in stable renal transplant patients is correlated with mycophenolic acid trough levels.

BACKGROUND: Both mycophenolate mofetil (MMF) and azathioprine (AZA) are immunosuppressive drugs that inhibit purine synthesis. In theory, MMF selectively inhibits lymphocyte proliferation, while AZA has well-known effects on red blood cells and thrombocytes as well. In renal transplant recipients we replaced CsA therapy by MMF in an attempt to reduce the immunosuppressive load 1 year after kidney transplantation. During this study we observed the effect of MMF on haematological parameters such as haemoglobin (Hb), leukocytes, and thrombocytes. METHODS: One year after kidney transplantation 26 stable patients were converted from cyclosporin A (CsA) to MMF (2 g/day). Thereafter, these patients were tapered twice in their MMF dose from 2 g to 1.5 g (4 months after conversion) and from 1.5 to 1 g (8 months after conversion) per day. The Hb levels, leukocyte and thrombocyte counts, and mycophenolic acid (MPA) trough levels were routinely measured. RESULTS: After conversion from CsA to MMF not only creatinine levels and the number of leukocytes, but also the haemoglobin (Hb) level significantly decreased in 21/26 patients (P=0.0004). In eight patients the Hb level dropped more than 1 mmol/l (=1.61 g/dl). Only in two of eight patients was an explanation for blood loss found. The effect on Hb level did not ameliorate after the first MMF dose reduction to 1.5 g/day. After tapering the MMF dose to 1 g/day, the Hb approached the pre-conversion level. Not only the MMF dose but also the mycophenolic acid (MPA) trough level correlated with the Hb level. CONCLUSIONS: After conversion from CsA to MMF 1 year after kidney transplantation, a decrease in Hb level and leukocyte count was observed. The MPA trough level correlated also with the Hb level. The effect on the Hb level was reversible after dose reduction. This finding suggests that MMF exerts a negative effect on erythropoietic cells.     

Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement.

BACKGROUND: Ionic dialysance was recently introduced as a means to assess Kt/V (K(ID)t/V). With this method, urea distribution volume (V) has to be estimated. The primary aim of the present study was to assess the agreement between equilibrated Kt/V assessed by urea kinetic modelling (eKt/V) with K(ID)t/V taking into account different estimates of V, and to assess the monthly variation in V. Secondly, the mechanisms behind the intra-treatment changes in ionic dialysance and inter-treatment variability of K(ID)t/V were assessed. METHODS: Sixty-six patients were included. eKt/V was estimated using 30 min post-treatment sampling in the second generation Daugirdas equation. V was assessed by the formulae of Watson and Chertow (V(Watson); V(Chertow)), double-pool urea kinetic modelling (V(UKM)) and by ionic dialysance (V(IOD)) [Diascan; Hospal(R)]. RESULTS: The use of V(UKM) or V(IOD) instead of V(Watson) or V(Chertow) improved the relation between eKt/V and K(ID)t/V (both r = 0.93; P < 0.001 vs r = 0.84 and r = 0.81; P < 0.001). Mean values of eKt/V (1.19 +/- 0.21), K(ID)t/V(UKM) (1.19 +/- 0.30) and K(ID)t/V(IOD) (1.21 +/- 0.25) were comparable. Intra-class correlation coefficient of V(IOD) was 0.87 with a 1-month interval and <0.75 after 2 and 3 months. Intra-class correlation coefficient of V(DP) was 0.79 with a 1-month interval and <0.75 after 2 and 3 months. Inter-treatment variation in K(ID)t/V during six consecutive dialysis sessions was 6.1% +/- 0.6%. Changes in blood flow were the main determinant of variations in K(ID)t/V (P < 0.05). During treatment, ionic dialysance decreased by 12 +/- 13 ml/min (P < 0.001). The decline in blood volume was the major determinant of the intra-dialytic change in ionic dialysance (P < 0.05). CONCLUSION: The use of V(IOD) and V(UKM) results in better agreement between eKt/V and K(ID)t/V compared with anthropometric formulae. K(ID)t/V was comparable with eKt/V and thus lower than expected for a single-pool method. V(IOD) and V(UKM), should be assessed at least monthly. K(ID)t/V varies widely between consecutive dialysis sessions, mainly due to differences in blood flow. During treatment, ionic dialysance decreases, which is related to the relative decline in blood volume.     

抗氧化治疗对糖尿病肾脏病患者肾功能的保护作用

目的探讨维生素E联合维生素C抗氧化治疗对2型糖尿病肾脏病患者肾功能的保护作用。方法选择我院2型糖尿病肾脏病患者80例,随机分为2组,对照组（A组）接受常规治疗;抗氧化治疗组（B组）除常规治疗外,口服维生素E（0．1g／次,每日1次）、维生素C（0．2g／次,每日3次）。每3个月随访1次,观察记录患者的肾功能,以血肌酐（SCr）升高1倍为随访终点,SCr升高1倍所经历的时间为肾功能生存时间,最长随访时间为2年。结果A组肾功能平均生存时间为（14．78±0．64）个月;B组平均生存时间为（18．16±0．68）个月,2组比较有统计学差异（P〈0．05）。结论维生素E联合维生素c抗氧化治疗对糖尿病肾脏病患者肾功能具有保护作用。     

Effectiveness of oral desmopressin therapy in posterior urethral valve patients with polyuria and detection of factors affecting the therapy

OBJECTIVES: The present study aims to evaluate the effect of desmopressin treatment on urine output, density and glomerular filtration rate (GFR) in patients with posterior urethral valve (PUV) and the factors affecting the response to this treatment. METHODS: A total of 68 PUV patients who were followed-up after valve ablation were examined with the fluid intake, urine output and GFR. Sixteen patients who were polyuric (a urine output more than 30 ml/kg/day) and had hypoosmolar urine (urinary density of 1015 or lower) included in the study. Blood chemistry and serum ADH level were studied. Following 5 days of observation, patients were given DDAVP perorally with a dosage of 0.4 mg/day, two equal doses per day. After 7 days and after a 3 month period of treatment, voiding characteristics, day-time and night-time urine densities and also GFR have been re-evaluated. RESULTS: The mean age was 6.8 years (range 2 to 11 years). The mean age at valve ablation was 20.7 months (range 5 months to 6 years). The mean daily urine output during first week and at the third month of the treatment had decreased significantly (p=0.004 and p=0.006). There was increase in night-time and day-time urine density in 10 patients (62%) and in 13 patients (81%) respectively at the third month evaluation. Increments in urine density were statistically significant for the third month evaluation. Nine (56%) patients had ADH levels within normal (<7 pcg/ml) levels and 7 patients had higher levels. There was no statistically significant difference between pretreatment and posttreatment micturation characteristics. However patients with voiding dysfunction responded better to DDAVP treatment. CONCLUSIONS: Desmopressin treatment improves polyuria in PUV patients. The responses are better particularly in PUV patients with significant bladder dysfunction. This supports the harmful role of polyuria on bladder dysfunction. The DDAVP treatment improves the day-time and night-time in PUV patients. Combination of DDAVP treatment with overnight catheterization may be a good alternative that needs to be evaluated by further prospective randomized studies.     

Comparison of effect of vitamin E-coated dialyzer and oral vitamin E on hemodialysis-induced Cu/Zn-superoxide dismutase

BACKGROUND: We reported earlier that production of Cu/Zn-superoxide dismutase (SOD) increases markedly in hemodialysis patients but not in non-dialyzed chronic renal failure (CRF) patients. In this study, we compared the antioxidant effects of oral vitamin E supplementation (VE-PO) and vitamin E coating of a dialyzer (VE-BMD) by measuring increased Cu/Zn-SOD in hemodialysis patients. METHODS: 31 hemodialysis patients were divided into two groups: 16 hemodialysis patients underwent usual dialysis with vitamin E supplementation 600 mg/day while 15 others were dialyzed using vitamin E-coated membrane for 6 months. Total plasma SOD activity was determined by NBT method, plasma Cu/Zn-SOD contents by ELISA and Cu/Zn-SOD mRNA in leukocytes by RT-PCR. RESULTS: VE-PO and VE-BMD showed almost comparable effects on Cu/Zn-SOD contents and its mRNA levels in hemodialysis patients. VE-PO resulted in a progressive decrease of Cu/Zn-SOD content (p < 0.001). A comparable progressive decrease was observed also in VE-BMD (p < 0.0001). Both VE-PO and VE-BMD resulted in a progressive decrease of Cu/Zn-SOD mRNA (p < 0.01), which reached the level of non-dialyzed CRF patients.     

Dissociation between the Correlation of Peritoneal and Urine Kt/V with Sodium and Fluid Removal: A Possible Explanation of their Difference on Patient Survival

Background: It has been shown that residual renal function but not peritoneal clearance predicted patients’ survival in peritoneal dialysis therapy. In the present study, we tried to explore the potential causes resulting in the difference between residual renal function and peritoneal dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods: A cross sectional study was performed during July and August 2003 to evaluate the dialysis adequacy in CAPD patients who were clinically stable and had daily urinary volume more than 100 ml. Results: A total of 45 patients (male 27 and female 18) with an average ( ± SD) age of 61.76 ± 13.27 years were included in this study. The daily urinary volume and dialysate ultrafiltration volume were 570.33 ± 395.47 ml and 726.09 ± 454.01 ml, respectively. Peritoneal urea clearance (Kt/V) correlated significantly with the drained daily dialysate volume (r = 0.362, P < 0.01), but not with peritoneal net fluid removal (ultrafiltration) (r = 0.232, P > 0.05) and sodium removal (r = 0.139, P > 0.05). On the other hand, there were strong positive correlations between residual renal Kt/V and daily urine volume (r = 0.802, P < 0.001), as well as between residual renal Kt/V and urinary sodium removal (r = 0.670, P < 0.001). Conclusions: High residual renal Kt/Vurea represents both higher solute clearance and higher sodium and fluid removal, but higher peritoneal Kt/Vurea is not necessarily associated with better sodium and fluid removal. This dissociation might explain the differences on the survival of patients and peritoneal clearances.     

Lack of efficacy of dual intragastric balloon therapy on weight loss and patient dissatisfaction

BackgroundDual intragastric balloon (DIGB) therapy is a non-surgical, restrictive method of weight loss. We evaluated weight loss and patient satisfaction after DIGB removal.MethodsBetween 2016 and 2019, 35 patients had DIGB therapy. A retrospective review of weight loss at balloon removal and follow-up, adverse events during DIGB therapy, and patient satisfaction was performed.ResultsAt follow-up after balloon removal (22.3 ± 10.5 months), mean percent excess weight loss (%EWL) was significantly decreased compared to %EWL at removal (4.7 ± 42.7% vs 32.4 ± 38.8%, p = .001). Weight regain occurred in 22/31 (71%) patients. Adverse events during DIGB therapy included: nausea, abdominal pain, reflux, pancreatitis, and gastric outlet obstruction. Twenty-five (71.4%) patients completed a satisfaction questionnaire. Only 3/25 (12%) patients were satisfied, and 92% would not choose DIGB for weight loss.ConclusionWeight loss achieved from DIGB on average was not maintained after balloon removal. Most patients were not satisfied and would not choose DIGB again.     

Influence of oral vitamin E therapy on micro-inflammation and cardiovascular disease markers in chronic hemodialysis patients

BACKGROUND: The aim of this study was to evaluate the influence of oral vitamin E therapy on serum concentrations of several markers of micro-inflammation and cardiovascular disease in chronic hemodialysis (HD) patients. METHODS: 29 HD patients were randomized into two groups: 15 patients were treated orally with 400 mg of vitamin E daily for a period of five weeks, and 14 patients received no antioxidant supplementation. Before and after vitamin E therapy, serum concentrations of vitamin E (high-performance liquid chromatography), pregnancy-associated plasma protein-A (immunochemical--TRACE assay), C-reactive protein (nephelometry), intercellular adhesion molecule-1 (ELISA), and E-selectin (ELISA) were measured. HD patients were compared with 16 healthy controls. RESULTS: Baseline serum concentrations of PAPP-A and CRP were significantly higher in HD patients than in healthy controls (PAPP-A: 26.23+/-11.94 vs. 11.41+/-1.94 mIU/L, p<0.001; CRP: 5.20+/-3.50 vs. 3.40+/-3.80 mg/L, p<0.05). After five weeks of oral vitamin E intake, serum PAPP-A, CRP, ICAM-1, and E-selectin concentrations remained unchanged in both groups of HD patients. CONCLUSION: Chronic micro-inflammation in HD patients is documented by the elevation of CRP and PAPP-A. A daily oral dose of 400 mg of vitamin E does not seem to be able to reduce enhanced oxidative stress and micro-inflammation in chronic HD patients.     

Effects of oral vitamin C supplementation on oxidative stress and inflammation status in haemodialysis patients.

BACKGROUND: There is increasing evidence for the presence of oxidative stress and vitamin C deficiency in dialysis patients. Limited data, however, are available regarding the effects of vitamin C supplementation on oxidative stress and inflammation markers in such patients. METHODS: We ran a prospective, randomized, open-label trial to assess the effects of oral vitamin C supplementation (250 mg three times per week) for 2 months on well-defined oxidative and inflammatory markers in 33 chronic haemodialysis (HD) patients. RESULTS: Normalization of plasma total vitamin C and ascorbate levels by oral vitamin C supplementation did not modify plasma levels of carbonyls, C-reactive protein and albumin, or erythrocyte concentrations of reduced and oxidized glutathione. CONCLUSION: Short-term oral vitamin C supplementation did not modify well-defined oxidative/antioxidative stress and inflammation markers in HD patients. Whether a higher oral dose or the intravenous route can modify these markers remains to be determined.     

Hyperhomocysteinaemia, folate and vitamin B12 in unsupplemented haemodialysis patients: effect of oral therapy with folic acid and vitamin B12.

BACKGROUND: Hyperhomocysteinaemia, a risk factor for atherosclerosis, is common in dialysis patients and particularly in those homozygous for a common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene (C677T transition). B-complex vitamin supplements have been shown to lower plasma total homocysteine (tHcy) concentrations, but the respective effectiveness of folate and oral vitamin B12 is not yet known. Our objectives were: (i) to determine the status of folate and vitamin B12 in a cohort of unsupplemented dialysis patients (ii) to assess the homocysteine-lowering effect of a folate supplement and then of a folate supplement with added vitamin B12. The responses were analysed for the C677T genotypes of MTHFR. METHODS: Plasma tHcy, folate and vitamin B12 were measured in 51 haemodialysis patients genotyped for the C677T MTHFR mutation (homozygotes, TT; heterozygotes, CT; without mutation, CC). All patients were then given daily supplements of 15 mg of folic acid for 2 months. They were given daily supplements of 1 mg of vitamin B12 in addition to the folate supplements for a further 2 months. Plasma tHcy, folate and vitamin B12 were monitored after each intervention. RESULTS: At baseline folate and vitamin B12 deficiencies were found in 10% and 6% of the patients. Initial plasma tHcy concentrations were high in all patients (mean 38.1+/-15 micromol/l). CC patients tended to have a lower tHcy concentration than pooled CT and TT patients. After 2 months of folate therapy, tHcy concentration decreased significantly to 20.2+/-7 micromol/l (P<0.001) and no significant differences were observed between the different genotype subgroups (19.4+/-6 for CC, 21.3+/-8 for CT, 18.5+/-4 for TT). A significant positive relationship was found between the reduction of tHcy and its initial value (rho=0.615, P<0.0001). The impact of the added vitamin B12 was negligible since tHcy concentrations did not change for the patients as a whole (19.8+/-7 micromol/l, NS) or in any subgroup (19.1+/-5 for CC, 20.3+/-9 for CT and 20+/-7 micromol/l for TT). CONCLUSIONS: (i) Folate and vitamin B12 deficiencies were observed in 10% and 6% respectively of our unsupplemented dialysis patients. (ii) After folate therapy, tHcy levels decreased significantly in all patients and were identical between the three C677T MTHFR genotype subgroups. (iii) Vitamin B12 supplements are useful in folate treated patients to prevent cobalamin deficiency and its neurological consequences but they did not lower tHcy plasma levels for the patients as a group or for any of the MTHFR subgroups.     

维生素C注射液联合右美托咪定对口腔颌面部恶性肿瘤术后炎症反应和氧化应激的影响

目的 探讨维生素C注射液联合右美托咪定对口腔颌面部恶性肿瘤患者术后炎症反应和氧化应激的影响。
方法 选择择期行口腔颌面部恶性肿瘤根治术患者72例,男47例,女25例,年龄29~82岁,BMI 20~31 kg/m²,ASA Ⅰ或Ⅱ级,所有患者术毕保留气管导管或气切套管入中心ICU。采用随机数字表法分为两组：观察组和对照组,每组36例。所有患者术后给予常规机械通气、镇痛镇静、预防性抗感染、消肿、营养支持等治疗,对照组10 min内静脉泵入右美托咪定0.5 μg/kg,继之以0.4 μg·kg^-1·h^-1持续静脉泵入,维持3 d后停药;观察组在对照组的基础上静脉滴注维生素C注射液3 g（以5%葡萄糖注射液500 ml稀释）,每日1次,连续3 d。于用药前、用药后1、3、7 d检测血清肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、C反应蛋白（CRP）、丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）浓度。记录术后出血、术区感染、胃肠道功能紊乱、低血压、心动过缓、头晕、晕厥等并发症的发生情况。
结果 与用药前比较,用药后1、3、7 d两组血清TNF-α、CRP浓度明显降低（P＜0.05）,用药后7 d两组血清IL-6浓度明显降低（P＜0.05）。与对照组比较,用药后1、3、7 d观察组血清TNF-α、IL-6、CRP浓度明显降低（P＜0.05）。与用药前比较,用药后1、3、7 d两组血清MDA浓度明显降低（P＜0.05）,血清SOD、CAT、GSH-Px浓度明显升高（P＜0.05）。与对照组比较,用药后1、3、7 d观察组血清MDA浓度明显降低（P＜0.05）,血清SOD、CAT、GSH-Px浓度明显升高（P＜0.05）。与对照组比较,观察组术后出血、术区感染、胃肠道功能紊乱发生率明显降低（P＜0.05）。两组低血压、心动过缓、头晕等发生率差异无统计学意义。
结论 与单用右美托咪定比较,联合使用维生素C注射液和右美托咪定治疗可有效降低口腔颌面部肿瘤术后患者炎症反应和氧化应激反应,减少术后并发症的发生。