Homocysteine, vitamin B12, and serum and erythrocyte folate in peritoneal dialysis and hemodialysis patients.

BACKGROUND: Plasma homocysteine (Hcy) is an independent risk factor for cardiovascular disease. High levels of plasma Hcy have been observed in end-stage renal disease patients. Few studies have compared peritoneal dialysis (PD) and hemodialysis (HD) patients and few data are available on erythrocyte folate (ery-F) levels in dialysis patients. OBJECTIVES: To evaluate plasma Hcy concentrations, vitamin B12 (B12), and folate status in dialysis patients; to analyze the possible causes of high Hcy levels; to follow up changes in folate and B12 concentrations after 6 months. DESIGN: A cross-sectional observational study. SETTING: Nephrology division and laboratory of hematology in a university and clinical research hospital. PATIENTS: The study included 82 patients treated with PD for 37 + 37 months and 70 patients treated with HD for 136 + 95 months. LABORATORY METHODS: Plasma Hcy was measured by the immunoenzymatic IMx Hcy FPIA method (Abbott Laboratories, Diagnostic Division, Abbott Park, IL, U.S.A.), serum folate (s-F) and ery-F by the Stratus folate fluorometric enzyme-linked assay, and B12 by the Stratus vitamin B12 fluorometric enzyme-linked assay (DADE-Behring, Newark, DE, U.S.A.). RESULTS: Ninety-six percent of PD and 97% of HD patients had Hcy levels above the cutoff (13.5 micromol/L). Homocysteine level was higher in HD than in PD patients, while the prevalence of hyperhomocysteinemia was similar with the two techniques. Erythrocyte folate was significantly higher in PD (1333 +/- 519 pmol/L) than in HD (1049 +/-511 pmol/L, p < 0.01). Statistically significant correlations were observed between Hcy and B12, s-F, ery-F, and dialysis duration. Multivariate analysis showed a strong correlation between s-F and Hcy. After 6 months there were no differences in Hcy, B12, s-F, and ery-F levels. CONCLUSIONS: Plasma Hcy levels were high in more than 95% of our dialysis patients, with no relation to the type of dialysis. Vitamin B12 and folate were normal in the majority of our patients. However, serum folate was the major determinant of Hcy levels. Such a relation between Hcy and folate suggests that levels of folate within the reference interval are inadequate for dialysis patients.     

Continuous ambulatory peritoneal dialysis in patients with hepatitis B liver disease.

OBJECTIVE: We hypothesized that patients with hepatitis B virus infection and cirrhosis are more susceptible to peritonitis as a complication of peritoneal dialysis (PD). METHODS: A retrospective study was carried out to compare peritonitis rates between cirrhotic and non-cirrhotic patients with hepatitis B virus infection. RESULTS: Between 1994 and 2004, 25 PD patients with hepatitis B cirrhosis and 36 patients with hepatitis B without cirrhosis were included for analysis. Mean follow-up duration was 52 months. Subjects with hepatitis B cirrhosis consisted of more males and had higher total body weight. No cirrhotic patients (20 of them being Child-Pugh class A, 2 class B, and 3 class C) had undergone portosystemic shunting or liver transplantation. Cirrhotic patients had slightly higher bilirubin concentration than the non-cirrhotic group (22 +/- 50 vs 9 +/- 4 micromol/L, p = 0.16). There was no difference in median peritonitis-free survival between cirrhotic and non-cirrhotic patients (40 vs 37 months, p = 0.64 by log-rank test). The average peritonitis rate was 1 episode every 19.2 patient-months in the cirrhotic group and 1 episode every 20.5 patient-months in the non-cirrhotic group. Time to first peritonitis did not differ between the two groups with respect to gram-negative organisms (p = 0.88) or gram-positive organisms (p = 0.52). Cirrhotic patients had more frequent Streptococcus species peritonitis, which accounted for 13% of all peritonitis episodes, as opposed to 2% among the non-cirrhotic patients (p = 0.01). Overall treatment response rate and outcome did not differ between patients with and patients without cirrhosis. CONCLUSIONS: Peritonitis-free survival of cirrhosis patients infected by hepatitis B virus compares favorably with thatin patients without cirrhosis. The presence of liver cirrhosis does not appear to compromise PD outcome.     

Procalcitonin levels in peritoneal dialysis patients.

OBJECTIVE: To examine whether the levels of procalcitonin (PCT), a new marker of infection and/or inflammation, differ between peritoneal dialysis (PD) patients and healthy volunteers, and whether PCT is detectable in uninfected drained dialysate. DESIGN: Observational cross-sectional study. SETTING: PD unit, department of medicine, in a university hospital. PATIENTS: A total of 28 PD patients, free of systemic infection, and 28 age- and sex-matched healthy volunteers. METHODS: PCT was determined by immunoluminometry; detection range 0.01 - 500 ng/mL, reference range < 0.5 ng/mL. RESULTS: Plasma levels of PCT were significantly higher (Wilcoxon's paired test, p < 0.001) in PD patients (median 0.33 ng/mL) compared with healthy volunteers (0.18 ng/mL). Spearman's test demonstrated a significant positive correlation between PCT and serum C-reactive protein (CRP) (r = 0.59, p < 0.01); correlations between PCT and transferrin, total weekly creatinine clearance (ClCr), and the renal components of ClCr and Kt/V urea were negative. PCT levels in dialysate (PCTd) were 0.07 ng/mL and correlated positively with plasma PCT, serum CRP, and dialysate fibrinogen levels. The dialysate-to-plasma ratio (D/P) of PCT was 0.2. Neither PCTd nor D/P PCT correlated with D/P creatinine at 4-hours of dwell. CONCLUSION: Compared with healthy volunteers, PD patients without overt signs of infection showed increased plasma PCT levels. Given the study design, it is impossible to determine to what extent the increase in plasma PCT is due to reduced elimination and to what extent it reflects the microinflammation of uremia. Based on the D/P PCT gradient, we assume that PCT transport is more likely to occur from the systemic circulation to the peritoneal cavity than vice versa.     

Fungal peritonitis in peritoneal dialysis patients.

Peritonitis is one of the most frequent complications of peritoneal dialysis (PD) and 1% - 15% of episodes are caused by fungal infections. The mortality rate of fungal peritonitis (FP) varies from 5% to 53%; failure to resume PD occurs in up to 40% of patients. The majority of these FP episodes are caused by Candida species. Candida albicans has historically been reported to be a more common cause than non-albicans Candida species, but in recent reports a shift has been observed and non-albicans Candida may now be more common. Unusual, often "nonpathogenic," fungi are being increasingly reported as etiologic agents in FP. Clinical features of FP are not different from those of bacterial peritonitis. Phenotypic identification of fungi in clinical microbiology laboratories is often difficult and delayed. New molecular diagnostic techniques (e.g., polymerase chain reaction) are being developed and evaluated, and may improve diagnosis and so facilitate early treatment of infected patients. Abdominal pain, abdominal pain with fever, and catheter left in situ are risk factors for mortality and technique failure in FP. In programs with high baseline rates of FP, nystatin prophylaxis may be beneficial. Each program must examine its own history of FP to decide whether prophylaxis would be beneficial. Catheter removal is indicated immediately after fungi are identified by Gram stain or culture in all patients with FP. Prolonged treatment with antifungal agents to determine response and attempt clearance is not encouraged. Antifungals should be continued for 10 days to 2 weeks after catheter removal. Attempts at reinsertion should be made only after waiting for 4 - 6 weeks.     

腹膜透析患者维生素D水平与血管钙化相关性研究

目的 了解持续不卧床腹膜透析(continuous ambulatory peritoneal dialysis,CAPD)患者血1,25(OH)2D3水平及血管钙化情况,探讨CAPD患者血管钙化的相关因素及血1,25(OH)2D3水平测定在腹主动脉钙化(abdominal aortic calcification, AAC)中的作用及意义。方法 选取河北医科大学第二医院行CAPD 3个月以上患者84例,收集其临床资料,侧位X线平片评估AAC情况,计算腹主动脉钙化积分(abdominal aortic calcification score,AACs)。酶联免疫吸附测定检测血清1,25(OH)2D3浓度。相关分析法分析1,25(OH)2D3与AACs关系,Logistic回归法和多元回归法进行血管钙化相关危险因素分析,受试者工作曲线（ROC）评价1,25(OH)2D3预测AAC的准确性。结果 84例CAPD患者中,AAC患者34例(42.5%),CAPD患者血清1,25(OH)2D3水平较低,与AAC呈负相关,口服骨化三醇可提高血清1,25(OH)2D3浓度。Logistic回归分析显示高龄、罹患糖尿病、服用骨化三醇、高胆固醇、高磷、高血尿酸、低1,25(OH)2D3为血管钙化发生的危险因素(P<0.05),多元回归分析结果显示去除混杂因素后,年龄、血磷、1, 25(OH)2D3是AAC进展的独立影响因素(P<0.05)。1,25(OH)2D3 ROC曲线下面积(AUC)为0.652（95%CI=0.442~0.696,P<0.05）, 提示1,25(OH)2D3预测AAC有一定准确性,取1,25(OH)2D3浓度为250.43 pg/ml作为截点时,其预测AAC的敏感性为55.9%,特异性为66%,约登指数为0.219。结论 CAPD患者血清1,25(OH)2D3水平与AAC程度呈负相关,低血清1,25(OH)2D3水平是AAC的独立危险因素之一。口服骨化三醇可改善CAPD患者1,25(OH)2D3水平,但口服骨化三醇可增加血管钙化的风险,监测1,25(OH)2D3水平可预测血管钙化的风险。     

腹膜透析患者高血压的预防与治疗措施

<正>1腹膜透析患者高血压的流行病学腹膜透析患者高血压的流行病学资料至少包括透析刚开始时高血压的发病率(incidence)以及慢性透析患者(一般以超过3个月来定义)的患病率     

Weight management in patients on peritoneal dialysis.

In summary, patients on PD, along with their health care providers, can be taught tools to manage weight. These techniques include, but are not limited to, judicious use of dialysis solution to provide adequate dialysis and ultrafiltration with the least exposure to glucose, careful attention to diet including salt and calories consumed, and physical activity.     

Resting energy expenditure in peritoneal dialysis patients.

OBJECTIVES: This study aimed to evaluate whether resting energy expenditure (REE) of patients undergoing peritoneal dialysis (PD) therapy differs from that of healthy individuals, as well as to investigate the factors associated with REE in this sample of patients. DESIGN: Cross-sectional study. SETTING: Dialysis Unit of the Nephrology Division, Federal University of Sao Paulo-Oswaldo Ramos Foundation, Brazil. Subjects and METHODS: The study examined the REE of 37 patients (20 males, age 44.5 +/- 13 years) undergoing PD therapy. Only patients older than 18 years, on PD for at least 3 months, without catabolic illness, and with normal thyroid function were included. Patients were pair matched for age and gender with 37 healthy individuals. REE was measured by indirect calorimetry. Body composition was assessed by dual-energy x-ray absorptiometry in the patients and by bioelectrical impedance in the healthy individuals. RESULTS: The REE of PD patients was similar to that of pair-matched controls (1372 +/- 266 and 1453 +/- 252 kcal/day respectively, p = 0.13) even when adjusted for lean body mass and gender (p = 0.56). The REE of PD patients was positively correlated with lean body mass (r = 0.60, p < 0.01), fat mass (r = 0.43, p < 0.01), body mass index (r = 0.60, p < 0.01), serum glucose (r = 0.36, p < 0.05), and protein equivalent of nitrogen appearance (PNA; r = 0.42, p < 0.01). There were no correlations between REE and glucose absorption, dialysis-related parameters, C-reactive protein, and energy or protein intake by 3-day food diary. In the multiple linear regression analysis, using REE as the dependent variable, the final model showed that lean body mass and female gender were determinants of REE in PD patients (R(2) = 0.44). When separate analysis by gender was performed, REE correlated directly with body fat in female patients (r = 0.70, p < 0.01) but not in male patients (r = 0.29, p = 0.21). On the other hand, lean body mass was significantly correlated with REE in male patients (r = 0.78, p < 0.01) but not in female patients (r = 0.47, p = 0.06). CONCLUSIONS: This study showed that REE of PD patients did not differ from that of healthy individuals. The strong association between body fat and REE in female patients remains to be further investigated.     

Alterations in lipoprotein composition in peritoneal dialysis patients.

OBJECTIVE: Dyslipidemia is common among patients with end-stage renal disease, whether treated by hemodialysis (HD) or peritoneal dialysis (PD). To better understand the specific lipoprotein abnormalities in PD patients, we measured the lipid and apolipoprotein (Apo) composition of the four major classes of plasma lipoproteins in PD patients, HD patients, and healthy control subjects: very low density (VLDL), intermediate density (IDL), low density (LDL), and high density lipoproteins (HDL). DESIGN: Fasting plasma samples were obtained from 15 nondiabetic PD patients, 15 nondiabetic HD patients, and 16 healthy control subjects, all from a cross section of patients and subjects in the region of G?teborg, Sweden. Lipoproteins were isolated by preparative ultracentrifugation, and lipid and apolipoprotein concentrations were measured by gas chromatography and electroimmunoassay, respectively. RESULTS: Alterations in lipoprotein composition were apparent in all four lipoprotein density classes from PD and HD patients. VLDL contained a significantly higher concentration of ApoCIII in both HD and PD patients, and an elevation of free cholesterol, triglyceride, ApoB, ApoCII, and ApoE in PD patients. IDL from both PD and HD patients contained an excess of free and esterified cholesterol and triglyceride and significantly elevated levels of ApoB, ApoCII, ApoCIII, and ApoE. LDL had a higher concentration of ApoB in PD patients and elevated triglyceride and ApoCIII in both PD and HD patients. HDL isolated from PD patients had lower free cholesterol and ApoAI levels compared to control subjects, but these were not significantly different from HD patients. CONCLUSIONS: An increase in lipid and apolipoprotein mass in IDL, and an enrichment of ApoCIII in VLDL, IDL, and LDL were observed in both HD and PD patients. The predominant alteration in lipoprotein composition distinguishing PD patients from HD patients was an elevation of ApoB in LDL. Further study of these alterations in lipoprotein composition in PD patients will be helpful in understanding the underlying causes of dyslipidemia and, ultimately, to the selection of hypolipidemic drugs or other treatments to reduce the cardiovascular risks associated with dyslipidemia in these patients.     

腹膜透析腹膜纤维化防治的研究进展

腹膜透析作为肾脏替代治疗方法已经有20多年的历史,它的疗效已得到极大地提高,目前已证明腹膜透析与血液透析一样有效,而且在某些方面优于血液透析。然而,腹膜透析要进一步得到患者更广泛的接受,还有许多需克服的问题,腹膜纤维化就是近年来越来越重要的一个影响因素。研究表明,随着插管技术的改进,感染率的下降,腹膜纤维化导     

Pharmacokinetics of metronidazole in patients undergoing peritoneal dialysis.

After a single 500-mg intravenous dose of metronidazole, plasma and dialysate levels were measured over a 7.5-h period in five patients undergoing peritoneal dialysis for terminal renal failure. Approximately 10% of this dose was removed by dialysis during that period, and therapeutic levels were maintained in plasma. No routine adjustment in the dosage of metronidazole appears necessary in patients undergoing peritoneal dialysis.     

Hemoperitoneum: bloody peritoneal dialysate in ESRD patients receiving peritoneal dialysis.

Hemoperitoneum is seen in patients receiving peritoneal dialysis (PD) because the PD catheter provides a window to the peritoneum. Gynecological associated phenomena account for the majority of cases. Intra-abdominal pathology of solid organs such as the kidney, liver, and spleen as well as the gastrointestinal tract is recognized. Unique to PD patients, hemoperitoneum may be associated with the catheter itself, uremic bleeding, or peritonitis. A successful PD program requires nephrologists, PD nurses, and patients assess and manage hemoperitoneum in a systematic fashion. This paper reviews hemoperitoneum in adult PD patients.     

腹膜透析患者伴发的结核性腹膜炎

时至今日,结核仍然是全球性的严重威胁人类健康的疾病,每年全世界约有13000000人死于结核,尤其在发展中国家。慢性肾衰竭（CRF）患者,由于存在免疫功能低下,以及营养不良、贫血的高发生率,易并发结核感染。根据文献的报告,CRF患者的结核发病率是肾功能正常人群的6～25倍,