Obesity is associated with worse peritoneal dialysis outcomes in the Australia and New Zealand patient populations

Although obesity is associated with increased risks of morbidity and death in the general population, a number of studies of patients undergoing hemodialysis have demonstrated that increasing body mass index (BMI) is correlated with decreased mortality risk. Whether this association holds true among patients treated with peritoneal dialysis (PD) has been less well studied. The aim of this investigation was to examine the association between BMI and outcomes among new PD patients in a large cohort, with long-term follow-up monitoring. Using data from the Australia and New Zealand Dialysis and Transplant Registry, an analysis of all new adult patients (n = 9679) who underwent an episode of PD treatment in Australia or New Zealand between April 1, 1991, and March 31, 2002, was performed. Patients were classified as obese (BMI of >/=30 kg/m(2)), overweight (BMI of 25.0 to 29.9 kg/m(2)), normal weight (BMI of 20 to 24.9 kg/m(2)), or underweight (BMI of <20 kg/m(2)). In multivariate analyses, obesity was independently associated with death during PD treatment (hazard ratio, 1.36; 95% confidence interval, 1.14 to 1.54; P < 0.05) and technique failure (hazard ratio, 1.17; 95% confidence interval, 1.07 to 1.26; P < 0.01), except among patients of New Zealand Maori/Pacific Islander origin, for whom there was no significant relationship between BMI and death during PD treatment. A supplementary fractional polynomial analysis modeled BMI as a continuous predictor and indicated a J-shaped relationship between BMI and patient mortality rates and a steady increase in death-censored technique failure rates up to a BMI of 40 kg/m(2); the mortality risk was lowest for BMI values of approximately 20 kg/m(2). In conclusion, obesity at the commencement of renal replacement therapy is a significant risk factor for death and technique failure. Such patients should be closely monitored during PD and should be considered for early transfer to an alternative renal replacement therapy if difficulties are experienced.     

Meta-analysis: peritoneal membrane transport, mortality, and technique failure in peritoneal dialysis

Peritoneal membrane solute transport in peritoneal dialysis (PD) patients is assessed by the peritoneal equilibration test, which measures the ratio of creatinine in the dialysate to plasma after a standardized 4-h dwell (D/Pc). Patients then are classified as high, high-average, low-average, or low transporters on the basis of this result. A meta-analysis of observational studies was carried out to characterize the relationship between D/Pc and mortality and technique failure in patients who are on PD. Citations were identified in Medline by using a combination of Medical Subject Heading search terms and key words related to PD, peritoneal membrane permeability/transport, and mortality and technique failure. The table of contents of relevant journals and bibliographies of relevant citations were reviewed in duplicate. Twenty studies that met study criteria were identified. Nineteen studies were pooled to generate a summary mortality relative risk of 1.15 for every 0.1 increase in the D/Pc (95% confidence interval 1.07 to 1.23; P < 001). This result equated to an increased mortality risk of 21.9, 45.7, and 77.3% in low-average, high-average, and high transporters, respectively, as compared with patients with low transport status. Meta-regression analysis showed that the proportion of patients who were on continuous cycler PD within a study was inversely proportional to the mortality risk (P = 0.05). The pooled summary relative risk for death-censored technique failure was 1.18 (95% confidence interval 0.96 to 1.46; P = 0.12) for every 0.1 increase in the D/Pc. This meta-analysis demonstrates that a higher peritoneal membrane solute transport rate is associated with a higher mortality risk and a trend to higher technique failure.     

Effect of previously failed kidney transplantation on peritoneal dialysis outcomes in the Australian and New Zealand patient populations.

BACKGROUND: There is limited information about the outcomes of patients commencing peritoneal dialysis (PD) after failed kidney transplantation. The aim of the present study was to compare patient survival, death-censored technique survival and peritonitis-free survival between patients initiating PD after failed renal allografts and those after failed native kidneys. METHODS: The study included all patients from the ANZDATA Registry who started PD between April 1, 1991 and March 31, 2004. Times to death, death-censored technique failure and first peritonitis episode were examined by multivariate Cox proportional hazards models. For all outcomes, conditional risk set models were utilized for the multiple failure data, and analyses were stratified by failure order. Standard errors were calculated by using robust variance estimation for the cluster-correlated data. RESULTS: In total, 13,947 episodes of PD were recorded in 23,579 person-years. Of these, 309 PD episodes were started after allograft failure. Compared with PD patients who had never undergone kidney transplantation, those with failed renal allografts were more likely to be younger, Caucasian, New Zealand residents and life-long non-smokers with lower body mass index (BMI), poorer initial renal function and a longer period from commencement of the first renal replacement therapy to PD. On multivariate analysis, PD patients with failed kidney transplants had comparable patient mortality [weighted hazards ratio (HR) 1.09, 95% confidence interval (CI) 0.81-1.45, P = 0.582], death-censored technique failure (adjusted HR 0.91, 95% CI 0.75-1.10, P = 0.315) and peritonitis-free survival (adjusted HR 0.92, 95% CI 0.72-1.16, P = 0.444) with those PD patients who had failed native kidneys. Similar findings were observed in a subset of patients (n = 5496) for whom peritoneal transport status was known and included in the models as a covariate. CONCLUSION: Patients commencing PD after renal allograft failure experienced outcomes comparable with those with failed native kidneys. PD appears to be a viable option for patients with failed kidney allografts.     

Platelet-to-albumin ratio: a risk factor associated with technique failure and mortality in peritoneal dialysis patients

BackgroundPeritoneal dialysis (PD) patients have a high incidence of poor clinical outcomes, which is related to the inflammatory and nutritional status of this population. Platelet-to-albumin ratio (PAR), recently identified as a useful biomarker to monitor inflammation and nutrition, can predict a poor prognosis in various diseases. The aim of this study was to investigate the association between PAR and technique failure and mortality in PD patients.MethodsThis single-center retrospective study enrolled 405 PD patients from 1 January 2011 to 31 December 2019 and collected complete demographic characteristics, clinical laboratory baseline data. The outcomes were technique failure and mortality. The associations between PAR and technique failure, death were analyzed by Cox proportional hazard models and competing risk regression models with kidney transplantation as a competing event. The areas under the curve (AUC) of receiver-operating characteristic analysis were used to determine the predictive values of PAR for technique failure and mortality.ResultsDuring a median follow-up period of 24.0 (range, 4.0–91.0) months, 139 (34.3%) PD patients experienced technique failure, 61 (15.1%) PD patients died. The patients with higher PAR levels had increased risk of technique failure and mortality. After adjustment for confounding factors, we found that high PAR levels were risk factor for both technique failure (subdistribution hazard ratio [SHR] 1.775; 95%CI, 1.157–2.720; p = 0.033] and mortality [SHR 3.710; 95%CI, 1.870–7.360; p < 0.001]. The predictive ability of PAR was superior to platelet and albumin based on AUC calculations for technique failure and mortality.ConclusionsPAR was a risk factor associated with technique failure and mortality in PD patients.     

Proton pump inhibitor usage is associated with higher all-cause mortality and CV events in peritoneal dialysis patients

ObjectivesA long period of inappropriate proton pump inhibitors (PPI) treatment has been proved to be associated with adverse prognosis in general population and hemodialysis patients. This study was conducted to clarify the impact of PPI usage on mortality and adverse cardiovascular (CV) events in peritoneal dialysis (PD) patients.Methods and designThis is a retrospective study. A total of 905 patients were enrolled from two PD centers, including 211 patients on PPI treatment and 618 patients not on PPIs. Kaplan–Meier curves were used to identify the incidence of adverse outcomes. Multivariate Cox regression models and inverse probability of treatment weighting (IPTW) were applied to analyze hazard ratios (HRs) for adverse outcomes.ResultsDuring follow-up, 162 deaths and 102 CV events were recorded. Kaplan–Meier curve demonstrated all-cause mortality (log-rank test p = .018) and CV events (log-rank test p = .024) were significantly higher in PPI usage group. Multivariate Cox regression models and IPTW showed that PPI usage was an indicator for all-cause mortality (HR = 1.35, 95%CI = 1.09–1.67, p = .006) and CV events (HR = 1.78, 95%CI = 1.35–2.32, p < .001).ConclusionsPPI usage is associated with higher all-cause mortality and CV events in PD patients. Clinicians are supposed to be more careful when using PPI and need to master the indications more rigorously in patients receiving PD treatment.     

The standard deviation of extracellular water/intracellular water is associated with all-cause mortality and technique failure in peritoneal dialysis patients

International Urology and Nephrology - The mortality rate of peritoneal dialysis (PD) patients is still high, and the predicting factors for PD patient mortality remain to be determined. This study...     

腹透相关性腹膜炎溶质转运与失超滤研究进展

腹膜炎和腹膜透析失超滤是腹膜透析最常见的并发症，是影响腹透病人透析质量和生存率的重要因素。对二者发生机制、病理生理改变及影响因素的深入探讨并制定有效的干预措施已是近些年的研究重点。本文对近年来在此领域的研究进展作一综述。     

Effect of renal center characteristics on mortality and technique failure on peritoneal dialysis

BACKGROUND: Recent studies report decreased mortality in patients on peritoneal dialysis (PD) over time, suggesting that advances in PD have resulted in improved patient outcomes. Our investigation sought to assess the effect of renal center characteristics on mortality and technique failure (TF) rates. METHODS: Covariates of interest included center-specific cumulative number of PD patients treated, percentage of patients who initiated dialysis on PD, and academic status. Using data obtained from the Canadian Organ Replacement Register, the 17,900 patients who received PD during the 1981 to 1997 period were studied. Mortality and TF rate ratios (RR) were estimated using Poisson regression, adjusting for age, gender, race, primary renal diagnosis, province, follow-up time, and type of PD. RESULTS: As the cumulative number of PD patients treated increased, covariate-adjusted mortality significantly decreased (P < 0.05); a weaker yet significant association was observed between number of PD patients treated and TF. As the percentage of patients initiating dialysis on PD increased, TF rates decreased significantly. No association was observed between center academic status and PD mortality or TF rates. CONCLUSIONS: These results imply that a center's experience with and degree of specialization toward PD impact strongly on PD outcomes. One hypothesis is that a center's propensity to exploit technical and non-technical advances in PD increases directly with these variables. It is also possible that, through experience, centers become more adept at identifying appropriate patients to receive PD. More detailed research is required to evaluate these hypotheses.     

High membrane transport status on peritoneal dialysis is not associated with reduced survival following transfer to haemodialysis.

BACKGROUND: High transporter status is associated with reduced survival of patients receiving peritoneal dialysis (PD). This may be due primarily to the development of complications related to the PD process, in which case the survival disadvantage may not persist following transfer to haemodialysis (HD). In this study, we aimed to assess the impact of peritoneal membrane transporter status on patient survival and the likelihood of return to PD following transfer from PD to HD. METHODS: The Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry was searched to identify all patients between 1 April 1999 and 31 March 2004 who had received PD and subsequently transferred to HD, in whom an incident 4 h dialysate: plasma creatinine ratio was recorded. A Cox proportional hazards model was used to identify factors significantly associated with patient and technique survival after commencement of HD. RESULTS: A total of 918 patients were included in the analysis. On multivariate Cox regression analysis there was no difference in survival between transport groups relative to the reference group of low average transporters (adjusted hazard ratio (HR) 0.71, 95% CI 0.42-1.19, P = 0.19, HR 0.94, 95% CI 0.63-1.38, P = 0.73 and HR 0.24, 95% CI 0.06-1.01, P = 0.051 for high, high average and low transporter groups, respectively). Significant predictors of mortality were duration of PD more than 22 months (HR 2.32, 95% CI 1.24-4.33, P = 0.01), increasing age, late referral to a nephrologist and a history of diabetes mellitus. The likelihood of returning to PD was increased if initial PD technique failure was due to mechanical complications compared with all other causes of failure [HR 3.65 (95% CI 2.78-4.79) P < 0.001] and decreased with higher body mass index [HR 0.97 per kg/m(2) (95% CI 0.94-0.99), P = 0.01] and the 4 h dialysate: plasma creatinine ratio considered as a continuous variable [4 h D:P Cr; HR 0.32 per unit (95% CI 0.12-0.89), P = 0.03]. CONCLUSIONS: The survival disadvantage associated with high peritoneal membrane transport status during PD treatment does not persist following transfer to HD. Early transfer to HD may be beneficial in this patient group.     

Takotsubo cardiomyopathy associated with peritonitis in peritoneal dialysis patient

Takotsubo cardiomyopathy (TTC) is characterized by clinical and electrocardiographic features that mimic acute myocardial infarction, normal or mildly elevated cardiac enzymes, distinctive left ventricular wall motion abnormalities, and absence of significant obstructive coronary artery disease. Often there is a history of emotional stress and usually encountered in postmenopausal women. Excessive catecholamine stimulation plays an important role in the pathogenesis of TTC. Usually, this condition is reversible within several weeks to months. Only two cases of TTC were described in patients on hemodialysis. To our knowledge, we report the first case of TTC in peritoneal dialysis and the first case associated with peritonitis.     

Epithelial-to-mesenchymal transition of mesothelial cells is an early event during peritoneal dialysis and is associated with high peritoneal transport

Ultrafiltration (UF) failure is a consequence of long-term peritoneal dialysis (PD). Fibrosis, angiogenesis, and vasculopathy are causes of this functional disorder after 3-8 years on PD. Epithelial-to-mesenchymal transition (EMT) of mesothelial cell (MC) is a key process leading to peritoneal fibrosis with functional deterioration. Our purpose was to study the peritoneal anatomical changes during the first months on PD, and to correlate them with peritoneal functional parameters. We studied 35 stable PD patients for up to 2 years on PD, with a mean age of 45.3+/-14.5 years. Seventy-four percent of patients presented loss of the mesothelial layer, 46% fibrosis (>150 microm) and 17% in situ evidence of EMT (submesothelial cytokeratin staining), which increased over time. All patients with EMT showed myofibroblasts, while only 36% of patients without EMT had myofibroblasts. The number of peritoneal vessels did not vary when we compared different times on PD. Vasculopathy was present in 17% of the samples. Functional studies were used to define the peritoneal transport status. Patients in the highest quartile of mass transfer area coefficient of creatinine (Cr-MTAC) (>11.8 ml min(-1)) showed significantly higher EMT prevalence (P=0.016) but similar number of peritoneal vessels. In the multivariate analysis, the highest quartile of Cr-MTAC remained as an independent factor predicting the presence of EMT (odds ratio 12.4; confidence interval: 1.6-92; P=0.013) after adjusting for fibrosis (P=0.018). We concluded that, during the first 2 PD years, EMT of MCs is a frequent morphological change in the peritoneal membrane. High solute transport status is associated with its presence but not with increased number of peritoneal vessels.     

Peritoneal thickening is not inevitable in long-term peritoneal dialysis and is associated with peritoneal transport characteristics: a two-centre sonographic study.

BACKGROUND: The peritoneum is subject to alterations in the life-long course of peritoneal dialysis (PD). Studies of the parietal peritoneum by non-invasive ultrasonography in PD patients are limited. We hypothesize that a prolonged PD duration is associated with a thicker peritoneum on ultrasonography and alterations in Doppler indexes of mesenteric vessels. METHODS: We recruited two groups of patients, 18 who had >7 years of PD and 18 who had <12 months of PD. We excluded patients with active peritonitis, history of major abdominal surgery, cirrhosis or malignancy. We measured the sonographic thickness of the parietal peritoneum and Doppler indexes of mesenteric vessels by trans-abdominal ultrasonography at two PD units in Taiwan. RESULTS: We found no significant difference between two groups of PD patients in peritoneal thickness and in Doppler indexes. However, our univariate and multivariate analysis indicated that peritoneal thickness is associated with peritoneal transport characteristics (dialysate/plasma creatinine) but not with age, duration of dialysis, body height, body weight or Doppler index. The peritoneum is significantly thicker in rapid transporters than in slow transporters (RUQ: 0.59 +/- 0.40 mm versus 0.27 +/- 0.29 mm, P = 0.01; LUQ: 0.60 +/- 0.40 mm versus 0.27 +/- 0.32 mm, P = 0.016; LQ: 1.07 +/- 0.85 mm versus 0.48 +/- 0.53 mm, P = 0.026). In addition, rapid transporters have a marginally lower Doppler resistive index of the superior mesenteric artery (0.87 +/- 0.08 versus 0.90 +/- 0.10, P = 0.028). CONCLUSIONS: Our data showed that peritoneal thickening is not inevitable in long-term PD patients. Sonographic thickness in the parietal peritoneum is associated with transport characteristics. Rapid transporters have a significantly thicker peritoneum. The Doppler index of mesenteric vessels had no association with PD duration or transport characteristics. Trans-abdominal ultrasonography is non-invasive and useful in evaluating peritoneal characteristics of PD patients.     

Unrecognized high brachial artery bifurcation is associated with higher rate of dialysis access failure

A thorough consideration of all factors contributing to successful dialysis access creation is necessary to achieve optimal outcomes. A high bifurcation of the brachial artery (brachioradial variant) occurs in greater than 20% of patients. Dialysis access was created in 22 limbs with this variant--15 fistula, and 7 prosthetic grafts. Nonmaturation occurred in 33% of fistula. Early thromboses occurred in 29% of prosthetic bridge grafts. In this experience, the brachioradial variant is associated with a relatively higher rate of fistula nonmaturation and prosthetic graft thromboses. These findings reinforce the critical role of preoperative imaging studies in dialysis access creation. A sound algorithm for the surgical management of the brachioradial variation facilitates decision making and will improve dialysis access outcomes.     

Increased peritoneal permeability is associated with decreased fluid and small-solute removal and higher mortality in CAPD patients

Background: Recent studies suggest that increased peritoneal membrane permeability is associated with higher morbidity and mortality in peritoneal dialysis patients. It is not known, however, whether the difference in clinical outcome among different peritoneal transport groups is due to differences in peritoneal fluid and solute removal. In the present study, we compared the peritoneal fluid and solute transport and clinical outcome in CAPD patients with high (H), high-average (H-A), low-average (L-A) and low (L) peritoneal transport patterns. Design: A 6-h study was performed in 46 patients with frequent dialysate and plasma samples using 21 of 3.86% glucose dialysate with ¹³¹I albumin as an intraperitoneal volume marker. The patients were divided into four transport groups according to their D/P of creatinine at 240 min. Results: The results showed that high transporters had significantly lower peritoneal fluid and small-solute removal but high glucose absorption and high protein loss during a 6-h exchange. The serum albumin was lower and blood pressure and triglycerides were higher in high transporters compared with the other groups. Two-year patient survival from the start of CAPD treatment was significantly lower for high transporters (64, 85, 90 and 100% for H, H-A, L-A and L respectively, P<0.01). The 1-year patient survival from the dwell study was also significantly lower in high transporters (16, 63, 90 and 100% for each group, P<0.01). Conclusion: Our results suggest that high transporters remove less fluid and small solutes and have higher protein loss and increased glucose absorption. These alterations may contribute to fluid overload, malnutrition and lipid abnormalities that perhaps contribute to the increased mortality among the high transporters. Key words: CAPD, adequacy, peritoneal transport, mortality      

Associations of vitamin K status with mortality and cardiovascular events in peritoneal dialysis patients

International Urology and Nephrology - Vitamin K deficiency, expressed by a high level of desphospho-uncarboxylated matrix GLA protein (dp-ucMGP), is highly prevalent in dialysis patients. However,...     

Serum apelin is associated with affective disorders in peritoneal dialysis patients

Objective: Depression and anxiety are prevalent affective disorders in peritoneal dialysis (PD) patients. Recent research has proposed a potential role of apelinergic system in pathogenesis of depression. The present study aimed to evaluate the frequency of depression and anxiety and their potential relation with serum apelin levels among PD patients.

Methods: A total of 40 PD patients were enrolled into the study. Depressive symptoms and anxiety were assessed with the Beck’s Depression Inventory and the Beck’s Anxiety Inventory. Serum apelin-12 levels were measured by immunoenzymatic assays using commercially available ELISA kit for standard human apelin.

Results: Of the patients, 16 (40%) had depression, 20 (50%) had anxiety. The patients with depression and anxiety had a significantly longer time on dialysis (p?<?0.001 for both), significantly higher serum apelin (p?<?0.001 for both) and C-reactive protein levels (p?<?0.001 for both) than those without depression and anxiety. In multivariate analysis, serum apelin was the only parameter associated independently with depression and anxiety scores.

Conclusions: A substantial number of PD patients had depression and anxiety. Increased levels of serum apelin may constitute a significant independent predictor of development of depression and anxiety in PD patients.     

Increases in peritoneal small solute transport in the first month of peritoneal dialysis predict technique survival

BACKGROUND: Peritoneal transport of small solutes generally increases during the first month of peritoneal dialysis (PD). The aim of this study was to prospectively evaluate the ability of the peritoneal equilibration test (PET), carried out 1 and 4 weeks after the commencement of PD, to predict subsequent technique survival. METHODS: Fifty consecutive patients commencing PD at the Princess Alexandra Hospital between 1 February 2001 and 31 May 2003 participated in the study. Paired 1 week and 1 month PET data were collated and correlated with subsequent technique survival. RESULTS: A significant increase was observed in the dialysate : plasma creatinine ratio at 4 h (D/P Cr) between 1 and 4 weeks after the onset of PD (0.55 +/- 0.12 vs 0.66 +/- 0.11, P <0.001). Mean death-censored technique survival was superior in patients who experienced > or =20% rise in D/P Cr during the first month of PD compared with those who did not (2.3 +/- 0.2 vs 1.6 +/- 0.2 years, P <0.05). Using a multivariate Cox proportional hazards model analysis, the significant independent predictors of death-censored technique survival were an increase in D/P Cr of greater than 20% during the first month (adjusted hazard ratio [HR] 0.20, 95% CI 0.05-0.75), the absence of diabetes mellitus, the absence of ischaemic heart disease, body mass index and baseline peritoneal creatinine clearance. CONCLUSIONS: A 20% or greater rise in D/P Cr during the first month of commencing PD is independently predictive of PD technique survival. Further investigations of the mechanisms underlying this phenomenon are warranted.