Association between inflammation and changes in residual renal function and peritoneal transport rate during the first year of dialysis.

BACKGROUND: Peritoneal transport rate, a major determinant of peritoneal dialysis (PD) patient survival, increases in most patients starting on PD, while in other patients peritoneal transport rate may decline. Although several factors may contribute to changes in peritoneal transport rate, inflammation is known to be associated with a high peritoneal transport rate, and residual renal function (RRF), which often declines after start of PD, may also be related to inflammation. Therefore, we hypothesized that changes in peritoneal transport rate during patients' first year on PD and declining RRF may be linked with inflammation. METHODS: A total of 76 PD patients (40 males, mean age 56.8+/-14.1 years), who underwent two peritoneal equilibration tests at a mean of 0.4 months and 1 year after beginning PD, were included in the study. Based on the change in dialysate to plasma creatinine concentration ratio at 4-h dwell (D/P Cr) during first year on PD, the patients were divided into decreased or unchanged (group DUC; n=22) and increased (group I; n=54) groups. RESULTS: Initially, group I had a lower proportion of high transporters and more often high serum C-reactive protein (sCRP, > or =10 mg/l) and lower RRF compared with the DUC group. In group I, serum albumin and RRF decreased significantly and dialysate protein loss and glucose absorption increased significantly during the first year on PD. When patients were divided into two groups based on median change in RRF (1.9 ml/min), patients with a decrease in RRF >1.9 ml/min during first year on PD had a higher proportion of high sCRP, higher D/P Cr, and higher changes in D/P Cr compared to patients with a decrease in RRF < or =1.9 ml/min. Patients with elevated sCRP at one year included a higher proportion of patients who had high sCRP at the start of PD, higher increase in D/P Cr, lower serum albumin, lower RRF, and more decrease in RRF during first year on PD compared with patients having normal sCRP. RRF was inversely correlated with changes in D/P Cr during the first year on PD (r=-0.28, P=0.02). Multiple regression analysis revealed that the only factors affecting changes in D/P Cr were high sCRP and a low RRF. CONCLUSIONS: Our preliminary short-term study suggests that changes in peritoneal transport rate during patients' first year on PD may be linked with inflammation and declining residual renal function. Inflammation and residual renal function were identified as the only independent factors determining peritoneal transport rate during the first year on PD. It is possible that inflammation may cause both an increase in peritoneal transport rate and a decline in residual renal function, or that the decline in residual renal function and the increase in peritoneal transport rate may induce or aggravate inflammation. Further studies are needed to confirm these findings.     

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.     

Association between residual renal function, inflammation and patient survival in new peritoneal dialysis patients.

BACKGROUND: The recent ADEMEX study (Paniagua R, Amato D, Vonesh E et al. J Am Soc Nephrol 2002; 13: 1307-1320) indicates that peritoneal small solute clearance is not as critical for the survival of peritoneal dialysis (PD) patients as thought previously. On the other hand, low residual renal function (RRF), inflammation and an increased peritoneal transport rate (PTR) as evaluated by the peritoneal equilibration test (PET) are reported to be associated with increased mortality in PD patients, but the relationships between these factors and their separate and combined impact on the survival of PD patients are not clear. In this retrospective analysis, we evaluated possible relationships between RRF, inflammation and initial PTR in patients starting PD and the impact of these factors on patient survival. METHODS: A total of 117 patients with initial assessments for RRF, serum C-reactive protein (CRP) and PET at a mean period of 0.4+/-0.2 months (range 0.1-1.0 months) after start of PD were included in this study. Based on RRF (cut-off point, 4 ml/min/1.73 m(2)), serum CRP (cut-off point, 10 mg/l), and the dialysate to plasma creatinine ratio at 4-h of dwell (mean+1 SD), the patients were divided into different groups: low RRF and high RRF group, high CRP and normal CRP group and high PTR and other PTR group, respectively. RESULTS: Of 117 patients, 54 patients (46%) were in low RRF (<4 ml/min/1.73 m(2)) group, 36 patients (31%) were in high serum CRP (> or = 10 mg/l) group and 17 patients (15%) were in high PTR group. Forty-nine patients (42%) had one of these characteristics, 26 patients (22%) had two of these characteristics, two patients (2%) had three, and 40 patients (34%) had none of these characteristics. Patients with low RRF were older and had a higher prevalence of high CRP, lower normalized protein equivalent of total nitrogen appearance (nPNA), lower total Kt/V(urea) and lower total creatinine clearance (CCr) whereas patients with high CRP were older and had a higher proportion of men, lower serum albumin, lower nPNA, lower RRF and lower total CCr. Patients with high PTR had lower serum albumin, higher RRF and higher total CCr compared with patients with other PTR. Upon logistic multiple regression analysis, age and RRF were identified as factors affecting inflammation. Overall patient survival was significantly lower in the patients with low RRF, with high CRP, and in patients with more than two of the following: low RRF, high CRP and high PTR. In contrast, in patients with none of the discriminators low RRF, high CRP and high PTR, the 5-year survival was 100%. A high PTR was associated with decreased survival during the initial year on PD, but not thereafter. Patients who died during the follow-up period had a higher prevalence of high CRP and lower serum albumin, lower RRF, lower Kt/V(urea) and lower total CCr. Upon Cox proportional hazards multivariate analysis, age and RRF were predictors of mortality. CONCLUSIONS: These results indicate that in patients starting PD, low initial RRF is associated with inflammation, and low RRF and inflammation are both associated with high overall mortality. A high PTR was associated with higher mortality, but only during the initial year on PD, whereas Kt/V(urea) did not predict mortality. These results indicate the importance of RRF and inflammation as predictors of mortality in PD patients whereas the predictive power of PTR as such may lose its significance if these two parameters are taken into consideration.     

Important differentiation of factors that predict outcome in peritoneal dialysis patients with different degrees of residual renal function.

BACKGROUND: Residual renal function (RRF) is an important predictor of outcome in peritoneal dialysis (PD) patients. Whether results from survival studies in dialysis patients with RRF can also be extrapolated to anuric patients remains uncertain. In this observational study, we examined the characteristics of PD patients with a residual glomerular filtration rate (GFR) > or =1 ml/min per 1.73 m2 vs those with complete anuria and differentiated factors that predict outcome in the two groups of patients. METHODS: Two hundred and forty-six continuous ambulatory peritoneal dialysis (CAPD) patients (39% being completely anuric) were recruited from a single regional dialysis centre. Assessments of haemodynamic, echocardiographic, nutritional and biochemical parameters and indices of dialysis adequacy were done at study baseline and were related to outcomes. RESULTS: During the prospective follow-up of 30.8+/-13.8 (mean+/-SD) months, 28.0% of patients with residual GFR > or =1 ml/min per 1.73 m2 vs 50.5% of anuric patients had died (P = 0.005). The overall 2 year patient survival was 89.7 and 65.0% for patients with GFR > or =1 ml/min per 1.73 m2 and anuric patients, respectively (P = 0.0012). Compared with patients with GFR > or =1 ml/min per 1.73 m2, anuric patients were dialysed for longer (P<0.001), were more anaemic (P<0.005), and had higher calcium-phosphorus product (P<0.01), higher C-reactive protein (P<0.001), lower serum albumin (P<0.05), greater prevalence of malnutrition according to subjective global assessment (P<0.05) and more severe cardiac hypertrophy (P<0.001) at baseline. Using multivariable Cox regression analysis, serum albumin, left ventricular mass index and residual GFR were significant factors associated with mortality in patients with GFR > or =1 ml/min per 1.73 m2, while increasing age, atherosclerotic vascular disease and higher C-reactive protein were associated with greater mortality in anuric PD patients. CONCLUSIONS: Our study demonstrates more adverse cardiovascular, inflammatory, nutritional and metabolic profiles as well as higher mortality in anuric PD patients. Furthermore, factors associated with mortality are also not equivalent for PD patients with and without RRF, suggesting that patients with and without RRF are qualitatively different.     

Comparison of clinical outcome between incremental peritoneal dialysis and conventional peritoneal dialysis: a propensity score matching study

BackgroundIncremental peritoneal dialysis (iPD) can be useful in patients with residual renal function (RRF). RRF was well preserved and similar survival was shown in iPD compared to conventional PD (cPD) in previous study. However, the long-term survival of iPD remains unclear compared to cPD in diabetic patients. This study evaluated whether patient survival, hospitalization and peritonitis, and PD survival in iPD were lower than cPD or not.MethodsWe conducted a 12-year retrospective observational study of 303 PD patients (232 cPD and 71 iPD) using propensity score matching by age, gender, and diabetes mellitus (DM). Finally, 78 cPD patients and 39 iPD patients were included and 44 patients had DM. Incremental PD was defined as starting PD with two or three manual exchanges per day.ResultsThe median duration of iPD was 24.1 months and iPD had higher RRF than cPD. Compared to cPD, the patient survival, PD survival and hospitalization benefits were not found in iPD but diabetic iPD patients had significantly longer survival and less hospitalization. Cumulative risk for peritonitis was lower iPD and PD duration of iPD was longer than those of cPD. The iPD was an independent factor associated with survival in patients with DM.ConclusionsIncremental PD may be a safe PD modality to initiate and maintain PD in less uremic patients with tolerable RRF. Incremental PD would be a benefit for survival in diabetic patients. Further prospective studies are necessary to confirm the effectiveness of iPD in PD patients with similar RRF.     

Inherent high peritoneal transport and ultrafiltration deficiency: their mid-term clinical relevance.

BACKGROUND: High peritoneal transport has been associated with poorer outcome in peritoneal dialysis (PD) patients, but not necessarily because of PD-dependent conditions. Our primary objective was to analyse the influences of baseline peritoneal small solute transport and ultrafiltration (UF) capacity on patient and technique survival, after adjusting for comorbid conditions. A secondary objective was to determine whether high transport was associated with basal comorbidity. METHODS: In this prospective observational patient/technique survival study, we followed 410 patients who started PD. At the baseline, we collected data to define comorbidities, tally the Charlson index, determine the baseline mass transfer area coefficients (MTAC) of urea and creatinine, net UF, plasma albumin and residual renal function (RRF). No data other than the information on patient and technique survival were recorded after baseline. RESULTS: The mean follow-up was 33 +/- 28 months. Dropouts during the study were due to renal transplantation in 140 cases, death in 142 cases and transfer to haemodialysis (HD) in 77 cases. Patients with inherent UF deficiency, high transport rate or both were not significantly different in the survival analysis from the rest. In the Cox hazards analysis, only age, Charlson index and a lower RRF were the significant mortality risk factors. None of the baseline parameters studied was a predictor of technique failure. High transporter patients had lower plasma albumin and UF capacity, comorbidity and more frequent liver diseases than the rest. Moderate to severe liver disease (n = 14) was significantly associated with the inherent high transport status, but was never accompanied by UF failure (UFF). UFF patients showed higher RRF, creatinine-MTAC and age. CONCLUSIONS: Neither the high transport nor the inherent UFF status has any influence on patient and technique survival. The inherent high small solute transport status is associated with hypoalbuminaemia and a greater comorbidity index. The Charlson index, age and lower RRF are the only independent predictors of mortality. Technique dropout is not predicted by any of the variables studied at the baseline.     

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.     

Multicenter laparoscopic evaluation of the peritoneum in peritoneal dialysis patients

Laparoscopic findings have been used to confirm peritoneal degenerations in peritoneal dialysis (PD) therapy. This study evaluated morphological changes in the peritoneum and their clinical relevance in patients undergoing PD. Laparoscopic findings at the rectovesical peritoneum were evaluated and scored using an imaging system at the time of PD catheter removal in this multicenter study. Angiogenesis evaluated by the vascular score (VS), color changes score (CCS), plaque score (PS), PD duration, history of peritonitis, dialysate/plasma creatinine (D/P Cr) levels, and age at PD termination were statistically analyzed. The VS of patients with PD duration more than 96 months was significantly decreased compared with that of the other patients and was negatively correlated with D/P Cr levels at PD termination. The CCS for patients with PD duration more than 96 months were significantly higher than those for the other patients and positively correlated with D/P Cr levels at PD termination. The PS of patients with recurring peritonitis were significantly higher than those of the other patients. Diminished vascularity and increased color changes in the peritoneum may be predictive of D/P Cr levels with peritoneal degradation. Laparoscopic evaluation of the abdominal cavity can provide detailed information about peritoneal injury.     

Patient-related and centre-related factors influencing technique survival of peritoneal dialysis in The Netherlands.

BACKGROUND: Although technique failure occurs relatively frequently in peritoneal dialysis (PD), few data have been published on differences in technique failure between centres. METHODS: Using data from RENINE, the comprehensive dialysis registry of The Netherlands, we analysed PD technique failure rates in the period 1994-1999, with life table methods and Cox multiple regression analysis. Patient age, sex, and the presence or absence of diabetes were included in the analysis, as well as time of initiation of PD and the following centre characteristics: number of PD patients treated in the centre and percentage of patients on PD. RESULTS: Technique failure was higher in older patients: 2-year technique survival was 75% in those younger than 45 years, 68% in the group aged 45-64 years, and 60% in those over 64 years (P<0.0001). Sex and diabetes made no difference in technique survival. Mean annual technique failure rates varied greatly between centres (10-59%) and correlated with the number of patients on PD in the centre (r=-0.396, P=0.009) and with the fraction of patients on PD (r=-0.410, P=0.006). Low technique survival rates occurred mainly in centres with less than 20 patients on PD: relative risk for technique failure 1.68 as compared with larger centres. Patients starting PD in the period 1997-1999 had better technique survival than those starting in 1994-1996 (P=0.001). CONCLUSION: PD technique survival in The Netherlands has increased in recent years. Having less than 20 PD patients in a centre or having a small fraction of patients on PD carries an increased risk of technique failure. The variability in PD technique survival between centres indicates that in many centres further improvements should be possible.     

Initial survival advantage of peritoneal dialysis relative to haemodialysis.

BACKGROUND: The influence of dialysis modality on prognosis is controversial. In the absence of randomized trials, epidemiological investigations present the best method for studying the problem. METHODS: 4568 haemodialysis (HD) and 2443 peritoneal dialysis (PD) records in 4921 dialysis patients treated between 1990 and 1999 were retrieved from the Danish Terminal Uremia register in order to determine the influence of dialysis form on prognosis. The register is national, comprehensive, and incident. RESULTS: Factors reducing survival included age, cardiovascular disease, malignancy, lung disease, diabetes, alcoholism, haematological disease, but not sex or hypertension. Transplant non-candidacy was associated with an adjusted relative risk of 4.7 (CI 4.0-5.6). PD mortality relative to HD (after correction for comorbidity and transplant candidacy) was 0.65 (CI 0.59-0.72, P<0.001) on an "as treated" and "history" analysis and 0.86 (CI 0.78-0.95, P<0.01) on an intention-to-treat (ITT) analysis. The difference was confined to the first 2 years of dialysis. Change in dialysis modality was associated with increased mortality, and change from PD to HD with an accelerated mortality for the first 6 months. This was presumably due to the transfer of sick PD patients, but did not explain the difference. The relative advantage of PD was lower for diabetic patients, where it was not significant on ITT analysis. Dialysis prognosis improved by 14% during the period, with similar results for HD and PD patients. PD patients who were subsequently transplanted had a significantly shorter time to onset of graft function (3.5 vs 5.1 days, P<0.05). CONCLUSIONS: These results show a survival advantage for PD during the first 2 years of dialysis treatment. This may be due to unregistered differences in comorbidity at the start of treatment, or may be causal, possibly due to better preservation of residual renal function. The study lends credence to the "integrative care" approach to uraemia, where patients are started on PD and transferred to HD when PD related mortality increases.     

The potential of matrix metalloproteinase-2 as a marker of peritoneal injury, increased solute transport, or progression to encapsulating peritoneal sclerosis during peritoneal dialysis--a multicentre study in Japan.

BACKGROUND: Long-term peritoneal dialysis (PD) leads to peritoneal injury. At worst, peritoneal injury leads to encapsulating peritoneal sclerosis (EPS), which is a serious complication of PD. The mortality rate of EPS is extremely high. To perform PD safely, monitoring of peritoneal injury that leads to EPS is a necessity. METHODS: A total of 444 PD patients with end-stage renal disease at 60 centres in Japan were analysed (sex, 54% males; median age, 56 years; median PD duration, 55 months). Matrix metalloproteinase (MMP)-2 and MMP-9 in the peritoneal effluents were analysed with gelatin zymography or enzyme-linked immunosorbent assay. Cells expressing MMP-2 in the peritoneal tissue were investigated immunohistologically with anti-MMP-2 antibodies. Peritoneal solute transport was assessed with the peritoneal equilibration test (PET). RESULTS: The MMP-2 levels in peritoneal effluents obtained with the PET were significantly correlated with the D/P Cr ratio (R = 0.69, P < 0.001) and the D/D0 glucose ratio (R = -0.59, P < 0.001). The MMP-2 levels in patients with mild peritoneal injury, moderate peritoneal injury, severe peritoneal injury (EPS) and infectious peritonitis were significantly higher than those in control patients (P < 0.001, P < 0.001, P < 0.01 and P < 0.05, respectively). MMP-2 was produced by myofibroblast-like mesenchymal cells and macrophages in the peritoneum. The peritoneal effluents from patients with infectious peritonitis showed strong MMP-9 signals. CONCLUSIONS: From these results, MMP-2 levels in peritoneal effluents reflect peritoneal solute transport and changes in MMP-2 levels are associated with peritoneal injury that leads to EPS. MMP-2 may be a useful marker of peritoneal injury, increased solute transport or progression to EPS.     

Factors Associated with Above and Under 5-Year Survival in Peritoneal Dialysis Patients

Background/aims: A few patients stay on peritoneal dialysis (PD) for 5 years or longer from initiation of therapy. We investigated patient survival and factors affecting mortality in PD patients. Methods: This was a retrospective study including 354 PD patients. The demographic, clinical, and biochemical data were collected from the medical records. Two hundred patients were excluded. Evaluation was carried out on data from 154 patients, including 83 surviving 5 years or more and 71 who were taken as surviving less than 5 years. Results: Mean age, number of comorbid diseases, prevalence of diabetes mellitus (DM), rate of mandatory preference of PD, making their PD exchanges with help from anyone were lower in surviving patients, and education level was higher in surviving patients. Advanced age, high rate of mandatory preference of PD, high rate of baseline high, and high-average peritoneal transporters were associated with an increased risk of death. Conclusion: Long-term survival is possible for PD patients, particularly nondiabetics, those having higher education level, those with a self-preference of PD, and those making PD exchanges without any help.     

Is malnutrition an independent predictor of mortality in peritoneal dialysis patients?

BACKGROUND: It has been established that malnutrition (MN) is a strong predictor of mortality in peritoneal dialysis (PD) patients. However, MN is often the consequence of co-morbid diseases (CMD), and the confounding effect of CMD on mortality in malnourished PD patients has not been clearly defined. In this study, we tested the hypothesis that MN without CMD may not be associated with significant mortality. This study was, therefore, designed to dissociate the influence of CMD on mortality in PD patients from that of MN. METHODS: A total of 153 consecutive PD patients (88 males, mean age 53.3 +/- 12.3 years) were included in this study. All underwent initial assessment of nutrition, CMD survey and peritoneal equilibration test at a mean of 7 days (range 3-24 days) after beginning PD. Nutritional status was assessed by subjective global assessment (SGA) and other methods. CMD surveyed included diabetes, cardiovascular disease, liver disease and respiratory disease, and co-morbidity was graded by Davies index. Based on the nutritional status as assessed by SGA and presence of CMD, patients were divided into four groups; MN with (n = 50) or without (n = 14) CMD, and normal nutrition (NN) with (n = 53) or without (n = 36) CMD. RESULTS: Of 153 patients, 64 (41.8%) were malnourished and 103 (67.3%) had one or more CMD. Of the 103 patients with CMD, 48.5% had MN, and 78% of the 64 patients with MN had CMD. Patients with MN and CMD were older and had lower initial serum albumin (sAlb), serum creatinine, fat-free oedema-free body mass, percentage lean body mass and SGA score and higher initial dialysate/plasma creatinine concentration ratio at 4 h dwell (D4/P4 Cr) and co-morbidity score. On Kaplan-Meier analysis, 2-year patient survival was significantly lower in patients with MN and CMD than in the other groups (63.1, 90.9, 87.5 and 96.4% for subgroups with both MN and CMD, MN without CMD, NN with CMD and NN without CMD, respectively, P = 0.001). On Cox proportional hazards analysis, age, co-morbidity score and D4/P4 Cr, but not SGA score or sAlb concentration, were found to be independent risk factors for mortality. After adjustment for age, gender, sAlb, residual renal function and D4/P4 Cr, patients with both MN and CMD had a risk of mortality that was 3.3 times that of patients with MN but without CMD (risk ratio 9.01 vs 2.72). Patients with MN without CMD had a risk ratio of 2.72 compared with NN without CMD, but this difference was not statistically significant. In patients with NN and CMD, the risk ratio for mortality was five times that of patients with NN without CMD. CONCLUSIONS: This study demonstrates that there is a high prevalence of MN and CMD at the start of PD and that the combined presence of CMD and MN is associated with high mortality. MN alone is associated with a statistically insignificant increase in mortality. This underlines the importance of CMD as a cause of poor clinical outcome in malnourished PD patients. However, in the present study, a relatively limited number of patients with MN but without CMD were analysed and a type two error therefore cannot be excluded.     

Comparing long-term outcomes between early and delayed initiation of peritoneal dialysis following catheter implantation

Aim: The aim of this study was to compare peritonitis rates, peritoneal dialysis technique survival and patient survival between patients who started peritoneal dialysis earlier than 14 days (early starters) and 14 days or more (delayed starters) after insertion of a Tenckhoff catheter. Methods: Observational analysis was performed for all patients who underwent insertion of a Tenckhoff catheter at Far Eastern Memorial Hospital between 1 January 2006 and 31 December 2012. The patients were divided into two groups: early and delayed starters. The rate and outcomes of peritonitis were recorded. Peritoneal dialysis technique survival and patient survival were analyzed using the Kaplan–Meier method. Cox regression analysis was performed for peritoneal dialysis technique failure and patient mortality. Results: There were 80 early starters and 69 delayed starters. The peritonitis rate was 0.18 episodes per year in early starters and 0.13 episodes per year in delayed starters. There was no significant difference of peritonitis free survival (p?=?0.146), peritoneal dialysis technique survival (p?=?0.273) and patient survival (p?=?0.739) at 1, 3, 5 years between early starters and delayed starters. After adjustment with age, albumin and diabetes, early starters did not have an increased risk of peritonitis, technique failure and mortality compared to delayed starters. Conclusion: Compared to the patients who started peritoneal dialysis 14 days or more after catheter implantation, the patients who started earlier did not have an increased risk of peritonitis, peritoneal dialysis technique failure and mortality.     

辅助腹膜透析的预后分析

目的比较辅助腹膜透析和自主腹膜透析对腹膜透析(peritoneal dialysis,PD)患者的预后影响。方法回顾性收集1996年3月13日至2016年12月31日在北京协和医院行PD且资料完整的637例成人患者的临床资料,按照患者是否独立完成PD操作将将患者分为自主PD组和辅助PD组,按照PD的模式不同进一步将辅助PD组分为自动化腹膜透析组(automated peritoneal dialysis,APD)和持续非卧床腹膜透析组(continuous ambulatory peritoneal dialysis,CAPD),分别比较辅助PD和自主PD两组间以及辅助APD和辅助CAPD两组间患者生存、技术生存及无腹膜炎生存方面的差异。结果本研究纳入辅助PD组373例(APD 35例,CAPD 338例),自主PD组264例。与自主PD相比,辅助PD患者年龄更大,合并糖尿病、高血压及心血管疾病比例更高,透析开始时血白蛋白、钾、磷、血肌酐、尿素、甲状旁腺素和标准蛋白分解率更低,而血二氧化碳总量和估算肾小球滤过率更高。辅助APD组与辅助CAPD组比较则前者合并心血管疾病比例,护工辅助比例以及透析3个月后残余肾功能水平更高。辅助PD组患者生存不及自主PD组,但经多因素校正后辅助PD不是患者死亡的独立危险因素(HR1.479,95%CI 0.978~2.236,P=0.064),两组在技术生存及无腹膜炎生存方面相当。辅助APD与辅助CAPD比较,两组的患者生存、技术生存及无腹膜炎生存均无差异。结论辅助PD的患者生存劣于自主PD,而技术生存及无腹膜炎生存两组无差异。辅助APD的患者生存、技术生存和无腹膜炎生存与辅助CAPD无差异,可以作为有需求患者的治疗选择。     

Associates of mortality among peritoneal dialysis patients with special reference to peritoneal transport rates and solute clearance.

The current report describes the distributions of selected demographic and biochemical parameters, clearance, and other transport values among patients undergoing peritoneal dialysis (PD) and evaluates the associates of mortality using those values, with and without clearance and peritoneal equilibration test (PET) data. All patients receiving PD on January 1, 1994 were selected (n = 2,686). Patients who switched to another form of dialysis during the study period were removed from the study at the time of therapy change. Working files were constructed from the clinical database to include demographic, laboratory, and outcome data. Laboratory data were available in only 1,603 patients and were used to evaluate the biochemical associates of mortality after merging the biochemical, demographic, and outcome data. Patients with clearance data or PET studies underwent a second analysis to assess the effects of peritoneal and renal clearance on survival. The analysis of demographic and laboratory data confirmed the importance of age and serum albumin concentration as predictors of death. Residual renal function (RRF) was strongly correlated with survival, but peritoneal clearance was not. Several possible explanations for the lack of correlation between peritoneal clearance and survival are discussed. The data suggest that RRF and peritoneal clearance may be separate and not equivalent quantities. Substantial work is required to confirm or refute these findings, because the information is essential to establish the adequate dose of PD in patients with various degrees of RRF.     

Relation of ankle-brachial index to the rate of decline of residual renal function in peritoneal dialysis patients

Aim: The aim of this study was to determine whether ankle‐brachial index (ABI) predicts the rate of decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. Previous studies demonstrated the importance of loss of RRF in predicting all‐cause risk and cardiovascular mortality in PD patients. It is also known that patients with a low ABI value have a greater risk for deteriorating renal function in the general population. The relationship between ABI and the declining rate of RRF in PD patients with an additional dialysis‐specific risk factor is uncertain. Methods: Seventy‐four PD patients with RRF of more than 1 mL/min per 1.73 m² were analyzed. ABI was used as the surrogate measure of pre‐existing cardiovascular disease and atherosclerosis burden to further determine the outcome of RRF in this study. The slope of decline of RRF was used to determine the outcome. Results: Based on the multivariate analysis, only ABI (P < 0.001), diabetes (P = 0.02) and baseline RRF (P = 0.009) independently predicted a faster decline in RRF. A stepwise multiple linear regression analysis demonstrated that ABI was an independent predictor for the slope of decline of RRF (P < 0.001). Conclusion: A low ABI is an independent predictor of not only the known atherosclerotic events, but also of the rate of decline of RRF over time in PD patients.     

Quantifying comorbidity in peritoneal dialysis patients and its relationship to other predictors of survival.

BACKGROUND: Comorbidity is the single most important determinant of outcome in patients on renal replacement therapy. The aims of this study were to evaluate a semi-quantitative approach to comorbidity scoring in predicting survival of patients commencing peritoneal dialysis (PD), and to establish the interaction between this and other known predictors of patient outcome, in particular membrane function, residual renal function (RRF) and plasma albumin. METHODS: Comorbidity was recorded in a prospective, single centre cohort study of 303 patients commencing on PD. Using seven disease domains, chosen to reflect the dominance of cardiovascular morbidity in the end-stage renal failure population, comorbidity was graded as '0' when absent, '1' when one or two, and '2' when three or more conditions were present. The Wright comorbidity index, which includes age within the scoring method, was also evaluated. RRF, plasma albumin and peritoneal solute transport were measured every 6 months. Patients were censored at death. RESULTS: Median survival according to grade of comorbidity was 105, 42 and 29 months, respectively (P<0.0001), with good separation of the actuarial survival curves. Using Cox regression, the addition of age and the grade of comorbidity to Kt/V(urea), solute transport and plasma albumin increased the predictive power of the model. All were independent predictors of outcome with the exception of albumin. The Wright comorbidity index also enhanced the Cox model, although was not as powerful as when age and comorbidity were considered independently. At baseline, RRF was not different according to comorbidity unless diabetes was considered separately. Diabetics started with higher RRF, but after 6 months on PD this was the same as non-diabetic patients. Otherwise, initial rate of decline of RRF was similar across the comorbid grades, although the impact of higher drop-out due to earlier loss in patients with more comorbidity may have disguised earlier loss in these patients. Peritoneal solute transport tended to be higher in patients with increased comorbidity at baseline, chi(2) 13.8, P=0.032, and this was sustained with time on treatment. CONCLUSION: Comorbidity has a quantitative effect on survival that is independent of age, RRF and membrane function in PD patients. Comorbidity also appears to be associated with increased solute transport at the start of treatment, which is sustained. With the exception of diabetes, grade of comorbidity does not have a profound effect on loss of RRF.