Clinical Study On Peritoneal Dialysis Practice And Patient Outcomes In A Shanghai And A Macao Centre

PART Ⅰ Long-term clinical outcomes of peritoneal dialysis patients:13years’ experience from MacaoBackgroundPeritoneal dialysis (PD), as an established modality of renal replacement therapy for patients with end-stage renal disease (ESRD), has been rapidly developped during the past decade over the world. Avalable evidences showed that various inherent patient and center factors would affect the clinical outcomes of the PD patients. Moreover, published data also demonstrated various patient survival rate in different countries and regions. PD has been initially utilized since1999in Macao, however, no systematic analysis on long-term outcomes of PD patients has been reported in Macao. Therefore, the present study retrospectively investigated the center and the patient characteristics as well as the clinical outcomes of the PD patients in Macao. We also evaluated the possible risk factors for patient mortality and PD technique failure.MethodsThe study enrolled371patients on maintenance PD during January1,1999to June30,2012in Macao. The demographic, clincal, biochemical data and clincal outcomes were collected from the medical records. The patient survival rate was calculated from date of PD initiation to death or to the end of follow-up (June30,2012). The PD tecnique survival rate was culculated from date of PD initiation to termination of PD or to the end of follow-up. Technique failure was defined removal of the PD catheter and shift to hemodialysis more than three months or cessation of PD due to a PD-related complications. PD-related peritonitis, exit site infection and patient hospitalization also were analysized.ResultsIn Macao, median patient age at the start of PD was63years (range18～91years) and the median PD duration was34months (range3～142months). Diabetes mellitus was the most common cause of ESRD (43.13%), followed by chronic gromerular nephritis (39.89%). By the end of follow-up, there were150(40.43%) deaths.93(25.07%) patients transferred to hemodialysis and34(9.16%) patients received kidney transplantation. The1-,3-,5-,7-, and10-year patient survival rates were94.33%,84.80%,73.74%,51.53%,41.35%, and22.36%, respectively. Most deaths were the result of infection (40.67%) and cardiovascular disease (36%). Multivariate Cox proportional hazards analysis demostrated that old age (HR=1.764, p=0.029), diabetes mellitus (HR=1.582, p=0.015), continuous ambulatory peritoneal dialysis (CAPD) modality (HR=1.988,p=0.010), use of traditional PD solution (HR=1.566, p=0.029), and low serum albumin level (HR=2.149,p<0.001) independently predicted mortality of PD patients. The1-,3-,5-,7-, and10-year technique survival rates were94.60%,88.12%,78.81%,63.64%,51.59%, and35.98%, respectively. PD-related peritonitis was the main cause (50.54%) of shift to hemodialysis for PD patients. Multivariate Cox proportional hazards analysis demostrated that peritonitis rate (HR=2.624, p<0.001) was the significant risk factor for PD technique failure. The overall peritonitis incidence rate was0.3episodes per patient-year. Escherichia coli was the predominant causative micro-organism (15%). The overall exit site infection incidence rate was0.45episodes per patient-year. The most common causative micro-organism was Pseudomonas aeruginosa (34.9%). The median duration of hospitalization was12days (range0～180days). Peritonitis (21.9%), issue of fluid balance (14.4%) and cardiovascular disease (10.7%) were the main reasons for patient hospitalizations.ConclusionsOur retrospective study showed that patient survival and technique survival rates were good among chronic PD patients in Macao. Older age, comirbid diabetes mellitus, CAPD modality, use of traditional PD solution and lower serum albumin level were the independent risk factors for patient death. Individual choice for PD patients, clinical utilization of automated PD and low glucose degradation product PD solutions, early amelioration of malnutrition and effective prevention of PD-related peritonitis might be significantly important to improve the long-term outcomes of PD patients in Macao. PART Ⅱ Clinical outcomes in chronic peritoneal dialysis patients:a comparison between a Shanghai and a Macao centreBackgroundPeritoneal dialysis (PD) has been worldwidely used as an established renal replacement therapy for patients with end-stage renal disease (ESRD). However, the mortality of PD patients as a whole remains high and different patient outcomes were reported in different contries or centres. The reasons for high mortality may be multifactorial. But a number of studies have indicated that it may have been due to differences in centre and patient characteristics rather than race itself. Till now, almost all the available data on clinical outcomes of PD patients were acquired from regional renal registry system or single centre report. However, comparison on clincial outcomes in the same racial PD patients between difference PD centres has not been fully investigated. Therefore, we compared the centre and patient characteristics of the chronic PD patients between a Shanghai and a Macao centre and examined whether these differences influence patient survival in patients of same racial background.MethodsThe study enrolled all patients who initiated PD between1January2005to30June2009in Huashan Hospital, Fudan University, Shanghai and Centro Hospitalar Conde de Sao Januario, Macao. All patients were followed up from the date of PD initiation untill cession of PD, death, transfer to other centres of the end of the study (30June2012). The demographic, clincal, biochemical data, assessment of PD adequacy, peritoneal transport characteristics, quarlity of life and clincal outcomes were collected.ResultsA total of373patients chronic PD patients from Shanghai (212patients) and Macao (11patients) were included. Compared with Macao patients, Shanghai patients were older (p=0.049), but had lower hemodialysis (HD) history, lower estimated glomerular filtration rate and lower Charlson comorbidity index at the start of PD (all p values<0.001). The most common cause of ESRD was chronic glomerular nephritis in Shanghai (55.7%), but it was diabetes mellitus (DM) in Macao (40.4%). Serum albumin, pre-albumin, high-density lipoprotein, calcium, phosphate, calcium-phosphate product and C reactive protein level were significantly lower (all p value<0.01) but hemoglobin level was significantly higher (p<0.001) in Shanghai patients than in Macao patients. There was no difference in parameters of PD adequacy (all p values>0.05). But the dialysate to plasma creatinine concentration ration (D4/P2Cr) was significantly higher (p<0.001) in Shanghai patients compared with Macao patients. In Macao,29.2%PD patients were treated with automated PD,39.8%patients used icodextrin PD solution and45.3%patients used low glucose degradation product (GDP) PD solution. However, in Shanghai all patients were treated with continuous ambulatory peritoneal dialysis and no icodextrin or low GDP PD solutions were used. The PD-related peritonitis rate and exit site infectin rate were significantly higher in Macao than in Shanghai (p=0.011and <0.001, respectively). Compared with Macao patients, the mortality was significantly higher (p=0.006), but the rate of transfer to HD as well as kidney transplantation were significantly lower in Shanghai patients (p<0.001and=0.031, respectively). The1-,3-,5-, and7-year patient survival rates (PSR) were significantly lower in Shanghai (p=0.002). Older age at the start of PD (HR=1.067,p<0.001), DM history (HR=1.856, p=0.007), HD history (HR=4.195,p<0.001), and lower serum hemoglobin level (HR=0.800, p=0.001) were found to be the independent predictors of mortality in Shanghai patients, whereas older age at the start of PD (HR=1.046, p=0.002), cardiovascular disease history (HR=2.008,p=0.029) were independently predicted mortality in Macao patients. The1-,3-,5-, and7-year PD technique survival rates (TSR) were significantly higher in Shanghai (p=0.001). Higher peritonitis incidence rate (HR=2.911,p<0.001) and higher Triglycerides level (HR=1.269,p=0.007) were found to be the independent predictors of technique failure in Shanghai patients, whereas higher peritonitis incidence rate (HR=5.186,p<0.001) and lower serum pre-albumin level (HR=0.957, p=0.025) were indepedently predicted technique failure in Macao patients. The peritonitis-free survival rate was significantly higher in Shanghai patients than in Macao patients (p=0.031). At the end of follow-up, according to K/DOQI guidelines the targeted rate of blood pressure was significantly lower, but the targeted rate of serum albumin level was significantly higher in Macao patients (all p values<0.001). Compared with Shanghai patients, the overall quarlity of life score assessed by KDQOL-SFTM was significantly higher in Macao patients (p=0.038).ConclusionThe present study showed that there were significant differences in centre and patients characteristics between two centres. The PSR was higher, but the TSR was lower in Macao patients than in Shanghai patients. Part of the clinical and biochemical parameters haven’t reached the K/DOQI guideline target in both centres which requires further investigation in the future. The quarlity of life was lower in Shanghai patients than in Macao patients, and augement of social surpport, reinforce of medical policy and enhancement of PD facility may contribute to improvement on quarlity of life in PD patients. PART III Brachial-ankle pulse wave velocity as an independent predictor of clinical outcome in peritoneal dialysis patients:a prospective cohort studyBackgroundCardiovascular disease (CVD) is the leading cause of mortality and morbidity in peritoneal dialysis (PD) patients. Increased arterial stiffness determined by brachial-ankle pulse wave velocity (baPWV) has been established as an independent predictor of cardiovascular mortality in end-stage renal disease patients. However, available reports on arterial stiffness in PD patients were limited and the clinical value of baPWV in chronic PD patients has not yet been fully evaluated. The present study aims to investigate the relationship between arterial stiffness and its associated risk factors in PD patients. We also prospectively evaluated the predictive value of baPWV on CVD events and clinical outcomes in chronic PD patients.MethodsA total of96chronic PD patients (48males/48females) were included on30June2010in the propective cohort study. Arterial stiffness was assessed by baPWV. Patients were divided into two subgroups according to mean baPWV value. On enrollment, clinical characteristics, biochemical parameters, PD adequacy, and peritoneal transport characteristics were collected. Patients were followed for24months (ended study on30June2012). During follow-up, all CVD events and patient outcomes were recorded.ResultsThe average age of all included PD patients was63.92±14.24years old, and the mean PD duration was44.47±27.89months. Patients were divided into two groups according to mean baPWV value (21.20±5.63m/s),56patients in high baPWV group and40patients in low baPWV group. Compared with low baPWV group patients, high baPWV group patients were significant older (p<0.001) and more likely to have a high proportion of female gender (p=0.004) as well as previous CVD history (p=0.008). Serum albumin, pre-albumin levels and residual renal creatinine clearance (CCr) were significantly lower but the serum ferritin level was significantly higher in high baPWV group patients than in low baPWV group patients (all p values<0.01). BaPWV was positively associated with age (r=0.534,p<0.001), Charlson comorbidity index (r=0.350,p<0.001) and serum ferritin level (r=0.340,p=0.001). Meanwhile, baPWV negatively correlated with serum albumin (r=-0.479,p<0.001), pre-albumin levels (r=-0.320,p=0.003) and residual renal CCr (r=-0.177,p=0.048). Age-adjusted partial correlation test found a significant correlation between baPWV and C reactive protein (CRP)(r=0.462,p<0.001). Multivariate linear regression analysis showed that baPWV was independently associated with age (p<0.001), serum albumin level (p=0.015), CRP (p=0.019) and residual renal CCr (p=0.045). A total of18CVD events were recorded in high baPWVgroup patients, but only6CVD events were recorded in low baPWVgroup patients. The CVD incidence rate was significantly higher in high baPWV group patients than in low baPWV group patients (0.25epsodes per patient-year Vs0.06episodes per patient-year,p<0.001). Compared with high baPWV group patients, the CVD-free survival rate and patient survival rate were significantly higher in low baPWV group patients (all p values<0.001). However, there was no significant difference in PD technique survival rate between two groups patients (p=0.793).ConclusionArterial stiffness, assessed by baPWV, had an independent correlation with age, serum albumin level, CRP level and residual renal CCr among PD patients. BaPWV was established as predictors of CVD events and mortality in chronic PD patients.