Abstract
Background and Aims
Peritoneal protein loss (PPL) through peritoneal effluent has been a well-recognized detrimental result of peritoneal dialysis (PD). The amount of protein lost will depend on dialysis time, protein size, its serum concentration and other factors including patients’ clinical status. Peritoneal protein loss may be a manifestation of endothelial dysfunction, as with another type of capillary protein leakage, microalbuminuria, a recognized endothelial dysfunction marker. The aim of this study was to retrospectively evaluate the influence of PPL on cardiovascular mortality of peritoneal dialysis patients
Method
This is a single center retrospective study of 84 PD patients (m=54, f=30) with mean age of 65.2±17 years, mean PD duration of 43.2±24.9 months conducted for the time period from 2006 to 2019 (13 years). The patients were divided into two groups according to the amount of protein excreted during the modified Peritoneal Equilibration Test (PET) procedure using PD solution of 3.86% DW, 2 Lt infusion volume for total time of 4 hours. The total amount of proteins excreted was calculate from PET by multiplying the concentration of proteins at the end of the test with the total volume of PD fluid at the same time. Group A excreted a total amount of proteins < 1.55 gr (median value) at the end of PET test and Group B > 1.55 gr. The cumulative all-cause and cardiovascular survival of the PD patients was calculated by Kaplan Meier while the possible effect of any parameter in survival rates was evaluated by using Cox Regression analysis
Results
There was not any statistically significant difference between the two groups according to PD duration, age, dialysis adequacy targets, Residual Renal Function(RRF), BMI, ultrafiltration volume during PET and their transport status. The cumulative all-cause survival using Kaplan-Meier analysis revealed no statistically significant deference between the two groups (Log Rank p=0.55) even though mortality risk was adjusted for several factors (Cox Regression). When cardiovascular survival, using Cox Regression analysis, was adjusted for age, sex, Diabetes, PD modality, dialysis Kt/V and RRF we found that Group A (with protein excretion < 1.55 gr) had statistically significant better cardiovascular survival (p=0.029) compared to Group B. We confirm these results while trying to find among the total of our patients the possible risk factors for cardiovascular mortality. Using Cox Regression analysis, the amount of protein excreted during PET procedure and the type of PD solutions (high or low in GDPs) used were statistically significant (p=0.019 and p=0.04 respectively) independent risk factors for cardiovascular survival in our patients.
Conclusion
These results indicate that protein loss during peritoneal dialysis procedure has negative impact on cardiovascular mortality and survival of PD patients. Additionally, the use of PD solutions with low Glucose Degradation Products (GDPs) and AGEs may improve PD patient’s cardiovascular survival. Randomized interventional studies are encouraged to address the pathological concern of PPL in the future, namely its effects on cardiovascular conditions or its role as marker and effort to reduce PPL using ACE inhibitors or vit D should be considered only if it diminishes cardiovascular morbidity or mortality.
Association of serum angiopoietin-2 with malnutrition, inflammation, atherosclerosis and valvular calcification syndrome and outcome in peritoneal dialysis patients: a prospective cohort study
