Peritoneal protein clearance and not peritoneal membrane transport status predicts survival in a contemporary cohort of peritoneal dialysis patients

Abstract

Background and objectives: Fast peritoneal membrane transport status may be due to inflammation or increased peritoneal membrane surface area. We evaluated the ability of peritoneal protein clearance (Pcl) to distinguish fast peritoneal membrane transport status as a consequence of peritoneal membrane inflammation and assess its impact on patient survival.

Design, setting, participants, & measurements: Patients who initiated peritoneal dialysis at our center since January 1998 and had a baseline peritoneal equilibration test, measurement of dialysis adequacy, and 24-h dialysate Pcl were included. Demography, comorbidities, and biochemical data were prospectively collected. Follow-up was until death or the end of the period studied. Multivariate regression analysis identified factors that were associated with Pcl. A Cox proportional hazards model was used to identify factors that were associated with survival.

Results: A total of 192 patients (56% men, mean age 54.3 +/- 15.3; 32% with diabetes) were included. On univariate analysis, Pcl was negatively correlated with serum albumin and positively correlated with age, dialysate/plasma creatinine ratio (D/Pcr), the presence of peripheral vascular disease, and urine volume. On multivariate analysis, serum albumin, D/Pcr, urine volume, and peripheral vascular disease remained significant. Predictors of mortality were age, comorbidity grade, and Pcl but not D/Pcr.

Conclusions: In this cohort, peritoneal transport status no longer predicted survival, whereas Pcl remained a predictor. Increased large-pore protein loss may reflect the severity of underlying cardiovascular disease, portending a poor prognosis for these patients.

Figure 1.

Association between peritoneal protein clearance (Pcl) and peritoneal membrane transport status. *P value by ANOVA. L, low; LA, low average; HA, high average; H, high.

Figure 2.

Association between peritoneal Pcl and pulse pressure.

Figure 3.

Survival of patients above and below the median value of daily peritoneal Pcl. Peritoneal Pcl was divided into high and low by separation of patients above and below the median value of 78.4 ml/d.