Peritoneal Albumin and Protein Losses Do Not Predict Outcome in Peritoneal Dialysis Patients

Abstract

SummaryBackground and objectives Peritoneal clearance of albumin-unlike the transport of small molecules-is defined by both vascular surface area and size-selective permeability. Few studies have supported a positive correlation between peritoneal albumin loss and mortality. The aim of this study was to investigate whether baseline peritoneal loss and clearance of albumin and other proteins is a risk factor of death in peritoneal dialysis patients.Design, setting, participants, & measurements All incident peritoneal dialysis patients in our center during the last 15 years were included. Mass-transfer area coefficient of creatinine and peritoneal clearances of albumin, ␤ 2 -microglobulin, ␣ 2 -macroglobulin, and immunoglobulin G were calculated during a standard peritoneal permeability analysis. The total amount of albumin loss in the dialysate was also calculated. Overall mortality was studied with an intention-to-treat analysis.Results Two hundred fifty-seven patients were included. High baseline albumin clearance was associated with fast transport status, the presence of peripheral arterial disease, and a high comorbidity index, whereas C-reactive protein levels did not differ from the patients with low albumin clearance. Age, high comorbidity score, C-reactive protein levels Ͼ10 mg/L, and a low serum albumin were associated with mortality. Peritoneal albumin clearances and albumin loss were not associated with death in crude and adjusted analysis. Similarly, peritoneal clearances of immunoglobulin G, ␣ 2 -macroglobulin, and ␤ 2 -microglobulin were not determinants of survival. ConclusionsBaseline peritoneal albumin and protein clearances are associated with signs of comorbidity, but this does not have a measurable effect on patient survival.

Association of Lean Body Mass Index and Peritoneal Protein Clearance in Peritoneal Dialysis Patients

“…However, such conclusions have been queried by many other studies [4, 8]. A longitudinal study included 540 PD patients found that higher PPCl was associated with higher risk of overall mortality in the univariate model, however, while this effect attenuated to a non-statistical significance when adjusting for confounders [4].…”

“…However, newly studies failed to draw similar conclusions [4, 8-10]. These conflicting results arouse new insights on the peritoneal protein metabolism during PD treatment, especially the relationship between PPCl and nutritional status has been questioned [11].…”

Serum β₂-Microglobulin Predicts Mortality in Peritoneal Dialysis Patients: A Prospective Cohort Study

“…Kim et al [15] explained these contrasting results because of the relative malnutrition status in participants with reverse epidemiologic characteristics, compared with previous studies. As for peritoneal β 2 -M clearance in PD, there was no correlation with all-cause mortality in incident PD patients, as well as chronic HD patients using high-flux membranes [16,17]. Thus, the association of serum β 2 -M levels with clinical outcome was different from that of peritoneal β 2 -M clearance in PD patients or dialyzer β 2 -M clearance in HD patients.…”

Longitudinal Study of Small Solute Transport and Peritoneal Protein Clearance in Peritoneal Dialysis Patients

“…This is further confused by the observation that peritoneal protein clearance (Pcl) is associated with increased age and comorbidity at the start of treatment. Moreover, in some (8,(11)(12)(13)(14) but not all (15) studies it is an independent predictor of survival, resulting in the potential confounding of longitudinal data due to earlier dropout of patients with high Pcl (informative censoring).…”