Role of Peritoneal Loss of Albumin in the Hypoalbuminemia of Continuous Ambulatory Peritoneal Dialysis Patients: Relationship to Peritoneal Transport of Solutes

Abstract

The effects of peritoneal albumin loss and the consequences of heterogeneous peritoneal solute transport on serum albumin levels were investigated in 25 adult patients on standard continuous ambulatory peritoneal dialysis (0-58 months). The patients were divided into three groups according to their albumin concentrations (g/l/1.73 m²) in 8-hour overnight effluents: group 1 ( < 0.6, n = 5), group 2 (0.6- 1.1; n = 14), and group 3 ( > l.l; n = 6). Significant differences (mean ± SD) were observed in serum albumin levels (4.4 ± 0.2, 3.7 ± 0.3, and 3.1 ± 0.5 g/dl, respectively) and in net ultrafiltration (0.37 ± 0.13, 0.19 ± 0.21, and -0.06 ± 0.20 liters/8 h/1.73m², respectively). The serum albumin levels were strongly correlated with 8-hour peritoneal mass transfer, clearance of albumin, 8-hour effluent concentrations of protein and glucose, and ultrafiltration rate. Moreover, the serum albumin levels showed significant negative correlations with dialysate-to-serum ratios of small solutes (urea, creatinine, and uric acid) and macromolecules (IgG, IgA, and IgM) estimated from 8-, 4-, and 1-hour dwell times. In addition, an overnight dialysate glucose-to-protein ratio < 1.0 was highly predictive of low serum albumin levels ( < 3.5 g/dl) and poor ultrafiltration. From the results of this study we conclude that peritoneal loss of albumin as well as peritoneal transport of other solutes of wide size (‘permeability’) contribute to the low serum albumin levels during continuous ambulatory peritoneal dialysis, especially in patients with a high peritoneal permeability.

Association between vitamin C deficiency and dialysis modalities

“…In the present study, we found that serum prealbumin level is approximately 70 mg/L higher in PD than HD, while serum albumin is approximately 2.8 g/L lower in PD, which was paralleled with previous studies 29–31 . The reason for the decrease in serum albumin in PD is probably due to the peritoneal loss of albumin; 32,33 however, the reason for the increase in prealbumin in PD is unknown. It has been hypothesized that serum prealbumin is increased as a result of the stimulation of hepatic synthesis by the large loss of albumin and/or the resultant hypoalbuminemia hepatic synthesis or reduced systemic catabolism 31,34–36 …”

Higher Peritoneal Transport Status Is Associated with Higher Mortality and Technique Failure in the Australian and New Zealand Peritoneal Dialysis Patient Populations

“…Nolph et al (33) and Kang et al (27) demonstrated that high peritoneal permeability was associated with a reduced normalized protein catabolic rate and composite nutritional index, but these associations were not confirmed by the CANUSA study (7). The greater prevalence of hypoalbuminemia in high transporters may also arise from hemodilution secondary to suboptimal ultrafiltration (34) or from excessive peritoneal protein losses (28). Alternatively, hypoalbuminemia in high transporters may reflect a greater incidence of underlying chronic inflammation (12,35), although other studies have not observed a significant correlation between D:P Cr 4 h and various inflammatory markers, such as C-reactive protein (4,36).…”

Pathogenic Effects of a High Peritoneal Transport Rate

“…HTs have lower levels of plasma albumin (3-5, 8, 10, 20, 26-28). Serum albumin is generally found to be negatively correlated to peritoneal loss of albumin (3,5,8,22,(29)(30)(31)(32) and both are correlated to transport status (3,8,10,11,26,31,33). Peritoneal protein loss is substantial in HTs (8-13 g/day) compared to LTs (5-6 g/day), and is clearly in the nephrotic range.…”