The effect of low-GDP solution on ultrafiltration and solute transport in continuous ambulatory peritoneal dialysis patients

Abstract

Background: Several studies have reported benefits for human peritoneal mesothelial cell function of a neutral-pH dialysate low in glucose degradation products (GDPs). However, the effects of low-GDP solution on ultrafiltration (UF), transport of solutes, and control of body water remain elusive. We therefore investigated the effect of low-GDP solution on UF, solute transport, and control of body water.

Methods: Among 79 new continuous ambulatory peritoneal dialysis (CAPD) patients, 60 completed a 12-month protocol (28 in a lactate-based high-GDP solution group, 32 in a lactate-based low-GDP solution group). Clinical indices--including 24-hour UF volume (UFV), 24-hour urine volume (UV), residual renal function, and dialysis adequacy--were measured at months 1, 6, and 12. At months 1, 6, and 12, UFV, glucose absorption, 4-hour dialysate-to-plasma (D/P) creatinine, and 1-hour D/P Na(+) were assessed during a modified 4.25% peritoneal equilibration test (PET). Body composition by bioelectric impedance analysis was measured at months 1 and 12 in 26 CAPD patients.

Results: Daily UFV was lower in the low-GDP group. Despite similar solute transport and aquaporin function, the low-GDP group also showed lower UFV and higher glucose absorption during the PET. Factors associated with UFV during the PET were lactate-based high-GDP solution and 1-hour D/P Na(+). No differences in volume status and obesity at month 12 were observed, and improvements in hypervolemia were equal in both groups.

Conclusions: Compared with the high-GDP group, the low-GDP group had a lower UFV during a PET and a lower daily UFV during the first year after peritoneal dialysis initiation. Although the low-GDP group had a lower daily UFV, no difficulties in controlling edema were encountered.

Keywords: Low-GDP solution; solute transport; ultrafiltration.

Figure 1

— Summary of patient flow through the study.

Figure 2

— Data from the modified peritoneal equilibration test (PET) for the low-glucose degradation product [GDP (filled bars, n = 32)] and high-GDP groups (open bars, n = 28). (A) Ultrafiltration volume (UFV) during the modified PET. (B) Glucose absorption during the modified 4.25% PET. ^* p < 0.05 and ^** p < 0.01 comparing the low-GDP group with the high-GDP group. ^‡ p < 0.01 compared with month 1.