Low-Sodium Peritoneal Dialysis Solution (Na 126 mmol/L) for Enhanced Sodium Removal: A Multicenter Randomized Controlled Trial

Fluid overload is a major cause of treatment failure in patients receiving peritoneal dialysis (PD), and insufficient sodium removal is involved with this condition. This study evaluated the efficacy and safety of a novel low-sodium (LS) PD solution (Na 126 mmol/L, glucose 1.6%) combined with standard-sodium (SS) PD solutions as a new approach to enhance sodium removal.

In this multicenter, double-blind, randomized, parallel-group study, outpatient PD patients at 20 facilities in Japan were randomly assigned (2:1) to the LS PD solution group or the SS PD solution group (Na 135 mmol/L, glucose 1.35%).

The test solution replaced 1 daily exchange and was combined with at least 1 standard PD solution. Patients who met dose-escalation criteria at week 4 switched to twice-daily dosing.

The primary outcome was the change in daily peritoneal sodium removal from baseline to week 8. Secondary outcomes included peritoneal sodium removal per bag exchange, total daily (peritoneal and urinary) sodium, water removal, and dialysis adequacy.

Efficacy, including sodium removal in PD treatment, was analyzed in the full analysis set; safety was assessed in all patients.

The mean change in daily peritoneal sodium removal was significantly higher in the LS PD solution group (n = 51, 28.7 ± 36.2 mmol/d) than in the SS PD solution group (n = 27, -6.3 ± 26.2 mmol/d; P < 0.001). Other outcomes showed no significant differences. Drug-related adverse events (mainly hyponatremia) were observed in the LS PD solution group; however, they were generally mild and completely reversible.

Participants with relatively preserved residual kidney function and incremental PD were overrepresented.

The LS PD solution, when combined with standard PD solutions, increased sodium removal without compromising dialysis adequacy or residual kidney function.