Low-Sodium Versus Standard-Sodium Peritoneal Dialysis Solution in Hypertensive Patients: A Randomized Controlled Trial

Background Peritoneal dialysis (PD) solutions with reduced sodium content may have advantages for hypertensive patients; however, they have lower osmolarity and solvent drag, so the achieved Kt/V urea may be lower. Furthermore, the increased transperitoneal membrane sodium gradient can influence sodium balance with consequences for blood pressure (BP) control. Study Design Prospective, randomized, double-blind clinical trial to prove the noninferiority of total weekly Kt/V urea with low-sodium versus standard-sodium PD solution, with the lower confidence limit above the clinically accepted difference of −0.5. Setting & Participants Hypertensive patients (≥1 antihypertensive drug, including diuretics, or office systolic BP≥130mmHg) on continuous ambulatory PD therapy from 17 sites. Intervention 108 patients were randomly assigned (1:1) to 6-month treatments with either low-sodium (125mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 338-491mOsm/L) or standard-sodium (134mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 356-509mOsm/L) PD solution. Outcomes Primary end point: weekly total Kt/V urea ; secondary outcomes: BP control, safety, and tolerability. Measurements Total Kt/V urea was determined from 24-hour dialysate and urine collection; BP, by office measurement. Results Total Kt/V urea after 12 weeks was 2.53±0.89 in the low-sodium group (n=40) and 2.97±1.58 in the control group (n=42). The noninferiority of total Kt/V urea could not be confirmed. There was no difference for peritoneal Kt/V urea (1.70±0.38 with low sodium, 1.77±0.44 with standard sodium), but there was a difference in renal Kt/V urea (0.83±0.80 with low sodium, 1.20±1.54 with standard sodium). Mean daily sodium removal with dialysate at week 12 was 1.188g higher in the low-sodium group ( P Limitations Broader variability of study population than anticipated, particularly regarding residual kidney function. Conclusions The noninferiority of the low-sodium PD solution for total Kt/V urea could not be proved; however, it showed beneficial clinical effects on sodium removal and BP.