Single-dwell treatment with a low-sodium solution in hypertensive peritoneal dialysis patients

Background: Patients on peritoneal dialysis (PD) may suffer from sodium (Na) and fluid overload, hypertension and increased cardiovascular risk. Low-Na dialysis solution, by increasing the diffusive removal of Na, might improve blood pressure (BP) management. Methods: A glucose-compensated, low-Na PD solution (112 mmol/L Na and 2% glucose) was compared to a standard-Na solution (133 mmol/L Na and 1.5% glucose) in a prospective, randomised, single-blind study in hypertensive patients on PD. One daily exchange of the standard dialysis regimen was substituted by either of the study solutions for 6 months. The primary outcome (response) was defined as either a decrease of 24-h systolic BP (SBP) by ≥6 mmHg or a fall in BP requiring a medical intervention (e.g. a reduction of antihypertensive medication) at 8 weeks. Results: One hundred twenty-three patients were assessed for efficacy. Response criteria were achieved in 34.5% and 29.1% of patients using low- and standard-Na solutions, respectively ( p = 0.51). Small reductions in 24 h, office, and self-measured BP were observed, more marked with low-Na than with standard-Na solution, but only the between-group difference for self-measured SBP and diastolic BP was significant ( p = 0.002 and p = 0.003). Total body water decreased in the low-Na group and increased in the control group, but between-group differences were not significant. Hypotension and dizziness occurred in 27.0% and in 11.1% of patients in the low-Na group and in 16.9% and 4.6% in the control group, respectively. Conclusions: Superiority of low-Na PD solution over standard-Na solution for control of BP could not be shown. The once daily use of a low-Na PD solution was associated with more hypotensive episodes, suggesting the need to reassess the overall concept of how Na-reduced solutions might be incorporated within the treatment schedule.