Sodium Intake Targets in Peritoneal Dialysis Patients: A Real-Life Challenge

Abstract

Introduction: Optimal fluid balance in peritoneal dialysis requires adequate urinary and peritoneal water and sodium removal and restriction of dietary sodium intake (<2 g/day). We aim to study the relationship between sodium intake, blood pressure control and medication burden in peritoneal dialysis patients. Methods: Observational, cross-sectional study of chronic peritoneal dialysis patients followed in our hospital in March 2022. We estimated patient’s sodium intake according to the equations proposed by Kim et al. Mean ambulatory blood pressure was categorized in controlled, stage one, stage two and stage three hypertension. A qualitative evaluation of sodium intake was done by asking patients about their compliance with a low-salt diet. Results: Eighty-two patients: mostly men, with a mean age of 54.1±14.7 years and dialysis vintage of 26.2±18.7 months. Most patients were on continuous ambulatory peritoneal dialysis (63.4%) and the mean weekly Kt/V was 2.2±0.4. A percentage of 85.4% of our patients had residual diuresis, averaged at 1257±867 mL/day. Mean dietary sodium intake was 3.5±1.1 g; it was higher in men and patients with uncontrolled hypertension, regardless of age, dialysis vintage and other comorbidities. We found a strong correlation between dietary sodium intake and residual diuresis, systolic blood pressure, diastolic blood pressure and the number of anti-hypertensive drugs. Patients with a sodium intake ≥ 3.3 g had higher risk of uncontrolled BP and higher medication burden. Qualitative evaluation of this sub-population revealed that only 2.3% (n=1) admitted non-compliance with a low-sodium diet. Conclusion: We found a strong correlation between estimated dietary sodium consumption, blood pressure control and medication burden. Most importantly, there was a striking difference between patient’s perception of sodium consumption and the actual results. Our results highlight the importance of dietary salt restriction in blood pressure control and reinforce the need for a dietary consultation in peritoneal dialysis patients.

Keywords

• peritoneal dialysis
• sodium
• dietary