The effect of dietary salt restriction on hypertension in peritoneal dialysis patients

Abstract

Background/aim: To investigate the effect of dietary salt restriction on blood pressure levels, total sodium removal, and hydration status of peritoneal dialysis (PD) patients.Materials and methods: Thirty-one stable PD patients who consulted a renal dietitian monthly for dietary recommendations, including restricted salt intake <5 g/day, and education about hypertension and hypervolemia were included in this study. Baseline and third month clinical and laboratory findings, bioelectrical impedance analysis results, and urinary and peritoneal sodium removal values were recorded. Results:The mean age of the patients was 47.6 years and the mean time on PD was 39.6 months. The mean total sodium removal decreased slightly from 139.4 ± 69.1 to 136.2 ± 64.8 mmol/day (P > 0.05) for the whole sample, and from 164.3 ± 70.9 to 154.2 ± 72.3 mmol/day (P > 0.05) for the hypertensive subgroup (n: 17). Systolic blood pressure (from 134.3 ± 20.1 to 127.2 ± 19.5 mmHg, P: 0.01), diastolic blood pressure (from 83.2 ± 12.0 to 77.4 ± 10.5 mmHg, P: 0.01) and total body water (from 39.2 ± 10.9 to 38.3 ± 9.3 L, P: 0.04) decreased significantly. Conclusion:We demonstrated that even a little reduction in daily dietary sodium intake caused significant decreases in blood pressure levels and fluid overload.

Blood pressure and volume management in dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

“…However, small studies have shown that restricting salt intake can reduce IDWG in patients receiving HD, 167 and BP in patients receiving PD. 168 Although the serum sodium level that triggers thirst varies across individuals, 169 most patients maintain their pre-dialysis sodium levels within the normal range. This finding suggests that water intake is adjusted to match salt intake, underscoring the importance of emphasizing salt restriction, rather than the overly simplistic advice to just restrict fluid intake.…”

Estimated dietary sodium intake in peritoneal dialysis patients using food frequency questionnaires and total urinary and peritoneal sodium losses and assessment of extracellular volumes

“…For haemodialysis patients, restricting sodium intake and increasing sodium removal by the use of lower dialysate sodium concentrations leads to an improvement in blood pressure control [19][20][21]. Similarly, both dietary sodium restriction and lower sodium dialysates been reported to lower blood pressure in peritoneal dialysis patients in the short term [13,22].…”

“…Most haemodialysis patients are oligo-anuric and there are potential errors in collecting and estimating dialysate sodium losses [12], we chose to study peritoneal dialysis patients as 24-hour urine and dialysate effluent collections are collected as part of routine clinical practice in the management of peritoneal dialysis patients. A previous study in peritoneal dialysis patients reported that a reduction in dietary sodium resulted in a reduction in total body water and blood pressure in normotensive patients [13], we wished to evaluate the usefulness of FFQs in clinical practice. We used 2 FFQs developed for use in the UK; the "Derby Salt Questionnaire" (DSQ) and the "Royal Free Salt Questionnaire (RFSQ) to estimate dietary sodium intake and to determine whether there was any association between DSQ and RFSQ scores and blood pressure, and the amount of extracellular water in peritoneal dialysis patients [10,14].…”

Health beliefs of salt intake among patients undergoing haemodialysis

“…61.2% participants had blood pressure above 160/100 mmHg with 19.9% patients who also had cardiac disease. İnal et al () demonstrated that even a small reduction in daily dietary salt intake can cause a significant decrease in blood pressure levels and fluid overload in patients undergoing peritoneal dialysis (İnal et al ).…”