Salt intake and hypervolemia in the development of hypertension in peritoneal dialysis patients

Peritoneal dialysis (PD) patients are often volume-expanded and have higher-than-normal blood pressure (BP) levels. In the present study, we aimed to investigate the role of fluid balance and salt intake for BP control in our PD patients. The study included 37 patients undergoing PD and having complete data for 3 consecutive months. Patients were allocated to one of two groups based on measured BP in the preceding 3 months: hypertensive patients (BP > 140/90 mmHg) and normotensive patients (did not meet the hypertensive BP criteria). Volume status was evaluated by bioimpedance analysis. The 37 patients (18 women, 19 men) had a mean age of 46.4 years. The hypertensive and normotensive groups included 17 and 20 patients respectively. Sex, age, and time on PD were similar between the groups. Weight (77.3 +/- 20.3 kg vs. 64.5 +/- 9.8 kg, p < 0.05), total sodium load (2649.2 +/- 621.9 mmol vs. 2272.4 +/- 511.9 mmol, p < 0.05), daily total sodium removal (160.5 +/- 74.4 mmol vs. 112.1 +/- 48.0 mmol, p < 0.05), extracellular water (19.4 +/- 4.3 L vs. 16.4 +/- 3.5 L, p < 0.05), and normalized extracellular water (11.6 +/- 1.9 L vs. 10.1 +/- 1.8 L, p < 0.05) were all significantly higher in the hypertensive group. Despite higher fluid and sodium removal, hypertensive patients were more hypervolemic than normotensive patients. Increasing fluid and salt removal by peritoneal ultrafiltration results in an increased financial burden and also causes serious clinical problems. Restricting fluid and salt intake is an alternative and safer strategy to maintain good fluid balance.