Effects of Increasing Diffusive Sodium Removal on Blood Pressure Control in Hemodialysis Patients with Optimal Dry Weight

Abstract

BACKGROUND: Sodium, apart from volume, may have an independent effect on blood pressure (BP) regulation. METHODS: Sixteen hypertensive hemodialysis patients were enrolled, who have achieved their dry weight assessed by bioimpedance methods, with pre-dialysis plasma sodium levels slightly higher than the facility dialysate sodium concentration 138 mmol/l. After a 1-month period of dialysis with standard dialysate sodium concentration of 138 mmol/l, the patients were followed up for a 4-month period with dialysate sodium set at 136 mmol/l. RESULTS: Along with lowering dialysate sodium, there were significant decreases (-10 mm Hg and -6 mm Hg) in 44-hour ambulatory systolic and diastolic BP at 4 months. Interdialytic weight gain adjusted to the estimated dry weight mildly but significantly decreased (4.81 ± 1.51 vs. 4.36 ± 1.37%, p = 0.047). The post-dialysis volume parameters remained constant throughout the study period. CONCLUSION: In selected hypertensive hemodialysis patients with optimal dry weight, increasing diffusive sodium removal resulted in significant BP decrease. It was probably due to a volume-independent effect.