Effects of increasing diffusive sodium removal on blood pressure control in hemodialysis patients with optimal dry...

Sodium, apart from volume, may have an independent effect on blood pressure (BP) regulation.

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.

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.

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.