Impact of Dialysate Sodium Concentration Lowering on Home Blood Pressure Variability in Hemodialysis Patients.

Abstract

Blood pressure variability is an independent risk factor for mortality and cardiovascular events in hemodialysis patients. Dialysate sodium concentration may not only have effects on blood pressure but also on blood pressure variability. We investigated whether dialysate sodium concentration lowering could decrease home blood pressure variability in hemodialysis patients. Forty-three hemodialysis patients at their dry weight assessed by bioimpedance methods with pre-dialysis serum sodium >136 mmol/L were recruited. Firstly, patients underwent a 1-month standard dialysis with dialysate sodium concentration of 138 mmol/L, and then the dialysate sodium concentration was decreased to 136 mmol/L for 8 weeks. Home blood pressure was assessed on waking up and at bedtime for 1 week. Coefficient of variation was used to define home blood pressure variability. After the intervention, whole-day systolic blood pressure variability decreased from 5.7 ± 2.6% to 4.3 ± 1.7% and evening systolic blood pressure variability decreased from 7.9 ± 4.1% to 6.2 ± 3.1%. Morning systolic blood pressure variability had a reduction from 7.8 ± 2.4% to 5.9 ± 3.3% but did not achieve statistical significance (P = 0.077). Whole-day, morning and evening systolic blood pressure were decreased significantly. Less changes were observed in diastolic blood pressure parameters. Interdialytic weight gain mildly but significantly decreased. Volume parameters, dietary sodium intake and incidence of adverse events were similar throughout the study period. Lowering dialysate sodium concentration could improve home blood pressure variability among hemodialysis patients who had achieved their dry weight.