Effect of Low Versus High Dialysate Sodium Concentration on Blood Pressure and Endothelial-Derived Vasoregulators During Hemodialysis: A Randomized Crossover Study

• DOI: 10.1053/j.ajkd.2014.10.021
• Publication Date: 2014-12-17T04:46:40Z
• Authors: Jula K. Inrig; Christopher Molina; Kristin D’Silva; Catherine Kim; Peter Van Buren; Jason D. Allen; Robert Toto
• Keywords: Male; hypertension; 610; Blood Pressure; 03 medical and health sciences; 0302 clinical medicine; Renal Dialysis; Dialysis Solutions; intradialytic hypertension; Humans; Single-Blind Method; Prospective Studies; Nitrites; Exercise and Active Living (ISEAL); Aged; Cross-Over Studies; Endothelin-1; Sodium; blood pressure; Middle Aged; Institute of Sport; 3. Good health; Treatment Outcome; mechanisms and treatment; Hypertension; Female; 1106 Human Movement and Sports Science; Endothelium, Vascular; endothelin; PB

Intradialytic hypertension affects ∼15% of hemodialysis patients and is associated with increased morbidity and mortality. While intradialytic hypertension is associated with increases in endothelin 1 relative to nitric oxide (NO), the cause of these imbalances is unknown. In vitro evidence suggests that altering plasma sodium levels could affect endothelial-derived vasoregulators and blood pressure (BP). Thus, we hypothesized that compared to high dialysate sodium, low dialysate sodium concentration would lower endothelin 1 levels, increase NO release, and reduce BP.3-week, 2-arm, randomized, crossover study.16 patients with intradialytic hypertension.Low (5 mEq/L below serum sodium) versus high (5 mEq/L above serum sodium) dialysate sodium concentration.Endothelin 1, nitrite (NO2(-)), and BP.Mixed linear regression was used to compare the effect of dialysate sodium (low vs high) and randomization arm (low-then-high vs high-then-low) on intradialytic changes in endothelin 1, NO2(-), and BP values.The average systolic BP throughout all hemodialysis treatments in a given week was lower with low dialysate sodium concentrations compared with treatments with high dialysate sodium concentrations (parameter estimate, -9.9 [95% CI, -13.3 to -6.4] mm Hg; P < 0.001). The average change in systolic BP during hemodialysis also was significantly lower with low vs high dialysate sodium concentrations (parameter estimate, -6.1 [95% CI, -9.0 to -3.2] mm Hg; P < 0.001). There were no significant differences in intradialytic levels of endothelin 1 or NO2(-) with low vs high dialysate sodium concentrations.Carryover effects limited the power to detect significant changes in endothelial-derived vasoregulators, and future studies will require parallel trial designs.Low dialysate sodium concentrations significantly decreased systolic BP and ameliorated intradialytic hypertension. Longer studies are needed to determine the long-term effects of low dialysate sodium concentrations on BP and clinical outcomes.