The effect of different dialysate sodium concentrations on ambulatory blood pressure in hemodialysis patients: a prospective interventional study

Abstract

Abstract Background Hypertension is associated with increased morbidity and mortality in hemodialysis patients. Existing recommendations suggest reduction of sodium load, but the effect of dialysate sodium on blood pressure (BP) is not fully elucidated. The aim of the present study is to investigate the effect of different dialysate sodium concentrations on 72-h ambulatory BP in hemodialysis patients. Methods This prospective study included patients on standard thrice-weekly hemodialysis. All patients initially underwent six sessions with dialysate sodium concentration of 137meq/L, followed consecutively by another six sessions with dialysate sodium of 139meq/L and, finally, six sessions with dialysate sodium of 141meq/L. At the start of the sixth hemodialysis session on each sodium concentration, 72-h ABPM was performed over the long interdialytic interval to evaluate ambulatory systolic and diastolic BP (SBP and DBP) during the overall 72-h, different 24-h, day-time and night-time periods. Results 25 patients were included in the final analysis. A significant increase in the mean 72-h SBP was observed with higher dialysate sodium concentrations (124.8 ± 16.6 mmHg with 137meq/L vs 126.3 ± 17.5 mmHg with 139meq/L vs 132.3 ± 19.31 mmHg with 141meq/L, P = 0.002). Similar differences were noted for DBP; 72-h DBP was significantly higher with increasing dialysate sodium concentrations (75.1 ± 11.3 mmHg with 137meq/L vs 76.3 ± 13.7 mmHg with 139meq/L vs 79.5 ± 13.9 mmHg with 141meq/L dialysate sodium, P = 0.01). Ambulatory BP during the different 24-h intervals, day-time and night-time periods was also progressively increasing with increasing dialysate sodium concentration. Conclusions This pilot study showed a progressive increase in ambulatory BP with higher dialysate sodium concentrations. These findings support that lower dialysate sodium concentration may help towards better BP control in hemodialysis patients.