The Effects of Lowering Dialysate Sodium in Hypertensive Hemodialysis Patients

Overview

Unfavorably high sodium intakes remain prevalent around the world. A negative sodium gradient in hemodialysis treatment results in absolute sodium removal via diffusive transport of sodium from the blood to the dialysate, and it may be a potentially useful tool to improve sodium loading due to excess dietary sodium intake. The purpose of this study is to determine whether a in small negative sodium gradient could improve blood pressure level, arterial stiffness and left ventricular hypertrophy in hypertensive hemodialysis patients, who had been achieving and maintaining their dry weight assessed by bioimpedance spectroscopy.

A number of studies have shown that lowering dialysate sodium concentration could improve blood pressure (BP) control, and the lower BPs are considered to be a result of an improvement in volume status via increasing sodium removal. However, sodium, apart from volume, may have an independent effect on BP regulation. It is speculated that a reduction in exchangeable sodium, even without a change in body water content, may improve BP control. Unfortunately, as of yet, no clinical studies have actually provided the evidence in this field. In general population, dietary salt loading produces significant increase in aortic pulse wave velocity, which is reversed by lowering sodium intake. To the investigators knowledge, the effect of sodium on arterial stiffness has not been investigated in hemodialysis patients. A regression of left ventricular hypertrophy (LVH) has been achieved through strict dietary sodium restriction in hemodialysis patients. Lack of effect on LVH was observed in low sodium dialysis which may be due to the shorter time interval.