In this study the investigators aim to test the effect of lowering dialysate sodium concentration on visit-to-visit blood pressure variability in hemodialysis patients who have achieved their dry weight.

Cardiovascular diseases are considered the major cause of mortality in maintenance hemodialysis patients. Nevertheless, hypertension is recognized as an important modifiable risk factor for cardiovascular disease among hemodialysis (HD) patients.

Apart from blood pressure levels, BP variability, which reflects the fluctuation in BP, has been described as an independent risk factor that linearly associated with all-cause and cardiovascular mortality in HD patients.

BPV is categorized as either long or short term, based on the time interval over which it is considered. In the dialysis population, long-term BPV is typically defined on the basis of BP measurements taken at the start of each thrice-weekly hemodialysis treatment (interdialytic BPV). On the other hand, short-term BPV among dialysis patients can be considered in terms of variability that occurs during hemodialysis treatments (intradialytic BPV). Researchers believed that the mitigation strategies of BPV must be paid attention to.

Sodium load is associated with thirst, fluid retention, interdialysis weight gain and hypertension for hemodialysis patients, therefore the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline highlighted the importance of limiting sodium intake and adequate sodium removal which is considered one of the most important goals of the dialysis therapy.

Interestingly, a recent study showed that mild decrease in dialysate sodium concentration could improve systolic blood pressure variability in HD patients at their dry weight, thus improving blood pressure complications and subsequent complications. However, whether improving sodium balance could potentially contribute to better BPV management in HD patients has not been assessed in a randomized manner. Therefore, this study aims to investigate whether lowering dialysate sodium concentration could help mitigate long term (interdialytic) BPV in hemodialysis patients in a randomized controlled manner.

Inclusion Criteria:

• Patients' age ≥18 years
• Patients who had been on regular hemodialysis for at least 3 months.
• Patients' residual daily urine output is less than 100 mL/day.
• Pre study one week average systolic BP ≥120 mmHg but ≤ 180 mmHg.
• Patients who have achieved their dry weight as assessed by clinical examination.
• Predialytic serum sodium level ≥ 140mmol/l.
• Kt/V ≥ 1.2

Exclusion Criteria:

• Patients who have advanced heart failure or permanent atrial fibrillation decompensated liver disease, neoplastic illness, overt edema.
• History of acute cardiovascular accidents or infections during 3 months preceding entry into the study.
• Patients prone to hypotension or other intradialytic adverse events.
• Patients participating in another interventional study that may affect blood pressure.