Nephrology - Original Paper

International Urology and Nephrology

, Volume 45, Issue 5, pp 1365-1372

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

The dual blockade of the renin–angiotensin system in hemodialysis patients requires decreased dialysate sodium concentration

  • Rafał ZwiechAffiliated withDepartment of Kidney Transplantation, Dialysis Department, Norbert Barlicki Memorial Teaching Hospital No. 1, Medical University of Lodz Email author 
  • , Agnieszka Bruzda-ZwiechAffiliated withDepartment of Pediatric Dentistry, Medical University of Lodz



The study evaluated whether the dual blockade of the renin–angiotensin system may influence the sodium balance in hemodialysis.


The study involved 148 hemodialysis patients (male 85, female 63), mean age 59.6 ± 12.9 years. Participants were randomly selected to receive either angiotensin-converting enzyme inhibitor (ACEI)—subgroup A—or dual blockade ACEI and angiotensin receptor blocker (ARB)—subgroup AA.


At baseline, in the A versus AA subgroups, the pre-dialysis sodium concentrations (mmol/l) were 137.7 ± 0.5 versus 137.9 ± 0.8, the sodium gradients 2.6 ± 0.5 versus 2.9 ± 0.4, interdialytic weight gain (IWG) (kg) 3.1 ± 0.2 versus 3.0 ± 0.3, and thirst inventory score (points) 18.1 ± 1.0 versus 19.0 ± 1.7, respectively. After 3 months of therapy, a decrease in sodium concentration to 134.5 ± 0.5 and the increase of its gradient to 5.5 ± 0.5 were noted in the AA subgroup. An elevation of mean interdialytic weight gain to 3.47 ± 0.2 and thirst score to 21.3 ± 2.1 was observed. No significant changes in subgroup A were found. One month of the dialysate sodium concentration being lowered from 140 mmol/l to 138 mmol/l was associated with reduced serum sodium concentration and gradient, decreased IWG and restored moderate thirst score in the AA subgroup (137.5 ± 0.6 and 2.9 ± 0.6, 3.0 ± 0.5 and 19.2 ± 1.3, respectively).


The dual blockade of the renin–angiotensin system affects sodium balance, increasing the sodium gradient, thus elevating thirst sensation and enhancing interdialytic weight gain. In maintenance hemodialysis patients treated with both ACEI and ARB, lowered dialysate sodium levels should be prescribed.


Serum angiotensin-converting enzyme inhibitors Angiotensin receptor blockers Sodium concentration Sodium gradient Hemodialysis Interdialytic weight gain Thirst inventory