The evaluation of relationship between blood pressure and dialysate Na concentration in chronic hemodialysis patients

INTRODUCTION Hypertension is one of the traditional risk factors of cardiovascular disease (CVD). Extra cellular volume expansion and Na retention remain the main cause of hypertension. OBJECTIVES The aim of this study was to investigate the relation between concentration of Na dialysate and blood pressure (BP) in chronic hemodialysis (HD) patient. PATIENTS AND METHODS This cross-sectional study was performed on 266 adult patients undergoing HD for at least three months. Pre-HD systolic BP (SBP) and post-HD SBP during 4 weeks were measured in relation to Na dialysate concentration. The other main factors affecting the post-dialysis BP, such as body mass index (BMI), pump speed, dialysis solution temperature, duration of dialysis and intradialysis weight gain (IDWG) were also considered. Mean of ΔSBP (post-HD SBP - pre-HD SBP) in each patient in 12 session of HD was measured and statistically analyzed in relation to dialysate Na with SPSS 21. Backward multivariable linear regression analysis and Pearson's correlation coefficients were used to evaluate the correlation between sodium gradient and ΔSBP. RESULTS SBP was significantly changed before and after dialysis in relation to dialysate Na (P<0.001). The Pearson's correlation between ΔSBP with dialysate sodium and blood flow rate (pump speed) were statistically significant(P<0.05). CONCLUSION We found that changes in SBP before and after dialysis is significantly associated with dialysate sodium concentration.