Impact of Low Sodium Concentration in Dialysis Fluid on Hemodynamic Parameters in Chronic Hemodialysis Patients

Background: Chronic kidney disease (CKD) is defined as kidney damage or reduced kidney function for three months or more, regardless of the cause. Hemodialysis (HD) has become the dominant renal replacement therapy in many parts of the world. Currently, due to the absence of definitive evidence on safety and efficacy, there is no consensus on the optimal sodium concentration in dialysis. Objectives: Considering the importance of sodium regulation in HD patients, we conducted a study on the impact of low sodium levels in dialysis fluid on the hemodynamics of chronic HD patients. Methods: In this double-blind randomized controlled clinical trial, 84 adult patients undergoing chronic HD at the dialysis centers of Golestan and Imam Khomeini Hospitals in Ahvaz, Iran, in 2023 were enrolled. One group of patients was treated with HD using a sodium concentration of 140 mmol/L, and another group was treated with a sodium concentration of 135 mmol/L. Patients underwent HD sessions three times a week for 3 to 4 hours. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and weight before and after dialysis were compared between the 135 and 140 mmol/L groups. Results: The mean age of the patients was 53.99 ± 14.61 years, and the duration of dialysis was 7.95 ± 3.45 years. Systolic blood pressure after dialysis was 122.73 ± 7.01 mm Hg and 122.90 ± 6.97 mm Hg for the 135 and 140 mmol/L groups, respectively, with no significant difference between the two groups (P = 0.91). Diastolic blood pressure after dialysis was 74.94 ± 3.74 mm Hg and 75.51 ± 2.78 mm Hg for the 135 and 140 mmol/L groups, respectively, with no significant difference (P = 0.42). The weight after dialysis was 63.99 ± 14.16 kg and 69.91 ± 14.69 kg for the 135 and 140 mmol/L groups, respectively, with no significant difference observed (P = 0.06). The mean ultrafiltration (UF) rate was 1.87 ± 0.44 and 1.99 ± 0.40 for the 135 and 140 mmol/L groups, respectively (P = 0.20). Conclusions: Reducing the sodium concentration in dialysis fluid had no significant effect on weight control and blood pressure. Further studies with larger sample sizes are suggested to determine the effect of low sodium levels in dialysis fluid on the hemodynamics of patients undergoing chronic HD.