Effect of dialysate sodium concentration and sodium gradient on patients with maintenance hemodialysis

Backgrounds: Patients with maintenance hemodialysis (MHD) have a high risk of cardiovascular disease, which is the leading cause of morbidity and mortality. The aim of the present study was to explore the relationship between the sodium gradient and the water load of MHD patients. Methods: Eighty one MHD patients were selected in the study. The serum sodium concentration, sodium gradient, interdialysis weight gain (IDWG), IDWG% of the patients and the incidence of hypotension were analyzed. Correlation analysis was carried out. Results: The serum sodium concentrations were 138.81 ± 3.27 mmol/L and 137.81 ± 2.88 mmol/L before and after dialysis, respectively. The sodium concentration of dialysis solution was 135 mmol/L. The absolute sodium gradient was 3.92 ± 2.69 mmol/L. The absolute sodium concentration difference after dialysis was 2.79 ± 2.14 mmol/L. IDWG was 2.06 ± 0.82 kg and the value of IDWG% was 3.71 ± 1.42%. The absolute sodium gradient was positively correlated with IDWG (r=0.349, P=0.001) and IDWG% (r=0.269, P=0.013). Dialysis with the lowest IDWG had the least effect on sodium load and water load in patients. Age was negatively correlated with the sodium concentration before dialysis (r=-0.349, P=0.014), the absolute sodium gradient (r=-0.321, P=0.031), IDWG (r=-0.483, P=0.001) and IDWG% (r=-0.452, P=0.002). Conclusion: The absolute sodium gradient was significantly correlated with IDWG, which contributes to improving water load in MHD patients.