Randomized Crossover Trial of Low Sodium Dialysate on Tissue Sodium Accumulation in Hemodialysis

Patients on maintenance hemodialysis (MHD) have higher tissue sodium accumulation in skin and muscle. In this randomized, crossover clinical trial, we assessed the safety and efficacy of low sodium dialysate on skin and muscle sodium accumulation, and systemic markers of inflammation.

Patients on MHD were assigned to initial treatment with either 4-weeks of low sodium dialysate (132 mEq/l) or high sodium dialysate (138 mEq/l). Tissue sodium was assessed with ²³Na magnetic resonance imaging at the end of each treatment.

Of 28 randomized participants, 23 completed both treatments. The least-squares mean treatment difference in tissue sodium from high-sodium to low-sodium dialysate were -0.8 for muscle sodium and -1.5 for skin sodium and did not reach statistical significance (P = 0.27 and 0.09, respectively). In models adjusted for baseline tissue sodium and ultrafiltration rate, low dialysate treatment was associated with decrease in skin sodium but not muscle sodium. Higher ultrafiltration rate was significantly associated with decrease in both skin and muscle sodium. No significant change was seen in high-sensitivity C-reactive protein (hs-CRP) and prealbumin between treatments. There was no serious study-related adverse event (AE) during either treatment.

Our study suggests that both low-sodium dialysate and ultrafiltration rate may modify tissue sodium. Future larger studies are needed to evaluate the effects of low-sodium dialysate and high ultrafiltration rate, individually and combined on tissue sodium accumulation and clinical outcomes.