Effect of Sodium Thiosulfate on Arterial Stiffness in End-Stage Renal Disease Patients Undergoing Chronic Hemodialysis (Sodium Thiosulfate-Hemodialysis Study): A Randomized Controlled Trial

<b><i>Background:</i></b> Arterial stiffness (AS) and vascular calcification are significantly related to a high cardiovascular mortality risk in hemodialysis (HD) patients. Intravenous sodium thiosulfate (IV STS) can prevent and delay the vascular calcification progression in uremic states; however, the STS effect on AS has not been assessed. This study aimed to evaluate the STS efficacy on vascular calcification and AS in HD patients. <b><i>Methods:</i></b> Fifty HD patients with abnormal AS, as measured via the cardio-ankle vascular index (CAVI ≥8), were prospectively randomized to open-label 12.5 g IV STS during the last HD hour twice weekly for 6 months (<i>n</i> = 24) or the usual care (control group; <i>n</i> = 26). Patients and treating physicians were not blinded. The CAVI, coronary artery calcification (CAC) score, hemodynamics, and biochemical parameters were measured at the baseline and at 3 and 6 months. <b><i>Results:</i></b> All the baseline parameters were comparable. The IV STS significantly reduced the CAVI when compared to the control group (mean CAVI difference = –0.53; 95% CI –1.00 to –0.06; <i>p</i> = 0.03). A significant CAVI improvement was seen in those patients without diabetes mellitus. The natural logarithm of the CAC volume score was significantly increased in the control group. The high sensitivity C-reactive protein level was slightly lowered in the IV STS group (not significant). <b><i>Conclusion:</i></b> The intradialytic STS treatment significantly reduced the AS, as measured by the CAVI, and stabilized the vascular calcification in the HD patients. STS may be a novel therapeutic strategy for delaying and treating the structural and functional vascular wall abnormalities in HD patients.