Effects of intravenous sodium thiosulfate on vascular calcification in dialysis patients with end-stage renal disease: a systematic review and meta-analysis

Background: In dialysis patients, vascular calcification is a common complication and is closely related to the morbid-ity and mortality of cardiovascular disease. We performed a systematic review to determine the efficacy and safety of sodium thiosulfate (STS) in the progression of vascular calci-fication in dialysis patients with end-stage renal disease.Methods: The PubMed, Web of Science, Embase, Cochrane Library, Wanfang, CNKI, China Biology Medicine disc and Weipu databases were searched up to 9 March 2022 for clini-cal trials to synthesise findings on the efficacy and safety of STS in the progression of vascular calcification in dialysis patients. The primary outcome was coronary artery calcifica-tion scores (CACS) or abdominal aortic calcification scores (AACS) or Kauppila index. The secondary outcome was pulse-wave velocity (PWV). Laboratory data were shown in safety data. A random-effect model was used to provide the summary measures of effect [standardised mean difference (SMD) and 95% confidence interval (CI)].Results: Seven randomised, controlled trials and one non-randomised, controlled trial involving 370 patients were included. Six studies reported that the progression of CACS or AACS was slower in the intravenous STS group compared with the control group (SMD -3.24, 95% CI: -5.29, -1.18, p = 0.002). Two studies showed the increase in PWV was less in the STS group compared with the control group (SMD -0.52, 95% CI: -0.92, -0.13, p = 0.009). During the trial period, a lower high-sensitivity C-reactive protein level (SMD 1.61, 95% CI: 0.19, 3.04, p = 0.03), a decrease in serum bicarbonate level (SMD 0.67, 95% CI: 0.22, 1.11, p = 0.003) and an increase in serum phosphate level (SMD -0.32, 95% CI: -0.62, -0.03, p = 0.03) were noted in the intravenous STS group compared with the control group. However, serum calcium and parathyroid hormone levels showed no difference between the two groups after the trials. The most common adverse events were temporary nausea and vomiting, which occurred in 12.5 to 75% of patients. Conclusions: Intravenous STS may slow down the progression of vascular calcification and ameliorate arterial stiffness in dialysis patients. Reliably defining the efficacy and safety of intravenous STS in attenuating the progression of vascular calcification requires a high-quality trial with a large sample size.