Fermented Ophiocordyceps sinensis mycelium products for preventing contrast-associated acute kidney injury: a systematic review of randomized controlled trials

Background: To evaluate the efficacy, effectiveness and safety of fermented Ophiocordyceps sinensis mycelium (FOSM) products for preventing contrast-associated acute kidney injury (CA-AKI).Methods: Randomized controlled trials were searched from four Chinese and four English electronic databases and three clinical trial registries up to July 2023. Methodological quality was assessed by using the Cochrane risk-of-bias tool 2.0. Risk difference (RD) or risk ratio (RR) and mean difference (MD) were calculated along with the 95% confidence intervals (CIs).Results: Fourteen trials testing three types of FOSM products (Bailing, Zhiling, and Jinshuibao capsules) involving 1271 participants injected contrast agents were included. For the risk of bias, all trials were rated as some concerns. Compared with routine preventive procedure (RPP) (saline hydration and alprostadil), FOSM products plus RPP showed beneficial effects in reducing the incidence of CA-AKI (14.62% and 5.35%, respectively; RD -0.06, 95% CI -0.09 to -0.03). Subgroup analysis showed that Bailing/Jinshuibao plus RPP demonstrated lower incidence of CA-AKI compared to RPP. However, there was no statistically significant difference between Zhiling with RPP and RPP in the incidence of CA-AKI. Additionally, only when FOSM products were taken before injection of the contrast, it was superior to RPP in reducing the incidence of CA-AKI. There was no statistical difference in adverse events between these two groups.Conclusions: Low certainty evidence suggests that preventive oral use of FOSM products as an adjuvant agent was safe and might decrease the incidence of CA-AKI. However, high-quality placebo-controlled trials are needed to confirm its benefit.