Oral Chinese patent medicines for diabetic kidney disease: An overview of systematic reviews

Diabetic kidney disease (DKD) has become a global public health problem with a significant disease burden. A number of Chinese patent medicines (CPMs) are widely used in the treatment of DKD in China. An overview of systematic reviews (SRs) can summarize the overall evidence of its effectiveness and safety for both practice and research. SRs and/or meta-analyses based on randomized controlled trials (RCTs) of oral CPMs for DKD were identified. Eight databases were searched from their inception to October 2021. The AMSTAR 2 tool was applied to appraise the methodological quality of the included SRs by two authors. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to summarize the certainty of evidence of the included reviews. A total of 88 SRs were included, of which three were published as abstracts only. The methodological quality using the AMSTAR 2 approach was assessed as "low" for five SRs and "critically low" for 80 SRs. Renal end-point events and quality of life were not reported in all SRs. Most of the reviews reported surrogate outcomes. Serum creatinine and 24-hour urinary total protein were the two most commonly reported indicators, and regrettably, no high-quality evidence with GRADE assessment was found. Regarding safety, except for Tripterygium glycosides tablet, other CPMs had mild adverse effects. Due to the lack of end-point outcomes and high-quality evidence, the effectiveness and safety of oral CPMs for DKD remain uncertain. Future studies with more critical methodological designs are needed to provide robust evidence. A core outcome set for adults with DKD could help improve the consistency and relevance of outcomes from clinical trials.