Backgroud: Zi Cui Yin decoction created by Xichun Zhang in the Qing dynasty has been used on diabetes mellitus and complications for more than two centuries in China. Huangkui capsule (HKC) is a listed Chinese patent medicine to treat diabetic kidney disease. To determine whether Zi Cui Yin is non-inferior to HKC in the treatment of diabetic kidney disease, a multicenter, parallel-control, open-label, randomized clinical trial was conducted.
Methods: In this clinical trial, 88 diabetic kidney disease patients were recruited at three centers in Tianjin from January 2018 to December 2019. They were randomized to receive HKC (2.5 g, TID) or Zi Cui Yin (crude drug amount 75 g, 150 ml, BID) for eight weeks based on routine treatment. The primary outcome was the change of estimated glomerular filtration rate (eGFR). The secondary outcomes included change of serum creatinine (SCr), urinary albumin excretion rate, 24 h urinary protein, urinary albumin-creatinine ratio, glycosylated hemoglobin A1c, symptom scores, and microbiota compositions profiles.
Results: The change of eGFR in HKC and ZCY groups were -7.08 ± 24.65 and 2.57 ± 18.49 ml/min/1.73 m2, respectively (p < 0.05). The 95% lower confidence limit for the difference between the estimated means was 1.93 ml/min/1.73 m2, establishing the superiority of Zi Cui Yin. Compared to HKC, Zi Cui Yin could significantly decrease SCr and symptom scores (p < 0.05). There were no significant differences in other outcomes between the two groups (p > 0.05). Zi Cui Yin ameliorated gut microbiota dysbiosis, including increased Prevotellaceae and Lactobacillaceae and decreased Enterobacteriales, Clostridiaceae and Micrococcaceae. No severe adverse events were reported in any group.
Conclusions: Zi Cui Yin had better efficacy in improving and protecting kidney function. It would be an alternative option to treat diabetic kidney disease, especially those who decline eGFR and gut microbiota dysbiosis.