Abstract: OBJECTIVE: To assess the efficacy and safety of Sancai powder in patients with type 2 diabetes mellitus(T2DM) inadequately controlled with single oral metformin in a randomized controlled trial(RCT).METHODS: A total of 132 patients with T2 DM were enrolled in the study, who only took metformin(500-1000 mg/day) for at least three months and with inadequate glycemic control(7.0% ≤ hemoglobin A1 c ≤ 9.0%) in the past three months.The patients stopped taking metformin with lifestyle interventions for three weeks, and 105 patients qualified for the program. They were randomly divided into the Sancai powder group and the metformin group(1500 mg/day). The follow-up period was for 12 weeks. Comparisons of several variables were analyzed.RESULTS: No significant differences were found between the two groups in hemoglobin A1c(Hb A1c),fasting plasma glucose(FPG) and 2 h post-meal glucose(2h PG), although they had decreased significantly(P < 0.01). Homeostasis model assessment of beta cell function index was significantly improved in Sancai powder group(P < 0.01), and there were significant differences in the changes of homeostasis model assessment of insulin resistance and insulin sensitivity index in the two groups(P < 0.05). Sancai powder significantly reduced triglyceride level(P < 0.05), although there was no significant difference in the body weight and body mass index in the two groups.CONCLUSION: In this 12-week study, Sancai powder could significantly reduce hemoglobin A1 c,FPG and 2h PG levels, improved beta-cell function and insulin resistance of the T2 DM inadequately controlled with metformin.

Key words: Diabetes Mellitus, Type 2, Sancai powder, Metformin, Treatment outcome, Randomized controlled trial