Effectiveness and safety of Daixie Decoction granules combined with metformin for the treatment of T2DM patients with obesity: study protocol for a randomized, double-blinded, placebo-controlled, multicentre clinical trial

Background Type 2 diabetes mellitus (T2DM) with obesity is a glycolipid metabolism disorder, which makes hypoglycaemic treatment more complex and increases the proportion of multidrug combinations. In addition, patients are more prone to adverse reactions and gradually lose compliance with treatment. Previous clinical trials have demonstrated that Daixie Decoction granules (DDG) can reduce body weight and blood lipids and improve the quality of life of T2DM with obesity. But there are a lack of further evaluations for the efficacy and safety of DDG combined with metformin. Methods/design The study is designed as a multicentre, randomized, double-blind, placebo-controlled clinical trial. Participants who meet the Nathrow criteria will be randomly assigned to the intervention group and control group ( n 1 = n 2 = 133). Based on a unified diet control and exercise therapy, the intervention group will be treated with DDG and metformin, and the control group will be treated with DDG placebo and metformin. All subjects will receive a 6-month treatment followed by a 6-month follow-up. Effective rate of a 1% decrease in HbA1c and 3% decrease in body weight will serve as the primary outcome. The secondary outcome include fasting plasma glucose, blood lipids, C-peptides, insulin, inflammatory factors, insulin resistance index (HOMA-IR) and the subcutaneous and visceral fat content in the upper abdomen measured by MRI. Blood routine, urine routine, stool routine, liver and kidney function, EKG and other safety indicators and major adverse reactions were monitored during total treatment and follow-up time. Discussion We aimed to determine the efficacy and safety of DDG combined with metformin for the treatment of T2DM patients with obesity. Trial registration Trial registration: ChiCTR, ChiCTR2000036290. Registered 22 August 2014, http://www.chictr.org.cn/showprojen.aspx? proj=59001