Background: Lower extremity artery disease (LEAD) is greatly harmful to Type 2 Diabetes Mellitus patients. Traditional Chinese Medicine (TCM) is an alternative therapy to delay the development of macrovascular diseases, but the existing evidence of its efficacy, safety and mechanism of action is insufficient. We report a study protocol of a multi-center, randomized, double-blind, placebo-controlled trial that aims to use well-designed clinical trial to evaluate the efficacy and safety of Chinese herbal medicine (CHM) Shen-Qi Hua-Yu formula, and to explore efficacy mechanism of the TCM granules and the biomarkers of TCM syndrome.
Methods: This is a multi-center, double-blind, randomized, and placebo-controlled study that randomized 120 participants into 2 groups. The treatment group will receive TCM granules and conventional medicine, while the control group will receive placebo in addition to conventional medicine. Two groups will receive 12-week treatment and 48-week follow-up, with a total of 13 visits. Primary efficacy outcomes included ankle brachial index. Secondary efficacy outcomes included fasting plasma glucose, blood lipid, hemorheology indexes, advanced glycation end products, the inner diameter, peak systolic velocity, end diastolic velocity and mean average velocity of the anterior tibial artery, posterior tibial artery and dorsalis pedis artery, and TCM syndrome score. The safety and endpoint outcomes will be evaluated in this trial. The study will explain the biological therapeutic mechanism of Shen-Qi Hua-Yu formula for diabetic LEAD, and try to use Isobaric tags for Relative and Absolute Quantitation (iTRAQ) and Western blot to screen biomarkers of characteristic diagnosis and clinical efficiency evaluation of the TCM syndrome.
Discussion: This study is a multi-center, randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of CHM in patients with diabetic LEAD, and to interpret the therapeutic mechanism of Shen-Qi Hua-Yu formula in treatment of diabetic LEAD through proteomics technology, and to screen biomarkers with characteristics of TCM diagnosis and clinical efficacy evaluation. On the other hand, to our knowledge, this study may be the first trial of CHM formulas to observe cardiovascular outcomes through long-term follow-up for the treatment of diabetic LEAD, which is of great value.
Trial registration: This study is registered on the Chinese Clinical Trial Registry: ChiCTR1900026372.