The effect of Sang-qi Granules on blood pressure and endothelial dysfunction in stageⅠ or Ⅱ hypertension: study protocol for a randomized double-blind double-simulation controlled trial

Background: Hypertension is an important worldwide public health challenge because of its high prevalence and concomitant risks of cardiovascular disease. It induces half of the coronary heart disease and approximately two-thirds of the cerebrovascular disease burdens. Vascular endothelial dysfunction plays important roles in the pathophysiology of essential hypertension. Sang-qi Granules (SQG), a Chinese herbal formula, is used to treat I or II hypertension by traditional Chinese medicine (TCM) practitioners. Several animal experimental studies have showed that SQG can lower blood pressure and myocardial fibrosis by suppressing inflammatory responses. However, there is no standard clinical trial to confirm this and whether SQG can improve endothelial cell function is unknown. Methods: In this randomized, double-blind, double-simulation controlled trial, 300 patients with stage I or Ⅱ hypertension were recruited and randomly allocated in a 1:1:1 ratio to group A(treatment with SQG and placebo of Cozaar), group B(treatment with Cozaar and placebo of SQG),and group C(treatment with SQG and Cozaar). Each group will receive SQG(or its placebo) and Cozaar(or its placebo). SQG(or its placebo) will be administrated twice a day at the doze of 10g each time, and 50mg Cozaar(or its placebo) will be administrated once in the morning. The primary outcome is the composite index of blood pressure and flow-mediated dilation(FMD). Efficacy rates were compared among the three groups. Effective standard need to satisfy the blood pressure effectively and FMD value decreased by 2%. The secondary outcomes include target organ damage assessment, symptom improvement assessment(Hypertension symptom scale, TCM syndrome integral scale, Pittsburgh sleep quality index scale, Self-Rating Anxiety Scale(SAS) and Self-rating depression scale(SDS), The Short Form-36 Health Survey(SF-36)), cardiovascular risk factors assessment, vascular endothelial function assessment. Discussion: This study will provide evidence for the effectiveness and safety of SQG and provide evidence to identify whether SQG improves endothelial cell function as compared with Cozaar in treating hypertensive patients. Trial registration: Chinese Clinical Trials Registry, ChiCTR1800016427. Registered on 1st June 2018. http://www.chictr.org.cn/edit.aspx?pid=27688&htm=4