Gastrodia and Uncaria Recipe in Treating Stage-one Hypertension: an Evidence-based Optimization Study

Evidence-based Optimization of Gastrodia and Uncaria Recipe in Treating Stage-one Hypertension: a Multi-center, Randomized, Double-blind, Placebo Controlled Trial

Gastrodia and Uncaria Recipe is a well-known effective prescription in Traditional Chinese Medicine (TCM) to treat hypertension of liver yang hyperactivity type, which manifests symptom of headache or dizziness. However, it lacks consolidated evidence by multi-center randomized controlled trials. The hypothesis of this study is that Gastrodia and Uncaria granule may have significant anti-hypertensive effect on patients with stage-one hypertension and liver-yang hyperactivity syndrome than placebo.

This study is a randomized, controlled, multi-center, double-blind clinical trial. This study aims to recruit 500 hypertension patients who 1) are untreated or taking anti-hypertensive medicine for at least two weeks and 2) have an office systolic blood pressure of 140-159 mmHg, an office diastolic blood pressure of <100 mmHg, and a 24-hour ambulatory mean systolic blood pressure of >=130 mmHg. The patients will be stratified according to center, sex, and the TCM type of liver yang hyperactivity/ liver yang non-hyperactivity, and are then randomly assigned to the treatment of Gastrodia and Uncaria granules or placebo for 2 months. The blood pressure lowering effect is evaluated by 24-hour ambulatory systolic blood pressure (primary outcome) / diastolic blood pressure, as well as by home and office blood pressures.

Inclusion Criteria:

1. Male and female sex, aged 18-80 years.
2. Not taking anti-hypertensive drugs for at least two weeks, or taking anti-hypertensive drugs for more than two weeks.
3. Office blood pressure averages of three consecutive readings per visit, at two screening visits all meet the limits: systolic blood pressure ranges from 140 to 159 mmHg, and diastolic blood pressure <100 mmHg.
4. 24h ambulatory mean systolic blood pressure >= 130mmHg.
5. Agreed to participant, able to join follow-up and to come to hospital at each visit.
6. Signed informed consent.

Exclusion Criteria:

1. Secondary hypertension, confirmed or suspected.
2. Failed at ambulatory blood pressure monitoring: effective reading < 70%, or the number of awakening BP reading <20, or sleep time BP reading <7.
3. Taking drugs that must be used for other diseases but have a potential effect on blood pressure, such as males taking alpha blockers for prostatic hypertrophy.
4. Having the onset of cardiovascular and cerebrovascular diseases such as stroke, myocardial infarction or heart failure within 6 months.
5. Having a history of atrial fibrillation or frequent arrhythmia.
6. Having abnormal lab test results: liver function (ALT, AST, TBL) ≥ 2 times the upper normal limit, or serum creatinine ≥ 176umol/L, or serum potassium ≥ 5.5mmol/L.
7. Pregnant or breastfeeding (for females).
8. Complicating other diseases that are not suitable for the trial, such as thyroid disease with active medication, acute infectious diseases, chronic mental illness, and tumors.
9. Possible poor compliance with the research process.