Nitric Oxide Mediated Vasodilatory Response to Hawthorn Standardized Extract

Study Overview
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Brief Summary
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Prehypertension and mild hypertension affect an estimated 157 million U.S. adults. Cardiovascular disease (CVD) risk and associated mortality is elevated in this population. Treatment options are limited consisting of lifestyle modification, which is often ineffective, or drug therapy, which carries risk of side effects. Highly safe, efficacious, and acceptable treatment options for this population are needed. Hawthorn standardized extract (HSE) is approved for use in Europe to treat heart failure, and preliminary evidence suggests it may have a blood pressure lowering effect. However, prior trials of hawthorn have based dosage recommendations on animal studies. Therefore, the investigators propose a dose-finding study to measure the pharmacodynamic effect of three doses of standardized hawthorn extract and placebo.

Official Title
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Nitric Oxide Mediated Vasodilatory Response to Hawthorn Standardized Extract

Conditions
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Prehypertension, Mild Hypertension

Intervention / Treatment
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* Dietary Supplement: Hawthorn
* Dietary Supplement: Placebo capsule


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Recent ambulatory daytime systolic BP average between 120 - 155 mmHg or diastolic BP between 80-95 mmHg Age 18 years and older. Ability to speak English Exclusion Criteria: Any antihypertensive medication use (ACE inhibitors, ARB, beta-blockers, calcium channel blockers, diuretics, alpha agonists or antagonists, nitrates, direct vasodilators such as hydralazine, aldosterone antagonists, direct renin inhibitors, endothelin antagonists) Current tobacco use. Diagnosed with diabetes, known coronary artery disease, severe aortic stenosis, idiopathic hypertrophic subaortic stenosis (IHSS), or upper extremity vascular obstruction. Pregnancy or breast feeding. Using estrogen-containing birth control methods. Unwillingness to forgo vitamins C and E, fish oil, niacin, arginine, OTC decongestants, and NSAIDs such as advil, motrin, and nuprin during the study period. Unwillingness to forgo use of phosphodiesterase inhibitors (sildenafil - 36 hours, vardenafil - 36 hours, tadalafil - 96 hours) prior to study visits. Unwillingness to refrain from vigorous exercise on the morning of study visits. Women with childbearing potential who do not agree to practice effective birth control (condom, diaphragm, cervical cap, copper IUD, abstinence).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Placebo capsule | Dietary Supplement: Placebo capsule<br>* Matched placebo liquid capsule<br>|
| Active Comparator: Low dose<br> | Dietary Supplement: Hawthorn<br>* Hawthorn standardized extract liquid capsule<br>* Other names: Gaia Hawthorn Supreme;|
| Active Comparator: Mid dose<br> | Dietary Supplement: Hawthorn<br>* Hawthorn standardized extract liquid capsule<br>* Other names: Gaia Hawthorn Supreme;|
| Active Comparator: High dose<br> | Dietary Supplement: Hawthorn<br>* Hawthorn standardized extract liquid capsule<br>* Other names: Gaia Hawthorn Supreme;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FMD Max | Brachial artery flow mediated dilation max (%) | 7d | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BP | Blood pressure | 7d | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Prehypertension, Mild hypertension, Flow mediated dilation, Hawthorn