Nitric Oxide Mediated Vasodilatory Response to Hawthorn Standardized Extract

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.

• Prehypertension
• Mild Hypertension

• Dietary Supplement: Hawthorn
  Hawthorn standardized extract liquid capsule
  Other Name: Gaia Hawthorn Supreme
• Dietary Supplement: Placebo capsule
  Matched placebo liquid capsule

• Placebo Comparator: Placebo
  Placebo capsule
  Intervention: Dietary Supplement: Placebo capsule
• Active Comparator: Low dose
  Intervention: Dietary Supplement: Hawthorn
• Active Comparator: Mid dose
  Intervention: Dietary Supplement: Hawthorn
• Active Comparator: High dose
  Intervention: Dietary Supplement: Hawthorn

Inclusion Criteria:

1. Recent ambulatory daytime systolic BP average between 120 - 155 mmHg or diastolic BP between 80-95 mmHg
2. Age 18 years and older.
3. Ability to speak English

Exclusion Criteria:

1. 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)
2. Current tobacco use.
3. Diagnosed with diabetes, known coronary artery disease, severe aortic stenosis, idiopathic hypertrophic subaortic stenosis (IHSS), or upper extremity vascular obstruction.
4. Pregnancy or breast feeding.
5. Using estrogen-containing birth control methods.
6. 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.
7. Unwillingness to forgo use of phosphodiesterase inhibitors (sildenafil - 36 hours, vardenafil - 36 hours, tadalafil - 96 hours) prior to study visits.
8. Unwillingness to refrain from vigorous exercise on the morning of study visits.
9. Women with childbearing potential who do not agree to practice effective birth control (condom, diaphragm, cervical cap, copper IUD, abstinence).