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.

Study Overview

• Status: Completed
• Conditions: Prehypertension; Mild Hypertension
• Intervention / Treatment: Dietary supplement: Placebo capsule; Dietary supplement: Hawthorn

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • UNC Department of Family Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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).

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: High dose	Dietary supplement: Hawthorn; Hawthorn standardized extract liquid capsule; Other Names: Gaia Hawthorn Supreme
Active Comparator: Low dose	Dietary supplement: Hawthorn; Hawthorn standardized extract liquid capsule; Other Names: Gaia Hawthorn Supreme
Placebo Comparator: Placebo; Placebo capsule	Dietary supplement: Placebo capsule; Matched placebo liquid capsule
Active Comparator: Mid dose	Dietary supplement: Hawthorn; Hawthorn standardized extract liquid capsule; Other Names: Gaia Hawthorn Supreme

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: University of North Carolina, Chapel Hill

Publications and helpful links

General Publications

• Asher GN, Viera AJ, Weaver MA, Dominik R, Caughey M, Hinderliter AL. Effect of hawthorn standardized extract on flow mediated dilation in prehypertensive and mildly hypertensive adults: a randomized, controlled cross-over trial. BMC Complement Altern Med. 2012 Mar 29;12:26. doi: 10.1186/1472-6882-12-26.

Study record dates

Study Major Dates

• Study Start: May 1, 2010
• Primary Completion (Actual): June 1, 2011
• Study Completion (Actual): June 1, 2011

Study Registration Dates

• First Submitted: April 6, 2011
• First Submitted That Met QC Criteria: April 7, 2011
• First Posted (Estimate): April 8, 2011

Study Record Updates

• Last Update Posted (Estimate): February 7, 2013
• Last Update Submitted That Met QC Criteria: February 6, 2013
• Last Verified: December 1, 2011

More Information

Terms related to this study

• Keywords: Prehypertension; Flow mediated dilation; Hawthorn; Mild hypertension
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension; Prehypertension
• Other Study ID Numbers: 09-2279