Acute Effect of Nitrate From Natural Dietary Sources on Arterial Stiffness and Blood Pressures in Healthy Individuals

Phase 2

Completed

• Conditions: Healthy
• Interventions: Other: Spinach soup; Other: Asparagus soup

• Registration Number: NCT01604993
• Lead Sponsor: Unity Health Toronto

Brief Summary

The purpose of this study is to evaluate the acute effect of a meal high in dietary nitrates on aortic augmentation index, brachial and aortic blood pressures, and subendocardial viability ration (SEVR).

Detailed Description

Hypertension has become a common medical condition worldwide, raising public concern regarding the accompanying increase in cardiovascular disease risk and other health risks. Targets for optimal blood pressure are often unmet by conventional pharmaceutical therapies; consequently, complementary and alternative medicines are increasing in popularity among patients wishing to better manage their BP. In the case of hypertension, endothelial dysfunction and cardiovascular disease, a decline in the ability of blood vessels to dilate in response to shear stress is a major contributor to vascular pathology. At the core of these conditions is a decreased ability to synthesize nitric oxide, a potent vasodilatory agent. The proposed study will examine whether or not increasing the intake of dietary nitrate, which can be converted to nitric oxide endogenously, can improve three indices of vascular function that are validated risk factors for CVD: arterial stiffness, as measured by aortic augmentation index (AIx), aortic BP and brachial BP.

Study Timeline

• Study Start: 2011-10
• Study First Submitted: 2012-05-22
• Study First Submitted QC: 2012-05-22
• Study First Posted: 2012-05-24
• Primary Completion: 2012-11
• Study Completion: 2013-10
• Status Verified: 2014-03
• Last Update Submitted: 2014-03-07
• Last Update Posted: 2014-03-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 31

Inclusion Criteria

• Healthy volunteers aged 18-50
• Must consider themselves to be in good overall health and be free of any conditions or illnesses Women must be post-menopausal or not pregnant.
• Body mass index (BMI) must be <30kg/m^2.
• Normotensive, as defined by brachial SBP <140mmHg and DBP <90mmHg
• Subjects must also be willing to stop using mouthwash for the duration of their participation in the study.

Exclusion Criteria

• Women of childbearing age may not be pregnant, planning to become pregnant, or breastfeeding at the time of the study
• BMI >30kg/m^2
• Hypertensive as defined by brachial SBP >140mmHg and/or DBP >90mmHg
• Allergy or sensitivity to the study product, reference therapy or nitrates
• Having any gastrointestinal complication or condition
• Chronic use of medications such as prescription NSAIDs, antacids, blood-thinners, hypertensive medications, medications affecting NO synthesis such as Viagra, and use of antibiotics within one month of the study start
• Individuals who are involved in another clinical trial.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
High nitrate dietary source	Spinach soup	556 grams of high nitrate spinach soup that is orally consumed as a single dose for 7 days.
No Nitrate dietary source	Asparagus soup	556g low nitrate asparagus soup; orally consumed as a single does for 7 days.

Primary Outcome Measures

Name	Time	Method
Aortic augmentation index (arterial stiffness)	At each treatment visits, this measurement will be taken in at baseline, 1, 2, and 3 hours post-treatment.

Secondary Outcome Measures

Name	Time	Method
Peripheral (brachial) and central (aortic) systolic and diastolic blood pressure	Brachial blood pressure will be measured at 0 , 1, 2, and 3 hours post -treatmentbaseline and at 1, 2 and 3 hours at every visit.
Subendocardial viability ratio (SEVR)	At 1 hours intervals starting from baseline and ending at 3 hours.

Trial Locations

Locations (1)

Risk Factor Modification Centre; 🇨🇦 Toronto, Ontario, Canada