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

Acute Effect of Nitrate Supplementation From Natural Dietary Sources on Arterial Stiffness and Aortic and Brachial Blood Pressures: a Double-blind, Placebo-controlled, Randomized, Crossover Clinical Trial in Healthy Adults

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).

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: Spinach soup; Other: Asparagus soup

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 Type: Interventional
• Enrollment (Actual): 31
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5B 1W8
      • Risk Factor Modification Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High nitrate dietary source; 556 grams of high nitrate spinach soup that is orally consumed as a single dose for 7 days.	Other: Spinach soup; 556 g of high Nitrate spinach soup that is orally consumed as a single dose for 7 days
Placebo Comparator: No Nitrate dietary source; 556g low nitrate asparagus soup; orally consumed as a single does for 7 days.	Other: Asparagus soup; 556 grams of low nitrate asparagus soup that is orally consumed for a period of 7 days as a single does

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
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

Outcome Measure	Time Frame
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.

Collaborators and Investigators

• Sponsor: Unity Health Toronto
• Investigators: Principal Investigator: Vladimir Vuksan, PhD, Risk Factor Modification Centre - St. Michael's Hospital

Study record dates

Study Major Dates

• Study Start: October 1, 2011
• Primary Completion (Actual): November 1, 2012
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: May 22, 2012
• First Submitted That Met QC Criteria: May 22, 2012
• First Posted (Estimate): May 24, 2012

Study Record Updates

• Last Update Posted (Estimate): March 10, 2014
• Last Update Submitted That Met QC Criteria: March 7, 2014
• Last Verified: March 1, 2014

More Information

Terms related to this study

• Keywords: Arterial Stiffness; Blood pressure; Vascular; Dietary Nitrates
• Other Study ID Numbers: 11216 (DAIDS ES Registry Number)