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Effects of Dietary Nitrate Supplementation on Cardiorespiratory Control in Chronic Heart Failure

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02401126
Recruitment Status : Completed
First Posted : March 27, 2015
Last Update Posted : May 2, 2016
Information provided by (Responsible Party):
Dr. J. Alberto Neder, Queen's University

Brief Summary:
The main purpose of this study is to determine whether dietary nitrate supplementation via concentrated beetroot juice improves central and peripheral cardiovascular control and physical capacity in patients with systolic heart failure.

Condition or disease Intervention/treatment Phase
Heart Failure, Systolic Dietary Supplement: Nitrate supplementation Dietary Supplement: Placebo Phase 4

Detailed Description:

Chronic heart failure (CHF) is a leading cause of morbidity and mortality worldwide. Although affecting the heart at first, it is now recognized that disability is largely due to impaired cerebral and skeletal muscle blood flow and consequently microvascular oxygenation. Reduced muscle oxygenation compromises oxidative metabolism and thus contractile performance. Impaired cerebral oxygenation not only reduces motor output (thus exacerbating muscle fatigue) but also constitutes a predictor of cerebral ischemic events and an independent prognostic risk factor.

Reduced levels of the vasodilator nitric oxide (NO) contribute to impaired blood flow and oxygenation in CHF. Development of new effective therapeutic strategies is therefore crucial given that current pharmacological treatment has failed to abrogate oxygenation deficits in CHF patients. Emerging evidence shows that nitrate serves as an alternative source for NO and improves muscle blood flow and oxygenation in health. Another striking feature of nitrate is that it can improve muscle work efficiency, a tenet of physiology that was once considered immutable.

Objective: To investigate systematically the role of dietary nitrate supplementation on central and peripheral cardiovascular function in CHF patients.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 13 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Dietary Nitrate Supplementation and Cardiorespiratory Control in Chronic Heart Failure: a Randomized, Placebo-controlled Trial
Study Start Date : March 2015
Actual Primary Completion Date : April 2016
Actual Study Completion Date : April 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Failure

Arm Intervention/treatment
Active Comparator: Nitrate supplementation
Concentrated nitrate-rich beetroot juice
Dietary Supplement: Nitrate supplementation
Nitrate supplementation: concentrated nitrate-rich beetroot juice (2 x 70 ml/day; approximately 10 mmol nitrate/day; Beet It, James White Drinks, Ipswich, UK) for 8 consecutive days.
Other Name: Concentrated nitrate-rich beetroot juice

Placebo Comparator: Placebo
Nitrate-depleted beetroot juice
Dietary Supplement: Placebo
Placebo: nitrate-depleted beetroot juice (2 x 70 ml/day; approximately 0.01 mmol nitrate/day; Beet It, James White Drinks, Ipswich, UK) for 8 consecutive days. The placebo juice is similar to the concentrated beetroot juice in appearance, texture, smell and taste and is obtained by removing nitrate ions from the latter.
Other Name: Nitrate-depleted beetroot juice

Primary Outcome Measures :
  1. Exercise tolerance [ Time Frame: 8 days ]
    Cycle ergometer exercise test to the limit of tolerance

Secondary Outcome Measures :
  1. Plasma nitrate and nitrite concentrations [ Time Frame: 8 days ]
    Assessed by chemiluminescence

  2. Central and peripheral fatigue [ Time Frame: 8 days ]
    Assessed by transcutaneous femoral nerve magnetic stimulation

  3. Skeletal muscle and cerebral blood flow and oxygenation [ Time Frame: 8 days ]
    Assessed by near-infrared spectroscopy and the rate of appearance of the optically-dense indocyanine green dye

  4. Neuromuscular activity [ Time Frame: 8 days ]
    Assessed by electromyography

  5. Dyspnea and leg effort scores [ Time Frame: 8 days ]
    Evaluated via a 10-point Borg scale

  6. Cognitive performance [ Time Frame: 8 days ]
    Assessed by computer-based tests

  7. Cardiorespiratory responses to exercise [ Time Frame: 8 days ]
    Non-invasive evaluation of cardiac (mean arterial pressure, cardiac output, stroke volume and heart rate) and pulmonary gas exchange (e.g., minute ventilation and oxygen uptake) responses during the transition from rest to exercise

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Ages Eligible for Study:   40 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

- previous diagnosis of systolic heart failure (left ventricular ejection fraction <40%) under optimized clinical treatment as judged by the accompanying physician.

Exclusion Criteria:

  • hospital admission in the previous 6 weeks;
  • exercise training program in the previous 6 months;
  • nitrate therapy (e.g., isosorbide dinitrate);
  • tabagism;
  • any condition that could interfere with the ability to exercise;
  • diagnosed psychiatric or cognitive disorders;
  • type I insulin-dependent diabetes mellitus;
  • excessively over-weight (BMI>35kg/m²);
  • other diagnosed cardiorespiratory disorders (e.g., chronic obstructive pulmonary disease, peripheral artery disease).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02401126

Sponsors and Collaborators
Queen's University
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Principal Investigator: J. Alberto Neder, MD, PhD Queen's University
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Responsible Party: Dr. J. Alberto Neder, Principal Investigator, Queen's University Identifier: NCT02401126    
Other Study ID Numbers: 6012610
First Posted: March 27, 2015    Key Record Dates
Last Update Posted: May 2, 2016
Last Verified: April 2016
Additional relevant MeSH terms:
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Heart Failure
Heart Failure, Systolic
Heart Diseases
Cardiovascular Diseases