Condition category
Circulatory System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
This study aims to find out if taking in nitrate through the diet has any effect on the brain’s ability to regulate blood flow in stroke patients. The ability to maintain a constant blood flow within the brain despite changes in the body's blood pressure is termed cerebral autoregulation. A high nitrate diet has previously been shown to improve blood flow to parts of the brain. Cerebral autoregulation is impaired in stroke and nitrate may have a role. It would be useful to know if beetroot juice has any effect on cerebral autoregulation as it could lead to further research in its use as a treatment in stroke patients. We can detect changes in the blood flow within the brain by placing ultrasound probes over the temples of the head. This is called transcranial ultrasound and is non-invasive. Any changes in the ultrasound signals from the blood flow in the brain are recorded and analysed via the computer.

Who can participate?
Participants will be invited to participate if they have had a stroke in the past 14 days, are able to attend hospital twice and are able to swallow liquids. Participants need to be between the ages of 18 and 90.

What does the study involve?
Participants will be randomly assigned to drink a small amount of either beetroot juice or a placebo (dummy) juice and the response to this will be assessed 2 hours after drinking the juice by taking an ultrasound of the head just by the temples. By taking a blood sample we will be able to tell the amount of nitrates in the system.

What are the possible benefits and risks of participating?
There is expected to be no immediate benefit to study participants but the results collected will help inform future larger studies and potential for use in clinical practice. There are no major risks or side effects associated with treatment or the study.

Where is the study run from?
Torbay Hospital (UK)

When is the study starting and how long is it expected to run for?
The study started in May 2014 and is expected to run until November 2014.

Who is funding the study?
South Devon Healthcare NHS Foundation Trust (UK).

Who is the main contact?
Dr Isam Salih

Trial website

Contact information



Primary contact

Dr Isam Salih


Contact details

Stroke Department
Torbay Hospital
Lawes Bridge
United Kingdom
+44 (0) 1803 656635

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The effect of dietary nitrate supplementation on dynamic cerebral autoregulation in ischaemic stroke: a pilot randomised controlled trial


Study hypothesis

We hypothesize that subjects within 2 weeks of stroke onset who receive a single dose of dietary nitrate will show a significantly lower Correlation Coefficient (nMx) (i.e., more favorable dynamic cerebral autoregulation) than subjects who receive placebo.

Ethics approval

Not provided at time of registration – submission pending

Study design

Single-centre feasibility/pilot study, randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please email or phone +44 (0) 1803 656635 to request a patient information sheet




1. Transcranial acoustic window with transcranial ultrasound
2. Measuring dynamic cerebral autoregulation
3. Venous blood sample for plasma nitrate
4. Clinical neurological examination
5. Thigh blood pressure cuff inflation and deflation
6. Participants are randomized to drink 70 ml of either beetroot juice or placebo juice

Intervention type



Not Applicable

Drug names

Primary outcome measures

The Correlation Coefficient (nMx), a marker of dynamic cerebral autoregulation, at 2 hours following ingestion of the investigational product

Secondary outcome measures

1. Plasma nitrate level
2. Mean arterial blood pressure
3. Standard cerebral haemodynamics
4. National Institutes of Health Stroke Scale (NIHSS)
5. Modified Rankin Score (mRS)

Measured at 2 hours following ingestion of the investigational product.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Subjects must have a confirmed onset of acute ischaemic stroke within the last 14 days
2. Age 18-90
3. Able to lie supine and still for 30 minutes
4. Able to take liquid orally
5. Able to give full informed consent
6. Adequate temporal acoustic window as assessed with transcranial doppler ultrasound

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Stroke onset within 24 hours
2. Haemorrhagic stroke
3. Pregnant women
4. Dysphagia precluding oral intake of liquid
5. Inadequate temporal acoustic window for transcranial ultrasound
6. Exclude vasoactive drugs including calcium channel blockers
7. Regularly taking organic nitrates, nicorandil, glitazones, phosphodiesterase inhibitors
8. Pre-existing dementia
9. Significant carotid stenosis >70% on carotid doppler
10. Severe peripheral vascular disease

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Stroke Department
United Kingdom

Sponsor information


South Devon Healthcare NHS Foundation Trust (UK)

Sponsor details

Research and Development Dept.
South Devon Healthcare NHS Foundation Trust
Horizon Centre
Torbay Hospital
Lawes Bridge
United Kingdom
+44 (0)1803 656635

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

South Devon Healthcare NHS Foundation Trust (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes