Cardiovascular DiseasesPhase 1NCT04889274
Investigation of the Effects of Dietary Nitrate and Sex on COVID-19 Vaccine Induced Vascular Dysfunction in Healthy Men and Women (DiNOVasc-COVID-19)
A Phase 1 study testing COVID-19 vaccine, Concentrate beetroot Juice and Nitrate-deplete beetroot juice in people with Cardiovascular Diseases and Endothelial Dysfunction, run by Queen Mary University of London at 1 site in United Kingdom.
Trial summary
Inorganic nitrate can protect blood vessels from the damage that occurs during cardiovascular disease. Early experimental work suggests that nitrate-induced improvements in vascular function relate to the suppression of inflammatory pathways. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Cardiovascular Diseases, Endothelial Dysfunction
- What is being tested?
- COVID-19 vaccine, Concentrate beetroot Juice and Nitrate-deplete beetroot juice
- Type of treatment
- Vaccines
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 42 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 10 May 2021to 2 Dec 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy volunteers with a booking for COVID-19 vaccination slot as per government guidelines
- Aged 18-60
- Volunteers who are willing to sign the consent form
Who cannot join
- Aged <18 or >60 years
- Healthy subjects unwilling to consent
- Pregnant, or any possibility that a subject may be pregnant
- History of any serious illnesses, including recent infections or trauma
- Subjects taking systemic medication (other than the oral contraceptive pill)
- Subjects with self-reported use of mouthwash or tongue scrapes
Show all 10Show fewer
- Subjects with recent (2 weeks) or current antibiotic use
- Subjects with a history, or recent treatment of (within last 3 months) any oral condition (excluding caries), including gingivitis, periodontitis and halitosis
- Subjects with a history of COVID-19 vaccination
- Subjects with any history of a blood-borne infectious
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
The William Harvey Research Institute
London, EC1M 6BQ
About this study
Official title: A Double-blind, Randomised, Placebo-controlled Parallel Study to Investigate the Effect of Dietary Nitrate and Sex on COVID-19 Vaccine Induced Vascular Dysfunction in Healthy Men and Women
Inorganic nitrate can protect blood vessels from the damage that occurs during cardiovascular disease. Early experimental work suggests that nitrate-induced improvements in vascular function relate to the suppression of inflammatory pathways. Whether this protection against inflammation-induced damage to the blood vessel wall might also be functional in the setting of COVID-19 vaccination will be investigated.
Vascular function will be assessed before and after the healthy participant has received their COVID-19-vaccination. Whether there might be differences in the response to the vaccine between the sexes and whether a dietary nitrate intervention impacts upon the effects of vaccination will be investigated.
Read more
The study is in two parts:
Part A: To assess sex differences in the vascular response to COVID-19 vaccination.
Part B: To assess whether inorganic nitrate, in the form of dietary inorganic nitrate supplementation compared to placebo control, can raise circulating plasma nitrite levels and thereby prevent the systemic inflammation that causes vascular dysfunction.
Read the detailed description
Whether the COVID-19 vaccine can be used to study endothelial dysfunction and whether inorganic nitrate might be useful in restoring the function of the endothelium in a scenario simulating the COVID-19 infection setting will be investigated.
Furthermore, sex differences in the vascular response to the COVID-19 vaccination will be investigated.
Design: A prospective randomised, double-blind, placebo-controlled trial.
Target population: A total of 98 healthy participants will be recruited. Part A: 30 participants (15 male, 15 female.) Part B: 68 participants (34 intervention, 34 placebo). Participants will be recruited prior to receiving the COVID-19 vaccination, via Barts Health NHS Trust approved vaccination hubs.
Setting: Equal numbers of healthy male and female volunteers, aged between 18 and 60 years of age, will be recruited. Following recruitment, participants will undergo baseline measurements of vascular function of flow mediated dilatation (FMD) and pulse wave analysis/velocity (PWA, PWV), in addition to haematological and clinical biochemical analyses. Volunteers will then be randomised into one of the 2 study Parts (Part A: sex differences in vascular response to COVID-19 vaccine, Part B: influence of dietary nitrate upon vascular responses to COVID-19 vaccine). If randomised to Part B, volunteers will be treated with 3 days of either 4-5mmol nitrate-containing beetroot juice or placebo. If randomised to Part A, the volunteers will not receive an intervention. On day 3, all participants will receive their COVID-19 vaccine. At 8±2hours after the vaccine, the participants will undergo repeat measurements of vascular function. A quality of life questionnaire will be obtained 28 days after the vaccine has been administered.
Intervention: All volunteers will receive COVID-19 vaccination in Part A and Part B. In Part B of the study, volunteers will be randomised in a 1:1 fashion to receive either nitrate-containing beetroot juice (4-5mmol nitrate) or nitrate-deplete placebo.
The study will take place in the Clinical Research Centre at The William Harvey Research Institute.
Analysis: For the analysis of Part A linear regression will be used to compare change in vascular dysfunction from pre- to post-vaccination between the sexes, unadjusted and adjusted for important risk factors including age, BMI and baseline vessel diameter. For Part B analysis of covariance (ANCOVA) will be used to compare change in vascular dysfunction from pre- to post-vaccination between dietary nitrate and placebo control groups adjusting for pre-vaccination level, and to compare change in plasma nitrite between dietary nitrate and placebo control groups adjusting for baseline nitrite level.
- Conditions
- Cardiovascular Diseases, Endothelial Dysfunction
- Being tested
- COVID-19 vaccine, Concentrate beetroot Juice, Nitrate-deplete beetroot juice
- Keywords
- COVID-19, endothelial dysfunction, nitrate, nitrite, sex
- Medical subject headings
- Cardiovascular Diseases, COVID-19, Coitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
COVID-19 vaccineBiological
COVID-19 vaccine as offered by NHS England
Concentrate beetroot JuiceBiological
Beetroot juice containing approximately 5mmol/l nitrate
Nitrate-deplete beetroot juiceBiological
Beetroot juice with nitrate removed
| Study group | Role | What they receive |
|---|---|---|
| Part A: Male healthy volunteers | Experimental | Not described Receives: Biological: COVID-19 vaccine |
| Part A: Female healthy volunteers | Experimental | Not described Receives: Biological: COVID-19 vaccine |
| Part B: Nitrate-rich beetroot juice | Active comparator | Dietary Supplement: Concentrate beetroot Juice (70 ml) containing ~5mmol of inorganic nitrate Receives: Biological: COVID-19 vaccine; Biological: Concentrate beetroot Juice |
| Part B: Nitrate-deplete beetroot juice | Placebo comparator | Dietary Supplement: Concentrate beetroot Juice (70 ml) which is nitrate-depleted Receives: Biological: COVID-19 vaccine; Biological: Nitrate-deplete beetroot juice |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of change in FMD from baseline between the sexes after COVID-19 vaccination
A measurement of brachial artery diameter using ultrasound (FMD, flow mediated dilatation) will be conducted at visits 2 and 3 (i.e. pre- and post-vaccine). This outcome measure will compare these 2 measurements, and change in FMD will be calculated as subtracting the value collected at visit 3 from visit 2, and expressed as a percentage (%). Comparisons will then be made between the sexes (i.e. males vs females) in Part A.
Measured: Up to 28 days
Comparison of change in FMD from baseline after COVID-19 vaccination following inorganic nitrate versus placebo supplementation
A measurement of brachial artery diameter using ultrasound (FMD, flow mediated dilatation) will be conducted at visits 2 and 3 (i.e. pre- and post-vaccine). This outcome measure will compare these 2 measurements, and change in FMD will be calculated as subtracting the value collected at visit 3 from visit 2, and expressed as a percentage (%). Comparisons will then be made between intervention and placebo in Part B.
Measured: Up to 28 days
Comparison of change in plasma [NO2-] following inorganic nitrate versus placebo supplementation
Quantification of [NO2-] will be made using ozone chemiluminescence. Samples of blood, urine and saliva will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Measurement of [NO2-] will be made in all matrices at both timepoints, and a comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Secondary outcomes (5)
Comparison between the sexes in the systemic inflammatory response to COVID-19 vaccination
Comparisons of the inflammatory response will be made using a combination of clinical haematology and chemistry to assess leukocyte sub-types, and inflammatory markers such as C-reactive protein. Samples of blood will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Comparison between nitrate and placebo with respect to inflammatory cell activation state
Comparisons of the inflammatory cell activation state will be made through the assessment of inflammatory cytokines and chemokines (bead array analyser). Samples of blood plasma will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Comparison between nitrate and placebo with respect to circulating inflammatory mediators
Comparisons of the inflammatory mediators will be made through the assessment of inflammatory cytokines and chemokines (bead array analyser). Samples of blood plasma will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Comparison between nitrate and placebo with respect to platelet function during systemic inflammation
Comparisons of the platelet function will be made through the use of a platelet aggregometer and flow cytometry. Samples of citrate containing whole blood will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Comparison between nitrate and placebo with respect to endothelium independent vasodilation of the brachial artery
Comparisons of endothelium independent vascular function will be made through the use brachial artery ultrasound and sublingual glyceryl trinitrate. Vascular ultrasound will be conducted at visit 2 and visit 3 (i.e. pre- and post-vaccine). Comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
Measured: Up to 28 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 May 2021
- Study start10 May 2021
- Primary completion2 Dec 2025
- Study completion2 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Cardiovascular DiseasesStudies of the same condition, open and under way.
- More trials run by Queen Mary University of LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 42 participants (actual)
Sponsor and investigators
- Lead sponsor
- Queen Mary University of London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04889274
- Sponsor's protocol ID
- 21/SC/0154
- Status last verified
- Sep 2026
- First submitted
- 6 May 2021
- Last updated
- 25 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Rathod KS, Kapil V, Velmurugan S, Khambata RS, Siddique U, Khan S, Van Eijl S, Gee LC, Bansal J, Pitrola K, Shaw C, D'Acquisto F, Colas RA, Marelli-Berg F, Dalli J, Ahluwalia A. Accelerated resolution of inflammation underlies sex differences in inflammatory responses in humans. J Clin Invest. 2017 Jan 3;127(1):169-182. doi: 10.1172/JCI89429. Epub 2016 Nov 28.
PubMed 27893465Kapil V, Khambata RS, Jones DA, Rathod K, Primus C, Massimo G, Fukuto JM, Ahluwalia A. The Noncanonical Pathway for In Vivo Nitric Oxide Generation: The Nitrate-Nitrite-Nitric Oxide Pathway. Pharmacol Rev. 2020 Jul;72(3):692-766. doi: 10.1124/pr.120.019240.
PubMed 32576603Shabbir A, Rathod KS, Khambata RS, Ahluwalia A. Sex Differences in the Inflammatory Response: Pharmacological Opportunities for Therapeutics for Coronary Artery Disease. Annu Rev Pharmacol Toxicol. 2021 Jan 6;61:333-359. doi: 10.1146/annurev-pharmtox-010919-023229. Epub 2020 Oct 9.
PubMed 33035428Shabbir A, Chhetri I, Khambata RS, Parakaw T, Lau C, Aubdool MABN, Massimo G, Dyson N, Kapil V, Godec T, Apea V, Flint J, Orkin C, Rathod KS, Ahluwalia A. A double-blind, randomised, placebo-controlled parallel study to investigate the effect of sex and dietary nitrate on COVID-19 vaccine-induced vascular dysfunction in healthy men and women: protocol of the DiNOVasc-COVID-19 study. Trials. 2023 Sep 16;24(1):593. doi: 10.1186/s13063-023-07616-2.
PubMed 37715222
Study at a glance
From the registry record, last updated by the sponsor on 25 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Double-blind, Randomised, Placebo-controlled Parallel Study to Investigate the Effect of Dietary Nitrate and Sex on COVID-19 Vaccine Induced Vascular Dysfunction in Healthy Men and Women
- ClinicalTrials.gov ID
- NCT04889274
- Acronym / sponsor ID
- 21/SC/0154
- Conditions
- Cardiovascular Diseases, Endothelial Dysfunction
- Keywords
- COVID-19, endothelial dysfunction, nitrate, nitrite, sex
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 42 participants (actual)
- Lead sponsor
- Queen Mary University of LondonUniversity, hospital or other
- Study start
- 10 May 2021 (actual)
- Primary completion
- 2 Dec 2025 (actual)
- Study completion
- 2 Dec 2025 (actual)
- First posted
- 17 May 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Inorganic nitrate can protect blood vessels from the damage that occurs during cardiovascular disease. Early experimental work suggests that nitrate-induced improvements in vascular function relate to the suppression of inflammatory pathways. Whether this protection against inflammation-induced damage to the blood vessel wall might also be functional in the setting of COVID-19 vaccination will be investigated.
Vascular function will be assessed before and after the healthy participant has received their COVID-19-vaccination. Whether there might be differences in the response to the vaccine between the sexes and whether a dietary nitrate intervention impacts upon the effects of vaccination will be investigated.
The study is in two parts:
Part A: To assess sex differences in the vascular response to COVID-19 vaccination.
Part B: To assess whether inorganic nitrate, in the form of dietary inorganic nitrate supplementation compared to placebo control, can raise circulating plasma nitrite levels and thereby prevent the systemic inflammation that causes vascular dysfunction.
Detailed description
Whether the COVID-19 vaccine can be used to study endothelial dysfunction and whether inorganic nitrate might be useful in restoring the function of the endothelium in a scenario simulating the COVID-19 infection setting will be investigated.
Furthermore, sex differences in the vascular response to the COVID-19 vaccination will be investigated.
Design: A prospective randomised, double-blind, placebo-controlled trial.
Target population: A total of 98 healthy participants will be recruited. Part A: 30 participants (15 male, 15 female.) Part B: 68 participants (34 intervention, 34 placebo). Participants will be recruited prior to receiving the COVID-19 vaccination, via Barts Health NHS Trust approved vaccination hubs.
Setting: Equal numbers of healthy male and female volunteers, aged between 18 and 60 years of age, will be recruited. Following recruitment, participants will undergo baseline measurements of vascular function of flow mediated dilatation (FMD) and pulse wave analysis/velocity (PWA, PWV), in addition to haematological and clinical biochemical analyses. Volunteers will then be randomised into one of the 2 study Parts (Part A: sex differences in vascular response to COVID-19 vaccine, Part B: influence of dietary nitrate upon vascular responses to COVID-19 vaccine). If randomised to Part B, volunteers will be treated with 3 days of either 4-5mmol nitrate-containing beetroot juice or placebo. If randomised to Part A, the volunteers will not receive an intervention. On day 3, all participants will receive their COVID-19 vaccine. At 8±2hours after the vaccine, the participants will undergo repeat measurements of vascular function. A quality of life questionnaire will be obtained 28 days after the vaccine has been administered.
Intervention: All volunteers will receive COVID-19 vaccination in Part A and Part B. In Part B of the study, volunteers will be randomised in a 1:1 fashion to receive either nitrate-containing beetroot juice (4-5mmol nitrate) or nitrate-deplete placebo.
The study will take place in the Clinical Research Centre at The William Harvey Research Institute.
Analysis: For the analysis of Part A linear regression will be used to compare change in vascular dysfunction from pre- to post-vaccination between the sexes, unadjusted and adjusted for important risk factors including age, BMI and baseline vessel diameter. For Part B analysis of covariance (ANCOVA) will be used to compare change in vascular dysfunction from pre- to post-vaccination between dietary nitrate and placebo control groups adjusting for pre-vaccination level, and to compare change in plasma nitrite between dietary nitrate and placebo control groups adjusting for baseline nitrite level.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Part A: Male healthy volunteers | Experimental | Biological: COVID-19 vaccine |
| Part A: Female healthy volunteers | Experimental | Biological: COVID-19 vaccine |
| Part B: Nitrate-rich beetroot juice | Active comparator | Biological: COVID-19 vaccine, Biological: Concentrate beetroot JuiceDietary Supplement: Concentrate beetroot Juice (70 ml) containing ~5mmol of inorganic nitrate |
| Part B: Nitrate-deplete beetroot juice | Placebo comparator | Biological: COVID-19 vaccine, Biological: Nitrate-deplete beetroot juiceDietary Supplement: Concentrate beetroot Juice (70 ml) which is nitrate-depleted |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Healthy volunteers with a booking for COVID-19 vaccination slot as per government guidelines
- Aged 18-60
- Volunteers who are willing to sign the consent form
Key exclusion criteria (10 listed)
- Aged <18 or >60 years
- Healthy subjects unwilling to consent
- Pregnant, or any possibility that a subject may be pregnant
- History of any serious illnesses, including recent infections or trauma
- Subjects taking systemic medication (other than the oral contraceptive pill)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| COVID-19 vaccineCOVID-19 vaccine as offered by NHS England | Biological | Part A: Female healthy volunteers, Part A: Male healthy volunteers, Part B: Nitrate-deplete beetroot juice, Part B: Nitrate-rich beetroot juice |
| Concentrate beetroot JuiceBeetroot juice containing approximately 5mmol/l nitrate | Biological | Part B: Nitrate-rich beetroot juice |
| Nitrate-deplete beetroot juiceBeetroot juice with nitrate removed | Biological | Part B: Nitrate-deplete beetroot juice |
Primary outcome
Comparison of change in FMD from baseline between the sexes after COVID-19 vaccination
Time frame: Up to 28 days
A measurement of brachial artery diameter using ultrasound (FMD, flow mediated dilatation) will be conducted at visits 2 and 3 (i.e. pre- and post-vaccine). This outcome measure will compare these 2 measurements, and change in FMD will be calculated as subtracting the value collected at visit 3 from visit 2, and expressed as a percentage (%). Comparisons will then be made between the sexes (i.e. males vs females) in Part A.
Comparison of change in FMD from baseline after COVID-19 vaccination following inorganic nitrate versus placebo supplementation
Time frame: Up to 28 days
A measurement of brachial artery diameter using ultrasound (FMD, flow mediated dilatation) will be conducted at visits 2 and 3 (i.e. pre- and post-vaccine). This outcome measure will compare these 2 measurements, and change in FMD will be calculated as subtracting the value collected at visit 3 from visit 2, and expressed as a percentage (%). Comparisons will then be made between intervention and placebo in Part B.
Comparison of change in plasma [NO2-] following inorganic nitrate versus placebo supplementation
Time frame: Up to 28 days
Quantification of [NO2-] will be made using ozone chemiluminescence. Samples of blood, urine and saliva will be acquired at visit 2 and visit 3 (i.e. pre- and post-vaccine). Measurement of [NO2-] will be made in all matrices at both timepoints, and a comparison will be made (for this we plan on using 2-way ANOVA, using GraphPad Prism statistics package) to compare time and intervention.
5 secondary outcomes
Comparison between the sexes in the systemic inflammatory response to COVID-19 vaccination
Time frame: Up to 28 days
Comparison between nitrate and placebo with respect to inflammatory cell activation state
Time frame: Up to 28 days
Comparison between nitrate and placebo with respect to circulating inflammatory mediators
Time frame: Up to 28 days
Comparison between nitrate and placebo with respect to platelet function during systemic inflammation
Time frame: Up to 28 days
Comparison between nitrate and placebo with respect to endothelium independent vasodilation of the brachial artery
Time frame: Up to 28 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Sep 2026.
- Results publication: PubMed 27893465Rathod KS, Kapil V, Velmurugan S, Khambata RS, Siddique U, Khan S, Van Eijl S, Gee LC, Bansal J, Pitrola K, Shaw C, D'Acquisto F, Colas RA, Marelli-Berg F, Dalli J, Ahluwalia A. Accelerated resolution of inflammation underlies sex differences in inflammatory responses in humans. J Clin Invest. 2017 Jan 3;127(1):169-182. doi: 10.1172/JCI89429. Epub 2016 Nov 28.
- Results publication: PubMed 32576603Kapil V, Khambata RS, Jones DA, Rathod K, Primus C, Massimo G, Fukuto JM, Ahluwalia A. The Noncanonical Pathway for In Vivo Nitric Oxide Generation: The Nitrate-Nitrite-Nitric Oxide Pathway. Pharmacol Rev. 2020 Jul;72(3):692-766. doi: 10.1124/pr.120.019240.
- Results publication: PubMed 33035428Shabbir A, Rathod KS, Khambata RS, Ahluwalia A. Sex Differences in the Inflammatory Response: Pharmacological Opportunities for Therapeutics for Coronary Artery Disease. Annu Rev Pharmacol Toxicol. 2021 Jan 6;61:333-359. doi: 10.1146/annurev-pharmtox-010919-023229. Epub 2020 Oct 9.
- Derived from this study: PubMed 37715222Shabbir A, Chhetri I, Khambata RS, Parakaw T, Lau C, Aubdool MABN, Massimo G, Dyson N, Kapil V, Godec T, Apea V, Flint J, Orkin C, Rathod KS, Ahluwalia A. A double-blind, randomised, placebo-controlled parallel study to investigate the effect of sex and dietary nitrate on COVID-19 vaccine-induced vascular dysfunction in healthy men and women: protocol of the DiNOVasc-COVID-19 study. Trials. 2023 Sep 16;24(1):593. doi: 10.1186/s13063-023-07616-2.
Related trials for Cardiovascular Diseases
Active, not recruitingPhase 3
ENDOTHELION Study Group: Effect of Bosentan in NAION Patients
Ischemic Optic Neuropathy
Active, not recruiting
Digital Reinforcement of Motivational Interviewing Micro-Skills Among Primary Care Healthcare Professionals
Hypertension (Without Type 2 Diabetes Mellitus)
Not yet recruitingPhase 2
Study of YKST02 in Adults With Relapsed or Refractory Multiple Myeloma
Relapsed or Refractory Multiple Myeloma (RRMM)
RecruitingPhase 2
Engaging T-cells to Eliminate MRD in Newly Diagnosed Myeloma Optimizing Response With Talquetmab and Teclistamab (ROTATE)
Multiple Myeloma
Recruiting
PAW-Hydrogel for Chronic Wound Healing
Diabetic Foot Ulcer (DFU), Pressure Ulcer (PU)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing COVID-19 vaccine, Concentrate beetroot Juice and Nitrate-deplete beetroot juice in people with Cardiovascular Diseases and Endothelial Dysfunction, run by Queen Mary University of London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison of change in FMD from baseline between the sexes after COVID-19 vaccination (time frame: Up to 28 days). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04889274, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Sep 2026.