Nitrate Vasodilator Adverse ReactionNCT05178875
Estimation of Dietary Nitrate Intake in a Representative UK cohort_V1
An observational study of Nitrate Vasodilator Adverse Reaction, run by University of Reading at 1 site in United Kingdom.
Trial summary
Dietary nitrate has been shown to have health benefits including lowering blood pressure and improving the health and elasticity of blood vessels. The main source of dietary nitrate in the human diet is vegetables. Read more about this study
- Who is it for?
- Ages 19 to 64 years
- Conditions the study is for
- Nitrate Vasodilator Adverse Reaction
- How many people
- 2,444 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 15 Nov 2018to 15 Dec 2020
- Phase
- Observational
- 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 19 to 64 years
- All sexes
- Adult
Study population: Healthy participants
Who may be able to join
- Adults aged 19-64 y with a complete 4-day diet diary and a biobanked urine sample
Who cannot join
- not consented to the future analysis of the biobanked urine sample for nutrition and health research
- the diet diary was not completed
- insufficient urine sample available for the urinary nitrate and metabolite analysis.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading
Reading, Berkshire, RG6 6AP
About this study
Official title: Estimation of Dietary and Urinary Nitrate Concentration in a Representative UK Population Using Data From the National Diet and Nutrition Survey (Years 1-8).
Dietary nitrate has been shown to have health benefits including lowering blood pressure and improving the health and elasticity of blood vessels. The main source of dietary nitrate in the human diet is vegetables. Drinking water is another important contributor to nitrate intake but the nitrate level of drinking water varies on a daily basis and between different water authorities in the UK. Furthermore, the data available on dietary analysis software on the levels of nitrate in vegetables and vegetable-based foods is very limited. Therefore, there is an urgent need to more accurately estimate the levels of dietary nitrate intake in the UK population, and determine how the level of intake from all dietary sources (vegetables and drinking water) relate to risk factors for developing heart disease.
This project aims to analyse biobanked urine samples collected during Years 1 to 8 of the National Diet and Nutrition Survey (NDNS), which is conducted in a representative sample of the UK population. We will measure the levels of nitrate and its break down products (metabolites) in urine by using HPLC to estimate the levels of intake of dietary nitrate in the study participants. In addition, we will determine the level of intake from the diet diaries of the study participants using our database of nitrate levels in vegetables and drinking water to estimate the dietary intake, and compare this data with the urine analysis as a potential biomarker of dietary intake.
The NDNS study participants have previously consented for their urine samples to be used for future tests relating to nutrition and health as long as these tests have been approved by a NHS ethics committee. We have been granted permission to analyse the urine samples by the NDNS Bioresource Panel but must first gain ethical approval before the samples can be released to us for
Read the detailed description
In this laboratory study, we will estimate the average dietary nitrate intake of each participant of the NDNS study using both the analyse of 2500 biobanked urine samples collected from participants of the National Diet and Nutrition Survey. As part of the consent process for the 24 h urine collection for the NDNS study (NREC reference number 07/H0604/113) participants were given the option to consent for any of their remaining urine samples to be used in tests relating to nutrition and health which had been approved by a NHS ethics committee.
The main inclusion criteria of this laboratory project are:
- Adults aged 19-64 y with a complete 4-day diet diary and a biobanked urine sample
For the dietary analysis, the nitrate levels of each food item consumed (mainly vegetables and drinking water) will be estimated using UK and European food nitrate values and from previously published studies in the literature. In addition, the nitrate content of drinking water will be estimated for each participant by contacting DWI and the local water suppliers in the UK to collect the quality control of the nitrate content of the drinking water in the UK. The nitrate and nitrite level data will be sent to the NatCen Social Research staff to match the data to each participant based on their postcode and the year the volunteers participated in the NDNS study.
To associate the estimated daily intake of dietary nitrate with health markers and risk factors for cardiovascular disease, analysis of covariance will be used to detect statistically significant differences between high and low nitrate containing diets with blood pressure and other risk factors for cardiovascular disease, controlling for age, sex and total energy intake (MJ). Post-hoc pair-wise analysis will detect differences between quartiles of dietary nitrate intake.
To compare the agreement of the urine nitrate data with the dietary nitrate data, statistical tests such as Bland Altman analysis and principal components analysis will be performed.
- Conditions
- Nitrate Vasodilator Adverse Reaction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| NDNS participants | Random participants from all the UK (including England, Scotland, Wales and North Ireland) |
What is being measured
The primary outcome is the main question the study is designed to answer.
The relationship between the estimated daily dietary nitrate intake with blood pressure and other risk factors for cardiovascular disease in UK adults (aged 19-64 years) of the National Diet and Nutrition Survey.
The daily nitrate intake will be estimated from both analysis of urine samples for nitrate and its metabolites, and also from the diet diary.
Measured: 1 year
Secondary outcomes (2)
associations between diets containing high and low intakes of nitrate with blood pressure and other risk factors for cardiovascular disease
participant will be devided in quartiles based on their nitrate intake then link these data with blood pressure and other CVD risk factors.
Measured: 1 year
if measurement of nitrate and its metabolites in urine represents a suitable biomarker to estimate dietary nitrate intake.
urinary nitrate will be compared with nitrate intake and linked with blood pressure and other CVD risk factors and
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jan 2022
- Study start15 Nov 2018
- Primary completion15 Jul 2020
- Study completion15 Dec 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Nitrate Vasodilator Adverse ReactionStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 2,444 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Reading
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Julie Lovegrove, University of Reading
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05178875
- Sponsor's protocol ID
- 18/NS/0085
- Status last verified
- Dec 2021
- First submitted
- 16 Dec 2021
- Last updated
- 5 Jan 2022
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Alzahrani HS, McKenna HB, Hobbs DA, Jackson KG, Lovegrove JA. Dietary Sources of Nitrate and Nitrite and Associations with Blood Pressure and Other Cardiovascular Disease Risk Factors in a Representative United Kingdom Population. J Nutr. 2026 Feb;156(2):101249. doi: 10.1016/j.tjnut.2025.11.018. Epub 2025 Nov 24.
PubMed 41297631
Study at a glance
From the registry record, last updated by the sponsor on 5 Jan 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Estimation of Dietary and Urinary Nitrate Concentration in a Representative UK Population Using Data From the National Diet and Nutrition Survey (Years 1-8).
- ClinicalTrials.gov ID
- NCT05178875
- Acronym / sponsor ID
- 18/NS/0085
- Conditions
- Nitrate Vasodilator Adverse Reaction
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 2,444 participants (actual)
- Lead sponsor
- University of ReadingUniversity, hospital or other
- Study start
- 15 Nov 2018 (actual)
- Primary completion
- 15 Jul 2020 (actual)
- Study completion
- 15 Dec 2020 (actual)
- First posted
- 5 Jan 2022 (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.
Dietary nitrate has been shown to have health benefits including lowering blood pressure and improving the health and elasticity of blood vessels. The main source of dietary nitrate in the human diet is vegetables. Drinking water is another important contributor to nitrate intake but the nitrate level of drinking water varies on a daily basis and between different water authorities in the UK. Furthermore, the data available on dietary analysis software on the levels of nitrate in vegetables and vegetable-based foods is very limited. Therefore, there is an urgent need to more accurately estimate the levels of dietary nitrate intake in the UK population, and determine how the level of intake from all dietary sources (vegetables and drinking water) relate to risk factors for developing heart disease.
This project aims to analyse biobanked urine samples collected during Years 1 to 8 of the National Diet and Nutrition Survey (NDNS), which is conducted in a representative sample of the UK population. We will measure the levels of nitrate and its break down products (metabolites) in urine by using HPLC to estimate the levels of intake of dietary nitrate in the study participants. In addition, we will determine the level of intake from the diet diaries of the study participants using our database of nitrate levels in vegetables and drinking water to estimate the dietary intake, and compare this data with the urine analysis as a potential biomarker of dietary intake.
The NDNS study participants have previously consented for their urine samples to be used for future tests relating to nutrition and health as long as these tests have been approved by a NHS ethics committee. We have been granted permission to analyse the urine samples by the NDNS Bioresource Panel but must first gain ethical approval before the samples can be released to us for
Detailed description
In this laboratory study, we will estimate the average dietary nitrate intake of each participant of the NDNS study using both the analyse of 2500 biobanked urine samples collected from participants of the National Diet and Nutrition Survey. As part of the consent process for the 24 h urine collection for the NDNS study (NREC reference number 07/H0604/113) participants were given the option to consent for any of their remaining urine samples to be used in tests relating to nutrition and health which had been approved by a NHS ethics committee.
The main inclusion criteria of this laboratory project are:
- Adults aged 19-64 y with a complete 4-day diet diary and a biobanked urine sample
For the dietary analysis, the nitrate levels of each food item consumed (mainly vegetables and drinking water) will be estimated using UK and European food nitrate values and from previously published studies in the literature. In addition, the nitrate content of drinking water will be estimated for each participant by contacting DWI and the local water suppliers in the UK to collect the quality control of the nitrate content of the drinking water in the UK. The nitrate and nitrite level data will be sent to the NatCen Social Research staff to match the data to each participant based on their postcode and the year the volunteers participated in the NDNS study.
To associate the estimated daily intake of dietary nitrate with health markers and risk factors for cardiovascular disease, analysis of covariance will be used to detect statistically significant differences between high and low nitrate containing diets with blood pressure and other risk factors for cardiovascular disease, controlling for age, sex and total energy intake (MJ). Post-hoc pair-wise analysis will detect differences between quartiles of dietary nitrate intake.
To compare the agreement of the urine nitrate data with the dietary nitrate data, statistical tests such as Bland Altman analysis and principal components analysis will be performed.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| NDNS participants | – | –Random participants from all the UK (including England, Scotland, Wales and North Ireland) |
Who may qualify
- Ages
- 19 to 64 years
- Sex
- All
- Age groups
- Adult
- Study population
- Healthy participants
Key inclusion criteria (1 listed)
- Adults aged 19-64 y with a complete 4-day diet diary and a biobanked urine sample
Key exclusion criteria (3 listed)
- not consented to the future analysis of the biobanked urine sample for nutrition and health research
- the diet diary was not completed
- insufficient urine sample available for the urinary nitrate and metabolite analysis.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
The relationship between the estimated daily dietary nitrate intake with blood pressure and other risk factors for cardiovascular disease in UK adults (aged 19-64 years) of the National Diet and Nutrition Survey.
Time frame: 1 year
The daily nitrate intake will be estimated from both analysis of urine samples for nitrate and its metabolites, and also from the diet diary.
2 secondary outcomes
associations between diets containing high and low intakes of nitrate with blood pressure and other risk factors for cardiovascular disease
Time frame: 1 year
if measurement of nitrate and its metabolites in urine represents a suitable biomarker to estimate dietary nitrate intake.
Time frame: 1 year
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 5 Jan 2022.
- Derived from this study: PubMed 41297631Alzahrani HS, McKenna HB, Hobbs DA, Jackson KG, Lovegrove JA. Dietary Sources of Nitrate and Nitrite and Associations with Blood Pressure and Other Cardiovascular Disease Risk Factors in a Representative United Kingdom Population. J Nutr. 2026 Feb;156(2):101249. doi: 10.1016/j.tjnut.2025.11.018. Epub 2025 Nov 24.
- Individual participant dataSharing planned: Undecided
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?
An observational study of Nitrate Vasodilator Adverse Reaction, run by University of Reading 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 1 inclusion and 3 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 5 Jan 2022. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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?
The relationship between the estimated daily dietary nitrate intake with blood pressure and other risk factors for cardiovascular disease in UK adults (aged 19-64 years) of the National Diet and Nutrition Survey. (time frame: 1 year). 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 NCT05178875, which also lists 1 linked publication.
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 5 Jan 2022.