HypertensionNCT01785511
Does Ultraviolet Irradiation Reduce Platelet Reactivity and Improve Coronary Microvascular Function in Man?
A study testing UVA Radiation in people with Hypertension, run by University of Edinburgh at 1 site in United Kingdom.
Trial summary
Endothelium derived nitric oxide (NO) regulates vascular tone and blood pressure in man. NO also inhibits platelet aggregation and mediates a variety of beneficial anti-inflammatory and repair mechanisms. Read more about this study
- Who is it for?
- Ages 18 to 45 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Hypertension
- What is being tested?
- UVA Radiation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Mar 2012to Aug 2012
- Phase
- Interventional
- 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 45 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy male volunteers aged between 18-45 years (inclusive).
Who cannot join
- Inability to provide informed consent
- Co-existent systemic disease (including any history of asthma, reactive airways disease or hypertension)
- Contraindication to UVA treatment
- Any history of cardiac conduction abnormality (including bundle branch block or atrial fibrillation)
- Smoker
- Current intake of aspirin, other non-steroid anti-inflammatory medications or any regular medication.
- Recent infective/inflammatory condition
- Echocardiographic evidence of left ventricular hypertrophy (left ventricular septal diameter >1.2 cm in diastole), systolic dysfunction or significant valvular stenosis or regurgitation.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
University of Edinburgh
Edinburgh, Lothian, Eh16 4SA
About this study
Endothelium derived nitric oxide (NO) regulates vascular tone and blood pressure in man. NO also inhibits platelet aggregation and mediates a variety of beneficial anti-inflammatory and repair mechanisms. NO may also be a mediator in the release of the endogenous fibrinolytic factor, tissue-plasminogen activating factor (t-PA) from the endothelium.1 Via these actions it plays a very important role in protection of the vasculature from atherothrombosis and clinical sequelae such as myocardial infarction and stroke.
Visible and ultraviolet (UV) light relax vascular smooth muscles by producing NO in a phenomenon known as photorelaxation.2 The investigators have demonstrated significant stores of pre-formed, bound NO and other nitrosospecies in human skin, which are rapidly released upon exposure to UVA.3 The investigators have demonstrated recently that serum nitrite and nitroso-species are increased after standing in a UVA phototherapy cabinet and that local UVA exposure is associated with increased forearm arterial blood flow that is independent of skin temperature. The investigators have also demonstrated a fall in mean arterial blood pressure in subjects exposed UVA.
Read more
Cardiovascular morbidity and the prevalence of hypertension vary with latitude. The investigators hypothesise that some of this geographical variation may be explained by a diminished sunlight/UVA exposure with attendant negative effects upon NO bio-availability.4 To further examine the potential beneficial effects of UVA exposure we will examine the effects of whole-body UVA upon platelet activation and upon myocardial/coronary arterial flow reserve. The investigators will correlate these measures with systemic nitrate, nitrite and nitroso-species content in healthy volunteers.
HYPOTHESES
- UVA irradiation enhances coronary flow reserve in healthy volunteers.
- UVA irradiation suppresses platelet activation in healthy volunteers.
- UVA irradiation enhances the release of endogenous fibrinolytic factors in healthy volunteers.
- Conditions
- Hypertension
- Being tested
- UVA Radiation
- Keywords
- hypertension, UV radiation, coronary flow reserve, nitric oxide
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
UVA RadiationRadiation
UVA radiation exposure for 20 minutes
| Study group | Role | What they receive |
|---|---|---|
| Sham UVA | Sham comparator | sham exposure will be provided by covering the UVA lamps with space blanket. Receives: Radiation: UVA Radiation |
| UVA Radiation | Experimental | Patients will be exposed to UVA radiation for 20 minutes Receives: Radiation: UVA Radiation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Coronary Flow Reserve
Change in coronary flow assessed pre and post UVA radiation versus control
Measured: 0, 20, 40 and 60 mins
Secondary outcomes (2)
Platelet Activation
Platelet activation assessed using platelet monocyte activity
Measured: 0, 20, 40 and 60 mins
Endogenous Fibrinolysis
Assessed using flow cytometry
Measured: 0, 20, 40 and 60 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Feb 2013 (estimated)
- Study startMar 2012
- Primary completionAug 2012
- Study completionAug 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- More trials run by University of EdinburghThe 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Ninian Lang, MbChB, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01785511
- Sponsor's protocol ID
- UVA Study
- Status last verified
- Feb 2013
- First submitted
- 20 Jun 2012
- Last updated
- 20 Feb 2013
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 20 Feb 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does Ultraviolet Irradiation Reduce Platelet Reactivity and Improve Coronary Microvascular Function in Man?
- ClinicalTrials.gov ID
- NCT01785511
- Acronym / sponsor ID
- UVA Study
- Conditions
- Hypertension
- Keywords
- hypertension, UV radiation, coronary flow reserve, nitric oxide
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Study start
- Mar 2012
- Primary completion
- Aug 2012 (actual)
- Study completion
- Aug 2012 (actual)
- First posted
- 7 Feb 2013 (estimated)
- 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.
Endothelium derived nitric oxide (NO) regulates vascular tone and blood pressure in man. NO also inhibits platelet aggregation and mediates a variety of beneficial anti-inflammatory and repair mechanisms. NO may also be a mediator in the release of the endogenous fibrinolytic factor, tissue-plasminogen activating factor (t-PA) from the endothelium.1 Via these actions it plays a very important role in protection of the vasculature from atherothrombosis and clinical sequelae such as myocardial infarction and stroke.
Visible and ultraviolet (UV) light relax vascular smooth muscles by producing NO in a phenomenon known as photorelaxation.2 The investigators have demonstrated significant stores of pre-formed, bound NO and other nitrosospecies in human skin, which are rapidly released upon exposure to UVA.3 The investigators have demonstrated recently that serum nitrite and nitroso-species are increased after standing in a UVA phototherapy cabinet and that local UVA exposure is associated with increased forearm arterial blood flow that is independent of skin temperature. The investigators have also demonstrated a fall in mean arterial blood pressure in subjects exposed UVA.
Cardiovascular morbidity and the prevalence of hypertension vary with latitude. The investigators hypothesise that some of this geographical variation may be explained by a diminished sunlight/UVA exposure with attendant negative effects upon NO bio-availability.4 To further examine the potential beneficial effects of UVA exposure we will examine the effects of whole-body UVA upon platelet activation and upon myocardial/coronary arterial flow reserve. The investigators will correlate these measures with systemic nitrate, nitrite and nitroso-species content in healthy volunteers.
HYPOTHESES
- UVA irradiation enhances coronary flow reserve in healthy volunteers.
- UVA irradiation suppresses platelet activation in healthy volunteers.
- UVA irradiation enhances the release of endogenous fibrinolytic factors in healthy volunteers.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sham UVA | Sham comparator | Radiation: UVA Radiationsham exposure will be provided by covering the UVA lamps with space blanket. |
| UVA Radiation | Experimental | Radiation: UVA RadiationPatients will be exposed to UVA radiation for 20 minutes |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Healthy male volunteers aged between 18-45 years (inclusive).
Key exclusion criteria (8 listed)
- Inability to provide informed consent
- Co-existent systemic disease (including any history of asthma, reactive airways disease or hypertension)
- Contraindication to UVA treatment
- Any history of cardiac conduction abnormality (including bundle branch block or atrial fibrillation)
- Smoker
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 |
|---|---|---|
| UVA RadiationUVA radiation exposure for 20 minutes | Radiation | Sham UVA, UVA Radiation |
Primary outcome
Coronary Flow Reserve
Time frame: 0, 20, 40 and 60 mins
Change in coronary flow assessed pre and post UVA radiation versus control
2 secondary outcomes
Platelet Activation
Time frame: 0, 20, 40 and 60 mins
Endogenous Fibrinolysis
Time frame: 0, 20, 40 and 60 minutes
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 20 Feb 2013.
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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.
Ninian Lang, MbChB principal investigator
University of Edinburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing UVA Radiation in people with Hypertension, run by University of Edinburgh 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 8 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 20 Feb 2013. 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.
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?
Coronary Flow Reserve (time frame: 0, 20, 40 and 60 mins). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 20 Feb 2013.