Vascular FunctionEarly Phase 1UMMC_PilotNCT04770155
Vascular Dysfunction in Black Individuals: Roles of Nitric Oxide and Endothelin-1
A Early Phase 1 study testing Dietary Nitrates 400 mg, L-citrulline 3 g and Sildenafil 100 mg in people with Vascular Function and Racial Disparity, run by University of Mississippi Medical Center at 1 site in United States.
Trial summary
The research aims of this proposal are: Specific Aim 1: To test whether an increase in nitric oxide signaling can increase vasodilator responses in young Black individuals. Specific Aim 2: To test whether a decrease in endothelin-1 signaling can increase vasodilator responses in young Black individuals. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Vascular Function, Racial Disparity
- What is being tested?
- Dietary Nitrates 400 mg, L-citrulline 3 g and Sildenafil 100 mg
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- 27 May 2021to 20 Sep 2021
- Phase
- Early Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Self-identification of their race and the race of their biological parents as being only Black (i.e., African American) or only White (i.e., Caucasian American)
- Born and raised in the United States
Who cannot join
- Mixed races
- Any chronic or ongoing disease
- Prescribed pharmacological treatment
- Smoking or tobacco use
- Obesity (body mass index > 30 kg / m2)
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Mississippi Medical Center
Jackson, Mississippi, 39216
About this study
The research aims of this proposal are:
- Specific Aim 1: To test whether an increase in nitric oxide signaling can increase vasodilator responses in young Black individuals.
- Specific Aim 2: To test whether a decrease in endothelin-1 signaling can increase vasodilator responses in young Black individuals.
Read the detailed description
Studies will be conducted in the Clinical Research and Trials Unit at the University of Mississippi Medical Center. All study visits will follow the same procedures, except for the drug or supplement being administered.
For Aim 1, double-blind, randomized, placebo-controlled crossover designs will examine the effects of increasing nitric oxide and cyclic guanosine monophosphate bioavailability on vascular function of young Black and White individuals. Three sets of two visits will be performed:
- Aim 1a: At the beginning of each visit, participants will ingest either a nitrate-rich beetroot juice or a nitrate-depleted beetroot juice (serving as placebo) in their liquid commercial form, which has a distinct color and flavor. The nitrates will be absorbed and reduced in the plasma to nitrite and nitric oxide, increasing endothelium-independent nitric oxide bioavailability.
- Aim 1b: Participants will receive a 7-day supplement of L-citrulline or placebo before each study visit, with a washout period of 7 days between visits. The activity of the endothelial nitric oxide synthase converts L-arginine into nitric oxide and L-citrulline, which is normally recycled back into L-arginine. Unlike L-arginine, oral ingestion of L-citrulline is not catabolized in the gut, nor is it extracted from systemic circulation through hepatic first-pass metabolism. Thus, ingested L-citrulline becomes available in large quantities in the plasma for enzymatic conversion into L-arginine, increasing endothelium-dependent nitric oxide bioavailability.
- Aim 1c: At the beginning of each visit, participants will ingest a liquid mixture prepared by Investigational Drug Services at the University of Mississippi Medical Center containing Sildenafil or placebo. Sildenafil inhibits phosphodiesterase 5, an enzyme that degrades cyclic guanosine monophosphate in the vascular smooth muscle cells inactivating the nitric oxide-mediated signal; thus, Sildenafil will prolong the availability of cyclic guanosine monophosphate, enhancing the nitric oxide-mediated intracellular cascade.
For Aim 2, a double-blind, randomized, placebo-controlled crossover design will examine the role of endothelin-1 on the vascular function of young Black and White individuals. Two visits will be performed, with a minimum of 7 days between them.
- Aim 2: At the beginning of each visit, participants will ingest a liquid mixture prepared by Investigational Drug Services at the University of Mississippi Medical Center containing Bosentan or placebo. Bosentan blocks ETA and ETB receptors, leading to a reduction in vasoconstrictor tone and a greater magnitude of vasodilator responses.
- Conditions
- Vascular Function, Racial Disparity
- Being tested
- Dietary Nitrates 400 mg, L-citrulline 3 g, Sildenafil 100 mg, Bosentan 125 mg
- Keywords
- Black, African American, White, Caucasian American, Hyperemia, Blood Flow, Conductance
- Medical subject headings
- Hyperemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dietary Nitrates 400 mgDietary supplement
Also called Beet It Sport Nitrate 400
The nitrates in the beetroot juice will be absorbed and reduced in the plasma to nitrite and nitric oxide, increasing endothelium-independent nitric oxide bioavailability.
L-citrulline 3 gDietary supplement
Ingested L-citrulline becomes available in large quantities in the plasma for enzymatic conversion into L-arginine. The activity of the endothelial nitric oxide synthase converts L-arginine into nitric oxide, increasing endothelium-dependent nitric oxide bioavailability.
Sildenafil 100 mgDrug
Also called Viagra, Revatio
Sildenafil inhibits phosphodiesterase 5, an enzyme that degrades cyclic guanosine monophosphate in the vascular smooth muscle cells inactivating the nitric oxide-mediated signal; thus, Sildenafil will prolong the availability of cyclic guanosine monophosphate, enhancing the nitric oxide-mediated intracellular cascade.
Bosentan 125 mgDrug
Also called Tracleer
Bosentan blocks endothelin-1 receptors ETA and ETB, leading to a reduction in vasoconstrictor tone and a greater magnitude of vasodilator responses.
| Study group | Role | What they receive |
|---|---|---|
| Beetroot juice (Aim 1a) | Active comparator | Upon arriving at the laboratory, participants will ingest 140 ml of beetroot juice containing a high (~12.8 mmol) concentration of nitrates (James White Drinks, Suffolk, UK). Receives: Dietary Supplement: Dietary Nitrates 400 mg |
| Placebo (Aim 1a) | Placebo comparator | Upon arriving at the laboratory, participants will ingest 140 ml of beetroot juice containing a low concentration (~0.0055 mmol) of nitrates (James White Drinks, Suffolk, UK). Receives: Dietary Supplement: Dietary Nitrates 400 mg |
| L-citrulline (Aim 1b) | Active comparator | Participants will receive pills containing 3 g of L-citrulline (Superior Labs, Park City, UT) to take twice daily for 7 days before the study visit. Receives: Dietary Supplement: L-citrulline 3 g |
| Placebo (Aim 1b) | Placebo comparator | Participants will receive pills containing a placebo to take twice daily for 7 days before the study visit. Receives: Dietary Supplement: L-citrulline 3 g |
| Sildenafil (Aim 1c) | Active comparator | Upon arriving at the laboratory, participants will ingest a liquid mixture containing Sildenafil (100 mg), an inhibitor of phosphodiesterase 5. Receives: Drug: Sildenafil 100 mg |
| Placebo (Aim 1c) | Placebo comparator | Upon arriving at the laboratory, participants will ingest a liquid mixture containing a placebo. Receives: Drug: Sildenafil 100 mg |
| Bosentan (Aim 2) | Active comparator | Upon arriving at the laboratory, participants will ingest a liquid mixture containing Bosentan (125 mg), a non-selective blocker of endothelin-1 receptors ETA and ETB. Receives: Drug: Bosentan 125 mg |
| Placebo (Aim 2) | Placebo comparator | Upon arriving at the laboratory, participants will ingest a liquid mixture containing a placebo. Receives: Drug: Bosentan 125 mg |
What is being measured
The primary outcome is the main question the study is designed to answer.
Flow-mediated Dilation
The percent change in arterial diameter normalized to arterial shear rate during reperfusion after 5 minutes of circulatory occlusion.
Measured: Within 4 hours of drug/supplement administration.
Reactive Hyperemia (Cuff Release)
Blood velocity area-under-the-curve from the beginning of reperfusion to return to resting values.
Measured: Within 4 hours of drug/supplement administration.
Muscle Hyperemia (Passive Leg Movement)
Peak and the area-under-the-curve of the change in femoral artery blood flow during 1 minute of passive leg movement.
Measured: Within 4 hours of drug/supplement administration.
Muscle Hyperemia (Rhythmic Handgrip Exercise)
Changes in brachial artery blood flow and conductance during single handgrip contractions at 3 intensities.
Measured: Baseline measurements with no drug/supplement administration before or after.
Muscle Hyperemia (Rhythmic Knee Extension Exercise)
Changes in femoral artery blood flow and conductance during 3 minutes of rhythmic knee extension exercise.
Measured: Within 4 hours of drug/supplement administration.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2021
- Study start27 May 2021
- Primary completion20 Sep 2021
- Study completion20 Sep 2021
Why it stopped: Despite significant effort, we were unable to obtain the supply of drugs and supplements needed for the various arms of this Clinical Trial.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Vascular FunctionStudies 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
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Mississippi Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Thales Coelho Barbosa, University of Mississippi Medical Center
- Investigators
- Thales C Barbosa, Ph.D., Principal investigator, University of Mississippi Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04770155
- Sponsor's protocol ID
- 2P20GM104357-08
- Acronym
- UMMC_Pilot
- Status last verified
- Oct 2023
- First submitted
- 16 Feb 2021
- Last updated
- 31 Oct 2023
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Doppler ultrasound videos, analog-digital recordings, participants' characteristics, and randomization codes will be available in an unidentified format.
Publications
Barbosa TC, Young BE, Stephens BY, Nandadeva D, Kaur J, Keller DM, Fadel PJ. Functional sympatholysis is preserved in healthy young Black men during rhythmic handgrip exercise. Am J Physiol Regul Integr Comp Physiol. 2020 Sep 1;319(3):R323-R328. doi: 10.1152/ajpregu.00105.2020. Epub 2020 Aug 12.
PubMed 32783690Barbosa TC, Kaur J, Stephens BY, Akins JD, Keller DM, Brothers RM, Fadel PJ. Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men. Am J Physiol Heart Circ Physiol. 2018 Nov 1;315(5):H1316-H1321. doi: 10.1152/ajpheart.00387.2018. Epub 2018 Aug 17.
PubMed 30118345Kaur J, Barbosa TC, Nandadeva D, Young BE, Stephens BY, Brothers RM, Fadel PJ. Attenuated Rapid-Onset Vasodilation to Forearm Muscle Contraction in Black Men. Med Sci Sports Exerc. 2021 Mar 1;53(3):590-596. doi: 10.1249/MSS.0000000000002511.
PubMed 32910095Young BE, Kaur J, Vranish JR, Stephens BY, Barbosa TC, Cloud JN, Wang J, Keller DM, Fadel PJ. Augmented resting beat-to-beat blood pressure variability in young, healthy, non-Hispanic black men. Exp Physiol. 2020 Jul;105(7):1102-1110. doi: 10.1113/EP088535. Epub 2020 May 27.
PubMed 32362031Vranish JR, Holwerda SW, Young BE, Credeur DP, Patik JC, Barbosa TC, Keller DM, Fadel PJ. Exaggerated Vasoconstriction to Spontaneous Bursts of Muscle Sympathetic Nerve Activity in Healthy Young Black Men. Hypertension. 2018 Jan;71(1):192-198. doi: 10.1161/HYPERTENSIONAHA.117.10229. Epub 2017 Dec 4.
PubMed 29203629
Study at a glance
From the registry record, last updated by the sponsor on 31 Oct 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vascular Dysfunction in Black Individuals: Roles of Nitric Oxide and Endothelin-1
- ClinicalTrials.gov ID
- NCT04770155
- Acronym / sponsor ID
- UMMC_Pilot / 2P20GM104357-08
- Conditions
- Vascular Function, Racial Disparity
- Keywords
- Black, African American, White, Caucasian American, Hyperemia, Blood Flow, Conductance
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Despite significant effort, we were unable to obtain the supply of drugs and supplements needed for the various arms of this Clinical Trial.
- Enrolment
- 8 participants (actual)
- Lead sponsor
- University of Mississippi Medical CenterUniversity, hospital or other
- Study start
- 27 May 2021 (actual)
- Primary completion
- 20 Sep 2021 (actual)
- Study completion
- 20 Sep 2021 (actual)
- First posted
- 25 Feb 2021 (actual)
- Results
- Posted 31 Oct 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The research aims of this proposal are:
- Specific Aim 1: To test whether an increase in nitric oxide signaling can increase vasodilator responses in young Black individuals.
- Specific Aim 2: To test whether a decrease in endothelin-1 signaling can increase vasodilator responses in young Black individuals.
Detailed description
Studies will be conducted in the Clinical Research and Trials Unit at the University of Mississippi Medical Center. All study visits will follow the same procedures, except for the drug or supplement being administered.
For Aim 1, double-blind, randomized, placebo-controlled crossover designs will examine the effects of increasing nitric oxide and cyclic guanosine monophosphate bioavailability on vascular function of young Black and White individuals. Three sets of two visits will be performed:
- Aim 1a: At the beginning of each visit, participants will ingest either a nitrate-rich beetroot juice or a nitrate-depleted beetroot juice (serving as placebo) in their liquid commercial form, which has a distinct color and flavor. The nitrates will be absorbed and reduced in the plasma to nitrite and nitric oxide, increasing endothelium-independent nitric oxide bioavailability.
- Aim 1b: Participants will receive a 7-day supplement of L-citrulline or placebo before each study visit, with a washout period of 7 days between visits. The activity of the endothelial nitric oxide synthase converts L-arginine into nitric oxide and L-citrulline, which is normally recycled back into L-arginine. Unlike L-arginine, oral ingestion of L-citrulline is not catabolized in the gut, nor is it extracted from systemic circulation through hepatic first-pass metabolism. Thus, ingested L-citrulline becomes available in large quantities in the plasma for enzymatic conversion into L-arginine, increasing endothelium-dependent nitric oxide bioavailability.
- Aim 1c: At the beginning of each visit, participants will ingest a liquid mixture prepared by Investigational Drug Services at the University of Mississippi Medical Center containing Sildenafil or placebo. Sildenafil inhibits phosphodiesterase 5, an enzyme that degrades cyclic guanosine monophosphate in the vascular smooth muscle cells inactivating the nitric oxide-mediated signal; thus, Sildenafil will prolong the availability of cyclic guanosine monophosphate, enhancing the nitric oxide-mediated intracellular cascade.
For Aim 2, a double-blind, randomized, placebo-controlled crossover design will examine the role of endothelin-1 on the vascular function of young Black and White individuals. Two visits will be performed, with a minimum of 7 days between them.
- Aim 2: At the beginning of each visit, participants will ingest a liquid mixture prepared by Investigational Drug Services at the University of Mississippi Medical Center containing Bosentan or placebo. Bosentan blocks ETA and ETB receptors, leading to a reduction in vasoconstrictor tone and a greater magnitude of vasodilator responses.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| Beetroot juice (Aim 1a) | Active comparator | Dietary Supplement: Dietary Nitrates 400 mgUpon arriving at the laboratory, participants will ingest 140 ml of beetroot juice containing a high (~12.8 mmol) concentration of nitrates (James White Drinks, Suffolk, UK). |
| Placebo (Aim 1a) | Placebo comparator | Dietary Supplement: Dietary Nitrates 400 mgUpon arriving at the laboratory, participants will ingest 140 ml of beetroot juice containing a low concentration (~0.0055 mmol) of nitrates (James White Drinks, Suffolk, UK). |
| L-citrulline (Aim 1b) | Active comparator | Dietary Supplement: L-citrulline 3 gParticipants will receive pills containing 3 g of L-citrulline (Superior Labs, Park City, UT) to take twice daily for 7 days before the study visit. |
| Placebo (Aim 1b) | Placebo comparator | Dietary Supplement: L-citrulline 3 gParticipants will receive pills containing a placebo to take twice daily for 7 days before the study visit. |
| Sildenafil (Aim 1c) | Active comparator | Drug: Sildenafil 100 mgUpon arriving at the laboratory, participants will ingest a liquid mixture containing Sildenafil (100 mg), an inhibitor of phosphodiesterase 5. |
| Placebo (Aim 1c) | Placebo comparator | Drug: Sildenafil 100 mgUpon arriving at the laboratory, participants will ingest a liquid mixture containing a placebo. |
| Bosentan (Aim 2) | Active comparator | Drug: Bosentan 125 mgUpon arriving at the laboratory, participants will ingest a liquid mixture containing Bosentan (125 mg), a non-selective blocker of endothelin-1 receptors ETA and ETB. |
| Placebo (Aim 2) | Placebo comparator | Drug: Bosentan 125 mgUpon arriving at the laboratory, participants will ingest a liquid mixture containing a placebo. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Self-identification of their race and the race of their biological parents as being only Black (i.e., African American) or only White (i.e., Caucasian American)
- Born and raised in the United States
Key exclusion criteria (5 listed)
- Mixed races
- Any chronic or ongoing disease
- Prescribed pharmacological treatment
- Smoking or tobacco use
- Obesity (body mass index > 30 kg / m2)
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 |
|---|---|---|
| Dietary Nitrates 400 mgAlso: Beet It Sport Nitrate 400The nitrates in the beetroot juice will be absorbed and reduced in the plasma to nitrite and nitric oxide, increasing endothelium-independent nitric oxide bioavailability. | Dietary supplement | Beetroot juice (Aim 1a), Placebo (Aim 1a) |
| L-citrulline 3 gIngested L-citrulline becomes available in large quantities in the plasma for enzymatic conversion into L-arginine. The activity of the endothelial nitric oxide synthase converts L-arginine into nitric oxide, increasing endothelium-dependent nitric oxide bioavailability. | Dietary supplement | L-citrulline (Aim 1b), Placebo (Aim 1b) |
| Sildenafil 100 mgAlso: Viagra, RevatioSildenafil inhibits phosphodiesterase 5, an enzyme that degrades cyclic guanosine monophosphate in the vascular smooth muscle cells inactivating the nitric oxide-mediated signal; thus, Sildenafil will prolong the availability of cyclic guanosine monophosphate, enhancing the nitric oxide-mediated intracellular cascade. | Drug | Placebo (Aim 1c), Sildenafil (Aim 1c) |
| Bosentan 125 mgAlso: TracleerBosentan blocks endothelin-1 receptors ETA and ETB, leading to a reduction in vasoconstrictor tone and a greater magnitude of vasodilator responses. | Drug | Bosentan (Aim 2), Placebo (Aim 2) |
Primary outcome
Flow-mediated Dilation
Time frame: Within 4 hours of drug/supplement administration.
The percent change in arterial diameter normalized to arterial shear rate during reperfusion after 5 minutes of circulatory occlusion.
Reactive Hyperemia (Cuff Release)
Time frame: Within 4 hours of drug/supplement administration.
Blood velocity area-under-the-curve from the beginning of reperfusion to return to resting values.
Muscle Hyperemia (Passive Leg Movement)
Time frame: Within 4 hours of drug/supplement administration.
Peak and the area-under-the-curve of the change in femoral artery blood flow during 1 minute of passive leg movement.
Muscle Hyperemia (Rhythmic Handgrip Exercise)
Time frame: Baseline measurements with no drug/supplement administration before or after.
Changes in brachial artery blood flow and conductance during single handgrip contractions at 3 intensities.
Muscle Hyperemia (Rhythmic Knee Extension Exercise)
Time frame: Within 4 hours of drug/supplement administration.
Changes in femoral artery blood flow and conductance during 3 minutes of rhythmic knee extension exercise.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Oct 2023.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 32783690Barbosa TC, Young BE, Stephens BY, Nandadeva D, Kaur J, Keller DM, Fadel PJ. Functional sympatholysis is preserved in healthy young Black men during rhythmic handgrip exercise. Am J Physiol Regul Integr Comp Physiol. 2020 Sep 1;319(3):R323-R328. doi: 10.1152/ajpregu.00105.2020. Epub 2020 Aug 12.
- Background: PubMed 30118345Barbosa TC, Kaur J, Stephens BY, Akins JD, Keller DM, Brothers RM, Fadel PJ. Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men. Am J Physiol Heart Circ Physiol. 2018 Nov 1;315(5):H1316-H1321. doi: 10.1152/ajpheart.00387.2018. Epub 2018 Aug 17.
- Background: PubMed 32910095Kaur J, Barbosa TC, Nandadeva D, Young BE, Stephens BY, Brothers RM, Fadel PJ. Attenuated Rapid-Onset Vasodilation to Forearm Muscle Contraction in Black Men. Med Sci Sports Exerc. 2021 Mar 1;53(3):590-596. doi: 10.1249/MSS.0000000000002511.
- Background: PubMed 32362031Young BE, Kaur J, Vranish JR, Stephens BY, Barbosa TC, Cloud JN, Wang J, Keller DM, Fadel PJ. Augmented resting beat-to-beat blood pressure variability in young, healthy, non-Hispanic black men. Exp Physiol. 2020 Jul;105(7):1102-1110. doi: 10.1113/EP088535. Epub 2020 May 27.
- Background: PubMed 29203629Vranish JR, Holwerda SW, Young BE, Credeur DP, Patik JC, Barbosa TC, Keller DM, Fadel PJ. Exaggerated Vasoconstriction to Spontaneous Bursts of Muscle Sympathetic Nerve Activity in Healthy Young Black Men. Hypertension. 2018 Jan;71(1):192-198. doi: 10.1161/HYPERTENSIONAHA.117.10229. Epub 2017 Dec 4.
- Individual participant dataSharing planned: Yes. Doppler ultrasound videos, analog-digital recordings, participants' characteristics, and randomization codes will be available in an unidentified format.
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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.
Thales C Barbosa, Ph.D. principal investigator
University of Mississippi Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Dietary Nitrates 400 mg, L-citrulline 3 g and Sildenafil 100 mg in people with Vascular Function and Racial Disparity, run by University of Mississippi Medical Center at 1 site in United States.
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 2 inclusion and 5 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: stopped early, as of the sponsor's last update on 31 Oct 2023. 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 States. 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?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 31 Oct 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Flow-mediated Dilation (time frame: Within 4 hours of drug/supplement administration.). The study lists 5 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 NCT04770155, which also lists 5 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 31 Oct 2023.