VasoconstrictionPhase 4STARSNCT05997732
Sympathetic Neurovascular Transduction: Role of Adrenergic Receptors and Sex Differences
A Phase 4 study testing Phenylephrine Hydrochloride, Isoproterenol Hydrochloride and Norepinephrine Bitartrate in people with Vasoconstriction and Vasodilation, run by University of Alberta at 1 site in Canada.
Trial summary
The main purpose of this interventional study is to examine differences in resting blood pressure control between healthy males and females. The main questions it aims to answer are: 1. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Vasoconstriction, Vasodilation
- What is being tested?
- Phenylephrine Hydrochloride, Isoproterenol Hydrochloride and Norepinephrine Bitartrate
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteCanada
- Study dates
- 31 Oct 2023to 1 Dec 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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
- Between ages 18-40 years
- No diagnosed medical history of cardiovascular, respiratory, nervous system, or metabolic disease.
- Females must be pre-menopausal.
- Prior to study visit: abstained from caffeine, alcohol, strenuous exercise, and medication not taken regularly for at least 12 hours.
Who cannot join
- Current diagnosis of cardiovascular, respiratory, nervous system, or metabolic disease that may impact blood pressure regulation. This will be assessed on a case-by-case basis by the study physician.
- Participants with bleeding or clotting disorders, or those currently taking blood thinners.
- Participants currently taking beta-agonist inhalers i.e. Ventolin (at least not in the last 24 hours).
- Females who are pregnant, confirmed by a pregnancy test.
- Females who have are less than 1 year postpartum or are breastfeeding.
- Females who are post-menopausal.
Show all 11Show fewer
- Participants that are classified as obese (body mass index > 30 kg ⋅ m2).
- Have a history of smoking regularly in the last 6 months (but nicotine substitutes (i.e. patch, gum) are not an exclusion criteria).
- Those with a known allergy to sulfites, or other components of the supplied solution of study drugs.
- Participants taking medications that are contraindicated with any of the study drugs, such as monoamine oxidase (MAO) inhibitors or tricyclic antidepressants.
- Participants who have not adhered to the pre-testing guidelines related to diet, alcohol or exercise will not be excluded, but will be rescheduled for a different day. This is to reduce experimental variability.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
University of Alberta
Edmonton, Alberta, T6G 2R3
Craig Steinback, PhD, (780)492-5553, craig.steinback@ualberta.ca
About this study
The main purpose of this interventional study is to examine differences in resting blood pressure control between healthy males and females. The main questions it aims to answer are:
- Are there sex differences in the communication between the sympathetic nervous system (also known as the "fight or flight" response) and peripheral blood vessels (which influence systemic blood pressure)?
- What is the role of specific vascular receptors that respond to sympathetic signals, and is it different between males and females?
Read more
Participants will complete one study visit of approximately 3 hours where they will:
- Have a blood sample taken to measure circulating sex hormone and sympathetic transmitters.
- Receive very small doses of medications commonly used to adjust blood pressure through an artery in their arm. The effects of these medications will be short-acting and localized to the forearm.
- Have their sympathetic nervous activity directly measured through two very small needles (similar to acupuncture needles) in the side of their leg.
- Have their blood pressure and heart rate recorded, and forearm blood flow measured using ultrasound.
Read the detailed description
Blood pressure is in part regulated by activity of your sympathetic nervous system (also known as your "fight or flight" response). Sympathetic nerve activity affects the size of your blood vessels, which in turn will affect your blood pressure. This communication between sympathetic impulses and the resulting change in vascular resistance is termed "sympathetic neurovascular transduction". In other words, transduction represents the reactivity of the blood vessels in response to individual sympathetic bursts of activity.
Males and females regulate their blood pressure in different ways; for example, females tend to have lower blood pressure and sympathetic nerve activity than males. Females also appear to have less constriction of their blood vessels in response to stress. This may be due to differences in the receptors which are activated by the sympathetic nervous system. These receptors are called α and β-adrenergic receptors and are located on vascular smooth muscle cells. They respond to sympathetic neurotransmitters such as norepinephrine in opposite directions: α-adrenoreceptors cause vasoconstriction (and an increase in vascular resistance), and β-adrenoreceptors cause vasodilation (and a decrease in vascular resistance) in part through the endothelium-dependent nitric oxide pathway.
Current evidence suggests that β-adrenergic receptors are more sensitive in females and contribute to paradoxical vasodilation when α-adrenergic receptors are stimulated by norepinephrine from sympathetic bursts. It has also been suggested that estrogen interacts with adrenergic receptors, contributing to this sex difference. This study will contribute to the understanding of sex differences in cardiovascular physiology and may have implications for clinical cardiovascular conditions.
- Conditions
- Vasoconstriction, Vasodilation
- Being tested
- Phenylephrine Hydrochloride, Isoproterenol Hydrochloride, Norepinephrine Bitartrate, Propranolol Hydrochloride, Phentolamine Mesylate
- Keywords
- sympathetic nerve activity, sex differences, adrenergic receptors, neurovascular transduction
- Medical subject headings
- Aneurysm
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Phenylephrine HydrochlorideDrug
Participants will receive three incremental doses via the brachial artery catheter to assess α1-adrenoreceptor mediated vasoconstriction.
Isoproterenol HydrochlorideDrug
Participants will receive four incremental doses via the brachial artery catheter to assess β-adrenoreceptor mediated vasodilation.
Norepinephrine BitartrateDrug
Participants will receive three incremental doses via the brachial artery catheter to assess nonspecific adrenoreceptor activation.
Propranolol HydrochlorideDrug
Propranolol will be continuously infused through the brachial artery catheter to induce β-adrenergic blockade locally in the forearm.
Phentolamine MesylateDrug
Phentolamine will be continuously infused through the brachial artery catheter to induce α-adrenergic blockade locally in the forearm.
Phenylephrine HydrochlorideDrug
Participants will receive one dose via the brachial artery catheter to evaluate the effectiveness of the α-adrenergic blockade.
Isoproterenol HydrochlorideDrug
Participants will receive one dose via the brachial artery catheter to evaluate the effectiveness of the β-adrenergic blockade.
Propranolol HydrochlorideDrug
Propranolol will be continuously co-infused with phentolamine to maintain the β-adrenergic blockade.
| Study group | Role | What they receive |
|---|---|---|
| Control Condition | Experimental | Normal saline will be infused through the brachial artery catheter at the same calculated rate as propranolol + phentolamine in the α+β-blockade condition to control for volumetric effects. Receives: Drug: Phenylephrine Hydrochloride; Drug: Isoproterenol Hydrochloride; Drug: Norepinephrine Bitartrate |
| β-Adrenergic Blockade | Experimental | β-adrenoreceptors will be blocked locally in the forearm using propranolol. Normal saline will be co-infused at the calculated rate of phentolamine in the α+β-blockade condition to control for volumetric effects. Receives: Drug: Norepinephrine Bitartrate; Drug: Propranolol Hydrochloride |
| α+β-Adrenergic Blockade | Experimental | α-adrenoreceptors will be blocked locally in the forearm using phentolamine. Propranolol will be co-infused to maintain β-blockade. Receives: Drug: Phentolamine Mesylate; Drug: Phenylephrine Hydrochloride; Drug: Isoproterenol Hydrochloride; Drug: Propranolol Hydrochloride |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forearm blood flow
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Measured: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Forearm vascular resistance
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Measured: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Forearm vascular conductance
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Measured: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Arterial blood pressure
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Measured: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Muscle sympathetic nerve activity
Resting baseline
Measured: 10 minutes per condition = 30 minutes
Circulating sex hormone concentrations
Blood samples
Measured: 2 minutes
Circulating sympathetic neurotransmitter concentrations
Blood sample
Measured: 2 minutes
Secondary outcomes (1)
Arterial-venous blood gas concentrations
Blood sample during each condition
Measured: 2 minutes per sample = 6 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Aug 2023
- Study start31 Oct 2023
- Primary completion1 Dec 2027 (estimated)
- Study completion1 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for VasoconstrictionStudies of the same condition, open and under way.
- More trials run by University of AlbertaThe 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 4
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Model description
- Participants will complete three pharmacological conditions, and serve as their own controls.
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Alberta
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Sean van Diepen, MD, MSc, Principal investigator, University of AlbertaCraig Steinback, PhD, Principal investigator, University of Alberta
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05997732
- Sponsor's protocol ID
- Pro00126600
- Acronym
- STARS
- Status last verified
- Jan 2026
- First submitted
- 2 Aug 2023
- Last updated
- 8 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Hart EC, Charkoudian N, Wallin BG, Curry TB, Eisenach JH, Joyner MJ. Sex differences in sympathetic neural-hemodynamic balance: implications for human blood pressure regulation. Hypertension. 2009 Mar;53(3):571-6. doi: 10.1161/HYPERTENSIONAHA.108.126391. Epub 2009 Jan 26.
PubMed 19171792Steinback CD, Fraser GM, Usselman CW, Reyes LM, Julian CG, Stickland MK, Chari RS, Khurana R, Davidge ST, Davenport MH. Blunted sympathetic neurovascular transduction during normotensive pregnancy. J Physiol. 2019 Jul;597(14):3687-3696. doi: 10.1113/JP277714. Epub 2019 Jun 13.
PubMed 31106429Fairfax ST, Holwerda SW, Credeur DP, Zuidema MY, Medley JH, Dyke PC 2nd, Wray DW, Davis MJ, Fadel PJ. The role of alpha-adrenergic receptors in mediating beat-by-beat sympathetic vascular transduction in the forearm of resting man. J Physiol. 2013 Jul 15;591(14):3637-49. doi: 10.1113/jphysiol.2013.250894. Epub 2013 May 7.
PubMed 23652594Dinenno FA, Eisenach JH, Dietz NM, Joyner MJ. Post-junctional alpha-adrenoceptors and basal limb vascular tone in healthy men. J Physiol. 2002 May 1;540(Pt 3):1103-10. doi: 10.1113/jphysiol.2001.015297.
PubMed 11986395Hissen SL, Taylor CE. Sex differences in vascular transduction of sympathetic nerve activity. Clin Auton Res. 2020 Oct;30(5):381-392. doi: 10.1007/s10286-020-00722-0. Epub 2020 Aug 31.
PubMed 32865664
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sympathetic Neurovascular Transduction: Role of Adrenergic Receptors and Sex Differences
- ClinicalTrials.gov ID
- NCT05997732
- Acronym / sponsor ID
- STARS / Pro00126600
- Conditions
- Vasoconstriction, Vasodilation
- Keywords
- sympathetic nerve activity, sex differences, adrenergic receptors, neurovascular transduction
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of AlbertaUniversity, hospital or other
- Study start
- 31 Oct 2023 (actual)
- Primary completion
- 1 Dec 2027 (estimated)
- Study completion
- 1 Dec 2027 (estimated)
- First posted
- 18 Aug 2023 (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.
The main purpose of this interventional study is to examine differences in resting blood pressure control between healthy males and females. The main questions it aims to answer are:
- Are there sex differences in the communication between the sympathetic nervous system (also known as the "fight or flight" response) and peripheral blood vessels (which influence systemic blood pressure)?
- What is the role of specific vascular receptors that respond to sympathetic signals, and is it different between males and females?
Participants will complete one study visit of approximately 3 hours where they will:
- Have a blood sample taken to measure circulating sex hormone and sympathetic transmitters.
- Receive very small doses of medications commonly used to adjust blood pressure through an artery in their arm. The effects of these medications will be short-acting and localized to the forearm.
- Have their sympathetic nervous activity directly measured through two very small needles (similar to acupuncture needles) in the side of their leg.
- Have their blood pressure and heart rate recorded, and forearm blood flow measured using ultrasound.
Detailed description
Blood pressure is in part regulated by activity of your sympathetic nervous system (also known as your "fight or flight" response). Sympathetic nerve activity affects the size of your blood vessels, which in turn will affect your blood pressure. This communication between sympathetic impulses and the resulting change in vascular resistance is termed "sympathetic neurovascular transduction". In other words, transduction represents the reactivity of the blood vessels in response to individual sympathetic bursts of activity.
Males and females regulate their blood pressure in different ways; for example, females tend to have lower blood pressure and sympathetic nerve activity than males. Females also appear to have less constriction of their blood vessels in response to stress. This may be due to differences in the receptors which are activated by the sympathetic nervous system. These receptors are called α and β-adrenergic receptors and are located on vascular smooth muscle cells. They respond to sympathetic neurotransmitters such as norepinephrine in opposite directions: α-adrenoreceptors cause vasoconstriction (and an increase in vascular resistance), and β-adrenoreceptors cause vasodilation (and a decrease in vascular resistance) in part through the endothelium-dependent nitric oxide pathway.
Current evidence suggests that β-adrenergic receptors are more sensitive in females and contribute to paradoxical vasodilation when α-adrenergic receptors are stimulated by norepinephrine from sympathetic bursts. It has also been suggested that estrogen interacts with adrenergic receptors, contributing to this sex difference. This study will contribute to the understanding of sex differences in cardiovascular physiology and may have implications for clinical cardiovascular conditions.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Participants will complete three pharmacological conditions, and serve as their own controls.
| Arm | Type | Receives |
|---|---|---|
| Control Condition | Experimental | Drug: Phenylephrine Hydrochloride, Drug: Isoproterenol Hydrochloride, Drug: Norepinephrine BitartrateNormal saline will be infused through the brachial artery catheter at the same calculated rate as propranolol + phentolamine in the α+β-blockade condition to control for volumetric effects. |
| β-Adrenergic Blockade | Experimental | Drug: Norepinephrine Bitartrate, Drug: Propranolol Hydrochlorideβ-adrenoreceptors will be blocked locally in the forearm using propranolol. Normal saline will be co-infused at the calculated rate of phentolamine in the α+β-blockade condition to control for volumetric effects. |
| α+β-Adrenergic Blockade | Experimental | Drug: Phentolamine Mesylate, Drug: Phenylephrine Hydrochloride, Drug: Isoproterenol Hydrochloride, Drug: Propranolol Hydrochlorideα-adrenoreceptors will be blocked locally in the forearm using phentolamine. Propranolol will be co-infused to maintain β-blockade. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Between ages 18-40 years
- No diagnosed medical history of cardiovascular, respiratory, nervous system, or metabolic disease.
- Females must be pre-menopausal.
- Prior to study visit: abstained from caffeine, alcohol, strenuous exercise, and medication not taken regularly for at least 12 hours.
Key exclusion criteria (11 listed)
- Current diagnosis of cardiovascular, respiratory, nervous system, or metabolic disease that may impact blood pressure regulation. This will be assessed on a case-by-case basis by the study physician.
- Participants with bleeding or clotting disorders, or those currently taking blood thinners.
- Participants currently taking beta-agonist inhalers i.e. Ventolin (at least not in the last 24 hours).
- Females who are pregnant, confirmed by a pregnancy test.
- Females who have are less than 1 year postpartum or are breastfeeding.
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 |
|---|---|---|
| Phenylephrine HydrochlorideParticipants will receive three incremental doses via the brachial artery catheter to assess α1-adrenoreceptor mediated vasoconstriction. | Drug | Control Condition |
| Isoproterenol HydrochlorideParticipants will receive four incremental doses via the brachial artery catheter to assess β-adrenoreceptor mediated vasodilation. | Drug | Control Condition |
| Norepinephrine BitartrateParticipants will receive three incremental doses via the brachial artery catheter to assess nonspecific adrenoreceptor activation. | Drug | Control Condition, β-Adrenergic Blockade |
| Propranolol HydrochloridePropranolol will be continuously infused through the brachial artery catheter to induce β-adrenergic blockade locally in the forearm. | Drug | β-Adrenergic Blockade |
| Phentolamine MesylatePhentolamine will be continuously infused through the brachial artery catheter to induce α-adrenergic blockade locally in the forearm. | Drug | α+β-Adrenergic Blockade |
| Phenylephrine HydrochlorideParticipants will receive one dose via the brachial artery catheter to evaluate the effectiveness of the α-adrenergic blockade. | Drug | α+β-Adrenergic Blockade |
| Isoproterenol HydrochlorideParticipants will receive one dose via the brachial artery catheter to evaluate the effectiveness of the β-adrenergic blockade. | Drug | α+β-Adrenergic Blockade |
| Propranolol HydrochloridePropranolol will be continuously co-infused with phentolamine to maintain the β-adrenergic blockade. | Drug | α+β-Adrenergic Blockade |
Primary outcome
Forearm blood flow
Time frame: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Forearm vascular resistance
Time frame: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Forearm vascular conductance
Time frame: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Arterial blood pressure
Time frame: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes
Measured during resting baseline; changes during phenylephrine, isoproterenol, and norepinephrine infusion to determine agonist sensitivity.
Muscle sympathetic nerve activity
Time frame: 10 minutes per condition = 30 minutes
Resting baseline
Circulating sex hormone concentrations
Time frame: 2 minutes
Blood samples
Circulating sympathetic neurotransmitter concentrations
Time frame: 2 minutes
Blood sample
1 secondary outcome
Arterial-venous blood gas concentrations
Time frame: 2 minutes per sample = 6 minutes
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2026.
- Background: PubMed 19171792Hart EC, Charkoudian N, Wallin BG, Curry TB, Eisenach JH, Joyner MJ. Sex differences in sympathetic neural-hemodynamic balance: implications for human blood pressure regulation. Hypertension. 2009 Mar;53(3):571-6. doi: 10.1161/HYPERTENSIONAHA.108.126391. Epub 2009 Jan 26.
- Background: PubMed 31106429Steinback CD, Fraser GM, Usselman CW, Reyes LM, Julian CG, Stickland MK, Chari RS, Khurana R, Davidge ST, Davenport MH. Blunted sympathetic neurovascular transduction during normotensive pregnancy. J Physiol. 2019 Jul;597(14):3687-3696. doi: 10.1113/JP277714. Epub 2019 Jun 13.
- Background: PubMed 23652594Fairfax ST, Holwerda SW, Credeur DP, Zuidema MY, Medley JH, Dyke PC 2nd, Wray DW, Davis MJ, Fadel PJ. The role of alpha-adrenergic receptors in mediating beat-by-beat sympathetic vascular transduction in the forearm of resting man. J Physiol. 2013 Jul 15;591(14):3637-49. doi: 10.1113/jphysiol.2013.250894. Epub 2013 May 7.
- Background: PubMed 11986395Dinenno FA, Eisenach JH, Dietz NM, Joyner MJ. Post-junctional alpha-adrenoceptors and basal limb vascular tone in healthy men. J Physiol. 2002 May 1;540(Pt 3):1103-10. doi: 10.1113/jphysiol.2001.015297.
- Background: PubMed 32865664Hissen SL, Taylor CE. Sex differences in vascular transduction of sympathetic nerve activity. Clin Auton Res. 2020 Oct;30(5):381-392. doi: 10.1007/s10286-020-00722-0. Epub 2020 Aug 31.
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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.
Sean van Diepen, MD, MSc principal investigator
University of Alberta
Craig Steinback, PhD principal investigator
University of Alberta
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Phenylephrine Hydrochloride, Isoproterenol Hydrochloride and Norepinephrine Bitartrate in people with Vasoconstriction and Vasodilation, run by University of Alberta at 1 site in Canada.
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 4 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 8 Jan 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 Canada. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Emily Vanden Berg, MSc ((780)-492-5553, ervanden@ualberta.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Forearm blood flow (time frame: 10 minutes per condition + 2 minutes per agonist dose = 60 minutes). The study lists 7 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 NCT05997732, 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 8 Jan 2026.