Testosterone and Neurovascular Control in Humans

March 25, 2021 updated by: Kevin Shoemaker, Western University, Canada

Exploring the Role of Testosterone on Neurovascular Control in Humans

The purpose of these studies are to evaluate the role of testosterone on autonomic and vascular function in men.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Sex hormones play a pivotal role in neurovascular function in humans. In recent years, great strides have been made in elucidating the roles of estrogen and progesterone on autonomic and vascular control in women; however, very little is known about the impact of testosterone in men. Given that low testosterone levels are associated with an increased risk of cardiovascular disease, reduced exercise capacity and vascular dysfunction, it is evident that testosterone plays a pivotal role in autonomic and vascular function in men. Our current understanding of testosterone's effects on neurovascular control are confounded by numerous factors that independently alter autonomic and vascular function such as aging and chronic disease (e.g. cardiovascular disease, metabolic disease). The purpose of these studies are to evaluate the role of testosterone on autonomic and vascular function in young men to better isolate the effects of testosterone from the aforementioned confounding factors. The outcomes of these studies will provide novel information regarding the role of male sex hormones in autonomic and vascular control, and further our understanding of the influence of sex hormones on human physiology.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Andrew D'Souza, MSc
  • Phone Number: 88084 519-661-2111
  • Email: adsouz58@uwo.ca

Study Contact Backup

Study Locations

  • Canada
    • Ontario
      • London, Ontario, Canada, N6A 5B9
        • The University of Western Ontario

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 35 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Moderately active
  • Free of chronic disease

Exclusion Criteria:

  • congenital or acquired hypogonadism
  • drug/alcohol dependence
  • hypertension
  • current smoker
  • current opioid or cannabis user
  • diabetes
  • inability to provide written consent
  • parkinson's disease
  • cardiovascular disease
  • testosterone use within the last year

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: GnRH antagonist alone
Intervention: Cetrorelix acetate (Cetrotide)
Drug: Cetrorelix Acetate
GnRH antagonist - subcutaneous injection. Day 1: 1-3 mg; Days 2-14: 0.25mg/daily.
Other Names:
  • Cetrotide
Experimental: GnRH antagonist + Testosterone add-back
Intervention: Cetrorelix acetate (Cetrotide) + Testosterone gel (Androgel)
Drug: Cetrorelix Acetate
GnRH antagonist - subcutaneous injection. Day 1: 1-3 mg; Days 2-14: 0.25mg/daily.
Other Names:
  • Cetrotide
Drug: Testosterone gel
Testosterone gel - transdermal application of 5mg/day on Day 7-14 of GnRH antagonist
Other Names:
  • Androgel 1%

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Muscle sympathetic nerve activity
Time Frame: After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Multi-unit postganglionic muscle sympathetic nerve activity (MSNA) will be measured by inserting a unipolar tungsten microelectrode into the peroneal nerve near the fibular head of the leg. Neural signals will be amplified, filtered (bandwidth, 700-2,000 Hz), rectified, and integrated (time constant, 0.1 s) to obtain mean voltage neurograms. MSNA will be measured during both trials to evaluate the effect of testosterone on sympathetic activity directed toward the musculature.
After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Endothelial function
Time Frame: After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Brachial artery flow-mediated dilation (FMD). Brachial artery FMD measures will be performed non-invasively via Doppler ultrasound.
After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Forearm blood flow
Time Frame: After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Forearm blood flow will be measured using Doppler ultrasound at baseline and during stress (e.g. exercise)
After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Skeletal muscle microvascular blood flow
Time Frame: After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Microvascular blood flow will be measured using Diffuse correlation spectroscopy.
After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Sex hormones
Time Frame: After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone
Serum concentrations of total testosterone, estradiol, albumin, and sex hormone binding globulin (SHBG) will be measured to document changes in hormone concentrations. Free testosterone will be calculated using total testosterone, SHBG and albumin.
After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Western University, Canada

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Joel K Shoemaker, Ph.D., University of Western Ontario, Canada

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Anticipated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2021

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2023

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 22, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 26, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 26, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2021

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 117996

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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