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Testosterone and Neurovascular Control in Humans

Sponsor
Western University, Canada (Other)
Overall Status
Not yet recruiting
CT.gov ID
NCT04819204
Collaborator
(none)
20
Enrollment
1
Location
2
Arms
30
Anticipated Duration (Months)
0.7
Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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

Condition or Disease Intervention/Treatment Phase
  • Drug: Cetrorelix Acetate
  • Drug: Testosterone gel
 N/A

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 Design

Study Type:
Interventional
Anticipated Enrollment :
20 participants
Allocation:
Non-Randomized
Intervention Model:
Parallel Assignment
Masking:
None (Open Label)
Primary Purpose:
Basic Science
Official Title:
Exploring the Role of Testosterone on Neurovascular Control in Humans
Anticipated Study Start Date :
Jun 1, 2021
Anticipated Primary Completion Date :
Dec 1, 2023
Anticipated Study Completion Date :
Dec 1, 2023

Arms and Interventions

Arm Intervention/Treatment
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%

    		•

    Outcome Measures

    Primary Outcome Measures

    1. Muscle sympathetic nerve activity [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.

    2. Endothelial function [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.

    3. Forearm blood flow [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)

    Secondary Outcome Measures

    1. Skeletal muscle microvascular blood flow [After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone]

      Microvascular blood flow will be measured using Diffuse correlation spectroscopy.

    Other Outcome Measures

    1. Sex hormones [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.

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    18 Years to 35 Years
    Sexes Eligible for Study:
    Male
    Accepts Healthy Volunteers:
    Yes
    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

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 the University of Western Ontario London Ontario Canada N6A 5B9

    Sponsors and Collaborators

    • Western University, Canada

    Investigators

    • Principal Investigator: Joel K Shoemaker, Ph.D., University of Western Ontario, Canada

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    None provided.
    Responsible Party:
    Kevin Shoemaker, Principal Investigator, Western University, Canada
    ClinicalTrials.gov Identifier:
    NCT04819204
    Other Study ID Numbers:
    • 117996
    First Posted:
    Mar 26, 2021
    Last Update Posted:
    Mar 26, 2021
    Last Verified:
    Mar 1, 2021
    Individual Participant Data (IPD) Sharing Statement:
    No
    Plan to Share IPD:
    No
    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
    Additional relevant MeSH terms:
    Cetrorelix
    Testosterone

    Study Results

    No Results Posted as of Mar 26, 2021