Testosterone and Neurovascular Control in Humans

Healthy Clinical Trial

Official title:

Exploring the Role of Testosterone on Neurovascular Control in Humans

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT04819204
• Other study ID #: 117996
• Status: Not yet recruiting
• Phase: N/A
• Start date: June 2021
• Est. completion date: December 2023

Study information

• Verified date: March 2021
• Source: Western University, Canada
• Contact: Andrew D'Souza, MSc
• Phone: 519-661-2111
• Email: adsouz58[@]uwo.ca
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 20
• Est. completion date: December 2023
• Est. primary completion date: December 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 35 Years

Eligibility

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

Related Conditions & MeSH terms

• Healthy

Intervention

Drug:
• Cetrorelix Acetate
GnRH antagonist - subcutaneous injection. Day 1: 1-3 mg; Days 2-14: 0.25mg/daily.
• Testosterone gel
Testosterone gel - transdermal application of 5mg/day on Day 7-14 of GnRH antagonist

Locations

Country	Name	City	State
Canada	the University of Western Ontario	London	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
Western University, Canada

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Sex hormones	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
Primary	Muscle sympathetic nerve activity	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
Primary	Endothelial function	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
Primary	Forearm blood flow	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	Skeletal muscle microvascular blood flow	Microvascular blood flow will be measured using Diffuse correlation spectroscopy.	After 7 days GnRH antagonist alone and 7 days GnRH antagonist + Testosterone