Estrogen and Microvascular Function

Active, not recruiting

• Conditions: Microvasculature; Cardiovascular Diseases; Estrogen
• Interventions: Drug: Nω-nitro-L-arginine methyl ester (L-NAME); Drug: Acetylcholine; Drug: Sodium Nitroprusside

• Registration Number: NCT06043310
• Lead Sponsor: Medical College of Wisconsin

Brief Summary

The goal of this study is to learn how long-term use of estrogen affects blood vessels in healthy adults who were assigned male at birth.

Participants will:

* give one blood draw of 5 mL

* have a camera placed under the tongue to take pictures of blood vessels

* have 2 laser Doppler microdialysis catheters placed on the forearm to monitor blood vessels before and after local drug infusion

Researchers will compare blood vessel function of those who take estrogen supplements to those who do not.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-06-02
• Study First Submitted: 2023-09-12
• Study First Submitted QC: 2023-09-12
• Study First Posted: 2023-09-21
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-28
• Last Update Posted: 2025-05-01
• Primary Completion: 2029-12
• Study Completion: 2029-12

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: Male
• Target Recruitment: 20

Inclusion Criteria

• Adults aged 18-60 years
• Identify as assigned male at birth (AMAB) +/- continuous estrogen treatment for a minimum of 1 year.
• Blood pressure <140/ < 90 mmHg
• No more than 1 cardiovascular risk factor

Exclusion Criteria

• BMI >35
• Medications that could alter cardiovascular control
• Rash, skin disease, or pigmentation disorders
• Anemia
• Kidney Disease
• Known skin allergies
• Smoking or tobacco use within last 6 months
• Coronary Artery Disease
• > 1 cardiovascular risk factor
• Hypertension
• Diabetes
• Hypercholesterolemia
• Hyperlipidemia
• Bleeding disorders
• Use of anti-coagulants
• Allergies to study drugs
• Erectile dysfunction medication in the past 6 months
• Use of topical/non-topical steroids in last 6 months
• Internal mouth sores

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
AMAB + continuous estrogen	Nω-nitro-L-arginine methyl ester (L-NAME)	Identify as assigned male at birth (AMAB) who have had continuous estrogen treatment for a minimum of 1 year.
AMAB + continuous estrogen	Sodium Nitroprusside	Identify as assigned male at birth (AMAB) who have had continuous estrogen treatment for a minimum of 1 year.
AMAB - continuous estrogen	Nω-nitro-L-arginine methyl ester (L-NAME)	Identify as assigned male at birth (AMAB) who have not had continuous estrogen treatment for a minimum of 1 year.
AMAB - continuous estrogen	Sodium Nitroprusside	Identify as assigned male at birth (AMAB) who have not had continuous estrogen treatment for a minimum of 1 year.
AMAB + continuous estrogen	Acetylcholine	Identify as assigned male at birth (AMAB) who have had continuous estrogen treatment for a minimum of 1 year.
AMAB - continuous estrogen	Acetylcholine	Identify as assigned male at birth (AMAB) who have not had continuous estrogen treatment for a minimum of 1 year.

Primary Outcome Measures

Name	Time	Method
Change in blood vessel dilation	2 hours	Cutaneous vascular conductance in response to acetylcholine, L-NAME, and sodium nitroprusside infusions will be calculated as percentage of cardiovascular conductance.
Change in Perfused Vessel Density	0.5 hours	Total vessel density (TVD) will be calculated using the DeBacker Score manual analysis on all images that have a minimum microcirculation image quality score (MIQS) of 10. Perfused vessel density (PVD) will be calculated by multiplying total vessel density (TVD) x proportion of perfused vessels (PPV%).

Trial Locations

Locations (1)

Froedtert Hospital; 🇺🇸 Wauwatosa, Wisconsin, United States