Estrogen and Microvascular Function

July 27, 2026 updated by: Julie K. Freed, Medical College of Wisconsin

Effects of Continuous Estrogen on Human in Vivo Microvascular Function

The goal of this study is to learn how long-term use of estrogen affects blood vessels in healthy adults.

Participants will:

  • give one blood draw of 5 mL
  • have one Dexa Scan taken to measure adipose and muscle mass
  • 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 to those who do not.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

45

Contacts and Locations

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

Study Locations

  • United States
    • Wisconsin
      • Wauwatosa, Wisconsin, United States, 53226
        • Froedtert Hospital

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Community sample

Description

Inclusion Criteria:

Estrogen/Progestin Group

  • Adults aged 18-40 years
  • Females with estrogen/progestin treatment for a minimum of 1 year.
  • Blood pressure <140/ < 90 mmHg
  • No more than 1 cardiovascular risk factor Control Groups
  • Adults aged 18-40 years
  • Female with no estrogen/progestin treatment for minimum of 5 years.
  • Female undergoing progestin only treatment for a minimum of 1 year.
  • Blood pressure <140/ < 90 mmHg
  • No more than 1 cardiovascular risk factor

Exclusion Criteria:

  • Medications that could alter cardiovascular control
  • Rash, skin disease, or pigmentation disorders on both forearms
  • 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
  • Use of topical/non-topical steroids in last 6 months
  • Internal mouth sores
  • Forearms covered with tattoos
  • Pregnancy

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Continuous estrogen/progestin
Females who have had continuous estrogen/progestin treatment for a minimum of 1 year.
Drug: Nω-nitro-L-arginine methyl ester (L-NAME)
L-NAME will be infused locally through microdialysis catheters.
Drug: Acetylcholine
ACh will be infused locally through microdialysis catheters.
Drug: Sodium Nitroprusside
SNP will be infused locally through microdialysis catheters.
No Estrogen/progestin
Females who have not had continuous estrogen treatment for a minimum of 5 years.
Drug: Nω-nitro-L-arginine methyl ester (L-NAME)
L-NAME will be infused locally through microdialysis catheters.
Drug: Acetylcholine
ACh will be infused locally through microdialysis catheters.
Drug: Sodium Nitroprusside
SNP will be infused locally through microdialysis catheters.
Continuous progestin
Females who have had continuous progestin treatment for a minimum of 1 year.
Drug: Nω-nitro-L-arginine methyl ester (L-NAME)
L-NAME will be infused locally through microdialysis catheters.
Drug: Acetylcholine
ACh will be infused locally through microdialysis catheters.
Drug: Sodium Nitroprusside
SNP will be infused locally through microdialysis catheters.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Perfused Vessel Density
Time Frame: 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%).
0.5 hours
Change in blood vessel dilation
Time Frame: 2 hours
Cutaneous vascular conductance in response to acetylcholine, L-NAME, and sodium nitroprusside infusions will be calculated as percentage of cardiovascular conductance.
2 hours

Collaborators and Investigators

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

Sponsor

Medical College of Wisconsin

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 (Actual)

October 12, 2023

Primary Completion (Estimated)

December 1, 2031

Study Completion (Estimated)

December 1, 2031

Study Registration Dates

First Submitted

September 12, 2023

First Submitted That Met QC Criteria

September 12, 2023

First Posted (Actual)

September 21, 2023

Study Record Updates

Last Update Posted (Actual)

July 29, 2026

Last Update Submitted That Met QC Criteria

July 27, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PRO40920

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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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