Effects of Estrogen on Heart Health in Women With Primary Ovarian Insufficiency (ENCODE)

January 5, 2026 updated by: Sara L. Stockman, MD, PhD, Massachusetts General Hospital

Effects of Estrogen Replacement on Cardiometabolic Endpoints in Women With Primary Ovarian Insufficiency

The goal of this observational study is to study the effects of treating women with Primary Ovarian Insufficiency (POI) with estrogen replacement therapy to bolster the evidence backing cardiometabolic preventive care in women with POI. The main question it aims to answer is:

Does 6 months of estrogen replacement therapy for women with POI improved markers of heart health?

Women newly diagnosed with POI (within 6 months) who are planning to start estrogen replacement therapy from their clinical provider will undergo assessment of markers of heart health before and after 6 months of treatment. These markers will also be compared to those obtained from healthy women without POI.

Study Overview

Detailed Description

Primary Ovarian Insufficiency (POI) is known to adversely affect bone and CV health. Despite the established role for ERT in bone health and the potential cardioprotection suggested by recent studies, few women with POI receive treatment. In this proposed study, we aim to characterize potential salient short-term benefits of ERT on CV surrogates. We hypothesize that among women newly diagnosed with POI, clinical initiation of ERT with transdermal estrogen will improve cardiometabolic risk surrogates, including endothelial function. This study will enhance the body of evidence underpinning guideline-directed approaches to cardiometabolic preventive health care for women with POI.

For this observational study, women newly diagnosed with POI (within 6 months) who are planning to clinically initiate hormonal replacement with 100mcg transdermal 17beta-estradiol twice weekly and micro-ionized progesterone (either 200mg cyclically or 100mg daily) will undergo assessment of cardiometabolic endpoints before and after 6 months of treatment. For comparison, healthy women without POI matched 1:1 on age, BMI, and PREVENT™ risk score category (low-high risk) will undergo parallel assessments at baseline.

Participants will undergo a medical history, physical exam, anthropomorphic measurements, blood sampling, brachial artery flow-mediated dilation (FMD), as a measure of peripheral endothelial function relevant to development of incident CVD, and whole-body DXA to assess body composition. Case participants with POI will participate in two in-person study visits that occur just prior to initiation of ERT and 6-months into treatment. Healthy control participants only participate in a single baseline visit.

The primary endpoint will be brachial artery flow-mediated dilation (FMD). Secondary endpoints will include measures of metabolic dysregulation (possibly including, but not limited to, hemoglobin A1c, circulating lipid levels, HOMA-IR for insulin resistance and DEXA-derived visceral adipose tissue) and characterization of circulating immune/inflammatory biomarkers (possibly including, but not limited to, CRP and pro-inflammatory cytokines IL-6 and TNF-α).

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 Contact

Study Contact Backup

Study Locations

    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General 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

The study population is comprised of women newly diagnosed with POI (within 6 months) who are planning to clinically initiate hormonal replacement with 100mcg transdermal 17beta-estradiol twice weekly and micro-ionized progesterone (either 200mg cyclically or 100mg daily). For comparison, healthy women without POI matched 1:1 on age, BMI, and PREVENT™ risk score category (low-high risk) will also be studied.

Description

Inclusion criteria (I):

  • female sex
  • age 30-40
  • CASE PARTICIPANTS ONLY: clinically documented POI diagnosis within 6 months
  • CASE PARTICIPANTS ONLY: planning to clinically initiate 100mcg transdermal 17beta-estradiol twice weekly and micro-ionized progesterone (either 100mg daily or 200mg cyclically)
  • CONTROL PARTICIPANTS ONLY: regular menstrual cycles every 21-35 days

Exclusion criteria (E):

  • CASE PARTICIPANTS ONLY: genetic POI etiology
  • CASE PARTICIPANTS ONLY: any prior initiation of ERT
  • systemic estrogen, progesterone or testosterone therapy within the past 6 months (including contraception, except for locally acting intrauterine devices - IUDs)
  • lipid lowering therapy within the past 6 months
  • use of antihypertensive medication within the past 6 months
  • current treatment with prescription, systemic (oral, IV, or IM) steroids or anti-inflammatory/immune suppressant medical therapies (excluding topical therapies, UV therapy, ASA-derivative therapies, or NSAIDS) for autoimmune/inflammatory diseases (psoriasis, RA, IBD, lupus), post-transplant care, asthma, or pain syndromes
  • use of oral steroids or prescription oral anti-inflammatory/immune suppressant medication for >7 days within the past 1 month
  • use of IV or IM steroids or IV or IM anti-inflammatory/immune suppressant medication within the past 3 months
  • self-reported history of breast and/or estrogen dependent malignancy
  • self-reported history of deep vein thromboembolism, pulmonary embolism or stroke
  • self-reported severe liver disease such as cirrhosis
  • self-reported hypercoagulable disorder
  • uncontrolled hypertension at baseline Visit #1- systolic blood pressure (SBP) ≥180 and/or diastolic blood pressure (DBP) ≥110
  • tobacco use within 6 months
  • self-reported history of myocardial infarction, stroke, coronary revascularization or diabetes as a CVD risk equivalent
  • stable or unstable angina
  • self-reported history of heart failure
  • pregnancy or breastfeeding
  • concurrent enrollment in conflicting research study

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
Case participants with Primary Ovarian Insufficiency
This group is comprised of women (assigned female at birth), age 30-40yo who have a clinically documented diagnosis of primary ovarian insufficiency (POI) within 6 months and be planning to clinically initiate estrogen replacement therapy (with 100mcg transdermal 17beta-estradiol twice weekly and micro-ionized progesterone either 100mg daily or 200mg cyclically) with their own provider. Women in the group may not be on systemic estrogen, progesterone or testosterone therapy, have contraindications for estrogen administration or known atherosclerotic cardiovascular disease or equivalents. They must also not take lipid lowering therapy or antihypertensive or anti-inflammatory/immune suppressant medications or be pregnant or breastfeeding. After a telephone screen to determine eligibility, the group will engage in two in-person study visits. The first occurs prior to the initiating estrogen replacement therapy and the second after 6 months of treatment.
Health control participants without Primary Ovarian Insufficiency
This group is compromised of women (assigned female at birth), age 30-40yo who have regular menstrual cycles every 21-35 days. Women in the group may not be on systemic estrogen, progesterone or testosterone therapy, have contraindications for estrogen administration or known atherosclerotic cardiovascular disease or equivalents. They must also not take lipid lowering therapy or antihypertensive or anti-inflammatory/immune suppressant medications or be pregnant or breastfeeding. After a telephone screen to determine eligibility, the group will in a single in-person study visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Brachial artery Flow Mediated Vasodilation (FMD)
Time Frame: 6 months
Brachial artery flow-mediated dilation (FMD) is a non-invasive measure of endothelial function relevant to the development of incident cardiovascular disease. Brachial artery FMD will be reported as a percentage (%FMD), calculated by comparing the change in brachial artery diameter during reactive hyperemia to the baseline diameter. %FMD will be compared between case participants with POI and healthy control participants at baseline. The change in %FMD after 6 months of estrogen replacement therapy will be determined for case participants with POI.
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Metabolic biomarkers
Time Frame: 6 months
Urine and serum biomarkers relating to metabolism (including glucose and lipid metabolism, body composition)
6 months
Immune/inflammatory biomarkers
Time Frame: 6 months
Urine and serum biomarkers relating to inflammation and immune activation
6 months

Collaborators and Investigators

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

Investigators

  • Study Chair: Markella V. Zanni, MD, MGH/HMS

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 (Estimated)

March 1, 2026

Primary Completion (Estimated)

April 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

March 4, 2025

First Submitted That Met QC Criteria

March 4, 2025

First Posted (Actual)

March 10, 2025

Study Record Updates

Last Update Posted (Actual)

January 7, 2026

Last Update Submitted That Met QC Criteria

January 5, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Plans are for IPD to be shared to the NIH BioLINCC data repository.

IPD Sharing Time Frame

Data will be made available 12 months after study completion and will remain available for a duration of time consonant with NIH policies.

IPD Sharing Access Criteria

Access criteria are as per the NIH BioLINCC data repository.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

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.

Clinical Trials on Primary Ovarian Insufficiency

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