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Updated: Jul 16, 2026
06:18
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Estrogen affects post-menopausal women differently than estrogen plus progestin replacement therapy
Richard L Tannen1, Mark G Weiner, Dawei Xie
1Department of Medicine, University of Pennsylvaniua School of Medicine, 36th and Hamilton Walk, Philadelphia, PA 19104, USA. tannen@mail.med.upenn.edu
Human Reproduction (Oxford, England)
|March 10, 2007
Summary
Estrogen-only therapy in post-menopausal women showed lower risks for myocardial infarction and breast cancer compared to combined hormone therapy. Results varied based on hormone regimens and cardiovascular disease prevalence in hysterectomized women.
Area of Science:
- Reproductive Endocrinology
- Cardiovascular Health
- Oncology
Background:
- The Women's Health Initiative Randomized Controlled Trial (WHI RCT) compared estrogen-only therapy to combined estrogen-progestin therapy.
- Estrogen-only treatment in the WHI RCT showed less coronary artery disease and no increase in breast cancer.
- This study aimed to replicate WHI RCT findings using the UK General Practice Research Database (GPRD).
Purpose of the Study:
- To investigate the effects of estrogen-only treatment in post-menopausal women who have undergone a hysterectomy.
- To compare the outcomes of estrogen-only therapy with combined estrogen-progestin therapy using GPRD data.
- To assess cardiovascular disease, breast cancer, and colorectal cancer risks associated with different hormone therapies.
Main Methods:
- A simulated estrogen-only WHI RCT was conducted using the GPRD, focusing on women aged 55-79 who had a hysterectomy.
- The study analyzed 11,572 unexposed women and 6,890 exposed women treated with conjugated equine estrogen.
- Outcomes were compared to a previous GPRD study of combined estrogen-progestin therapy.
Main Results:
- Women with a hysterectomy had higher baseline cardiovascular disease rates.
- Estrogen-only therapy was associated with significantly lower risks of myocardial infarction (HR 0.50) and breast cancer (HR 1.13).
- The risk for colorectal cancer was slightly higher (HR 1.18) with estrogen-only therapy, mirroring WHI RCT patterns.
Conclusions:
- Post-menopausal women respond differently to estrogen-only versus combined estrogen-progestin treatments.
- Differences in outcomes may be attributed to varying hormone regimens or increased cardiovascular disease in hysterectomized women.
- Findings support distinct risk profiles for different menopausal hormone therapy types.
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