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Soy Estrogen Alternative Study (SEA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00000612
Recruitment Status : Completed
First Posted : October 28, 1999
Last Update Posted : May 13, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To conduct a three-armed trial assessing the effect of soy phytoestrogens on menopausal complaints, plasma lipids and lipoproteins, vaginal bleeding and endometrial proliferation, and health related quality of life.

Condition or disease Intervention/treatment Phase
Cardiovascular Diseases Endometrial Hyperplasia Heart Diseases Menopausal Complaints Uterine Diseases Menopause Drug: estrogens, conjugated Behavioral: diet, soy proteins Behavioral: dietary supplements Phase 2

Detailed Description:


The results of many studies indicate that estrogen replacement therapy (ERT) reduces the risk of coronary heart disease (CHD) in postmenopausal women. However, less than 9 percent of these women choose to take ERT because of unwanted side effects and concerns about increased risk of cancer associated with ERT. Therefore, alternative therapies are needed.

The isoflavonoids found in soy protein (specifically genistein) have many properties that may reduce the risk of coronary heart disease. These include favorable effects on plasma lipids and coronary artery vasomotion. Furthermore, genistein is a tyrosine kinase (TK) inhibitor with inhibitory effects on thrombin activity and TK receptor-linked mitogens that may be associated with atherogenesis and neointimal formation after angioplasty.


Randomized, double-blind, placebo-controlled. The women were randomized into one of three groups: placebo, conjugated equine estrogens, or soy supplementation. Primary endpoints were the impact on menopausal complaints such as hot flushes, mood lability, anxiety, sleep disturbances; effects on plasma lipids and lipoproteins, including lipoprotein (a); effects on vaginal bleeding and endometrial proliferation; changes in health-related quality of life. Secondary endpoints included: assessment of the impact of these interventions on the progression of carotid artery intimal medial wall thickening as assessed by B-mode ultrasonography; bone density and bone turnover; additional measures to monitor the compliance and safety of the intervention such as mammography, anticipated or known side effects of hormone replacement therapy, blood levels of genistein, and clinical outcomes such as hospitalizations, physician visits, and symptoms. The study ended in December, 1998.

The study was a subproject within a program project on coronary atherosclerosis in females, primarily monkeys. Dr. Thomas B. Clarkson was the P.I. The subproject dollars were estimated based on the CRISP dollars assigned to the study which were approximately 12 percent of the total program project dollars and were broken down as follows: FY 1996 - 219,254; FY 1997 - $217,000; FY 1998 - $221,000.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

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Study Type : Interventional  (Clinical Trial)
Allocation: Randomized
Masking: Double
Primary Purpose: Prevention
Study Start Date : January 1996
Actual Study Completion Date : December 1998

Resource links provided by the National Library of Medicine

Drug Information available for: Estrogens

Information from the National Library of Medicine

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Ages Eligible for Study:   45 Years to 55 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Perimenopausal/menopausal women, ages 45 to 55.
Layout table for additonal information Identifier: NCT00000612    
Other Study ID Numbers: 115
P01HL045666 ( U.S. NIH Grant/Contract )
First Posted: October 28, 1999    Key Record Dates
Last Update Posted: May 13, 2016
Last Verified: November 2000
Additional relevant MeSH terms:
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Endometrial Hyperplasia
Uterine Diseases
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Genital Diseases, Female
Estrogens, Conjugated (USP)
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs