heart disease online : Heart Diseases resource HEART DISEASE ONLINE : Your resource for current and reliable information about HEART DISEASE.  It's so simple, even your child can understand !
Heart Disease information EVEN your child can understand !

Heart Disease articles heart disease articles
Heart Disease resources
Heart Disease reports heart disease reports
Heart Disease guides heart disease guides
Heart Disease books heart disease books
Heart Disease news heart disease news
Congenital Heart Disease congenital heart disease
Coronary Heart Disease coronary heart disease
Rheumatic Heart Disease rheumatic heart disease
Ischemic Heart Disease ischemic heart disease
acute coronary syndrome acute coronary syndrome
high cholesterol levels high cholesterol levels
smoking cessation quit smoking
aerobic exercise at home aerobic exercise at home
what is hypertension what is hypertension
Heart Disease Online heart disease online
heart disease facts heart disease facts
Signs of a Heart Attack signs of a heart attack


home / ARTICLES You Are Here Now Heart Valve Disease Coronary Artery Disease Congenital Heart Disease Congenital Heart Disease
HEART DISEASE ONLINE - Your resource on Heart Disease - all about the heart written in such a simple manner, EVEN your child can understand !
Heart Disease Articles
- By your Heart Disease Online guide photo of your guide to Heart Disease

Have a suggestion ?
Offer A Heart Disease Suggestion
Click here to
Tell the Doc

State of the Heart

Heart Fitness for Life : The Essential Guide to Preventing and Reversing Heart Disease

A Practical Guide
to YOUR Heart
and Heart Surgery

Click For More Info

Stay Informed

Join our mailing list.
Get the latest heart news by e-mail.


Women, Hormones and the Heart

Heart Disease in Women is a very important, unique and exciting topic. This article is a part of a series that focuses on the special problems of Heart Disease in Women. You can find the others in the archives.

You can also review articles in the following interest areas dealing with heart disease:

And don't forget. You can post your comments on this article on the Heart Disease Bulletin Board or discuss it in the Chat Room.

This week, the topic is ....


A lot has been written about the role hormones play in causing or preventing heart disease and stroke in women. In this article, we will take a look at the still controversial issue of the role of hormones in heart disease in women.

The two major endogenous hormones (that is, hormones produeced in the body itself) in women are estrogen and progesterone. Each has a specific physiologic role in growth and development, pregnancy, lactation and other functions. Levels of both hormones alter at different stages of growth - pre-pubertal, reproductive age and after menopause. The varying levels cause different changes in the organ systems including the heart and blood vessels, some of which may increase or decrease the risks of disease.

In addition, hormones may be exogenous (administered in medication). The most common source of exogenous hormones in women is in oral contraceptive pills.

We will discuss first the impact birth control pills have had on the epidemiology of heart disease and later the effect of hormone replacement therapy in post-menopausal women.

Oral Contraceptives and Heart Disease

Ever since birth control pills were introduces in 1960, there have been reports suggesting an increased risk of heart attacks and stroke. The earlier pills contained high doses - around 150 micrograms - of estradiol (In contrast, pills in 1988 contain only 35 micrograms). Also, addition of progesterone derivatives further altered the effects of the pill. Recently, the addition of third-generation progesterones like desogestrel and gestodene lowers LDL cholesterol levels and raises HDL cholesterol - changes that reduce heart disease risk. For more on cholesterol effects, read my earlier article on heart disease prevention.

Prescribing patterns have also changed, following recognition that oral contraceptives raise blood pressure and pose additional risk in older women who smoke cigarettes. These changes in products and their use would be expected to reduce the cardiovascular risks associated with oral contraceptives.

A study carried out by the World Health Organization reported the association between current use of oral contraceptives and heart attack in more than 300 cases. The study suggested that the pill might be responsible for an increased risk of heart attacks. However, the absolute risk in nonsmoking women younger than 35 years was low. The risk was dramatically increased in older women who smoked, and in women with known hypertension whose blood pressure was not checked before prescription. Risk was not associated with dose or duration of use of estrogen and did not persist after oral contraceptives were discontinued.

In summary, new oral contraceptives carry a greatly reduced risk of cardiovascular complications compared with other high-dose preparations, but third-generation progestins appear to greatly increase risk of venous blood clots in the leg veins. Overall, the risk/benefit ratio is excellent except for women who smoke.

Post-menopausal Estrogen Therapy

Several reviews have provided evidence that a remarkably consistent reduced risk of coronary heart disease (CHD) and a somewhat less consistent reduced risk of stroke is seen in women using postmenopausal estrogen in the United States and Europe.

Because the risk of CHD exceeds the risk of all other estrogen-associated conditions combined in the United States, and because estrogen use has been associated with reduced mortality from all causes combined, post-menopausal estrogen has been proposed as the standard of care in countries where heart disease is the leading cause of death and a major cause of morbidity in women. An analysis of many studies carried out earlier, most from the US, it has been shown that post-menopausal estrogen reduces the risk of CHD by 35% to 50%. This means that on the basis of a calculation of overall risks and benefits, a healthy woman at no particular increased risk for heart disease, cancer, or osteoporosis would gain on average one additional year of life !

How does estrogen protect against Coronary Heart Disease ?

Multiple mechanisms may be involved. These include:

  • including favorable changes in lipids

  • altered lipoprotein profile

  • changes in fibrinogen and PAI-1

  • effects on blood vessel reactivity

  • antioxidant effects

Are these findings biased ?

It has been postulated that the striking differences noticed with post-menopausal estrogen therapy may be an artifact produced by pre-selecting low-risk patients. Estrogen replacement therapy is more likely to be prescribed to higher income, highly educated groups, who for different reasons are more likely to have fewer risk factors for heart disease.

Recently this "healthy woman selection bias" has been strikingly documented by the Healthy Women's Study, which followed 355 premenopausal women through menopause. Women who later elected to take hormones were, when premenopausal, significantly more educated and had significantly more favorable levels of HDL cholesterol, blood pressure, fasting insulin, body weight, alcohol intake, and physical activity. Thus, the amount of protection attributed to estrogen may be exaggerated.

Two major US trials have been designed to quantitate the cardioprotective effect of postmenopausal estrogen unconfounded by healthy woman selection bias.

  • HERS is a 5-year randomized placebo-controlled secondary prevention trial of conjugated equine estrogen plus medroxyprogesterone acetate (a form of progesterone) in women who already have CHD. This study of 2673 postmenopausal women is planned to end in 1998. Unopposed estrogen is not being evaluated.

  • The Women's Health Initiative (WHI), a placebo-controlled primary prevention trial in 27,500 postmenopausal women, is scheduled to complete randomization in 1998. The three major outcomes are CVD, osteoporosis, and breast cancer. Active treatments are conjugated equine estrogen alone for women without a uterus or conjugated equine estrogen plus continuous medroxyprogesterone acetate for women with an intact uterus, as compared with placebo. The WHI is planned to end in 2006. This trial will be the first to provide disease data in ethnic minority women on hormone therapy.

In summary, ongoing research suggests that estrogen replacement therapy reduces risk of CVD but may increase the risk of other diseases, including breast cancer and venous blood clots. The potential benefits and risks need to be confirmed in clinical trials such as those now in progress. Until more definitive data are available, clinicians should individualize therapy based on a woman's baseline risk for CVD and should weigh the potential net benefit on overall health.

Emerging data suggest selective estrogen receptive modulators, also known as "designer" estrogens, may have beneficial effects on the cardiovascular system as well as bone without untoward effects on breast or uterus. However, the clinical effectiveness of newer hormonal agents for disease prevention remains to be established.

home / ARTICLES You Are Here Now Heart Valve Disease Coronary Artery Disease Congenital Heart Disease Congenital Heart Disease





Heart Disease Online does not provide medical advice, diagnosis or treatment. Material on this site is provided for informational purposes only. The site is not intended to supply personalized answers or advice to patients. It is not meant to be a substitute for professional medical advice. The information should not be used to diagnose or treat a health problem, disease, or to prescribe any medication. In case of doubt, promptly contact your health care provider. Never disregard professional medical advice or delay seeking it because of something you have read on Heart Disease Online. Click here for additional information and to read the full disclaimer and terms of use

Comments are welcome

Copyright © 1997-2013 Heart Disease Online , All rights reserved.
Terms of Use | Privacy policy | Disclaimer

Text, graphics, and HTML code are protected by US and International Copyright Laws,
and may not be copied, reprinted, published, translated, hosted, or otherwise
distributed by any means without explicit permission. Legal notices

Heart Disease Online (tm)
663, 99th Street, Madras, TN 60107
Fax : (603)-908 4676     E-mail : webmaster@heartdiseaseonline.com
URL : http://www.HeartDiseaseOnline.com