Featured Research

from universities, journals, and other organizations

Study Confirms Replacing Estrogen By Skin Patches Decreases Nerve Activity, Blood Pressure In Postmenopausal Women

Date:
June 28, 2001
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
Researchers at UT Southwestern Medical Center at Dallas report that administering replacement estrogen via a skin patch is superior to oral estrogen replacement therapy in lowering blood pressure and sympathetic nerve activity - the neural control of blood pressure - in postmenopausal women.

DALLAS - June 19, 2001 - Researchers at UT Southwestern Medical Center at Dallas report that administering replacement estrogen via a skin patch is superior to oral estrogen replacement therapy in lowering blood pressure and sympathetic nerve activity - the neural control of blood pressure - in postmenopausal women.

The study, published in today's issue of Circulation, is the first to compare the effectiveness of oral and transdermal replacement therapies on sympathetic nerve activity in humans.

These findings suggest that how estrogen is administered is the key in optimizing the beneficial effects of estrogen replacement therapy on blood pressure, said Dr. Wanpen Vongpatanasin, assistant professor of internal medicine in hypertension and lead author of the study.

"Prevalence of hypertension is very low in young pre-menopausal women but increases markedly after menopause, suggesting a protective role of estrogen on blood pressure. Knowledge from this study may lead to an effective therapy to treat or prevent hypertension after menopause," she said.

Vongpatanasin and her colleagues reported that transdermal estrogen, or the estrogen patch, decreased nerve activity in postmenopausal women with normal blood pressure by 30 percent. The researchers also reported a small, but statistically significant, decrease in blood pressure in patients taking transdermal estrogen.

Both nerve activity and blood pressure were unaffected in patients taking oral estrogen. "This is an initial step that leads us to think that all estrogen preparations are not the same," Vongpantanasin said.

"This may be one of the reasons why large clinical trials failed to show a benefit of estrogen replacement therapy on blood pressure or any cardiovascular outcomes. It could very well be because only oral estrogen, the most popular preparation in the United States, has been used rather than transdermal estrogen."

Postmenopausal women have an excessive increase in nerve activity in the sympathetic nervous system. Increased nerve activity in this system causes blood vessels to constrict. An excessive increase may cause hypertension - one of the leading causes of death in women in the United States.

Transdermal estrogen replacement therapy has been shown to decrease nerve activity and blood pressure in female laboratory animals.

"In some female rats, removal of the ovaries leads to an increase in nerve activity and blood pressure. Estrogen replacement in the form of an implant under the skin (the effect of which is similar to transdermal estrogen in humans) reverses this problem," Vongpatanasin said. The 12 study participants randomly received transdermal estrogen replacement therapy for eight weeks, then switched to oral estrogen replacement therapy for eight weeks and a placebo for another eight weeks. The researchers used microelectrodes, which are similar to acupuncture needles, to record sympathetic nerve activity and ambulatory blood pressure readings. The researchers recorded about 50 blood pressure readings during a 24-hour period before and after each eight-week therapy.

In a second portion of the study, the researchers evaluated the effectiveness of intravenous estrogen on blood pressure and sympathetic nerve discharge and found no effect. When given orally, Vongpatanasin said, estrogen is transported to the liver, which converts the most active form of estrogen, called estradiol, into the weakest form of estrogen, called estrone. "In order to have similar blood estradiol levels to those seen with transdermal estrogen, a much higher dose of oral estrogen is needed," she said. "This increases the side effects related to the production of a coagulation protein in the liver, which causes blood clots to form in the legs. Other proteins in the liver may also interfere with the ability of estrogen to reduce blood pressure.

"This side effect is much less likely to occur in women on transdermal estrogen replacement therapy because estrogen is absorbed directly into the bloodstream through the skin before it goes through the liver; therefore, the most active form of estrogen remains intact."

Other researchers involved in the study included Debbie Arbique, a senior registered nurse in internal medicine; Dr. Yasser Mansour, a former research fellow; Dr. Meryem Tuncel Kara, a research fellow in internal medicine; and Dr. Ronald Victor, chief of hypertension.

The American Heart Association and the American College of Cardiology provided funding for this research.


Story Source:

The above story is based on materials provided by University Of Texas Southwestern Medical Center At Dallas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Southwestern Medical Center At Dallas. "Study Confirms Replacing Estrogen By Skin Patches Decreases Nerve Activity, Blood Pressure In Postmenopausal Women." ScienceDaily. ScienceDaily, 28 June 2001. <www.sciencedaily.com/releases/2001/06/010620073721.htm>.
University Of Texas Southwestern Medical Center At Dallas. (2001, June 28). Study Confirms Replacing Estrogen By Skin Patches Decreases Nerve Activity, Blood Pressure In Postmenopausal Women. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2001/06/010620073721.htm
University Of Texas Southwestern Medical Center At Dallas. "Study Confirms Replacing Estrogen By Skin Patches Decreases Nerve Activity, Blood Pressure In Postmenopausal Women." ScienceDaily. www.sciencedaily.com/releases/2001/06/010620073721.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Get on Your Bike! London Cycling Popularity Soars Despite Danger

Get on Your Bike! London Cycling Popularity Soars Despite Danger

AFP (Sep. 1, 2014) Wedged between buses, lorries and cars, cycling in London isn't for the faint hearted. Nevertheless the number of people choosing to bike in the British capital has doubled over the past 15 years. Duration: 02:27 Video provided by AFP
Powered by NewsLook.com
Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins