“Our research in monkeys suggests that stress can affect estrogen levels and may set the stage for heart disease later in life,” according to Jay Kaplan, Ph.D., professor of comparative medicine and director of the primate center. “It also suggests women need to start thinking about heart disease prevention before menopause. We found that the five years before menopause are when heart vessel disease begins to accelerate.”
Kaplan and Thomas Clarkson, D.V.M., have published numerous articles from their monkey research on the effects of hormone therapy on heart vessel disease. Their findings, along with research in humans, were a driving force behind the hypothesis that there is a “window of opportunity” during which hormone therapy can help prevent atherosclerosis. The theory was explored in the Women’s Health Initiative Coronary Artery Calcium Study (WHI-CAC).
WHI-CAC showed that younger postmenopausal women who take estrogen-alone hormone therapy have significantly less building of calcium plaque in their arteries compared to their peers who did not take hormone therapy. The plaque is considered a marker for future risk of atherosclerosis, the buildup of fatty deposits that can lead to heart attacks and strokes.
Clarkson began a study in 1988 funded by the National, Heart Lung and Blood Institute to study how hormone therapy affects heart disease risk in monkeys. He found that estrogen replacement administered to monkeys as soon as they were made surgically menopausal resulted in about a 70 percent inhibition in the progression of coronary artery atherosclerosis.
When treatment with estrogen or estrogen plus progestin was delayed for an equivalent of six years in women, however, there was no benefit. The work led to the hypothesis that estrogen inhibits the development of vessel disease, but may be ineffective, and even harmful, if the disease already exists.
“Clearly hormone therapy isn’t a drug for preventing or treating heart disease,” said Clarkson. “The question is whether, when hormone therapy is used for the treatment of menopausal symptoms, there are benefits associated with the cardiovascular system that might offset any documented risks.”
In addition to raising this important question about hormone therapy, the animal studies also have other important health implications for women. Women have traditionally been considered immune from heart disease until after menopause, when their estrogen levels dramatically drop. But the monkey studies suggest that stress can actually reduce estrogen levels much earlier in life and hasten the development of atherosclerosis, thus increasing the postmenopausal burden of coronary disease risk.
These effects may apply to up to half of premenopausal women, Kaplan said, emphasizing the need for young women to be educated about the relationship between reproductive health and chronic disease risk.
"Our research adds to the growing body of evidence that cardiovascular health after menopause is influenced by hormone levels many years earlier," said Kaplan. "The message for women is that anything that reduces estrogen levels in young adulthood - whether it be stress or exercise and diet habits - may put women on a high-risk course for heart disease."
Clarkson said that because cardiovascular disease is the leading cause of death among women over age 55 – and because studies show that declines in estrogen in perimenopause can lead to its development – it is imperative to identify risk factors and promote early prevention.
“The evidence that levels of atherosclerosis present at the time of menopause are determined by premenopausal estrogen exposure is underappreciated,” he said.
Karen Richardson | EurekAlert!
Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University
New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy