Menopause - A Change In Heart Health

Hot flashes and mood swings get most of the attention, but the health effects of menopause go right to the heart.

Prior to menopause, sex hormones help boost women's cardiovascular system. Estrogen and progesterone are thought to keep arteries healthy, helping lowering the risk of high blood pressure and related heart disease, the major killer of North American women.

But menopause marks the end of these heart-helpful hormones. And researchers are now asking whether hormone replacement therapy (HRT) will increase post-menopausal women's heart health.

"The jury is still out on this," says Dr. Sandra Davidge, the Canada Research Chair in Women's Cardiovascular Health at the University of Alberta. "This question still requires a lot of investigation, but what we're seeing is that the timing of the hormone replacement is probably critical to any potential cardiovascular benefits."

The benefits of HRT were very publicly called into question in 2002 with the release of the Women's Health Initiative study. The study, which made front-page news, reported that women on HRT actually had an increased rate of heart disease.

The results, says Davidge, pushed researchers to take a harder look at the timing of HRT. She notes that the heart and blood vessels have specific receptors, or contact sites, for the sex hormone molecules that are lost with menopause. Many of those in the Women's Health Initiative study received HRT years, or even decades, after menopause.

"In many of these cases, the estrogen was probably given too late," Davidge says. "If you give estrogen to aged blood vessels it might not be protective and it might have detrimental effects. But if you give it to women at the onset of menopause it probably has benefits."

That's the conclusion of research, funded by the Canadian Institutes of Health Research, in Davidge's lab on the role of estrogen in maintaining blood vessel health in animal models of menopause.

"We've found in our lab that estrogen acts as a powerful antioxidant and also suppresses some of the proteins that cause inflammation, thereby having a positive effect on the arteries," she says.

This raises the possibility that HRT might be effective in extending cardiovascular health if it's given at the onset of menopause, before the blood vessels have deteriorated.

Dr. Davidge notes that her lab results with aged rats need to be confirmed in menopausal women. That's currently being explored in the United States with a large-scale HRT trial called the Kronos Early Estrogen Prevention Study (KEEPS). (http://www.keepstudy.org/) 

For now, Dr. Davidge says the best thing for women's long-term heart health is to buffer the drop in sex hormones by improving their overall cardiovascular health as they enter menopause.

"If you start menopause with a healthy cardiovascular system through exercise and diet, you're in a much better condition to handle the heart effects of losing ovarian hormones," she says. (www.impact.cihr.gc.ca)

 

Source: NewsCanada