Review on November 19, 2009
The benefits of estrogen hormones during the symptoms of menopause or perimenopause symptoms are well known. When synthetic progestogen is added to the estrogen hormone the risk of endometrial cancer that the use of solely estrogen hormones in women is reduced. While estrogen hormones have a beneficial effect on symptoms of menopause, scientists wonder about their role in reducing cardiovascular disease. This is an important question to consider since cardiovascular disease is the number one cause of death in women who have survived menopause. Many studies have shown a strong link between use of estrogen hormones and reduced risk for a heart attack. The 2000 study by Micheal H. Davidson et al. "Effects of Continuous Estrogen and Estrogen-Progestin Replacement Regimens on Cardiovascular Risk Markers in Postmenopausal Women" explores this possibility in detail.
The objective of the study was to evaluate the influence of two replacement estrogen hormones on women who no longer had symptoms of menopause. 498 women who no longer had perimenopause symptoms or menopause symptoms were screened, but only 270 women were found eligible. A randomized, double-blind, placebo-controlled trial was conducted on 270 healthy women who no longer had menopause symptoms. These women who no longer had symptoms of menopause were divided into four treatment groups: placebo, unopposed estrogen hormones, estrogen hormones opposed with .25 mg of norethindrone acetate and estrogen hormones opposed with .5mg of norethindrone acetate.
During the trial, the women's cardiovascular risk markers were monitored carefully. Some of these risk markers are: lipoproteins, hemostatic variables, carbohydrate metabolism, and endothelial function. Norethindrone acetate was added to the estrogen hormones mix because it is a progestin whose use has been shown to counteract some of the negative effects of estrogen hormones mentioned earlier/previously while not blunting the positive effects of these estrogen hormones.
The results were that low-density lipoprotein cholesterol levels were reduced in all groups receiving estrogen hormones, whether they be opposed or unopposed. The effects of estrogen hormones combined with progestin were distinct but ambiguous.
It is important that the effects of opposed and unopposed estrogen hormones be studied in women who no longer have symptoms of menopause. Clinical trials such as this one have shown that estrogen hormones have a distinct impact on the cardiovascular health of women who no longer experience symptoms of menopause. It is important that further studies be undertaken.
- JAMA - The Journal of the American Medical AssociationArch Intern Med. 2000;160:3315-3325.