Study: Gene variant may identify women who could protect hearts by taking estrogen

<br>Testing women for a common genetic variation may help doctors predict which patients can lower their risk of heart disease by taking estrogen. <br><br>Millions of women take estrogen supplements to

Wednesday, March 27th 2002, 12:00 am

By: News On 6

Testing women for a common genetic variation may help doctors predict which patients can lower their risk of heart disease by taking estrogen.

Millions of women take estrogen supplements to relieve hot flashes and other symptoms of menopause, and it was long assumed the pills also prevented heart disease by improving cholesterol levels. But recent studies have raised doubts about an across-the-board benefit, adding to the confusion about who should get estrogen and for how long.

Now researchers say there could be a way to zero in on those women who might lower their risk of heart disease by taking estrogen. They found that a specific version of a gene appears to enhance estrogen's effect on HDL, the so-called good cholesterol.

Women with the gene variant had double the increase of HDL when taking estrogen, according to the study in Thursday's New England of Journal of Medicine.

``We don't yet know for sure whether this dramatic increase in HDL translates into a reduction in risk for heart disease. But it certainly is very promising,'' said Dr. David M. Herrington, one of the researchers at Wake Forest University School of Medicine.

If the heart benefits are confirmed, Herrington said, doctors could do a simple genetic test to find out if their patients have the gene variant. The results could help them decide whether to recommend hormone supplements and how much to prescribe.

``Hormone replacement therapy may no longer be considered a one-size-fits-all proposition,'' Herrington said. ``This may actually really help doctors individualize the way they treat women.''

The researchers analyzed DNA from 309 postmenopausal women with heart disease who were given either hormones or a dummy pill and followed for three years. They looked for variations in a gene that plays a key role in how the body's cells react to estrogen.

One particular variant was found in nearly 20 percent of the women taking hormones. Those women had a 27 percent increase in good cholesterol, compared with a 13 percent increase in the other women taking hormones. LDL, the bad cholesterol, decreased but the gene variant did not appear to make a significant difference.

Herrington said the study was too small to show whether the higher levels of good cholesterol actually helped the women's hearts.

Another issue is whether the gene makes women more sensitive to the other effects of estrogen, Herrington said. Hormones are used to prevent brittle bones and treat the symptoms of menopause such as hot flashes, night sweats and vaginal dryness. But long-term use of hormones may increase the risk of breast cancer.

Dr. Ronald M. Krauss, who wrote an accompanying editorial, said the study is a step toward explaining why some women show more of an HDL response to estrogen than others.

``Ideally, what you really want is to see whether or not in the end women who have this variant, who take estrogen, are actually healthier as a result of taking estrogen,'' said Krauss of Lawrence Berkeley National Laboratory in California. ``Those studies can and hopefully will be done.''

In the meantime, Herrington said doctors should follow the American Heart Association recommendation that women should not take hormones solely to prevent heart disease.