Study finds good cholesterol boost in HRT, gene combo

BOSTON, Massachusetts (CNN) -- A study presented in the New England Journal of Medicine on Thursday found that good cholesterol levels are enhanced for women who have a specific gene variation and take Hormone Replacement Therapy -- or HRT -- after menopause.

Study authors looked at 309 women with heart disease and found that women who had a variation or mutation in an estrogen gene had dramatically higher levels of HDL -- or good -- cholesterol when taking HRT than those without the variation.

This gene variation is common and can be found in about one in five women in the United States.

"This increase in good cholesterol was actually two or three times as much as we normally see when people take drugs that are designed to raise the good cholesterol and lower risk for heart disease," said cardiologist and lead author Dr. David Herrington of Wake Forest University, in Winston-Salem, North Carolina. "This suggests that certain genes enhance the effects of estrogen on good cholesterol."

The jury is still out, however on whether or not this increase in good cholesterol will translate into heart disease benefits. Studies with HRT thus far have not shown this to be so but Herrington says "it's possible this was because we were focusing on all women, rather than the sub-group with the gene variant."

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"Women are not being advised to get genetic testing at this point because this research is in the early stages," says cholesterol researcher Dr. Ronald Krauss from the University of California at Berkeley. "More studies will need to duplicate these findings before that step can be considered."

For years, postmenopausal women were told that HRT was good for the heart. Recent clinical trials have not supported this theory, at least not for women who already have heart disease.

In fact, the American Heart Association does not recommend that these woman take HRT solely to benefit the heart. Studies are under way in healthy postmenopausal women to determine whether or not HRT can prevent heart disease. It will be several years before there are answers.