COPENHAGEN, Denmark, Oct. 2 (UPI) -- How a woman takes replacement hormones may affect her risk of heart attack, Danish researchers say.
Dr. Ellen Lokkegaard, a gynecologist at the Rigshospitalet in Copenhagen, Denmark, led an observational study of 698,098 healthy Danish women, ages 51 to 69, who were followed between 1995 to 2001.
The study, published in the European Heart Journal, found that overall there was no increased risk of heart attacks in current users of HRT compared to women who had never taken HRT.
Continuous hormone replacement therapy -- a continuous combination of estrogen and progesterone -- carried a 35 percent increased risk of heart attacks compared with women who had never the treatment.
But if hormone replacement therapy was taken on a cyclical basis -- estrogen, followed by a combination of estrogen and progesterone -- there was a tendency for these women to have a reduced risk of heart attacks compared to wo men who never used it.
The study said that when the method of taking the estrogen was via a patch or gel on the skin the risk of heart attack was reduced by more than one-third.
"Our finding of lower risk with a cyclic combined regimen, which gives monthly bleeding, than with continuous combined estrogen/progesterone therapy, which does not cause bleeding, is potentially of great clinical importance," Lokkegaard said in a statement.