Study: Hormone Therapy Raises Blood Clot Risk in Menopausal Women　

By David McAlary

A new U.S. study highlights more negative health effects women might suffer if they take hormone supplements to combat the symptoms of aging. We know that taking the female hormones estrogen and progestin can lead to increased risk of breast cancer and stroke. Now we learn that hormone replacement therapy can lead to potentially fatal blood clots too.
Two years ago, Gail Berry was sitting at her desk when her leg swelled and ached badly. Doctors found that she had a blood clot.
"The ultrasound showed it was in the back of my right leg and I was admitted to the hospital for treatment," she said.
Ms. Berry also had a pulmonary embolus, which occurs when part of the blood clot breaks off and travels to the lung. That can be fatal. She had been taking estrogen with progestin to replace the lower natural levels of the hormones that occur during menopause. A new study of 16,000 women shows that the therapy significantly boosts the risk for a clot.
"The main finding of the study was that women who were assigned to take the hormone replacement therapy had about a doubling of the risk of blood clots, compared to women assigned to take placebo," said Mary Cushman. University of Vermont physician Mary Cushman led the study which appears in the Journal of the American Medical Association. She says it confirms what she sees among her private patients.
"In my practice I very commonly will see middle-aged women who are struggling with menopausal symptoms and have been prescribed hormone replacement therapy and subsequently experience a blood clot," she said.
Previous studies had suggested a higher chance for blood clots among hormone takers, but what researchers did not know until now was that certain groups of women are most susceptible. For example, the risk increases with age. Women over age 70 are at more than seven times the risk. Dr. Cushman says being overweight also raises the danger of a clot, known medically as thrombosis.
"The women who had both obesity and hormone replacement were almost seven times more likely to develop thrombosis, compared to thinner women," she said.
In addition, the study found that the group of women with a genetic trait called Factor-Five Leiden were also more susceptible to blood clots.
Normally, aspirin reduces the risk by thinning the blood, but the researchers found it did not help the women on hormones who took it.
But there are proven benefits for combined estrogen and progestin therapy. For one, it reduces the risk of the brittle bone disease osteoporosis. For another, it has been shown to lower the risk for colon cancer.
Because of these reasons, U.S. government health officials are not recommending a ban on hormone treatments for women, but they are urging caution.
"They should be used at the lowest does for the shortest possible time," said Dr. Barbara Alving, this is Dr. Barbara Alving acting director of the U.S. government's National Heart, Lung and Blood Institute. "If you have been on hormones for years and years and years because you just felt good and did not bother to go off them, you really need to think about [whether it is] time to go off the hormones, and discuss this with your physician and gradually taper off."
This is what Gail Berry has done.
"I have not gone back on the hormones," she said. "I have lost about 30 pounds, and I feel much better."
Dr. Cushman of the University of Vermont says that if women are considering beginning hormone therapy for menopausal symptoms, but have a family history of blood clots, they should undergo testing to determine whether they have the same genetic predisposition.
David McAlary, VOA News, Washington.

注释：
supplement 补充
combat 抗击
symptom 症状
estrogen 雌激素
progestin 黄体酮
placebo 安慰剂
University of Vermont 佛蒙特大学
menopausal 更年期的
thrombosis 血栓症
osteoporosis 骨质疏松症
predisposition 倾向，易患病的体质