This is Gwen Outen with the VOA Special English Health Report.

American researchers report more risks for older women who take the hormone replacement drugs estrogen and progestin. The researchers found that some women who take the hormones are at sharply higher risk for developing blockages in blood vessels in the legs and lungs.

Hormone replacement drugs are designed to help ease problems among older women during menopause. This is when a woman's body produces less of the hormones estrogen and progesterone. Lower hormone levels in menopause cause some women to feel hot, experience mood changes, and suffer bone loss. To help with these problems, some women have been taking estrogen or estrogen with progestin.

Earlier studies had suggested an increased risk of blood clots among women who took the hormones. But researchers did not know until now that some groups of women are at even greater risk.

Researchers studied 16,000 women between the ages of 50 and 79 years old. They found that the risk of blood clots for women who had taken the hormones was two times higher than for those who had not. The research showed that women over the age of 70 who took the hormones had more than seven times the risk. And the researchers found that being overweight also raises the danger of a blood clot among women who took the hormones.

Normally, taking aspirin reduces the risk of blood clots by thinning the blood. But researchers found that aspirin did not help the women who were also taking the hormones.

The latest findings come from a fifteen-year government study called the Women's Health Initiative.

For many years, health experts thought that the hormone drugs could help prevent heart disease, cancer and possibly mental illness in women. But many women stopped taking the drugs two years ago after a government study found that the hormones raised the risk of heart disease and some cancers.

Experts say taking estrogen and progestin does reduce the risk of the bone loss disease, osteoporosis. The drugs have also been shown to lower the risk for colon cancer. However, American health officials advise women to take the smallest amount of hormones needed for the shortest possible time.

This VOA Special English Health Report was written by Cynthia Kirk. This is Gwen Outen.

hormone: a substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism（荷尔蒙，一种物质，通常为肽或类固醇，由一组织产生，经由血液循环到达另一组织来影响生理活动，例如生长或新陈代谢）

estrogen: any of several steroid hormones produced chiefly by the ovaries and responsible for promoting estrus and the development and maintenance of female secondary sex characteristics（雌激素）

progestin: a natural or synthetic progestational substance that mimics some or all of the actions of progesterone（孕激素孕酮, 黄体酮）

menopause: the period marked by the natural and permanent cessation of menstruation, occurring usually between the ages of 45 and 55（绝经期，更年期）

osteoporosis: a disease in which the bones become extremely porous, are subject to fracture, and heal slowly, occurring especially in women following menopause and often leading to curvature of the spine from vertebral collapse（骨质疏松症）

colon cancer : 肠癌