Thu May 23, 2002
By Melissa Schorr
SAN FRANCISCO (Reuters Health) - Hormone replacement therapy (HRT) may raise a woman's likelihood of developing gallstones, British researchers reported Wednesday at Digestive Disease Week, an annual conference of gastroenterologists being held here.
"Women who took HRT were at three times greater risk to develop gallstones," study author Dr. Andrew R. Hart, a senior lecturer in gastroenterology at the University of East Anglia in Norwich, UK, told Reuters Health.
A gallstone can develop when bile, cholesterol, calcium salts and other substances come together to form a mass in the gallbladder, the tiny sac tucked under the liver that stores bile. Gallstones often exist without causing symptoms, but surgery is sometimes necessary when the stones cause severe pain.
Researchers studied more than 13,000 middle-aged women who enrolled in the European Prospective Investigation Into Cancer in 1993. The investigators followed up on the women an average of 3 years later and found that 58 of those women had developed gallstones.
Hart and his colleagues matched each of those women to four more women similar in age who did not develop gallstones and compared their use of hormone replacement therapy. They also took into account risk factors for gallstone, such as alcohol use, previous pregnancies and body weight.
Hart reported that the women who were using HRT were three times more likely to develop gallstones than women who were taking no HRT at all. This research confirms similar findings reported in the Nurses' Health Study, a large-scale population study taking place in the United States, he noted.
The researchers also found a dose-dependant response, with women who took HRT for less than 3 years 2.5 times more likely to develop gallstones, while those who took HRT for more than 3 years had 4 times the risk of developing gallstones.
Because gallstones are composed primarily of cholesterol, Hart said that researchers believe that the use of estrogen could promote an increase in cholesterol in bile that leads to gallstone formation. Among the women who developed gallstones, 33% of the cause could be accounted for by the use of estrogen.
"Women prescribed HRT should continue to take it for its benefits in areas like osteoporosis," Hart advised. "However, patients could be advised to modify their other risk factors for gallstones, such as losing weight and moderating alcohol intake."
SOURCE: Digestive Disease Week, an annual conference of gastroenterologists