Oct. 1, 2001 -- As you weigh the good and bad news about the effects of hormone replacement therapy (HRT) on your heart and bones, a study now shows that you also need to consider how your gallbladder might react to estrogen.
Women taking HRT may be at higher risk of developing gallstones, a painful problem usually requiring surgery. However, taking cholesterol-lowering drugs called "statins" may reduce the risk of gallstones.
The study showed that women taking HRT, consisting of the female hormones estrogen and progestin, were 30% to 40% more likely to need gallbladder surgery, says study author Joel A. Simon, MD, assistant professor of medicine and epidemiology at the University of California, San Francisco.
Although the chance of HRT leading to gallstones was not great, the study of more than 2,200 postmenopausal women does raise concerns. "We think it's a modest increased risk," Simon tells WebMD. He also is a staff physician at the San Francisco VA Medical Center. Results of his study appear in the Oct. 2 issue of Annals of Internal Medicine.
Other studies have shown similar findings, including an important study that looked at giving estrogen to men to prevent heart disease, says Simon. In that study, estrogen increased risk of gallbladder disease by 65%.
Simon adds that it makes sense why estrogen would have this effect, since this hormone changes the makeup of bile in the gallbladder so gallstones are more likely to form.
However, women taking statins -- the most popular type of cholesterol-lowering drug -- had a 45% drop in the chance they would need gallbladder surgery. That was a very significant finding, he says. Examples of statins include Lipitor, Pravachol, and Zocor.
"HRT is a mixed bag," he says, noting that the risk of hurting the gallbladder is "another factor to throw into the mix when considering whether to take HRT at all."
Doctors are comfortable with the fact that HRT helps relieve symptoms of menopause, such as hot flashes, and that it does offset the bone-thinning effects of osteoporosis. But the decision to use HRT or not is complicated since some medical research has shown it can increase the risk of breast cancer.
Plus, the jury's still out about HRT's long-term effects in terms of heart disease, he says. A recent groundbreaking study seemed to convince doctors that giving HRT to a woman known to have heart disease is a bad idea, since it can make things worse. But referring to an earlier study, "If women are already on HRT, the decision whether to continue or stop it is unclear," he says.
Two more studies are now looking at how well HRT can prevent heart disease in women who have never had heart problems. Simon adds that researchers have not tested whether using the estrogen skin patch could lead to gallstones, but because estrogens from a skin patch get processed in the body differently, it should not increase gallstone risk.
"So the end of the story isn't written," Simon tells WebMD. "It's just another factor for women to consider when trying to make a decision whether this is the right thing for them to do."
Because many women in the study were obese or had high cholesterol, they are naturally more likely to develop gallstones, says Gabriella Gosman, MD, assistant professor of ob-gyn and reproductive science at the University of Pittsburgh.
"You really can't generalize the results of this study to say they apply to all postmenopausal women," she tells WebMD.
However, she notes that previous studies have shown an even greater risk of developing gallstones with HRT than this current study did: two- to four-times the risk.
Lowering cholesterol, losing weight -- that's what has been proven to prevent gallstones, Gosman says.
As for HRT, Gosman says, "The ob-gyn community is still very committed to the benefits that we believe HRT has for women's long-term health and well-being, for quality of life," and for thought processes. "I think lot of [internal medicine specialists] are taking the other side, saying it's not a good choice."
"This study, all the conflicting studies about HRT, show us that each woman's case needs to be looked at individually to determine if it is right for her," she says.