Post-menopausal women who use hormone replacement therapy (HRT) are at an increased risk for gallbladder disease, including gallstones and inflammation of the gallbladder. According to an article in the July 11 Online First issue of the BMJ, use of transdermal hormone therapy (for example, a hormone patch) rather than oral hormone therapy over a 5-year period could avoid 1 cholecystectomy (in other words, gallbladder removal) in every 140 women.

Using participants of the Million Women Study, a study of over a million post-menopausal women in the United Kingdom, the researchers identified 19,889 women who were admitted to the hospital for gallbladder disease. Of these women, 17,190 had a cholecystectomy. The researchers found that current HRT users were more likely than never-users of HRT to be admitted for gallbladder disease. Higher doses of estrogen also increased the risk. The researchers also found that the risk for gallbladder disease was lower with transdermal hormone therapy than with oral hormone therapy.

Given the number of studies which have shown that HRT increases the risk of gallbladder disease, the findings of this study should be carefully considered by both post-menopausal patients and their physicians when discussing the risks, benefits, and options for hormone replacement.