News: Cholecystectomy risk greater for oral vs. transdermal HT

Postmenopausal women using hormone therapy (HT) are at higher risk of gallbladder disease if they use oral rather than transdermal drugs, according to study findings published July 10 in BMJ Online First.

Bette Liu, PhD, and colleagues at the University of Oxford in Oxford, UK, analyzed data from the Million Women Study of 1,001,391 postmenopausal women with a mean age of 56 years, of whom 19,889 were admitted to the hospital with gallbladder disease and 17,190 underwent cholecystectomy.

Overall, current users of HT were 1.64 times more likely than women who had never used it to have gallbladder disease, the investigators found. However, for those who used transdermal medication, the risk was only 1.17 times, versus 1.74 times for those on oral therapy. Thus, transdermal HT increased the risk of gallbladder disease by 1.3%, whereas oral therapy increases it by 2%, they note. However, transdermal HT is more costly and can cause local skin reactions, the report indicates. Equine estrogens carried a slightly greater risk than estradiol among women taking oral HT. The risk of gallbladder disease declined after HT treatment ceased, the researchers report.

Liu B, Beral V, Balkwill A, et al. Gallbladder disease and use of transdermal versus oral hormone replacement therapy in postmenopausal women: prospective cohort study. BMJ. 2008;337:a386. doi:10.1136/bmj.a386.