Hormone Replacement Therapy Increases Gallbladder Disease Risk

Scientists from the University of Oxford have found that hormone replacement therapy (HRT) in post-menopausal women increases the risk of gallbladder disease. They analyzed data from the Million Women Study, which involved 1,001,391 post-menopausal women from the UK with an average age of 56. The women were followed for an average of six years. During this time, 19,889 women were admitted to a hospital with gallbladder disease, 17,190 (86%) of whom underwent cholecystectomy (surgical removal of the gallbladder).

The higher the dosage of HRT, the higher the risk was. Once the therapy was discontinued, the risk decreased over time. Results also showed that there was a lower risk if the HRT was administered through skin patches, or as a gel; the risk increased if the HRT was administered orally. This may be because orally administered HRT is metabolized by the liver before it enters the rest of the system.

“Standardised hospital admission rates per 100 women over five years for cholecystectomy were 1.1 in never users, 1.3 with transdermal therapy, and 2.0 with oral therapy,” the researchers stated. “Use of transdermal therapy rather than oral therapy over a five year period could avoid one cholecystectomy in every 140 users.”

The full research findings were published in the British Medical Journal and can be found here.