IOWA CITY, IOWA. A new study casts further doubt over the benefits of hormone replacement therapy (HRT). For several decades, observational studies have suggested that estrogen therapy including the contraceptive pill and hormone replacement therapy can encourage formation of gallstones, formed when bile contains too much cholesterol. A third of the million people diagnosed annually with gallstones will develop cholecystitis (inflammation of the gallbladder), which can lead to frequent pain after eating, jaundice, nausea and fever. The risk of gallbladder disease is higher in women and increases with age.
A research team from Iowa University has now undertaken a large randomised trial of the effects of estrogen therapy in relation to gallbladder disease in postmenopausal women. They used two cohorts from the Women's Health Initiative (WHI) trial totaling 22,579 women at 40 clinical centers. Women with hysterectomy received estrogen or placebo and those without hysterectomy received estrogen plus progestin or placebo.
After five to seven years of follow-up, risk was increased for both formation of gallstones (80 per cent in
estrogen group and 54 per cent in combination group) and cholecystitis (86 per cent in estrogen group and
68 per cent in combination group). Risk of gallbladder disease or surgery was found to be 67 per cent higher
in the women on estrogen, and 59 per cent higher in women on the combined therapy. Risk of undergoing
cholecystectomy (gallbladder removal) was increased by 93 per cent for the women on estrogen and 67 per
cent for women on the combined therapy. The chance of other gall bladder surgery was, however, not
affected by estrogen therapy. The authors state that the results indicate oral estrogens are causally
associated with gallbladder disease, and suggest that this should be taken into account by women and their
doctors when considering estrogen therapy. WHI studies have previously found that estrogen therapy
increases the risk of stroke, decreases risk of hip fracture, and does not affect heart disease risk.