Women who take the most common form of hormone-replacement therapy (HRT) -- the type that includes progestin -- had 10-30 percent more hearing loss than women who did not have the therapy, according to the largest study to date on the topic.
In the 124-women study, those whose HRT included progestin had worse hearing than those who were taking estrogen alone or no HRT. The women on the progestin HRT had hearing of women five to 10 years older, and tests showed problems existed both in their inner ears and in the portions of the brain used for hearing. Other risks of HRT found by past studies include:
The researchers have plans to study women who have gone off HRT, to see if the hearing loss might be reversible, and they say that women on the birth control pill, which includes progesterone, should also be studied.
Science Daily September 6, 2006