Older women taking certain hormone replacement therapy may suffer hearing damage, scientists report.
A study of 124 postmenopausal women found that those taking hormone replacement therapy that included progestin had poorer speech understanding than women who were not taking hormones or who were using estrogen only.
The findings, by a team led by Dr. Robert D. Frisina at the University of Rochester Medical Center in Rochester, N.Y., are reported in Tuesday’s issue of Proceedings of the National Academy of Sciences.
The team previously had reported indications of hearing problems associated with hormone therapy and their new study says progestin is the likely culprit.
The research found problems in the inner ear and in some measures of brain function affecting hearing in women using hormone therapy with progestin, Frisina said in a telephone interview.
Since hearing problems can affect quality of life, including family and business activities, he urges increased hearing testing for women using this therapy.
“We feel this should be added to the list of possible side effects, so when a woman and her doctor make their decision she can weigh this,” Frisina said, adding it may be a particular concern for women who already have some hearing loss.
“I tell women to have their hearing tested if they are going to start” hormone replacement therapy, and to have it rechecked every six months, he said. If it starts getting worse they may want to reconsider the dosage or the use of progestin, he said.
Damage reversible?
Many birth control pills also contain progestin and Frisina said he is not aware of any studies to determine if that has an effect on women’s hearing. “It should be studied,” he said.
Meanwhile, his next step is to look at women who stop using progestin and see if the hearing damage is reversible.
Not everyone is convinced of the findings, however.
“The jury is still out” on the effects of hormone replacement therapy on hearing, says Dr. Karen S. Helfer of the University of Massachusetts at Amherst.
Helfer, who said she has done similar research on a smaller scale, said, “There are a number of reasons to suspect that (hormone replacement therapy) would have either a positive or a negative effect on hearing. Subtle differences in auditory abilities can be demonstrated during different phases of the menstrual cycle. There are also a number of animal studies that show either positive or negative hormonal influences on hearing.”
And Dr. Wendy S. Klein of Virginia Commonwealth University Medical Center noted that the study included only 32 women treated with progestin, which she said makes it difficult to generalize from the results. Thirty were taking estrogen only and 62 were not using hormones.
The study looked at women aged 60 to 86 who had received hormone treatment from five to 35 years. “If you asked an older patient what medications they had taken over the course of a lifetime, they may not remember with accuracy,” she said.
“Although the analyses regarding hearing loss was clearly done with careful attention to measurement of hearing, and to biostatistics ... I find it very difficult to draw any significant conclusions about causality from this study,” concluded Klein.
Klein and Helfer were not part of Frisina’s research team.
The study was funded by the National Institute on Aging, National Institute on Deafness and Communications Disorders and the International Center for Hearing and Speech Research in Rochester.