Auditory brainstem response in postmenopausal women treated with hormone replacement therapy: a pilot study

Area of Science:

• Neuroscience
• Endocrinology
• Audiology

Background:

• Postmenopausal women often undergo hormone replacement therapy (HRT).
• The audiological effects of HRT, specifically the nongenital targets of gonadal steroids, are not fully understood.
• Auditory brainstem response (ABR) provides objective measures of auditory pathway function.

Purpose of the Study:

• To investigate the audiological effects of HRT in postmenopausal women.
• To determine if gonadal steroids, particularly estrogen, influence auditory pathway function.
• To compare ABR measures in women on different HRT regimens and control groups.

Main Methods:

• Fifty postmenopausal women received various HRT regimens (transdermal estradiol, oral estradiol/nomegestrole acetate, oral conjugated estrogen/medroxyprogesterone acetate).
• Control groups included surgically and naturally menopausal women without HRT, and premenopausal women.
• Auditory brainstem response (ABR) was performed, measuring wave latencies and interpeak intervals.

Main Results:

• Women on HRT exhibited significantly shorter ABR wave and interpeak latencies compared to the postmenopausal control group (p < 0.05).
• HRT group latencies were comparable to those of premenopausal women (p > 0.05).
• Estrogen replacement therapy resulted in shorter latencies than combined hormone therapy (p < 0.05).

Conclusions:

• Fluctuating hormone levels, influenced by HRT, alter ABR measures in postmenopausal women.
• Estrogen may enhance neuronal plasticity and neurotransmitter metabolism, leading to faster auditory conduction.
• HRT appears to normalize auditory pathway conduction times towards premenopausal levels.