Effects of estrogen therapy on hearing in postmenopausal women

Objective: This study was undertaken to investigate how hormone therapy affects hearing in postmenopausal women. Study design: This prospective study involved 109 postmenopausal women. Twenty of the women were using estrogen therapy (ET group), 30 women were using hormone therapy (HT group), and 59 had not received hormone therapy of any kind (control group). Otoscopic examination revealed normal tympanic membranes in all 109 subjects. Each individual was tested with low- (250-2000 Hz) and high-frequency audiometry (4000-16000 Hz). Duration of hormone therapy was recorded, and patient characteristics (age, type of menopause, time since onset of menopause), body mass index (BMI), and hearing test results in the ET, HT, and control groups were compared. Results: There were no statistically significant differences between the treatment (ET and HT group) and control groups with respect to age, BMI, or time since onset of menopause. The mean time on HT and ET was 4.13+/-2.41 years and 3.35+/-2.20 years, respectively. The mean air conduction results at low frequencies (250, 500, 1000, and 2000 Hz) in the ET group were significantly higher than the corresponding findings in the control group (P<.001) and than the HT group (P<.001). When the same comparisons were made between the HT group and the control group, none of the differences was statistically significant (P>.05). The mean air-conduction results at high frequencies (4, 6, 8, 10, 12, 14, and 16 kHz) in the ET group were significantly higher than the corresponding results in the HT group (P<.008). ET versus controls and HT versus controls at high frequencies revealed no significant differences (P>.05). The mean bone conduction results in the ET group were significantly higher than the corresponding findings in the control group (P<.016). Analysis of the same comparisons between the, HT-ET and HT-control groups revealed no significant differences (P>.05). Conclusion: Estrogen therapy may slow down hearing loss in aging postmenopausal women; however, further studies of larger series are needed to confirm this, and the sites of hormonal action must also be explored. (C) 2004 Elsevier Inc. All rights reserved.