Auditory brainstem response in postmenopausal women treated with hormone replacement therapy: a pilot study.
OBJECTIVE
To research the nongenital audiological target for gonadal steroids in postmenopausal women who are treated with hormone replacement therapy.


METHODS
Fifty postmenopausal volunteers were treated with hormone replacement therapy. Women with an intact uterus had sequential weekly transdermal estradiol plus nomegestrole acetate 5 mg orally for 12 days per month or a continuous daily oral dose of conjugated estrogen 0.625 mg and medroxyprogesterone acetate 5 mg tablet. Eighteen surgically postmenopausal women received a weekly transdermal estradiol system. Twenty-five postmenopausal volunteers-5 with a natural menopause and 10 with a surgical menopause-and 20 premenopausal normally cycling women were used as a control group. Each woman performed auditory brainstem response by auditory-evoked potentials for waves I, III, and V and for interpeak I-III, I-V, and III-V intervals.


RESULTS
Women who were treated with hormone replacement therapy showed wave latencies and interpeak latencies shorter than those for postmenopausal women in the control group (p < or = 0.05), overlapping those of the premenopausal women (p > 0.05). Women who were treated with estrogen replacement therapy showed shorter time latencies than those treated with combined hormone replacement therapy (p < or = 0.05).


CONCLUSIONS
Our data suggest that fluctuating hormone levels cause changes in auditory brain-stem response waves, even if the exact mechanism of activity of the gonadal steroids is not clear. However, we believe that estrogen may influence the neuronal plasticity, the metabolic levels of neurotransmitters, and thus the neuronal conduction time into the audiological system.
Caruso
S
S
Department of Microbiological Science and Gynecological Science, School of Medicine, University of Catania, Italy.
Cianci
A
A
Grasso
D
D
Agnello
C
C
Galvani
F
F
Maiolino
L
L
Serra
A
A
D000279:Administration, Cutaneous; D000328:Adult; D000375:Aging; D004958:Estradiol / Q000008:administration & dosage; D015914:Estrogen Replacement Therapy; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008535:Megestrol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D010865:Pilot Projects; D017698:Postmenopause; D045167:Progesterone Congeners / Q000008:administration & dosage
D045167:Progesterone Congeners; C047637:nomegestrol; D004958:Estradiol; D008535:Megestrol