The Effect of Hormone Replacement Treatment on Hearing Function in Hypothyroid Patients.

Unlabelled: Congenital hypothyroidism causes physiologic, morphologic and developmental abnormalities of the auditory system. However, the effect of acquired hypothyroidism and hormone replacement treatment (HRT) on hearing function is still controversial. This study aimed to investigate hearing impairment and the effect of HRT on hearing function in patients with acquired hypothyroidism.

Materials And Methods: Fifty hypothyroid patients were included in this study. Levothyroxine (0.05-0.2 mg/dl) was used for HRT and its dosage was gradually increased until the patients became euthyroid. Otoscopy and microscope was used to evaluate tympanic membrane and hearing thresholds and pure tone avarages (PTA) were estimated by using pure tone audiometry before and after treatment.

Results: Patients with lower baseline free T4 (FT4) had significantly higher air conduction PTA ( < 0.05). Negative correlation between the severity of hypothyroidism and hearing gain were found (p < 0.05). Hearing improvements were at 250 and 8000 Hz after HRT.

Conclusion: Due to the correlation between baseline FT4 and hearing impairment in a negative direction, disease severity may have an effect on hearing impairment. In addition, patients with lower FT4 and higher thyroid-stimulating hormone levels had lower PTA improvement after HRT. HRT may not significantly improve hearing disorders in severe hypothyroidism.