Hearing assessment in transfusion dependent beta-thalassemia children on oral iron chelating agent.

Abstract

Background: Hearing deficit is one of the side effects of 1st generation iron chelators in β-thalassemia, however the risk of hearing deficits following 2nd generation iron chelators is not well known.

Aim: To assess hearing status of Transfusion Dependent β-thalassemia children on oral iron chelating agents and detect risk factors for hearing impairment.

Methods: This is a cross-sectional study recruited sixty children and adolescent with confirmed diagnosis of transfusion dependent β-thalassemia. Demographic and clinical characteristics collected, audiological testing were performed by the same audiologist using the same equipment for all patients including tympanometry, pure tone audiometry, speech audiometry, transient evoked otoacoustic emissions and distortion product otoacoustic emissions.

Results: Recruited children and adolescents with transfusion dependent β-thalassemia were 32 (53.3%) boys and 28 (46.7%) girls and their mean age was 11.34 ± 3.08, majority of patients 48 (80%) were on single Deferasirox. Our study revealed that among the 60 children evaluated, 16.6% exhibited some form of hearing loss. Sensorineural hearing loss (SNHL) was observed in 6.6% of the participants, while 10% had conductive hearing loss (CHL). Bilateral SNHL in 5% and bilateral CHL in 8.3% of all the cases. Hearing impairment was mild in nature, but predominantly affected high-frequency ranges, the most affected frequencies being 4000 Hz and 8000 Hz. There was no significant difference between studied thalassemia children with and without hearing impairment regarding gender, age at study entry, age at diagnosis, duration of disease and duration or dose of chelating agent (P > 0.05). Our study revealed significant difference between studied thalassemia children with and without hearing impairment regarding age of starting blood transfusion (p-value = 0.024), affected patients started blood transfusion at older age, also statistically significant difference in both groups regarding median serum ferritin was found (p-value = 0.028), lower levels were found in affected patients.

Conclusion: No significant effect of using oral iron chelation drugs was observed on frequency and type of hearing loss among the studied patients but instead the age at starting regular blood transfusion did. Screening of such group of patients for hearing impairment at diagnosis and at regular periods is recommended.