Audiologic evaluation in pediatric patients with type 1 diabetes mellitus

The aim of this study was to perform audiological evaluation of children with type 1 diabetes mellitus (DM).

One hundred DM patients (200 ears) were included in the study. Pure-tone audiometry at frequencies of 0.25, 0.5, 1, 2, 4, and 8 kHz; immittance measures including tympanometry and acoustic reflex testing; transient evoked otoacoustic emission (TEOAE); and auditory brainstem response (ABR) testing were performed in the patients. The results were statistically compared with metabolic control of DM, positive and negative autoantibodies, duration of DM, and present concomitant Hashimoto and celiac diseases.

The proportion with a result of 'fail' for the TEOAE test in the DM patients was not statistically significant among all groups (p > 0.05). The autoantibodies, blood glucose level, and present concomitant Hashimoto and celiac diseases were not associated with prolonged ABR latencies. However, ABR peripheral transmission time (wave I) was significantly delayed with the increasing duration of DM (p < 0.05).

Pediatric patients with type 1 DM do not frequently present with cochleovestibular symptoms, but show higher audiometric thresholds and the absence of or reduction in TEOAE amplitudes. In ABR testing, the increase in the peripheral transmission time (wave I) is more suggestive of retrocochlear alterations in pediatric cases of type 1 DM compared with conventional audiometric tests (e.g., pure-tone audiometry and OAEs), which may indicate possible initial auditory neuropathy. Further longitudinal investigations on a wide range of control and pediatric subjects with DM will be necessary to confirm the present data and to detect initial auditory neuropathy.