Is type 1 diabetes mellitus a cause for subtle hearing loss in pediatric patients?

The objective of this study is to investigate the effects of IDDM on the function of the auditory pathway from the cochlea to the auditory cortex in child patients. Totally, 140 ears of 70 children with IDDM and 60 ears of 30 age and gender-matched healthy controls were included in the study. The ages of patients and controls ranged from 4 to 14 years. Audiological assessment including pure-tone audiometry, otoacoustic emission testing (OAE) and auditory brainstem response testing (ABR) has been performed to all participants. There was no significant difference between the patients and controls regarding pure-tone thresholds on audiometry (p > 0.05). The latencies of waves I, III and V on ABR were not significantly different between the patients and controls (p > 0.05). The amplitudes on DPOAE testing obtained from both groups were not significantly different at the frequencies of 2,000 and 4,000 Hz (p > 0.05). However, the DPOAE amplitudes of the patients at 1,000 Hz were significantly lower than those of controls at the same frequency (p = 0.03). There was no difference between the patients who had chronic disease (>5 years) and healthy controls regarding pure-tone audiometry, ABR and DPOAE testing results (p > 0.05). In the light of the findings obtained with pure-tone audiometry, and OAE and ABR testing, it seems that auditory system is spared in children with IDDM at clinical level. Diabetes control and chronicity of the disease do not impact on the auditory system except for a subclinical involvement in the apical portion of the cochlea.