[Functional hearing examinations in patients suffering from diabetes mellitus type 1 in regard to disease duration].

Introduction: Problems of hearing disturbances in persons suffering from diabetes have been attracting great attention for many decades.

Material And Methods: In this study we examined the auditory function of 50 patients suffering from diabetes mellitus type 1 of different duration by analyzing results of pure-tone audiometry and brainstem auditory evoked potentials. The obtained results of measuring were compared to 30 healthy subjects from the corresponding age and gender group. The group of diabetic patients was divided according to the disease duration (I group 0-5 years; II group 6-10 years, III group over 10 years).

Results And Discussion: A statistically significant increase of sensorineural hearing loss was found in the diabetics according to the duration of their disease (I group = 14.09%, II group = 21.39%, III group = 104.89%). The results of the brain stem auditory evoked potentials, the significance threshold being p = 0.05 between the controls and the diabetics at all levels of absolute latency of right and left sides, did not show significant differences in the mean values. In the case of interwave latencies, the diabetic patients were found to have a significant qualitative difference of intervals I-III and I-V on both ears in the sense of internal distribution of response. In cases of sensorineural hearing loss we found a significant connection with prolonged latencies of I wave on the right ear and of I and V waves on the left ear. In all probability, the cause of these results could be found in distinctive individuality of the organism reactions to the consequences of this disease (disturbance in the distal part of N. cochlearis).

Conclusion: The results of research have shown the existence of a significant sensorineural hearing loss in the patients with diabetes mellitus type 1 in accordance to the disease duration. We also found qualitative changes of brainstem auditory evoked potentials in the diabetic patients in comparison to the controls as well as significant quantitative changes in regard to the presence of sensorineural hearing loss of the patients.