Abstract
Background: Diabetes is a chronic metabolic disorder and its complications pose a significant healthcare burden. Basic pathophysiology of diabetic complications is angiopathy leading to neuropathy. Angiopathy of small vessels of cochlea and neuropathy of cochlear nerve may lead to hearing impairment.

Aim and Objectives: The present study was taken up with an objective to evaluate the changes in the auditory brainstem evoked potentials in type 2 diabetic patients leading to hearing loss compared to healthy controls.

Materials and Methods: A total of 40 subjects in the age group of 40–60 were enrolled into the study and were categorized into 2 groups of 20 each. In the Group 1, age- and sex-matched healthy controls were included and in the Group 2 subjects with type 2 diabetes of more than 5 years duration were included in the study. Any hearing impairment caused by a known disease, drug or injury either traumatic, iatrogenic or noise induced were excluded from the study. They were subjected to auditory brainstem response test Brainstem evoked response audiometry. Absolute latency of wave I-V and interpeak latencies (IPL) I-III, III-V, and I-V was recorded. The data obtained were evaluated using VassarStats.

Results: There was no significant difference in the wave latency of wave I and II between the groups; however, the latencies of waves III, IV, and V was higher in the diabetic group compared to controls on both right and left ear stimulation and it was statistically significant. With respect to the IPL comparison, it was observed that IPL I-III, III-V, and I-V were significantly increased in diabetics with both right and left ear stimulation were statistically significant on comparison with the controls.

Conclusion: The delayed transmission of the auditory pathway at the level of brainstem and midbrain observed in the study advocates the presence of central neuropathy in patients with type 2 diabetes mellitus.

Key words: Diabetic Neuropathy; Brainstem Evoked Response Audiometry; Sensorineural Hearing Loss