Dysfunction of Vestibulocochlear Nerve in Type 2 Diabetes Mellitus

Hearing loss is one of the under-recognized diabetic consequences that impacts cognitive performance and quality of life. The study was carried out to assess the prevalence of hearing impairment and to investigate the type, degree, and pattern of hearing impairment in diabetics.  Materials and Methods The study was conducted as a case-control study including 60 diabetic patients and 25 healthy individuals after exclusion of confounding factors. Hearing assessment was done using pure tone audiometry.  Results The prevalence of hearing impairment in diabetics of age 30-60 years was 70% compared to normal population (30%). 7 out of 13 diabetic patients in the age group of 30- 40, 19 out of 27 diabetics in the age group of 40-50 & 16 out of 20 diabetics in the age group of 50-60 had hearing impairment. 18 out of 60 diabetic patients having HbA1c of < 7 and 42 out of 60 diabetic patients having HbA1c of >7 had hearing impairment. 24 out of 32 patients with diabetes duration of 5years had hearing impairment. Out of 42 diabetic patients who had hearing impairment, 27 (64%) had diabetic neuropathy.  Conclusion Diabetics frequently suffer from eighth nerve dysfunction. Its prevalence among diabetics increases with age and correlates favourably with diabetes duration and the presence of diabetic peripheral neuropathy. Its prevalence, however, did not reveal a favourable association with HbA1c levels.