Etiology of Noise-Induced Hearing Loss (NIHL) and its Symptomatic Correlation with Audiometry Observations in Type II Diabetes.

Type II diabetic mellitus (DM) is a chronic metabolic disease that impairs normal insulin production and glucose transport to the liver and muscles. In the India, about 1-5% population suffer from diabetes or related complication. So there is need to cure this disease. DM chronic auditory complications may include spiral ganglia atrophy, degeneration of the vestibulocochlear nerve myelin sheath, reduction of the number of spiral lamina nerve fibres, and thickening of the capillary walls of the stria vascularis and small arteries. This study aims to know the incidence of common parameters, blood sugar levels, levels of lipids and the hearing thresholds of individuals. It is a Noise-Induced Hearing Loss research study featuring hearing impairment in transport workers diagnosed as type II diabetic. All individuals were interviewed by various questioners related to listening ability of subjects and underwent a physical examination, blood investigations and audiometry. Hearing impairment was more prevalent among adults with diabetes. Sensory neuron hearing loss is predominant in both study groups. Mixed Bilateral Hearing Loss showed significant p value in (>.001) by audiometry. The percentage of hearing loss in diabetes (ranges 5.3-28.1%) and in non-diabetics (ranges 3.4-24.1%) and risk factors in diabetes (ranges 22.8-35.1%) over nondiabetics (ranges 17.2-20.1%) which is eye opener. The correlation between type II diabetes and hearing impairment was independent of known risk factors for hearing impairment, such as noise exposure, build-up wax, ototoxic medication, smoking, tobacco chewing etc.