Prevalence of Hearing Disorders among Type 2 Diabetes Mellitus Patients with and without Vitamin D Deficiency.

Most of the previous studies have marked hearing loss as another complication of diabetes mellitus, while some other authors had different ideas. The relation between diabetes mellitus and sensorineural hearing loss has been under investigation for a century. However, it has remained controversial. Changing in the metabolism of glucose alters inner ear function and leads to hearing and vestibular disorders. We performed a study on type 2 diabetes mellitus patients with vitamin D deficiency, vitamin D insufficiency and with normal levels of vitamin D in an attempt to find out the prevalence of hearing loss among them. Prevalence of hearing loss was significantly higher in the group with vitamin D insufficiency/deficiency based on X2 test. Results showed that diabetic patients with abnormal levels of vitamin D had a higher risk to develop hearing loss compared to those with normal levels. There was a significant difference between subjects with normal and abnormal levels of vitamin D in terms of hearing loss degree based on the X2 test. In general, hearing loss was more prevalent in patients with abnormal levels of vitamin D, the severity of the loss mostly including slight and mild degrees. The results of the present study suggest that abnormal levels of vitamin D may be associated with a higher risk of hearing loss.