Significance of audio-vestibular evaluation in diabetes mellitus patients- A study

Abstract

Introduction: Diabetes mellitus (DM) has a projected rise in its affected population to almost double by the year 2035 in India. Ongoing research regarding its microvascular complications has led to a disparity of opinion about involvement of the audio-vestibular system. Hence to evaluate the audio-vestibular functions in patients with diabetes mellitus and determine their correlation with duration and control of the disease, this study was conducted. Materials & Methods: 97 DM patients were included in this prospective, cross-sectional study and all of them underwent clinical examination, Dix-Hallpike maneuver and investigations like Pure tone audiometry (PTA) and Videonystagmography (VNG). Results: 64 of 97 patients, had varying degrees of sensorineural hearing loss on PTA and 16 patients had vestibular hypofunction noted on caloric test of VNG. It was identified that the occurrence of bilateral hearing loss and vestibular hypo-functioning were statistically significant with chi square test (p value 0.028 and <0.001 respectively), when 5years duration of DM was taken for cut off. Analysis of symptoms with PTA and VNG, found significant correlation of tinnitus and hearing loss (p value 0.03 and <0.001 respectively) with abnormal findings in both the investigations, revealing a subclinical nature of the vestibular dysfunction. However, there were no significant correlations found with the glycaemic control of DM. Conclusions: It is advisable to consider audio-vestibular evaluation with PTA and VNG, as screening tests for long term DM patients with or without symptoms of giddiness and hearing loss as a step for early identification of microvascular complications of the inner ear, though larger studies in other populations needs to be done for further confirmation of the correlation.