A study of sensorineural hearing loss in patients with diabetes mellitus by pure tone audiometry

Abstract

BACKGROUND: Diabetes mellitus is a significant public health problem with many secondary micro and macrovascular complications. [1] The most underestimated complication of diabetes mellitus is sensorineural hearing loss.[1] In 1857, Jordao was the first to document the correlation between diabetes mellitus and hearing impairment. Incidence of hearing loss in diabetes patients ranges up to 80%. The hearing loss observed in diabetic patients will be of progressive bilateral sensorineural type affecting high frequencies. [2] Goal of the present study is to establish a relationship between glycemic control and sensorineural hearing loss. OBJECTIVES OF THE STUDY:  To assess the association of sensorineural hearing loss in patients with diabetes mellitus.  To measure levels of HbA1c in diabetes mellitus patients to know the glycemic control and its influence on sensorineural hearing loss . DESIGN OF STUDY: Hospital based cross-sectional study. MATERIALS AND METHOD: Study included 70 patients among which 35 were clinically diagnosed diabetes mellitus patients experiencing hearing loss and 35 were non-diabetic patients with similar complaints who were selected from the ENT and Medicine outpatient departments at BLDE (Deemed to be University) Shri B.M.Patil Medical College and Research Centre , Vijayapura. All participants were < 60 years of age and were chosen based on specific inclusion and exclusion criteria. Comprehensive history XV Docusign Envelope ID: 7881F31D-DA44-40F2-B6DF-BB9E17B7154E taking, clinical examinations, and tuning fork tests were performed. Blood tests, including fasting blood sugars (FBS), postprandial blood sugars (PPBS), and HbA1c (glycosylated hemoglobin), performed on these patients. All the subjects underwent pure tone audiometry, and the results were analyzed and documented. RESULTS : In our study SNHL is more prevalent in cases i.e reduced hearing with known diabetic, whereas in non diabetic with reduced hearing controls only 20 % had SNHL according to PTA values (right ear) . According to PTA values (left ear) , SNHL is more prevalent in cases i.e reduced hearing with known diabetic, whereas in non diabetic with reduced hearing controls only 22.9 % had SNHL .This signifies that SNHL is more prevalent in diabetic patients compared to non -diabetic controls . Cases were further divided into two groups , HbA1C less than 7 were considered as good control and HbA1C more than 7 were considered as poor control . In our study out of 35 cases only 11(31.43%) were good control patients and the remaining 24(68.57%) were poor control patients. It was observed that all 11 good controlled dm patients experienced mild SNHL whereas in poorly controlled dm patients 3(40%) had severe SNHL and 16(66.7%) had moderate SNHL and 5 (14.3%) had mild SNHL in right ear . In the left ear out of 11 good controlled dm patients 7 (63.6%) experienced mild SNHL and 4 (36.4%) had moderate SNHL ,whereas in poorly controlled dm patients 3(8.6%) had very severe SNHL and 10 (28.6%) had severe SNHL and 14(40.0%) had moderate SNHL and 8 (22.9%) had mild SNHL in the left ear. pvalue is less than 0.001 showing strong significance which proves poorly controlled XVI Docusign Envelope ID: 7881F31D-DA44-40F2-B6DF-BB9E17B7154E diabetes mellitus patients exhibited more severe hearing loss compared to those with well-controlled diabetes. CONCLUSION: The prevalence of sensorineural hearing loss (SNHL) is higher in patients with type 2 diabetes based on PTA values, while patients with poorly controlled diabetes mellitus, as indicated by HbA1c values, exhibited more severe hearing loss. In our current study, we emphasize the importance of impact of diabetes on hearing health. Therefore complete audiological evaluation and maintaining strict glycemic control is crucial for reducing the impact of diabetes on hearing sensitivity.