Association Between Type 2 Diabetes Mellitus and Hearing Loss Among Patients in a Coastal City of South India

Diabetes mellitus (DM) is a metabolic culprit known to perpetuate several disease processes. The relationship between hearing loss (HL) and type 2 DM (T2DM) remains unclear despite the vast volume of research devoted to this topic. We conducted this study with the aim to evaluate HL among T2DM patients and to assess the relationship between severity of HL, glycosylated hemoglobin (HbA1c) levels and duration of T2DM. Design: a time bound descriptive crosssectional study. Setting: tertiary care hospital of South India. Subjects: subjects with T2DM, aged from 40 to 60 years (excluding hypertension, chronic noise exposure and history of smoking or ototoxicity) were included. Methods: Non-random convenience sampling. Details were gathered using a self-administered, semistructured questionnaire and the hearing was assessed by pure tone audiometry. Data was analysed using SPSS. A large proportion of the sampled population had audiological assessments suggestive of SensoriNeural HL (SNHL). 90.2% had a bilateral distribution of HL; however, only 39% of patients reported having any associated ear complaints. No statistically significant associations were obtained between severity of HL, glycaemic control, duration of diabetes or gender. Bilateral SNHL is a complication associated with T2DM. Duration and glycaemic control are independent variables and do not statistically influence the severity of HL. However, this study demonstrated that many patients with SNHL had no symptoms and also lacked awareness of HL in DM. Therefore routine assessment of hearing should be considered in the diabetic population.