Hearing Status in Patients with Type 2 Diabetes Mellitus According to Blood-Sugar Control: A Comparative Study

Introduction: it seems that diabetes mellitus (dm) can affect the auditory system due to neuropathy, micro-vascular complications, and hearing cell damage during hyperglycemic states. in the current study, we aimed to compare hearing status in patients with type 2 dm (t2dm) according to their blood-sugar control status. materials and methods: this cross-sectional study was carried out in 104 patients with t2dm attending the diabetic clinics of guilan university of medical sciences within a period of 1 year (2014–2015). one group consisted of 52 patients with poor control and the other consisted of patients with moderate-to-good control (according to glycated hemoglobin [hba1c] level). all subjects underwent pure tone audiometry (pta) and distortion product otoacoustic emission (dpoaes) assessments. a hearing threshold higher than 20 db and a signal-to-noise ratio ≤3 in each frequency were considered abnormal. results: in pta, poorly controlled patients showed more frequent hearing loss compared with the well-controlled group, especially at higher frequencies (8 khz: 67.3% vs 46.2% [p=0.029]; 10 khz: 46.2% vs 21.2% [p=0.025]). also, patients in the poorly controlled group had worse cochlear function according to the dpoae test (4 khz: 32.7% vs 17.3% [p= 0.002] and 8 khz: 70.6% vs 40.4% [p=0.006]). conclusion: dm and poor control status of diabetes can affect hearing sensation and cause hearing loss, especially at high frequencies. according to our findings, it seems that diabetic patients with a duration of diabetes >10 years, diabetic complications, poor control status or comorbidities should undergo both endocrine and audiologic follow-up to prevent greater sensory neural hearing loss.