Effects of Glycemic Control on Hearing Outcomes in Diabetes Patients With Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVE: This study aimed to analyze the effects of glycemic control on the hearing outcomes of type 2 diabetes patients with idiopathic sudden sensorineural hearing loss (ISSHL). METHODS: Type 2 diabetes patients with ISSHL were enrolled. All patients were admitted for 5 days and received systemic corticosteroid treatment. Patients were divided into groups according to their degree of glycemic control pre- (glycosylated hemoglobin) and post- (mean blood glucose) onset of ISSHL. Demographic, audiometric, and hearing outcome data were analyzed. Furthermore, a multivariate analysis was performed to determine the prognostic factors affecting the hearing outcomes in these patients. RESULTS: One hundred forty-four patients were enrolled. The hearing recovery rates were as follows: complete recovery, 19%; partial recovery, 15%; slight improvement, 22%; and no improvement, 44%. Initial hearing levels and diabetes duration were significantly higher in the pre-onset poor-controlled group (glycosylated hemoglobin ≥ 7.0%) than those in the well-controlled group. The hearing recovery rates did not differ significantly pre- or post-onset. In a multivariate analysis, duration from hearing loss onset to treatment, presence of vertigo, and initial hearing level were negative prognostic factors that affected hearing recovery. CONCLUSION: The degree of pre- or post-onset glycemic control did not affect hearing outcomes in patients with ISSHL and type 2 diabetes. Therefore, the administration of systemic corticosteroid is required for diabetes patients with ISSHL within allowable blood glucose levels.