Effects of Diabetes on Hearing and Cochlear Structures

Diabetes mellitus (DM) is a chronic systemic disease characterized by hyperglycemia, with various pathogenic mechanisms. From absolute or relative insulin deficiency, patients with DM often demonstrate various levels of metabolic disorders. Major clinical manifestations of DM include metabolic disorders, vascular lesions, circulatory disturbances and neurologic complications. Along with advances in DM research, reports of DM related tinnitus and hearing impairment have increased continuously. Research on DM related auditory system dysfunction has focused on cochlear microcirculation, cellular homeostasis, genetics and aging. Cochlear microcirculation plays an important role in cochlear physiology and its disorders are associated with many inner ear diseases. Ischemia and subsequent reperfusion seen in cochlear microcirculation disorders are important factors in hearing damage. Understanding cochlear microcirculation and structural as well as functional changes in DM patients with hearing loss and their causal factors will help reveal pathogenic mechanisms in diabetic hearing loss and provide new ideas in developing interventions and preventing damages caused by diabetes.