Effects of erythropoietin on changes of diabetes related auditory brainstem response (ABR) and otoacoustic emissions

ABR is based on postsynaptic and action potentials from the auditory electrical currents. OAE is another audiological test which is based on spontaneous or acoustic stimuli generated by outer hair cells in response to the low intensity of sound. DM is one of the pathologies that cause changes to the ABR and the OAE. DM is a chronic metabolic disease which is characterize with t he absence or relative deficiency of insulin and associated with high blood glucose levels, which causes disorder of many physiological functions. Acute and chronic complications may occur during the course of the disease. One of the chronic complications of DM is the hearing loss which is characterized bilaterally, involving high frequencies, symmetrical, progressive and sensorineural. Diagnostic findings support demonstrating the existence of damage to the brain stem and the auditory pathway by demonstrating prolonged latency period of III, IV. and V. waves and III-V IPL; these are not full diagnostic findings. Some of studies show prolonged latency period of I. wave is available, but some studies show that no significant effect, also has been reported in the literature. One of the agents used for removing of diabetes mellitus complications is EPO. EPO has also effects like anti-inflammatory, anti-apoptotic, immunomodulatory and neurotrophic, neuroprotective, antioxidant, and differentiation of endothelial cell proliferation with main function erythrogenesis stimulation. In injured tissue, EPO enhances tissue repair by mobilizing stem cells into the region of injury and increases neurite outgrowth and synaptogenesis. EPOR expression is demonstrated in the inner ear cells but not in the vestibular system In our study, we did not find any significant difference between Contol goup and DM group. At high frequency (16 kHz) DM + EPO group compared to the control group and DM group; we found a statistically significant difference in terms of latency and interpeak latency at some waves. According to our DPOAE measurements there were no cochlear pathology in DM and evidence supporting the protective effect of EPO could not be obtained..