Effect of liraglutide treatment on mitigation of hearing damage induced by multiday repeated high-intensity blasts

Exposures to blasts impair hearing, despite the protection of earplugs. Liraglutide showed therapeutic effects against hearing damage induced by single-day blasts. However, the effect of liraglutide on auditory damage caused by multiday repeated blasts remains unknown. Chinchillas protected by earplugs were exposed to three blasts at 15-25 psi on day 1, followed by an identical exposure on day 4. Animals were assigned to pre-blast treatment, post-blast treatment, or blast control groups based on the timing of liraglutide administration relative to the day 1 blasts. Auditory brainstem response (ABR), middle latency response, and distortion product otoacoustic emission were measured at multiple time points following the blast. Spiral ganglion neuron density was assessed histologically at the end of the study. The blast control group showed 20-30 dB ABR threshold shift across frequencies on both days 1 and 4. Pre-blast treatment reduced threshold shifts on days 1 and 4, while post-blast treatment was effective only on day 4. Post-blast treated ears showed higher ABR wave amplitudes and greater spiral ganglion neuron density after day 4 blasts compared to blast control ears. The liraglutide treatment significantly mitigated the blast-induced temporary damage when the blasts occurred during the treatment period.