The Effect of Atorvastatin on Preventing Noise-Induced Hearing Loss: An Experimental Study

BACKGROUND: Noise-induced hearing loss (NIHL) is a common, irreversible occupational disease. Statins have recently been proposed to prevent NIHL. OBJECTIVE: To assess the effect of atorvastatin for the prevention of NIHL in rats. METHODS: In this experimental study, forty 2–3-month-old Wistar male rats were divided into 5 groups of 8 animals. 3 groups of rats received atorvastatin at doses of 5, 25, and 50 mg/kg daily for 14 days. The 4(th) group of rats received normal saline; another group was the control group. After 2 weeks of treatment, the rats were exposed to broad-band noise (125– 20 000 Hz) at 110 dB-SPL intensity for 2 hours. Response amplitude of all ears at 5 frequencies was assessed by distortion product otoacoustic emissions (DP-OAE) at baseline, 2 hours, and 2 weeks after the exposure. RESULTS: Response amplitude was significantly decreased at all frequencies immediately after exposure to noise in all studied groups. The amplitude increased after 72 hours to a level higher than temporary threshold shift (TTS); this change was only significant in the group received 5 mg/kg atorvastatin. CONCLUSION: Low dose atorvastatin (5 mg/kg) used before exposure to noise can probably prevent NIHL in rats. This effect was not observed with higher doses of the drug.