Abstract:

To evaluate the relationship between noise induced hearing loss (NIHL) and levels of high density lipoprotein-cholesterol (HDL), low density lipoprotein-cholesterol (LDL-C) and Paraoxonase (PON1) activity in patients with NIHL compared to normal subjects. Thirty two patients with NIHL were recruited in the study. 30 subjects with normal hearing were included in the control group. Pure tone audiometry was applied to all patients and controls. Blood samples were obtained from all subjects to determine levels of HDL-C, LDL-C and PON1. PON1 activity and HDL-C levels were found to be significantly lower while the level of LDL-C was significantly higher in the patients with NIHL compared to healthy controls (p<0.05). In the study group the hearing loss was starting at 4000 Hz and reached to maximum at 6000 Hz. Present findings suggest that atherosclerosis at microlevels begin in cochlear artery. In this respect, decreasing in cochlear arterial perfussion may cause sensorineural hearing loss. Low levels of PON1 activity and HDL-Cand high levels of LDL-C may aggravate the noise induced hearing loss.

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