Affiliations: Guangzhou No. 12 Hospital, Guangzhou, China | Guangdong Prevention and Treatment Center for
Occupational Diseases, Guangzhou, China | Guangzhou Institute of Health Inspection, Guangzhou,
China | School of Public Health, Sun Yat-Sen University,
Guangzhou, China | School of Public Health, Guangdong Medical College,
Dongguan, China
Note: [] Corresponding author: Shao-Qi Rao, PhD, Department of Medical
Statistics and Epidemiology, School of Public Health, Sun Yat-Sen University,
74 Zhongshan Road 2, Guangzhou 510080, China. Tel.: +86 020 87332513; Fax: +86
020 87332513; E-mail: raoshaoq@mail.sysu.edu.cn
Abstract: Objective: To investigate whether single nucleotide polymorphisms
(SNPs) in the Mn-superoxide dismutase gene (SOD2) underlie the susceptibility
to noise-induced hearing loss (NIHL). Methods: Audiometric data from 2400
Chinese Han workers who exposed to occupational noise were analyzed. DNA
samples were collected from the 10% most susceptible and the 10% most
resistant individuals, and five SNPs (SOD2 rs2842980, rs5746136, rs2758331,
rs4880 and rs5746092) were genotyped by Taqman SNP Genotyping Kits. The SNP
main effects and interactions between noise exposure and SNP were analyzed
using logistic regression. Haplotypes were analyzed by using Haploview
software. Results: The CT genotype of rs4880 (SOD2 V16A SNP) was
associated with a higher risk of NIHL (covariates-adjusted OR, 2.18; 95% CI,
1.34–3.54, P=0.002). Haplotype analysis revealed that the frequency of
AGCCG at the five SNP loci was significantly higher in the susceptible group
(P=0.020). With AGCTG as the reference, the OR (95% CI) was 2.63 (1.14,
6.06). The rs4880 polymorphisms imposed larger effects when the carriers were
exposed to higher levels of noise, indicating the interaction between SNP and
noise exposure. Conclusions: Our results suggest that SOD2 V16A SNP in
the mitochondrial targeting sequence is associated with noise induced hearing
loss in Chinese workers, and this effect was enhanced by higher levels of noise exposure.
