Objectives: To investigate whether glutathione S-transferases (GST) genetic polymorphisms (GSTT1 rs1049055, GSTM1 rs10712361, and GSTP1 rs1695) are associated with susceptibility to noise-induced hearing loss (NIHL).
Methods: These polymorphisms were analyzed in 444 NIHL and 445 normal hearing workers. In addition, total plasma GST activity was measured in all subjects.
Results: Individuals with the GSTM1 null genotype had a statistically significantly increased risk of NIHL (odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.26 to 2.13) compared with those carrying a wild-type GSTM1 genotype. This effect was more pronounced among the workers exposed to 86 to 91 dB(A) (OR = 3.35, 95% CI = 1.54 to 7.31). Glutathione S-transferase activity of the NIHL workers was also lower than that of normal hearing workers (14.5 ± 5.1 U/ml vs 15.9 ± 6.3 U/ml, P = 0.010).
Conclusion: Our results suggest that GSTM1 polymorphism is associated with susceptibility to NIHL.
From the Department of Occupational Medicine and Environmental Health (Drs Shen, Huo, Xiuting Li, Wang, Xin Li, Zhengdong Zhang, and Zhu), the Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China; Institute of Occupational Disease Prevention (Drs Shen, Xiuting Li, Gong, Hengdon Zhang, Xu, and Zhu), Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, China; Department of Molecular & Genetic Toxicology (Drs Huo, Wang, Xin Li, and Zhengdong Zhang), Jiangsu Key Laboratory of Cancer Biomarkers, Prevention & Treatment, Cancer Center, Nanjing Medical University, Nanjing, China; Department of Disease Prevention, (Dr Kai Liu) The Third Affiliated Hospital of Nanjing Medical University, Yizheng, China; and Department of Safety (Dr Jing Zhang), Chenguang Machinery Manufacturing Group Corporation, Nanjing, China.
Address correspondence to: Baoli Zhu, Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Prevention and Control, 172 Jiangsu Road, Nanjing 210009, China (email@example.com); Zhengdong Zhang, Department of Molecular & Genetic Toxicology, School of Public Health, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, China (firstname.lastname@example.org).
The first three authors contributed equally to this work.
The authors declare no conflict of interest.
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Address for reprints: Baoli Zhu, Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Prevention and Control, 172 Jiangsu Road, Nanjing 210009, China (email@example.com).