title: [Effects of noise exposure level on the relationship between SNPs of SOD1 and the susceptibility to noise-induced hearing loss (NIHL)].
abstract: OBJECTIVE
  To explore the effects of noise exposure level and cumulative noise exposure (CNE) on the relationship between rs2070424 and rs10432782 SNPs in SOD1 and the susceptibility to noise-induced hearing loss (NIHL).
  
  
  METHODS
  A case-control study was performed for investigating the effects of environmental risk factors on the susceptibility to NIHL in 201 sensitive workers and 202 resistant workers.A questionnaire was utilized to investigate the occupational health and to identify the occupational risk factors. The noise exposure levels were detected according to the Chinese standard Measurement of noise in the workplace (GBZ/T 189.8-2007). The peripheral blood samples (5 ml blood for each sample) were from sensitive workers and resistant workers. Genomic DNA was extracted on the basis of the standard procedures of Takara kit. SNPs were detected using standard procedures of TaqMan probe allele identification method.
  
  
  RESULTS
  In group exposed to 85 - 92 dB noise (A), the risk of NIHL in the subjects with the AA genotype of rs2070424 was lower than that in the subjects with the GG genotype, OR = 0.37 (95%CI: 0.17∼ 0.80). In group exposed to > 82 dB CNE (A), the AA genotype of rs2070424 is a protective factor of NIHL, as compared with the GG genotype, OR = 0.25 (95%CI: 0.09 ∼ 0.70). In group exposed to 85 - 92 dB noise (A), the risk of NIHL in the subjects with the GG genotype of rs10432782 was compared with the risk of NIHL in the subjects with the TT genotype, OR = 3.17 (95%CI: 1.16 ∼ 6.89). The GT genotype was compared with TT genotype, OR = 2.39 (95%CI: 1.16 ∼ 4.97). In group exposed to 75 ∼ 82 dB CNE (A), the risk of NIHL in the subjects with the GG genotype was compared with the risk of NIHL in the subjects with the TT genotype, OR = 2.35 (95%CI: 0.96 ∼ 5.72), P = 0.06. The GG genotype may bea risk factor of NIHJ.
  
  
  CONCLUSIONS
  The noise exposure level and CNE may influence the relationship between rs2070424, rs10432782 SNPs in SOD1 and noise-induced hearing loss.
authors.affiliation: Guangzhou No12 Hospital, Guangzhou, China.
authors.forename: Wen-feng
authors.initials: WF
authors.lastname: Zeng
authors.forename: Xu-dong
authors.initials: XD
authors.lastname: Li
authors.forename: Yi-min
authors.initials: YM
authors.lastname: Liu
authors.forename: Jian-xiong
authors.initials: JX
authors.lastname: Chen
authors.forename: Shi-biao
authors.initials: SB
authors.lastname: Su
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006317:Hearing Loss, Noise-Induced / Q000209:etiology* / Q000235:genetics*; D006801:Humans; D008297:Male; D009623:Noise, Occupational / Q000009:adverse effects*; D020641:Polymorphism, Single Nucleotide; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1; D011795:Surveys and Questionnaires
chemical_list: C000606290:SOD1 protein, human; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1