[Current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry]

Objective: To investigate the current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry. Methods: From August 2015 to March 2016, the investigation method of collecting the data of past occupational health examinations and measuring noise in working environment was used to enroll 8 672 male workers. Results: Of all workers, 11.6% were diagnosed with hearing loss. There were significant differences in the distribution of hearing impairment among workers exposed to noise at different ages, device types and types of work (χ(2)=17.80, 77.80 and 30.53, all P<0.05) . The level of noise exposure≥85 dB (A) (OR=5.79, 95%CI 3.70-8.81) , working years with noise exposure (OR=1.57, 95%CI 1.05-2.43) , and 25 years (OR=3.29, 95%CI 2.08-5.71) were risk factors for hearing loss in workers with noise exposure in refining and chemical industry. Conclusion: The level of noise exposure and working years with noise exposure are main influencing factors for hearing loss in workers with noise exposure in refining and chemical industry.

[Association between CDH23 gene polymorphisms and susceptibility to noise-induced hearing loss in the Chinese population: a meta-analysis]

Objective: To investigate the association between cadherin-23 (CDH23) gene polymorphisms and susceptibility to noise-induced hearing loss (NIHL) in the Chinese population through a meta-analysis. Methods: In June 2016, CNKI, VIP, Wanfang Data, and PubMed were searched for studies on the association between CDH23 gene polymorphisms and susceptibility to NIHL in the Chinese population. The articles were screened according to inclusion and exclusion criteria and related data were extracted. RevMan 5.3 was used for the meta-analysis. Results: A total of three Chinese articles were included. For CDH23-rs1227049, the risk of NIHL in people with C allele was 0.82 times (95%CI 0.39-1.73) that in people with G allele, the risk of NIHL in people with CG+CC genotype in the dominant model was 0.70 times (95%CI 0.34-1.43) that in people with GG genotype, the risk of NIHL in people with CC genotype in the recessive model was 1.23 times (95%CI 0.28-5.43) that in people with CG+GG genotype, and the risk of NIHL in people with CC genotype in the additive model was 1.05 times (95%CI 0.20-5.44) that in people with GG genotype (all P>0.05) . For CDH23-rs1227051, the risk of NIHL in people with T allele was 0.98 times (95%CI 0.71-1.37) that in people with C allele, and the risk of NIHL in people with CT+CC genotype in the dominant model was 1.09 times (95%CI 0.75-1.57) that in patients with TT genotype (both P>0.05) . Conclusion: There is still no enough evidence for the determination of CDH23-rs1227049 and CDH23-rs1227051 to be the susceptibility gene loci of NIHL.