Objective: To investigate the association of cadherin 23 gene (CDH23) polymorphisms with the development of noise induced hearing loss (NIHL).
Methods: 194 workers exposed to occupational noise were drawn as the subjects in the cross-sectional epidemiology study. According to the result of audiometry, they were divided into two groups: the NIHL group and the normal group. The genotypes of 93 workers with NIHL and 101 normal workers were tested by polymerase chain reaction followed by restriction fragment polymorphism analysis (PCR-RFLP).
Results: There were no significant difference in the distribution of genotypes and alleles frequencies of the rs1227049 and rs1227051 positions between NIHL group and normal group (P > 0.05), there were significant differences between the two groups in the rs3802711 position and the terminal position of exon 7 (P < 0.01). After adjusted for age, sex, smoking, history of explosive noise exposure and cumulative noise exposure (CNE) with multiple logistic regression analysis, the risk of rs1227049 CC genotype was found significantly increased than that of the GG genotype, the OR value of which was 3.865 (95% CI 1.076 - 13.886), the risk of rs3802711 TT genotype was significantly higher than that of the CT genotype, the OR value of which was 6.088 (95% CI 2.485 - 14.917). GG genotype in the terminal position of exon 7 was also found a significantly higher risk than the AG genotype, the OR value of which was 5.769 (95% CI 2.745 - 12.121).
Conclusion: It was suggested that genetic polymorphism in cadherin CDH23 gene might play an important role in the development of NIHL in Chinese workers. The individuals with the rs1227049 CC genotype, rs3802711 TT genotype and GG genotype in the terminal position of exon 7 might be more susceptible to NIHL.