[Relationship between GSTM1 and GSTT1 gene polymorphisms and noise induced hearing loss in Chinese workers].

OBJECTIVE: To investigate the relationship of GSTM1 and GSTT1 gene polymorphisms with the development of noise induced hearing loss (NIHL) in Chinese workers.

METHODS: 194 workers exposed to occupational noise were drawn as the subjects in the cross-sectional epidemiological study. According to the result of audiometry, they were divided into two groups: the NIHL group and the normal group. The GSTM1 and GSTT1 genotypes of 93 workers with NIHL and 101 normal workers were tested by multiplex polymerase chain reaction. Results The study showed that there were no significant differences in the distribution of GSTM1 and GST1 existed/null genotypes frequencies between NIHL group and normal group (P > 0.05). After adjusted for age, sex, smoking, history of explosive noise exposure and cumulative noise exposure (CNE) with multiple logistic regression analysis, the risk of GSTT1 null group was found significantly higher than that of the GSTT1 non-null group (P < 0.05), the adjusted OR value of which was 1.952 (95% confidence interval 1.017 - 3.746). There was no significant difference between the GSTM1 null group and the GSTM1 non-null group in the risk of NIHL (P > 0.05).

CONCLUSION: The results suggested that genetic polymorphism in GSTTI1 gene might play an important role in the development of NIHL in Chinese workers; the individuals with the GSTT1 null genotype might be more susceptible to NIHL.