Association of the C47T polymorphism in superoxide dismutase gene 2 with noise-induced hearing loss: a meta-analysis()

INTRODUCTION: Currently, there is limited information about the relationship between manganese superoxide dismutase (sod2) c47t polymorphism and susceptibility to noise-induced hearing loss (NIHL). OBJECTIVE: The aim of this meta-analysis was to clarify the association between SOD2 C47T polymorphism and NIHL. METHODS: A search in PubMed and Web of Science was performed to collect data. All full-text, English-written studies containing sufficient and complete case-and-control data about the relationship between SOD2 C47T polymorphism and NIHL were included. Three eligible studies, comprising 1094 subjects, were identified. pooled odds ratios (ORs) and 95% confidence intervals (CI) were calculated to evaluate the strength of the association between SOD2 C47T polymorphism and NIHL. RESULTS: No significant association between C47T polymorphism and risk of NIHL was found with the following combinations: T vs. C (OR = 0.83; 95% CI = 0.63–1.09); TT vs. CC (OR = 0.49; 95% CI = 0.22–1.09); CT vs. CC (OR = 0.54; 95% CI = 0.25–1.17); TT vs. CC + CT (OR = 0.82; 95% CI = 0.50–1.32); CC vs. TT + TC (OR = 0.49; 95% CI = 0.23–1.04). However, in subgroup analysis, a significant association was found for TT vs. CC + CT (OR = 0.77; 95% CI = 0.42–1.41) in the Chinese population. CONCLUSION: The present meta-analysis suggests that SOD2 C47T polymorphism is significantly associated with increased risk of NIHL in the Chinese population. Further large and well-designed studies are needed to confirm this association.