Association between polymorphism of tumor necrosis factor alpha (tnfα) in the region -308 g/a with tinnitus in the elderly with a history of occupational noise exposure.

CONTEXT

Tinnitus is a common disorder that occurs frequently across all strata of population and has an important health concern and is often associated with different forms of the hearing loss of varying severity.

AIMS

To investigate the association between the polymorphism of tumor necrosis factor alpha (TNFα) in the region -308 G/A with the susceptibility to tinnitus in individuals with the history of exposure to occupational noise.

SETTINGS AND DESIGN

This was a cross-sectional study with a sample of 179 independent elderly people above 60 years of age.

MATERIALS AND METHODS

Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through polymerase chain reaction by restriction fragment length polymorphism.

STATISTICAL ANALYSIS USED

Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%.

RESULTS

Among elderly with tinnitus (43.01%), 33.76% had a history of exposure to occupational noise. A statistically significant association was found between genotype frequencies of the TNFα gene in the -308 G/A region and the complaint of tinnitus (P = 0.04 and χ = 4.19). The elderly with the G allele were less likely to have tinnitus due to occupational noise exposure when compared to those carrying the A allele (OR = 2.74; 95% CI: 1.56-4.81; P < 0.0005).

CONCLUSION

This study suggests an association between the TNFα with susceptibility to tinnitus in individuals with a history of exposure to occupational noise.