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 (TNF alpha) 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 TNF alpha gene in the -308 G/A region and the complaint of tinnitus (P = 0.04 and chi(2) = 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 TNF alpha with susceptibility to tinnitus in individuals with a history of exposure to occupational noise.