Association between polymorphism of interleukin-6 in the region -174G/C and tinnitus in the elderly with a history of occupational noise exposure

Abstract

Tinnitus is a symptom usually related to cochlear change that may arise from noise exposure and induces expression of proinflammatory cytokines including interleukin-6 (IL6). This study aimed to evaluate the association between the polymorphism of the IL6 gene in the region 174G/C and tinnitus in elderly with history of occupational noise exposure. Settings and Design: This was a cross-sectional study with a sample of 179 independent elderly individuals aged >60 years. 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 (PCR-RFLP). Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%. Among the study subjects, 24.6% were homozygous for the G allele, 39.7% were homozygous for the C allele, and 35.8% were heterozygous for IL6 (P > 0.05). Of these, 33.5% reported noise exposure history, with 42.5% having tinnitus. We found significant association between the genotype and allele frequencies of the IL6 −174 gene (rs1800795) and tinnitus among the elderly with history of exposure to occupational noise (P = 0.03). The elderly with the C allele were less likely to have tinnitus associated with history of exposure to occupational noise [OR = 0.167, confidence interval (CI) 95% 0.167-0.749; P = 0.004] when compared to those carrying the G allele. This study suggests that there is an association between polymorphisms in the IL6 gene at region – 174G/C and susceptibility to tinnitus.

Resistance to noise-induced gap detection impairment in FVB mice is correlated with reduced neuroinflammatory response and parvalbumin-positive neuron loss

“…Our results suggest that predisposition for neuroinflammatory responses may be a genetic risk factor for tinnitus. This interpretation is consistent with findings that polymorphisms of inflammatory cytokines, including TNF-α, are associated with the risk of tinnitus, especially in those with a history of occupational noise exposure [23][24][25] .…”

Comparative study of tinnitus and cardiorespiratory fitness among people post COVID-19

“…Studies show that immune deregulation with increased proinflammatory cytokines has been observed in patients with tinnitus, especially those exposed to occupational noise. This suggests an association between IL-1α gene polymorphism and susceptibility to tinnitus in individuals with no history of occupational noise, as well as an association between IL6 gene polymorphisms in the region -174G/C and susceptibility to tinnitus (20,21) .…”

Associations of Tinnitus Incidence with Use of Tumor Necrosis Factor-Alpha Inhibitors among Patients with Autoimmune Conditions

“…TNFα has been implicated in some exploratory human studies of tinnitus. Certain polymorphisms in the TNF gene are associated with susceptibility to tinnitus among older individuals with occupational noise exposure [21]. In patients with chronic tinnitus, relaxation training that significantly decreased tinnitus-related stress, depression, anger, and disturbance was associated with reduced serum TNFα levels [22].…”