Tinnitus, hearing loss and inflammatory processes in an older Portuguese population

Objective: Tinnitus is associated with various conditions such as presbycusis, infectious, autoimmune and many other diseases. Our study aims to identify an association between inflammatory markers and the presence of tinnitus or hearing loss (HL).Design: Exploratory study including a structured interview, complete ENT observation, audiological and inflammatory markers evaluation.Study Sample: Sixty women and 54 men (55 to 75 years) from the Portuguese population, with or without sensory presbycusis and/or tinnitus.Results: IL10 levels were significantly lower in participants with tinnitus than in those without tinnitus. Moreover, TGF-β was lower in older participants (p = 0.034), IL1α was higher in participants with tonal tinnitus (p = 0.033), and IL2 was lower in participants who reported partial or complete residual inhibition (p = 0.019). Additionally, we observed a negative correlation between tinnitus duration and IL10 levels (r= -.281), and between HSP70 levels and tinnitus loudness (r= -.377). TNF-α and HSP70 levels appears to be sensitive to the time when samples were collected (morning or afternoon).Conclusions: The results of our study showing fluctuations in inflammatory markers along the hearing loss process, reinforce the idea that inflammatory mechanisms are involved in hearing loss pathogenesis but also in tinnitus. IL10 levels appear significantly altered in tinnitus but not in hearing loss.