The Role of IL-6 in Inner Ear Impairment: Evidence from 146 Recovered Patients with Omicron Infected in Tianjin, China

Purpose: To explore the effect of inflammatory factors on inner ear impairment in a sample of Omicron-infected patients with a high rate of vaccination in China. Methods: One hundred and forty-six recovered Omicron-infected patients performed the distortion product otoacoustic emission (DPOAE) test and serum test for inflammatory factors; demographic data and vaccination statuses were collected from the questionnaire. Results: Out of 146 patients, the DPOAE pass rate was 81.5% (119/146). Inner ear impairment was significantly correlated with IL-6 titer. The odds ratio (aOR) was 1.24 (95% CI: 1.04–1.49) after adjusting for age, sex, and vaccine characteristics. Notably, this relationship only existed in the 18–60 years group. There were no significant protective effects of vaccination on inner ear function. Conclusions: Inner ear impairment still exists in Omicron-infected patients, which was significantly correlated with IL-6 titer. This relationship was mainly observed in young and middle-aged people, possibly due to a stronger immune response in this age group. The protective effect of vaccination on the inner ear could not be proved.