Obstructive sleep apnea risk and hearing impairment among occupational noise-exposed male workers

This study aimed to investigate the association between obstructive sleep apnea (OSA) risk and hearing impairment among workers exposed to occupational noise. A cross-sectional study was conducted among 607 healthy male workers at a tire-manufacturing factory. The subjects underwent audiometric testing, and their OSA risk was examined based on the STOP-Bang questionnaire. Hearing impairment was defined as a hearing threshold >25 dB hearing level (HL) in any frequency of 1, 2, 3 and 4 kHz in either ear. High OSA risk was defined as a STOP-bang score of ≥3. Hearing thresholds at 1, 2, 3 and 4 kHz in both ears were significantly higher among workers with high OSA risk than among those with low OSA risk after adjusting for confounders. Multiple logistic regression analysis examining the association of OSA risk and STOP-Bang score with hearing impairment revealed an odds ratio of 1.738 (95% confidence interval [CI] 1.113-2.713, p = 0.015) and 1.256 (95% CI 1.031-1.529, p = 0.023), respectively, after adjusting for confounders. In addition, when the hearing impairment was reclassified into high- and low-frequency hearing impairment, a statistically significant OR was seen for high-frequency hearing impairment. In conclusion, high OSA risk was associated with hearing impairment in occupational noise-exposed workers, especially in the high-frequency range of 3 and 4 kHz. More efforts are required to improve the management of OSA and its risk factors to preserve hearing in occupational noise-exposed workers.