Association between blood lipid levels and noise-induced hearing loss among workers with noisy operations in an auto parts factory

Objective To explore the potential association between blood lipid levels and noise-induced hearing loss (NIHL), providing a basis for guiding noise-exposed workers in controlling their blood lipid levels.

Methods Using cluster sampling, noise-exposed workers from an auto parts manufacturing company who participated in the 2023 occupational health examination were selected as subjects. Information regarding their demographics, occupational noise exposure, and protective measures was collected. Pure-tone audiometry tests and blood lipid level measurements were conducted. Logistic regression models were employed to analyze the influencing factors of hearing impairment.

Results Among 792 subjects, 242 exhibited hearing impairment with an occurrence rate of 30.56%, and 264 exhibited abnormal blood lipid levels with an occurrence rate of 33.33%. Multivariate logistic regression analysis revealed that compared to workers exposed to qualified noise levels, those exposed to higher-level (above the occupational exposure limit) noise had a 1.713-fold increased risk of hearing loss (P < 0.05). For each additional year of age and each 1 mmol/L increase in triglycerides (TG), the risk of hearing loss increased by 1.059 and 1.135 times, respectively (both P < 0.05).

Conclusions The prevalence of hearing loss among workers in this auto parts manufacturing company was relatively high. Active measures should be taken to control workplace noise levels and encourage workers to manage their blood lipid levels, particularly by reducing serum TG levels.