Relationship between cigarette smoking and hearing loss in China: A cross-sectional study in Zhejiang province.

INTRODUCTION Hearing loss and cigarette smoking are major challenges that affect public health in China. Revealing the effect of smoking on hearing loss in the Chinese general population is critical for hearing health protection. We investigated the relationship between smoking status and hearing loss in China, especially in stratified sex and age groups. METHODS A cross-sectional study was conducted on 4685 individuals aged 20- 80 years in Zhejiang province from 2016 to 2018, with audiometric testing for hearing loss and a structured questionnaire for collecting smoking status and covariates. Logistic regression was used to estimate the association between smoking and hearing loss. RESULTS Cigarette smoking was not significantly associated with hearing loss in females and young males. In middle-aged males, after adjusting for covariates, current smokers and past smokers had a significantly higher prevalence of speech-frequency loss (OR=1.65; 95% CI: 1.17-2.33 and OR=1.88; 95% CI: 1.11-3.17; respectively) and high-frequency hearing loss (OR=2.01; 95% CI: 1.43-2.84 and OR=2.64; 95% CI: 1.50-4.66; respectively). In older males, only past smokers had a significantly higher prevalence of speech-frequency hearing loss than never smokers (OR=2.58; 95% CI: 1.38-4.85). Regarding middle-aged and older current smokers, a dose-dependent relationship between smoking intensity and hearing loss was found. Passive smoking was not significantly associated with an increased hearing loss risk in all the three male groups. CONCLUSIONS The relationship between cigarette smoking and hearing loss varied according to gender and age. Therefore, the interventions for smoking need to be tailored according to age in males.