Impact of smoking on age-related deterioration in hearing: A cohort study using health checkups

This study aimed to investigate the association between smoking status and hearing loss, both at baseline and annually, using longitudinal health checkup data.

We analyzed data from 2349 participants (9250 health checkups) aged 20 years and older who underwent comprehensive health checkups at Takinomiya General Hospital in Kagawa, Japan, between 2015 and 2023. Hearing thresholds at 1.0 kHz and 4.0 kHz were measured using pure-tone audiometry, where higher thresholds indicate worse hearing. Smoking status was categorized as never-smoker, past smoker, or current smoker (<10 or ≥10 cigarettes/day). Multilevel linear regression models adjusted for age, sex, occupation, and medical history were used to assess baseline differences and annual changes in hearing thresholds.

At 1.0 kHz, smoking was not significantly associated with hearing thresholds. However, at 4.0 kHz, current smokers (≥10 cigarettes/day) had worse baseline hearing, with an adjusted threshold increase of 2.51 dB compared with never-smokers (p < 0.01). Additionally, past smokers and current smokers (≥10 cigarettes/day) experienced significantly faster deterioration in hearing annually at 4.0 kHz, with reductions of 0.73 dB/year (p < 0.01) and 0.78 dB/year (p < 0.01), respectively.

These findings suggest that smoking is associated with high-frequency hearing impairment and may contribute to accelerated age-related hearing loss. The effect of smoking cessation was not evident in past smokers, and further studies are warranted to examine this hypothesis.