Background: Some studies have indicated a possible link between cigarette smoking and hearing loss.
Objectives: To analyze the association between smoking and hearing loss, other than that induced by noise, and to characterize the type of HL impairment found in smokers.
Methods: We conducted a retrospective cross-sectional study in 13,308 men aged 20±68 (median 34.6 years) who underwent a hearing test as part of a routine periodic examination. For each subject, age, smoking status (current, past or non-smokers) and number of cigarettes per day were noted and a hearing test was performed. The test was performed in a sealed, soundproof room by an experienced audiologist and included pure tone audiometry of 250±8,000 Hz. The audiograms were analyzed and subjects were accordingly divided into two groups: those with HL and at least one of the following impairments in at least one ear: sensorineural, conductive or mixed; and those with no hearing loss (control). Audiograms showing HL typical to noise exposure were excluded.
Results: The prevalence of any type of HL among subjects <35 years was 4.5%, compared to 10.5% among those >35 years (P < 0.0001). A significantly higher incidence of any type of HL was found in current (11.8%) and past smokers (11.7%) than in non-smokers (8.1%) (P < 0.0001). The risk increment of the smoking status for developing HL among subjects under age 35 was 43%, and 17% among those above 35 years. Both mild, flat, sensorineural impairment and conductive impairment were found to be associated particularly with smoking (odds ratio 2.2 and 1.9, respectively).
Conclusions: The incidence of HL unrelated to noise exposure is higher in smokers than in non-smokers, and in young adults the effect is greater.