Results from a longitudinal study carried out in Japan have shown that smoking significantly increases the risk of hearing loss in a dose-dependent manner.
The study was conducted by investigators from the National Center for Global Health and Medicine, Tokyo, Japan, in collaboration with multiple commercial partners. The research found a 20% to 60% increased risk for hearing loss among current smokers versus non-smokers, Medscape reports.
“Smoking has been related with hearing loss in cross-sectional studies, but prospective evidence is few and conflicting,” lead author on the study Huanhuan Hu, PhD told Medscape Medical News. “Thus, we investigated the association between smoking and hearing loss using data from a large-scale cohort study in a Japanese working population.” The study cohort included over 50,000 employees, who were 20–64 years of age and free of hearing loss at baseline. Follow-up was for a maximum of 8 years.
Among the study participants, more than 3500 individuals (7%) developed high-frequency hearing loss, and over 1500 (3%) developed low-frequency hearing loss. The hazard ratio associated with current smoking was 1.6 (95% CI = 1.5 to 1.7) and 1.2 (95% CI = 1.1 to 1.4) for high- and low-frequency hearing loss, respectively, as compared with never smokers. Importantly, the risk increased with the number of cigarettes smoked per day.
Source: Medscape; Hu, H et al. Smoking, Smoking Cessation, and the Risk of Hearing Loss: Japan Epidemiology Collaboration on Occupational Health Study. Nicotine and Tobacco Research 2018 Mar 14.