A new study has found that smokers may be at an increased risk of hearing loss, particularly at 4 kHz.[i] To the researchers’ knowledge, this is the largest study to date, which has investigated the association between smoking and incident hearing loss.
The participants in the study were 50,195 Japanese employees, who were free of hearing loss at the start of the study. Pure-tone audiometry was performed annually, for up to 8 years, to identify hearing loss at 1 kHz and 4 kHz.
In follow up investigations, 3,532 individuals were found to have developed high-frequency hearing loss, and 1,575 developed low-frequency hearing loss.
Current smokers were 1.6 times more likely than individuals who had never smoked to develop hearing loss at 4 kHz, and 1.2 times more likely to develop hearing loss at 1 kHz. Further, the risk of both high- and low-frequency hearing loss increased with the number of cigarettes smoked per day.
There was a small increase in the risk of high-frequency hearing loss, but not low-frequency hearing loss, among former smokers. The analysis of data from former smokers showed that the risk of hearing loss reduced after stopping smoking, even among those who stopped just 5 years prior to the start of the study.
Consequently, researchers concluded that smoking is associated with increased risk of hearing loss, especially at the higher frequency, in a dose-response manner, and that the excess risk of hearing loss associated with smoking disappears in a relatively short period after quitting. Further research is required to supplement these findings.
[i] Hu, H. et al. Smoking, Smoking Cessation, and the Risk of Hearing Loss: Japan Epidemiology Collaboration on Occupational Health Study. Nicotine Tob Res doi:10.1093/ntr/nty026 https://academic.oup.com/ntr/advance-articleabstract/doi/10.1093/ntr/nty026/4925604?redirectedFrom=fulltext (accessed 28 March 2018)