Even passive smoking may increase the risk of hearing loss

RESEARCH

©Ilco/sxc.hu

Previous studies have suggested that smoking may be associated with hearing loss. New research confirms this risk and points to the dangers even of passive smoke exposure.

A study carried out by researchers at the University of Manchester, and colleagues from elsewhere in the UK and the USA, has shown that the risk of hearing loss in smokers is 25% higher than in non-smokers. The same is true for people exposed to secondhand smoke, but with a lower risk, i.e. 15%. In both cases, the exposure dose is correlated with the degree of hearing loss.

In addition, the results showed that people who stop smoking have a significantly lower risk of developing hearing loss. According to the authors, these unexpected results could be related to the fact that people who decide to stop smoking often do so as part of an overall move to improve their lifestyle and health.

To generate these findings, the researchers from various academic institutions and hospitals, performed a logistic regression analysis on a sample of 164,770 British subjects aged 40 to 69 years who completed a speech-in-noise hearing test (the Digit Triplet Test), after collecting data about their habits in terms of tobacco exposure, whether active or passive. To take account of other possible causes of hearing loss, the subjects were also asked about potential cardiovascular disorders, diabetes, and hypertension.

However, the study did not establish a causal association between tobacco and hearing (cross-sectional correlational study design). But according to the authors, certain toxic substances in cigarette smoke may affect the hearing system. Also, nicotine could impair correct functioning of the hearing system since it is a known vasoconstrictor.

Source: Dawes P., et al. Cigarette smoking, passive smoking, alcohol consumption, and hearing loss. Journal of the Association for Research in Otolaryngology. 2014 Aug;15(4):663-74

C.S.