Relationship of cigarette smoking and hearing loss in workers exposed to occupational noise

Abstract

ObjectivesTo investigate the effects of smoking on hearing loss among workers exposed to occupational noise.MethodsFrom the results of a special workers health examination performed in 2011, we enrolled 8,543 subjects exposed to occupational noise and reviewed the findings. Using self-reported questionnaires and health examination results, we collected data on age, smoking status, disease status, height, weight, and biochemistry and pure tone audiometry findings. We divided the workers into 3 groups according to smoking status (non-smoker, ex-smoker, current smoker). Current smokers (n = 3,593) were divided into 4 groups according to smoking amount (0.05–9.9, 10–19.9, 20–29.9, ≥30 pack-years). We analyzed the data to compare hearing thresholds between smoking statuses using analysis of covariance (ANCOVA) after controlling for confounder effects.ResultsAccording to ANCOVA, the hearing thresholds of current smokers at 2 k, 3 k, and 4 kHz were significantly higher than that of the other groups. Multiple logistic regression for smoking status (reference: non-smokers) showed that the adjusted odds ratios of current smokers were 1.291 (95% confidence interval [CI]: 1.055–1.580), 1.180 (95% CI: 1.007–1.383), 1.295 (95% CI: 1.125–1.491), and 1.321 (95% CI: 1.157–1.507) at 1 k, 2 k, 3 k, and 4 kHz, respectively. Based on smoking amount, the adjusted odds ratios were 1.562 (95% CI: 1.013–2.408) and 1.643 (95% CI: 1.023–2.640) for the 10–19.9 and ≥30 pack-years group, respectively, at 1 kHz (reference: 0.05–9.9 pack-years). At 2 kHz, the adjusted odds ratios were increased statistically significantly with smoking amount for all groups. At all frequencies tested, the hearing thresholds of noise-exposed workers were significantly influenced by current smoking, in particular, the increase of hearing loss at low frequencies according to smoking amount was more prevalent.ConclusionsCurrent smoking significantly influenced hearing loss at all frequencies in workers exposed to occupational noise, and heavier smoking influenced low-frequency hearing loss more greatly. There was a dose–response relationship between smoking amount and low-frequency hearing thresholds; however, this was not observed for high-frequency hearing thresholds. Therefore, well-designed prospective studies are needed to clarify the effects of smoking on the degree of hearing loss.

Associations Among Oral Hygiene Behavior and Hypertension Prevalence and Control: The 2008 to 2010 Korea National Health and Nutrition Examination Survey

“…Smoking status was categorized into three groups: 1) non‐smokers, who had never smoked or had smoked <100 cigarettes in their lifetime; 2) ex‐smokers, who had smoked in the past and had stopped smoking; and 3) current smokers, who were smoking currently and had smoked ≥100 cigarettes 15,16 …”

“…Smoking status was categorized into three groups: 1) non-smokers, who had never smoked or had smoked <100 cigarettes in their lifetime; 2) ex-smokers, who had smoked in the past and had stopped smoking; and 3) current smokers, who were smoking currently and had smoked ‡100 cigarettes. 15,16 The amount of pure alcohol consumed (grams per day) was calculated, and the participants were divided into three groups depending on the amount of alcohol consumption per day (non-drinker; light-tomoderate drinker [1 to 30 g/day]; and heavy drinker [>30 g/day]). 17,18 The nutrition surveys included questions about the participants' eating patterns, use of dietary supplements, knowledge of nutrition, and food intake using the 24-hour recall method.…”

Frequency of the Audiometric Notch Following Excessive Noise Exposure

“…A single gunshot (peak level) is approximately 140 to 170 dB (Rabinowitz, 2000). The noise induced hearing loss occurs when individuals are exposed to a noise that exceeds 85 dB (Sung et al, 2013). Agencies which regulate occupational noise exposure almost universally specify a permissible 8 h equivalent average (L A8,hn ) exposure of 85 dBA (assuming 2000 h work annually) (Neitzel et al, 2004).…”

Association between smoking and hearing status: a comparative study between smokers and non – smokers

“…Thus, there are conflicting reports on association of hearing loss with smoking. The possible mechanisms of smoking induced hearing loss may be attributed to multiple factors like hypoxia induced by reduction in blood supply to cochlea and spiral ganglion due to vasospasm and atherosclerotic damage; nicotine induced damage of neurotransmitter receptors ;smoking induced oxidative stress and changes in vascularity of auditory system [12][13][14][15][16][17][18][19]. Smoking is influenced by socioeconomic factors and education [20].…”