Is there a relevant effect of noise and smoking on hearing? A population-based aging study

Auditory function assessment in patients with chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease is a multisystem disease with multiple comorbidities. Hearing is dependent on the cochlear functions that may be affected by oxygenation. Affection of hearing is problematic and represents a major concern that should be seriously investigated as an important comorbidity in chronic obstructive pulmonary disease patients.

Objective

To assess auditory status among chronic obstructive pulmonary disease patients.

Methodology

The current study was carried out at Al-Azhar University Hospitals, Cairo, from 1 August 2021 to 2022, including 120 participants. In addition to the control group (60 healthy participants), there were two study groups: chronic obstructive pulmonary disease patients with respiratory failure group (30 patients) and non-respiratory failure group (30 patients). Hearing functions were studied using pure tone audiometry, and auditory brain stem response.

Results

There was statistically significant hearing impairment in chronic obstructive pulmonary disease patients in comparison to control group. The hearing impairment was more significant in chronic obstructive pulmonary disease with respiratory failure group in comparison to chronic obstructive pulmonary disease without respiratory failure group. The auditory impairment shows a negative interrelationship with oxygen tension (PaO2) and a positive interrelationship with the smoking index.

Conclusion

Hearing affection was meaningfully higher among chronic obstructive pulmonary disease patients and more prominent in patients with respiratory failure. Hypoxia results in deterioration of pure tone audiometry and increased absolute and interpeak latencies in auditory brain stem response. At every frequency, the mean pure tone audiometry thresholds were higher for chronic obstructive pulmonary disease groups than control group albeit remaining in the mild to moderate area of hearing loss. Retro-cochlear affection was suggested among patients with chronic obstructive pulmonary disease as evidenced with the prolongation of auditory brain stem response waves latencies.

Measuring the Effect of Smoking on Hearing and Tinnitus Among the Adult Population in the Kingdom of Saudi Arabia

BACKGROUND

The prevalence of cigarette smoking is a significant public health challenge in Saudi Arabia, as it is a known risk factor for many health problems. Hearing problems are also a major concern, as they are invisible disabilities that can negatively impact an individual's perception, communication, and social interactions. Studies have identified various risk factors for hearing loss, including genetics, diseases, infection, exposure to noise, and demographic factors such as age and gender. Smoking has been found to be associated with hearing loss, tinnitus, and vertigo, but the results of studies investigating this association have been inconsistent. It is crucial to understand the impact of smoking on hearing problems and tinnitus in the Saudi Arabian population to protect individual and societal health.

AIM

We aim to investigate whether smoking is related to tinnitus, hearing loss, or other hearing difficulties.

METHODS

A cross-sectional study was established from March to August 2022 among adults in the Kingdom of Saudi Arabia to determine whether smoking can affect hearing.

RESULTS

It has been observed that smokers experience hearing issues or trouble hearing more frequently than non-smokers. Additionally, as the number of cigarette smoking grows or as smoking persists for longer periods of time, there is a rise in hearing problems/hearing difficulty. In contrast, there is no conclusive evidence associating smoking and tinnitus.

CONCLUSION

These results should encourage more investigation into the impact of demographic factors on hearing problems/hearing difficulty, or tinnitus.

Relationship between tinnitus and olfactory dysfunction: audiovisual, olfactory, and medical examinations

Introduction

Sensory dysfunctions and cognitive impairments are related to each other. Although a relationship between tinnitus and subjective olfactory dysfunction has been reported, there have been no reports investigating the relationship between tinnitus and olfactory test results.

Methods

To investigate the relationship between tinnitus and olfactory test results, we conducted sensory tests, including hearing and visual examinations. The subjects included 510 community-dwelling individuals (295 women and 215 men) who attended a health checkup in Yakumo, Japan. The age of the subjects ranged from 40 to 91 years (mean ± standard deviation, 63.8 ± 9.9 years). The participants completed a self-reported questionnaire on subjective tinnitus, olfactory function, and hearing function, as well as their lifestyle. The health checkup included smell, hearing, vision, and blood examinations.

Results

After adjusting for age and sex, the presence of tinnitus was significantly associated with subjective olfactory dysfunction, poor olfactory test results, hearing deterioration, vertigo, and headache. Additionally, high serum calcium levels and a low albumin/globulin ratio were significantly associated with low physical activity and nutrition. Women scored higher than men in olfactory and hearing examinations, but there was no gender difference in vision examinations.

Conclusion

Subjective smell dysfunction and poor smell test results were significantly associated with tinnitus complaints. Hearing and vision were associated even after adjusting for age and sex. These findings suggest that evaluating the mutual relationships among sensory organs is important when evaluating the influence of sensory dysfunctions on cognitive function.

Self-reported and cotinine-verified smoking and increased risk of incident hearing loss

We examined the associations of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of new-onset HL. This cohort study was performed in 293,991 Korean adults free of HL who underwent a comprehensive screening examination and were followed for up to 8.8 years. HL was defined as a pure-tone average of thresholds at 0.5, 1.0, and 2.0 kHz ≥ 25 dB in both ears. During a median follow-up of 4.9 years, 2286 participants developed new-onset bilateral HL. Self-reported smoking status was associated with an increased risk of new-onset bilateral HL. Multivariable-adjusted HRs (95% CIs) for incident HL comparing former smokers and current smokers to never-smokers were 1.14 (1.004-1.30) and 1.40 (1.21-1.61), respectively. Number of cigarettes, pack-years, and urinary cotinine levels were consistently associated with incident HL. These associations were similarly observed when introducing changes in smoking status, urinary cotinine, and other confounders during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, smoking status based on both self-report and urinary cotinine level were independently associated with an increased incidence of bilateral HL. Our findings indicate smoking is an independent risk factor for HL.

Synergistic effect of smoking on age-related hearing loss in patients with diabetes

This study investigated the synergistic effects of risk factors on age-related hearing loss (ARHL) using nationwide cross-sectional data of 33,552 individuals from the 2010‒2013 Korea National Health and Nutrition Examination Survey. Patients with ARHL were selected based on their pure-tone audiometry results. Previously reported risk factors for ARHL were analyzed using logistic regression and propensity score-matching, and synergistic effects between risk factors were analyzed using propensity score-matching. Of the 12,570 individuals aged 40-79 years, 2002 (15.9%) met the criteria for ARHL. Male sex, exposure to occupational noise, and diabetes showed a significant relationship with ARHL (p < 0.05) in both the logistic regression and propensity score-matching analyses. Smoking and diabetes showed the strongest significant synergistic effect on ARHL (odds ratio [OR] 1.963, 95% confidence interval [CI] 1.285‒2.998; p = 0.002). In the subgroup analysis based on smoking status, current smokers with diabetes had a significant relationship with ARHL (OR 1.883, CI 1.191‒2.975; p = 0.009), whereas ex-smokers with diabetes did not (OR 1.250; CI 0.880‒1.775; p = 0.246). This implies that current smokers with diabetes may benefit from the cessation of smoking. In conclusion, patients with diabetes should strictly avoid or cease smoking to prevent the progression of ARHL.

An Exploratory Study of Early Auditory Evoked Potentials in Cannabis Smokers

Purpose Cannabis is widely used for medicinal and recreational purposes. Studies have evaluated its health benefits and consequences, although there is limited work on its effects on the auditory system. In this exploratory study, we evaluate the effects of cannabis smoking on early auditory evoked potentials. Method We investigated auditory brainstem response (ABR) and electrocochleography waveforms in 18 cannabis smokers (44% women, 54% men; M _age = 23.06 years, range: 21-28 years) and 19 nonsmoker controls (63% women, 37% men; M _age = 23.74 years, range: 21-33 years). Threshold ABRs were recorded using rarefaction clicks at a rate of 17.7/s from 80 dB nHL to Wave V threshold. Resulting amplitudes and latencies for Waves I, III, and V were compared via independent-samples t tests. Electrocochleograms obtained with 90 dB nHL (7.1/s) alternating clicks were assessed for summating and compound action potentials, which were compared between groups using independent-samples t tests. Results ABR Wave I amplitudes were significantly lower in smokers (M = 0.14 μV, SD = 0.11) compared to nonsmokers (M = 0.21 μV, SD = 0.10, p = .039) at 80 dB nHL. Wave V latencies were significantly delayed in smokers at 80 dB nHL. Wave I and III latencies did not differ significantly between the two groups. Summating potential/compound action potential ratios were significantly elevated in smokers (M = 0.30, SD = 0.04) versus nonsmokers (M = 0.21, SD = 0.05, p = .042). Conclusion We identified significant differences in electrophysiological outcomes between cannabis smokers and nonsmokers. Cannabis smoking may have a subtle neurotoxic effect on the auditory system. Larger confirmatory studies are warranted.

Association between Uncoupling Protein 2 Gene Ala55val Polymorphism and Sudden Sensorineural Hearing Loss

OBJECTIVES

The pathology of sudden sensorineural hearing loss, which is known as sudden deafness (SD), remains unknown. The purpose of this study was to investigate the association between mitochondrial uncoupling protein 2 (UCP2) polymorphism and SD risk.

MATERIALS AND METHODS

We compared 83 patients suffering from SD and 2048 controls who participated in the Longitudinal Study of Aging at the National Institute for Longevity Sciences. Multiple logistic regression was used to calculate the odds ratios (ORs) for SD with a polymorphism of the UCP2 (rs660339) gene.

RESULTS

Under the additive model of inheritance, UCP2 polymorphisms showed significant association with a SD risk. The OR was 1.468 (95% confidence interval, 1.056-2.040) with an adjustment for any past history, such as diabetes, dyslipidemia, or hypertension, and for age and sex.

CONCLUSION

Our results imply that the UCP2 (rs660339) polymorphism has a significant association with the risk of developing SD.

Effects of Smoking on the Auditory System: Is There a Gender Difference?

The main aim of our study is to evaluate whether the effect of smoking on the auditory system shows gender differences. Another aim is to evaluate whether smoking has any influence on the absorbance of sound. There were 236 volunteers including 90 nonsmokers (42 females and 48 males) and 146 smokers (72 females and 74 males) in the study. Smokers were grouped according to pack-years of smoking as 5 to 10 pack-years, 11 to 20 pack-years, and more than 20 pack-years. Pure tone audiometry and wideband tympanometry were performed in all individuals. Both female and male smokers who consume more than 20 pack-years had significantly higher hearing thresholds at 4 and 6 kHz and significantly lower sound energy absorbance rates at 4, 6, and 8 kHz. Moreover, female smokers with a consumption of 11 to 20 pack-years had significantly higher hearing thresholds at 6 kHz and significantly lower sound energy absorbance rates at 6 and 8 kHz. Smoking causes hearing loss at high frequencies in both females and males, especially in a dose-dependent manner affecting individuals with a consumption of more than 20 pack-years. The sound energy absorbance is significantly reduced at 4, 6, and 8 kHz. In addition, these effects may occur in women with even less exposure.

Behavioral Hearing Thresholds and Distortion Product Otoacoustic Emissions in Cannabis Smokers

Purpose Cannabis is a widely used drug both medically and recreationally. The aim of this study was to determine if cannabis smoking is associated with changes in auditory function, as measured by behavioral hearing thresholds and/or distortion product otoacoustic emissions (DPOAEs). Method We investigated hearing thresholds and 2f₁-f₂ DPOAEs in 20 cannabis smokers and 20 nonsmokers between 18 and 28 years old. Behavioral thresholds were obtained from 0.25 to 16 kHz. DPOAEs were measured using discrete tones between f₂ of 0.5 and 19.03 kHz using an f₂/f₁ ratio of 1.22 and L₁/L₂ = 65/55 dB SPL. Thresholds and DPOAE amplitudes were compared between groups using linear mixed-effects models with sex and frequency as predictors. Results Behavioral thresholds in smokers did not differ significantly between smokers and nonsmokers (all ps > .05). Although not significant, long-term smokers exhibited poorer thresholds than short-term smokers and nonsmokers. Smokers generally exhibited lower DPOAE amplitudes than nonsmokers, although the differences were not significant. Male smokers had significantly poorer DPOAE amplitudes than male nonsmokers in the low frequencies (f₂ ≤ 2 kHz; p = .0245). Conclusion Results indicate that smoking cannabis may negatively alter the function of outer hair cells in young men. This subtle cochleopathology is evident in the absence of measurable differences in behavioral hearing thresholds between cannabis smokers and nonsmokers.

The combined effects of occupational exposure to noise and other risk factors - a systematic review

PURPOSE

Noise-induced health effects exacerbate by many other risk factors. This systematic review aims at shedding light on the combined effects of co-exposure to occupational noise and other factors.

MATERIAL AND METHODS

A literature search in Web of Science, Scopus, PubMed, Science Direct, and Google Scholar, with appropriate keywords on combined effects of occupational noise, and co-exposure to noise and other factors, revealed 7928 articles which were screened by two researchers. A total of 775 articles were reviewed in full text. We found 149 articles that were relevant and had sufficient quality for analysis.

RESULTS

We identified 16 risk factors that exacerbate occupational noise-induced health effects. These factors were classified into four groups: chemical (carbon monoxide (CO), solvents, heavy metals, and other chemicals), physical (lighting, heat, vibration, and cold), personal (age, gender, genetics, smoking, medication, contextual diseases) and occupational (workload and shift work). Hearing loss, hypertension, reduced performance, and cardiovascular strains, are the most important risk factors combined effects due to concurrent exposure to noise and other risk factors.

CONCLUSION

Evidences of combined effects of solvents, vibration, heavy metals, CO, smoking, chemicals, aging, heat, and shiftwork were respectively stronger than for other factors. Most of the studies have investigated only the combined effects of risk factors on hearing, and the evidence for non-auditory effects is still limited, and more studies are warranted. Therefore, in the Hearing Conservation Programs, besides noise, aggravating factors of noise effects should also be taken into account.

The effect of simultaneous exposure to cigarette smoke and noise on distortion product otoacoustic emissions in rats

Cigarette smoking is a possible risk factor for hearing loss. However, the impact of simultaneous exposure to noise and smoke on hearing has remained controversial. This study investigated the combined effect of exposure to cigarette smoking and noise on hearing loss. Three groups of male Wistar rats (275 ± 25 g) were subjected to white noise (102 ± 0.5 dB), cigarette smoking (20 cigarettes), and both cigarette smoking and noise for 8 h and 10 days inside the exposure chamber. The control group was exposed to neither noise nor smoke. Distortion product otoacoustic emissions (DPOAE) were measured before any intervention, and it was repeated 1, 7, and 21 days after the last exposure. One-day postexposure to noise, cigarette smoking, and both cigarette smoking and noise, the mean of DPOAE amplitudes decreased significantly ( p < 0.05) between, respectively, 5.7-30.7, 1.5-7.5, and 5.2-32.6 dB within the frequency range of 4620-9960. Temporal DPOAE change in rats exposed to noise or both cigarette smoking and noise was not significantly different ( p > 0.05). DPOAE amplitudes returned to the baseline values in the group subjected to smoking 21 days postexposure. The most permanent change was observed in rats exposed to both cigarette smoking and noise. Accordingly, simultaneous subacute exposure to noise and cigarette smoking increases the effect of noise on permanent hearing loss. Therefore, smoking workers exposed to noise might be at a greater risk of developing hearing loss, and it is recommended that authorities in charge take note of this evidence.

Sex-Related Cochlear Impairment in Cigarette Smokers

Background

A number of studies have documented the influence of cigarette smoking on hearing. However, the association between sex and hearing impairment in smokers as measured by otoacoustic emissions (OAEs) has not been clearly established. The aim of this study was to analyze sex-specific effects of smoking on hearing via conventional and ultra-high-frequency pure tone audiometry (PTA), and OAEs, specifically spontaneous OAEs, click-evoked OAEs, and distortion-product OAEs.

Material/Methods

The study included 84 healthy volunteers aged 25–45 years (mean 34), among them 46 women (25 non-smokers and 21 smokers) and 38 men (16 non-smokers and 22 smokers). The protocol of the study included otoscopic examination, tympanometry, low-, moderate-, and ultra-high-frequency PTA, evaluation of spontaneous click-evoked (CEAOEs) and distortion-product otoacoustic emissions (DPOAEs), assessment of the DP-grams for 2f₁-f₂ (f₁ from 977 to5 164 Hz), and input/output function at L₂ primary tone level of 40–70 dB SPL.

Results

Smokers and non-smokers did not differ significantly in terms of their hearing thresholds assessed with tone audiometry. Male smokers presented with significantly lower levels of CEAOEs and DPOAEs than both male non-smokers and female smokers.

Conclusions

Smoking does not modulate a hearing threshold determined with PTA at low, moderate, and ultra-high frequencies, but causes a significant decrease in OAE levels. This effect was observed only in males, which implies that they are more susceptible to smoking-induced hearing impairment. Sex-specific differences in otoacoustic emissions level may reflect influences of genetic, hormonal, behavioral, and/or environmental factors.

Simultaneous effects of noise exposure and smoking on OAEs

Noise is one of the most pervasive hazardous factors in the workplace. Noise-induced hearing loss (NIHL) is the most common disorder related to noise exposure. Smoking is probably associated with hearing loss. The simultaneous effect of noise and smoking on hearing is a recent concern. In this study, we assessed the simultaneous effect of noise and smoking on standard pure tone audiometry (PTA) and distortion product otoacoustic emissions (DP-OAEs). This was an historical cohort study on 224 workers exposed to noise who were divided into two groups: Smokers and nonsmokers. DP-OAE response amplitudes were assessed. Data were analyzed by SPSS software (version 19) using Student's t-test and Mann-Whitney U test. One hundred and five subjects were smokers (case group) and 119 individuals were nonsmokers (control group). All the subjects were exposed to 91.08 + 2.29 dBA [time-weighted average (TWA) for an 8 h work shift]. Mean DP-OAE response amplitude at frequencies higher than 1,000 Hz was significantly higher in the smokers than the nonsmokers. This study showed that smoking can aggravate the effect of noise on hearing in DP-OAEs.

Occupational noise exposure and hearing: a systematic review

Purpose

To give a systematic review of the development of noise-induced hearing loss (NIHL) in working life.

Methods

A literature search in MEDLINE, Embase, Web of Science, Scopus, and Health and Safety Abstracts, with appropriate keywords on noise in the workplace and health, revealed 22,413 articles which were screened by six researchers. A total of 698 articles were reviewed in full text and scored with a checklist, and 187 articles were found to be relevant and of sufficient quality for further analysis.

Results

Occupational noise exposure causes between 7 and 21 % of the hearing loss among workers, lowest in the industrialized countries, where the incidence is going down, and highest in the developing countries. It is difficult to distinguish between NIHL and age-related hearing loss at an individual level. Most of the hearing loss is age related. Men lose hearing more than women do. Heredity also plays a part. Socioeconomic position, ethnicity and other factors, such as smoking, high blood pressure, diabetes, vibration and chemical substances, may also affect hearing. The use of firearms may be harmful to hearing, whereas most other sources of leisure-time noise seem to be less important. Impulse noise seems to be more deleterious to hearing than continuous noise. Occupational groups at high risk of NIHL are the military, construction workers, agriculture and others with high noise exposure.

Conclusion

The prevalence of NIHL is declining in most industrialized countries, probably due to preventive measures. Hearing loss is mainly related to increasing age.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-015-1083-5) contains supplementary material, which is available to authorized users.

Concurrent effect of noise exposure and smoking on extended high-frequency pure-tone thresholds

OBJECTIVE

Concurrent effect of noise and smoking on hearing loss is a recent concern. In this study, the concurrent effect of noise and smoking on hearing loss in conventional frequencies and frequencies higher than 8 kHz was assessed.

DESIGN

This was a cross-sectional study on workers exposed to noise who were divided into two groups: smokers and non-smokers. Hearing thresholds were assessed by conventional audiometry, and HFA. Data were analysed using non-parametric tests and Student's t-test.

STUDY SAMPLE

There were 212 workers.

RESULTS

Ninety-seven subjects were smokers and 115 individuals were non-smokers. All subjects were exposed to 92.1 ± 2.4 dBA (Leq8h). The highest threshold in conventional and high-frequency audiometry was observed at 6 kHz and 16 kHz, respectively. Hearing threshold at frequencies above 1 kHz was significantly higher in the smokers than non-smokers. There was no correlation between hearing thresholds and pack-years of smoking.

CONCLUSIONS

Concurrent exposure to noise and smoking may be associated with more hearing loss than exposure to noise alone in the conventional and high frequencies. However, other differences between smokers and non-smokers may explain these differences as well.

Cigarette smoking, passive smoking, alcohol consumption, and hearing loss

The objective of this large population-based cross-sectional study was to evaluate the association between smoking, passive smoking, alcohol consumption, and hearing loss. The study sample was a subset of the UK Biobank Resource, 164,770 adults aged between 40 and 69 years who completed a speech-in-noise hearing test (the Digit Triplet Test). Hearing loss was defined as speech recognition in noise in the better ear poorer than 2 standard deviations below the mean with reference to young normally hearing listeners. In multiple logistic regression controlling for potential confounders, current smokers were more likely to have a hearing loss than non-smokers (odds ratio (OR) 1.15, 95 % confidence interval (CI) 1.09-1.21). Among non-smokers, those who reported passive exposure to tobacco smoke were more likely to have a hearing loss (OR 1.28, 95 %CI 1.21-1.35). For both smoking and passive smoking, there was evidence of a dose-response effect. Those who consume alcohol were less likely to have a hearing loss than lifetime teetotalers. The association was similar across three levels of consumption by volume of alcohol (lightest 25 %, OR 0.61, 95 %CI 0.57-0.65; middle 50 % OR 0.62, 95 %CI 0.58-0.66; heaviest 25 % OR 0.65, 95 %CI 0.61-0.70). The results suggest that lifestyle factors may moderate the risk of hearing loss. Alcohol consumption was associated with a protective effect. Quitting or reducing smoking and avoiding passive exposure to tobacco smoke may also help prevent or moderate age-related hearing loss.

Relação da perda auditiva induzida por ruído e o uso de tabaco em trabalhadores de uma indústria alimentícia

Objetivo verificar se o uso do tabaco potencializa os efeitos do ruído causados na audição. Métodos 153 trabalhadores de ambos os sexos, fumantes e não-fumantes, de uma indústria do ramo alimentício, escolhidos aleatoriamente dentre 14 setores da empresa, cuja faixa de ruído apresentada teve uma variação de 85 a 109 dBNA, responderam a um questionário sobre tempo e exposição ao ruído bem como hábitos sobre fumo e passaram por exame de audiometria. Resultados os limiares auditivos da via aérea nas frequências de 4.000 Hz e 6.000Hz foram significantemente mais altos no grupo de fumantes/ex-fumantes quando comparados aos não-fumantes tanto na orelha direita quanto na orelha esquerda; limiares estes, característicos da perda auditiva induzida por ruído. Essas diferenças se mantiveram significantes após o ajuste pela idade e pelo tempo de exposição. Conclusão por meio dos resultados obtidos, concluiu-se que o uso do tabaco pode potencializar os danos causados pelo ruído à audição.

Interaction between noise and cigarette smoking for the outcome of hearing loss among women: a population-based study

BACKGROUND

We investigated the interaction between exposure to noise and smoking in relation to prevalence of hearing loss among women.

METHODS

A sample of women aged 20-49 years (n = 1,723) from a population-based cross-sectional study carried out in Brazil in 2006 was examined. Hearing loss was assessed using a yes-no validated question. Biological interaction was analyzed using the additive scale and measured with interaction contrast ratio (ICR) and assessment of dose-response relationship.

RESULTS

The combined effect of exposure to noise and cigarette smoking on hearing loss (adjusted prevalence ratio (PRadj) = 3.94, 95% confidence interval (CI): 2.81, 5.52) was greater than expected based on the additive single effects of smoking (PRadj = 1.39, 95% CI: 1.07, 1.81) and noise (PRadj = 2.66, 95% CI: 1.86, 3.82). ICR estimates were not statistically significant. The prevalence of hearing loss among noise-exposed women increased with duration of smoking (P trend = 0.026), number of cigarettes smoked per day (P trend = 0.034), cumulative tobacco use (P trend = 0.030), and early age at smoking initiation (P trend = 0.047).

CONCLUSIONS

Noise and smoking may have a combined effect on hearing loss but further studies are still needed. A dose-response relation of smoking for the noise effect among women is suggested.

Noise exposure and hearing impairment among Chinese restaurant workers and entertainment employees in Hong Kong

Background

Noise-induced hearing loss (NIHL) is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong.

Methods

This cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD); and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The “Klockhoff digit” method was used to classify NIHL in the present study.

Results

The main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7%) of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1–42.1%). Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees.

Conclusion

Excessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing conservation programs should be introduced to the service industry in Hong Kong.

Association between polymorphisms in genes encoding methylenetetrahydrofolate reductase and the risk of Ménière's disease

Folate metabolism is essential for cellular functioning. Despite extensive research on the roles of folate-metabolism-related gene polymorphisms in the pathophysiology of many diseases, such as cardiovascular disease, cancers, and sudden sensorineural hearing loss, little is known about their association with Ménière's disease (MD). The aim of this study was to investigate the effect of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) on the risk of MD in a Japanese population. We examined the C677T and A1298C (rs1801133 and rs1801131) polymorphisms in the MTHFR gene and compared them between 1946 adults (986 men and 960 women) participating in the National Institute for Longevity Sciences Longitudinal Study of Aging and 86 cases of MD. A multiple logistic regression was performed to obtain odds ratios (ORs) for the risk of MD regarding the MTHFR polymorphisms before (model 1) and after (model 2) adjustment for age and sex factors. The OR of MTHFR C677T for the risk of MD was 0.669 (95% confidence interval [CI], 0.479-0.934) in model 1 and 0.680 (95% CI, 0.484-0.954) in model 2. In contrast, the OR of MTHFR A1298C for the risk of MD was 1.503 (95% CI, 1.064-2.123) in model 1 and 1.505 (95% CI, 1.045-2.167) in model 2. Our results imply that the MTHFR C677T and A1298C polymorphisms are associated with the risk of MD.

Polymorphisms in genes involved in oxidative stress response in patients with sudden sensorineural hearing loss and Ménière's disease in a Japanese population

The etiologies of idiopathic sudden sensorineural hearing loss (SSNHL) and Ménière's disease remain unclear. Recently, accumulating evidence has demonstrated that oxidative stress is related to the pathology of inner ear disease. Because genetic factors may contribute partly to the etiologies of SSNHL and Ménière's disease, we investigated the associations between genetic polymorphisms located in oxidative stress response genes and susceptibility to SSNHL and Ménière's disease. We compared 84 patients affected by SSNHL, 82 patients affected by Ménière's disease, and 2107 adults (1056 men and 1051 women; mean age, 59.2 years; range, 40-79 years) who participated in the National Institute for Longevity Sciences, Longitudinal Study of Aging. Multiple logistic regression was used to calculate odds ratios for SSNHL and Ménière's disease in individuals with polymorphisms in the genes glutathione peroxidase 1 (GPX1) (Pro198Leu, rs1050450), paraoxonase 1 (PON1) (Gln192Arg, rs662; and Met55Leu, rs854560), PON2 (Ser311Cys, rs7493), and superoxide dismutase 2 (SOD2) (Val16Ala, rs4880), with adjustment for age and gender. No significant differences in the distribution of the genotypes at these polymorphisms were observed among individuals with SSNHL and Ménière's disease and controls. No significant risk for SSNHL and Ménière's disease was observed in the additive genetic model, regardless of moderating variables. The C allele of SOD2 (rs4880) was more frequent in Ménière's disease cases with a hearing level over 50 dB compared with cases with a hearing level below 50 dB, suggesting that this polymorphism is associated with progression of a hearing loss in Ménière's disease. In conclusion, no significant associations between the polymorphisms of GPX1, PON1, PON2, and SOD2 and risk of SSNHL and Ménière's disease were observed in this Japanese case-control study.

Ear diseases and other risk factors for hearing impairment among adults: an epidemiological study

OBJECTIVE

To investigate the prevalence of ear diseases, other otological risk factors potentially affecting hearing, and noise exposure among adults. Furthermore, subject-related factors possibly associated with hearing impairment (HI), i.e. handedness, eye color, and susceptibility to sunburn, were studied.

DESIGN

A cross-sectional, unscreened, population-based, epidemiological study among adults.

STUDY SAMPLE

The subjects (n = 850), aged 54-66 years, were randomly sampled from the population register. A questionnaire survey, an otological examination, and pure-tone audiometry were performed.

RESULTS

Chronic middle-ear disease (both active and inactive) was the most common ear disease with a prevalence of 5.3%, while the prevalence of otosclerosis was 1.3%, and that of Ménière's disease, 0.7%. Noise exposure was reported by 46% of the subjects, and it had no effect on hearing among those with no ear disease or other otological risk factors for HI. Dark eye color and non-susceptibility to sunburn were associated with HI among noise-exposed subjects.

CONCLUSIONS

Common ear diseases and other otological risk factors constitute a major part of the etiologies of HI among adults. Contrary to previous studies, noise exposure turned out to have only marginal effect on hearing among those with no otological risk factors.

Polymorphisms in genes involved in inflammatory pathways in patients with sudden sensorineural hearing loss

Although the etiology of idiopathic sudden sensorineural hearing loss (SSNHL) remains unclear, the pathologically increased permeability of blood vessels, elucidated by gadolinium-enhanced magnetic resonance imaging (MRI), suggests the involvement of inflammation. Because SSNHL is considered a multifactorial disease, possibly caused by interactions between genetic factors and environmental factors, the authors investigated the associations of polymorphisms of inflammatory mediator genes with susceptibility to SSNHL. The authors compared 72 patients affected by SSNHL and 2010 adults (1010 men and 1000 women; mean age 59.2 years; range 40-79) who participated in the National Institute for Longevity Sciences Longitudinal Study of Aging. Multiple logistic regression was used to obtain odds ratios (ORs) for SSNHL in subjects with polymorphisms in the genes IL-6 C - 572G, IL-4R G1902A, IL-10 A - 592C, TNFα C - 863A, TNFRSF1B G593A, VEGF C936T, VEGF C - 2578A, and VEGF G - 1154A, with adjustment for age, gender, and any history of hypertension, diabetes, or dyslipidemia. The per-allele OR for the risk of SSNHL in subjects bearing IL-6 C - 572G was 1.480 (95% confidence interval [CI], 1.037-2.111) in model 1 (no adjustment), 1.463 (CI, 1.022-2.094) in model 2 (adjusted for age and gender), and 1.460 (CI, 1.016-2.097) in model 3 (adjusted for age, gender, and a history of hypertension, diabetes, or dyslipidemia). Under the dominant model of inheritance, the ORs were 1.734 (CI, 1.080-2.783) in model 1, 1.690 (CI, 1.050-2.721) in model 2, and 1.669 (CI, 1.035-2.692) in model 3. The remaining seven polymorphisms failed to show any associations with the risk of SSNHL. These data need to be confirmed on larger series of patients. In conclusion, the IL-6 C - 572G polymorphism is associated with a risk of SSNHL. Because permeability of blood vessels in the inner ear is frequently increased in patients with SSNHL, inflammation of the inner ear might be involved.

Randomized trial of a hearing conservation intervention for rural students: long-term outcomes

OBJECTIVES

We had the rare opportunity to conduct a cluster-randomized controlled trial to observe the long-term (16-year) effects of a well-designed hearing conservation intervention for rural high school students. This trial assessed whether the intervention resulted in (1) reduced prevalence of noise-induced hearing loss (NIHL) assessed clinically and/or (2) sustained use of hearing protection devices.

METHODS

In 1992-1996, 34 rural Wisconsin schools were recruited and 17 were assigned randomly to receive a comprehensive, 3-year, hearing conservation intervention. In 2009-2010, extensive efforts were made to find and contact all students who completed the original trial. Participants in the 16-year follow-up study completed an exposure history questionnaire and a clinical audiometric examination. Rates of NIHL and use of hearing protection were compared.

RESULTS

We recruited 392 participants from the original trial, 200 (53%) from the intervention group and 192 (51%) from the control group. Among participants with exposure to agricultural noise, the intervention group reported significantly greater use of hearing protection compared with the control group (25.9% vs 19.6%; P = .015). The intervention group also reported significantly greater use of hearing protection for shooting guns (56.2% vs 41.6%; P = .029), but the groups reported similar uses of protection in other contexts. There was no significant difference between groups with respect to objective measures of NIHL.

CONCLUSION

This novel trial provides objective evidence that a comprehensive educational intervention by itself may be of limited effectiveness in preventing NIHL in a young rural population.

Effects of gene-environmental interaction on noise-induced hearing threshold levels for high frequencies (HTLHF)

In this study we assessed the interaction between glutathione S-transferase (GST) genetic polymorphisms and noise exposures, with regard to their effect on the hearing threshold levels for high frequencies (HTLHF). Research participants comprised 347 male workers, and each participant's cumulative noise exposure was determined using a job-exposure matrix. Approximately 64.6% of the participants' exposure in L(eq-8 h) was above 90 dBA. The mean HTLHF was 32.1 dB. A significant dose-response relationship was found between noise exposure and HTLHF. We further converted the estimated total noise exposure level over each participant's job history to a noise exposure level that corresponded to a 40-year exposure (L(eq-40y)). After we had adjusted the results for age, we found that workers carrying GSTM1 null, GSTT1 null, and GSTP1 Ile(105)/Ile(105) genotypes were susceptible to the HTLHF when their L(eq-40y) were above 90 dBA. Therefore, GST genetic polymorphisms might affect HTLHF only when workers are exposed to high noise levels.

Association of interleukin-1 gene polymorphisms with sudden sensorineural hearing loss and Ménière's disease

Sudden sensorineural hearing loss (SSNHL) and Ménière's disease are the most common inner ear diseases in which the causes are unknown. As recent magnetic resonance imaging has demonstrated disruption of the blood-labyrinth barrier in these inner ear diseases, inflammatory reaction associated with increased permeability of the blood vessels may be involved. The genotypes of interleukin 1A (IL1A) (-889C/T; rs1800587) and interleukin 1B (IL1B) (-511C/T; rs16944) were determined using an allele-specific primer-polymerase chain reaction method in 72 patients with SSNHL, 68 patients with Ménière's disease, and 2202 control subjects living almost in the same area as the patients. A significantly higher prevalence of the IL1A-889T allele was observed in SSNHL and Ménière's disease compared with controls, although no significant difference in distribution of IL1B-511C/T genotypes was observed between the patients and controls. Adjusted odd ratios for SSNHL and Ménière's disease risks in the -889TT genotypes were 25.89 (95% confidence interval (CI) 12.19-54.98) and 18.20 (95% CI 7.80-42.46), respectively, after age and gender were taken as moderator variables. Our results suggested that IL1A is closely associated with susceptibility of SSNHL and Ménière's disease.

A prospective study of cardiovascular risk factors and incident hearing loss in men

OBJECTIVES/HYPOTHESIS

Hearing loss is the most common sensory disorder in the United States, affecting more than 36 million people. Cardiovascular risk factors have been associated with the risk of hearing loss in cross-sectional studies, but prospective data are currently lacking.

STUDY DESIGN

Prospective cohort study.

METHODS

We prospectively evaluated the association between diagnosis of hypertension, diabetes mellitus, hypercholesterolemia, smoking, or body mass index (BMI) and incident hearing loss. Participants were 26,917 men in the Health Professionals Follow-up Study, aged 40 to 74 years at baseline in 1986. Study participants completed questionnaires about lifestyle and medical history every 2 years. Information on self-reported professionally diagnosed hearing loss and year of diagnosis was obtained from the 2004 questionnaire, and cases were defined as hearing loss diagnosed between 1986 and 2004. Multivariable-adjusted hazard ratios (HRs) were calculated using Cox proportional hazards regression models.

RESULTS

A total of 3,488 cases of hearing loss were identified. History of hypertension (HR 0.96; 95% confidence interval [CI], 0.88-1.03), diabetes mellitus (HR 0.92; 95% CI, 0.78-1.08), or obesity (HR 1.02; 95% CI, 0.90-1.15 for BMI >or=30 compared to normal range of 19-24.9) was not significantly associated with hearing-loss risk. Hypercholesterolemia (HR 1.10; 95% CI, 1.02-1.18) and past smoking history (HR 1.09; 95% CI, 1.01-1.17) were associated with a significantly increased risk of hearing loss after multivariate adjustment.

CONCLUSIONS

A history of hypertension, diabetes mellitus, or obesity is not associated with increased risk of hearing loss; a history of past smoking or hypercholesterolemia has a small but statistically significant association with increased risk of hearing loss in adult males.

Effect of smoking on transient evoked otoacoustic emissions and contralateral suppression

OBJECTIVE

The present study compared the amplitudes of transient evoked otoacoustic emissions (TEOAEs) and efferent suppression in smokers and non-smokers taking age into consideration.

METHODS

Fifty smokers and fifty non-smokers who had normal hearing sensitivity with age range of 20-69 years were considered for the present study. TEOAEs were measured in both the groups of subjects across different age groups. The functioning of the efferent auditory system was evaluated in both the groups by recording the TEOAEs in the presence of a contralateral white noise (CWN) of 70dB SPL.

RESULTS

Age did not have a significant effect on the TEOAEs amplitude in both the groups of subjects. However, the TEOAEs amplitude was significantly reduced in smokers compared to non-smokers. The results found a significant effect of age on the amplitude of efferent suppression in smokers, however, no significant effect was found in the non-smokers group.

CONCLUSIONS

It was found that the difference in the amplitude of efferent suppression in smokers was significantly greater for each age group between 20 and 49 years compared to each age group from 50 to 69 years. Results have important implication on the damage to the cochlear structures from smoking.

Low and high frequency tonal threshold audiometry: comparing hearing thresholds between smokers and non-smokers

Cigarette smoking can cause many potentially fatal diseases and worsen others. Numerous studies have shown the relationship between smoking and hearing loss. However, the increase in auditory threshold in high frequency arising from smoking has been very little described.

Aim

to compare low and high frequency auditory thresholds among a group of smoking and non-smoking male individuals between 18 and 40 years.

Study design

Cross-sectional.

Materials and Methods

by means of low and high frequency tonal threshold audiometry we studied 30 male individuals between 18 and 40 years and 30 non-smokers of matching age and gender.

Results

auditory thresholds were different between smokers and non-smokers, being worse in the former. Although within normal ranges, auditory thresholds in low frequencies were higher among smokers. In high frequencies we noticed a marked increase in auditory thresholds among smokers.

Conclusion

we found statistically significant difference in auditory thresholds in low and high frequencies, among young male individuals, smokers and non-smokers, being worse in the former.

Prevalence of hearing loss in Black and White elders: results of the Cardiovascular Health Study

PURPOSE

The goal of this study was to determine the impact of age, gender, and race on the prevalence and severity of hearing loss in elder adults, aged 72-96 years, after accounting for income, education, smoking, and clinical and subclinical cardiovascular disease. Methods Air-conduction thresholds for standard and extended high-frequency pure-tones were obtained from a cohort of 548 (out of 717) elderly adults (ages 72-96 years) who were recruited during the Year 11 clinical visit (1999-2000) of the Cardiovascular Health Study (CHS) at the Pittsburgh, Pennsylvania site. Participant smoking, income, education, and cardiovascular disease histories were obtained from the CHS database and were included as factors.

RESULTS

Hearing loss was more common and more severe for the participants in their 80s than for those in their 70s-the men more than the women and the White participants more than the Black participants. The inclusion of education, income, smoking, and cardiovascular disease (clinical and subclinical) histories as factors did not substantively impact the overall results.

CONCLUSION

Although the data reported in this article were cross-sectional and a cohort phenomenon might have been operational, they suggested that hearing loss is more substantive in the 8th than the 7th decade of life and that race and gender influence this decline in audition. Given the high prevalence in the aging population and the differences across groups, there is a clear need to understand the nature and causes of hearing loss across various groups in order to improve prevention and develop appropriate interventions.

Auditory assessment of patients with acute uncomplicated Plasmodium falciparum malaria treated with three-day mefloquine-artesunate on the north-western border of Thailand

Background

The use of artemisinin derivatives has increased exponentially with the deployment of artemisinin combination therapy (ACT) in all malarious areas. They are highly effective and are considered safe, but in animal studies artemisinin derivatives produce neurotoxicity targeting mainly the auditory and vestibular pathways. The debate remains as to whether artemisinin derivatives induce similar toxicity in humans.

Methods

This prospective study assessed the effects on auditory function of a standard 3-day oral dose of artesunate (4 mg/kg/day) combined with mefloquine (25 mg/kg) in patients with acute uncomplicated falciparum malaria treated at the Shoklo Malaria Research Unit, on the Thai-Burmese border. A complete auditory evaluation with tympanometry, audiometry and auditory brainstem responses (ABR) was performed before the first dose and seven days after initiation of the antimalarial treatment.

Results

Complete auditory tests at day 0 (D0) and day 7 (D7) were obtained for 93 patients. Hearing loss (threshold > 25 dB) on admission was common (57%) and associated with age only. No patient had a threshold change exceeding 10 dB between D0 and D7 at any tested frequency. No patient showed a shift in Wave III peak latency of more than 0.30 msec between baseline and D7.

Conclusion

Neither audiometric or the ABR tests showed clinical evidence of auditory toxicity seven days after receiving oral artesunate and mefloquine.

Hearing status among cabin crew in a Swedish commercial airline company

PURPOSE

To study hearing loss in commercial airline cabin crew (CC).

METHODS

Totally 155 male and 781 female CC (n = 936) in a Swedish airline company underwent repeated audiometric tests during 1974-2005. The last test was used to study hearing loss. The mean test values at 3, 4, 6 kHz were used for the ear with worse hearing loss. Data were compared with a Swedish population (n = 603) who were not occupationally exposed to noise. Equivalent noise levels (Leq) were measured in different aircraft.

RESULTS

Leq was 78-84 dB (A), maximum A-weighted exposure was 114 dB. Median values for all ages were close to the reference group. No association was found between years of employment and hearing loss, when adjusting for age and gender by multiple logistic regression analysis.

CONCLUSION

Cabin crew are exposed to equivalent noise levels below the current Swedish occupational standard, and have normal age-matched hearing threshold levels.

Hearing status among commercial pilots in a Swedish airline company

The aim was to study hearing impairment in commercial pilots. A total of 634 male and 30 female pilots (N=664) in a Swedish airline company underwent repeated audiological tests during the period 1974-2005. The last test was used to study hearing impairment. The mean values for the hearing test at 3, 4, and 6 kHz were used for the ear with worse hearing impairment. Data was compared with a general adult Swedish population (n=603) not occupationally exposed to noise. Equivalent noise levels gate to gate (Leq) were measured in the cockpit of different aircraft. Leq was 75-81 dB (A), peak exposures were 105 dB (A) from the cabin call signal. Median values were similar as in the reference group at all ages. There was no association between years of employment, tobacco smoking, and hearing impairment, when adjusted for age and gender by multiple logistic regressions analysis. In conclusion, pilots are exposed to equivalent noise levels below the current Swedish occupational standard of 85 dB (A), with short peak exposures above the standard, and have normal age-matched hearing thresholds.

Occupational noise, smoking, and a high body mass index are risk factors for age-related hearing impairment and moderate alcohol consumption is protective: a European population-based multicenter study

A multicenter study was set up to elucidate the environmental and medical risk factors contributing to age-related hearing impairment (ARHI). Nine subsamples, collected by nine audiological centers across Europe, added up to a total of 4,083 subjects between 53 and 67 years. Audiometric data (pure-tone average [PTA]) were collected and the participants filled out a questionnaire on environmental risk factors and medical history. People with a history of disease that could affect hearing were excluded. PTAs were adjusted for age and sex and tested for association with exposure to risk factors. Noise exposure was associated with a significant loss of hearing at high sound frequencies (>1 kHz). Smoking significantly increased high-frequency hearing loss, and the effect was dose-dependent. The effect of smoking remained significant when accounting for cardiovascular disease events. Taller people had better hearing on average with a more pronounced effect at low sound frequencies (<2 kHz). A high body mass index (BMI) correlated with hearing loss across the frequency range tested. Moderate alcohol consumption was inversely correlated with hearing loss. Significant associations were found in the high as well as in the low frequencies. The results suggest that a healthy lifestyle can protect against age-related hearing impairment.

Associations of carotid intima-media thickness, tobacco smoking and overweight with hearing disorder in a general population sample

It has been argued that smoking or overweight might contribute to hearing disorder by atherogenic narrowing of the nutrient arteries to the cochlea. The carotid intima-media thickness (CIMT) is a surrogate marker for generalized atherosclerosis. We analyzed a subgroup (n=2619) from a general population sample in north-eastern Germany aged 45-81 years (Study of Health in Pomerania, SHIP). Assessments included self-statements about hearing disorder and medical examinations of CIMT. Using ordinal logistic regression for data analysis and after adjustment for cigarettes per day, waist circumference, diabetes, exposure to noise, age and sex, we found CIMT remained a predictor of hearing disorder (odds ratio 1.8, 95% confidence interval 1.0-3.2). Cigarettes per day and waist circumference were related to CIMT but not to hearing disorder. The findings suggest a positive association between CIMT and hearing disorder.

Occupational exposure to noise, and hearing function among electro production workers

OBJECTIVE

The present study has the aim to investigate the prevalence and the determinants of hearing loss among electro production workers.

METHODS

Ninety-three electro production workers and 51 office workers underwent audiometric test. Information regarding, socio-demographics, present and past medical history of hearing problems, use of ototoxic drugs, hobbies, and smoking habit was obtained using a self administered questionnaire.

RESULTS

The levels of noise at workplace have also been measured. Electro production workers were exposed to high levels of noise. Statistical analysis has shown that 44% of electro production workers had sensorineural hearing loss located mainly at 4000 Hz. Multivariate analysis demonstrated that occupational exposure to noise appears to be the strongest predictor (odds ratio, OR: 7.51) of NIHL followed by aging (OR: 5.34), and last by smoking (OR: 2.47).

CONCLUSION

Our findings indicate that electro production workers are occupationally exposed to high levels of noise, and present high rates of noise-induced hearing loss (NIHL). The observed hearing loss was located mainly at 4000 Hz. These findings underline the need for interventions to reduce the risk for the development of NIHL among electro production workers.

Distortion product otoacoustic emissions and tympanometric measurements in an adult population-based study

OBJECTIVE

Otoacoustic emissions (OAEs) are useful clinical tools that can be used as a test to reflect hearing, especially cochlear function. When OAEs are recorded, the sound energy is conducted inwards and outwards through the middle ear system, but the degree to which the middle ear condition affects the OAEs level remains obscure. The objectives of the present study were to estimate the effect of the condition of the middle ear expressed by multifrequency tympanometry on the distortion product otoacoustic emissions (DPOAEs) adjusting for age and the corresponding pure-tone thresholds.

SUBJECTS AND METHODS

The evaluation was conducted using 1,043 subjects without a history of ear disease or occupational noise exposure out of a population-based sample of 2,259 adults aged 40-82 years. Multifrequency tympanometry, DPOAEs, and pure-tone audiometry were administered. The resonance frequency (RF), static admittance (SA) and tympanometric peak pressure (PP) were taken as variables representing middle ear function. Subjects were categorized into three groups of variables < or = 5th percentile, between 5th and 95th percentile, and > or = 95th percentile. The signal-to-noise ratio in DPOAE levels were compared among three groups adjusting for age and the pure-tone threshold level.

RESULTS

Both abnormally high and low RF exerted a negative effect on DPOAEs. Smaller RF values were related to smaller DPOAEs for the frequency around 1000 Hz, and greater RF values were related to smaller DPOAEs for the frequency around 4000 Hz. The tendency was similar between genders. Abnormally high SA had a negative influence on DPOAEs, while abnormally low SA had no significant effect on either gender. Smaller PP values were significantly related to smaller DPOAEs.

CONCLUSIONS

We interpreted the findings of the present study as verification of the effect of the condition of the middle ear on DPOAEs after adjustment for age and the pure-tone threshold level, although ears out of normal range in tympanometric variables might conceivably include not only middle ear dysfunction but also inner ear abnormality. Tympanometric assessment must always be taken into account when OAEs are analyzed for an estimation of the cochlea function.

Medical check-up findings characteristic of smokers: aimed at improving smoking cessation interventions by physicians

OBJECTIVE

The purpose of this study was to elucidate the medical check-up findings associated with smoking habit, which medical professionals, particularly physicians, should use for the promotion of quitting smoking.

METHODS

In 6,215 male and 1,627 female employees who participated in annual medical check-up, we compared the results of each test between smokers and nonsmokers.

RESULTS

Many results were significantly different between smokers and nonsmokers in both males and females. Among them, the hematocrit, leukocyte count, and levels of hemoglobin and triglyceride were significantly higher, the level of high-density lipoprotein cholesterol was significantly lower, and the frequencies of positive urinary occult blood and hearing loss were significantly higher in male smokers than in male nonsmokers. Furthermore, the hematocrit, leukocyte count, positive urinary occult blood, hearing loss, and levels of hemoglobin, triglyceride, and high-density lipoprotein cholesterol showed significant trends for male nonsmoker, and light, moderate, and heavy male smokers, that is, significant associations with larger numbers of cigarettes smoked per day.

CONCLUSION

Not only polycythemia and low high-density lipoprotein cholesterol level but also high leukocyte count, hearing loss, positive urinary occult blood, and high triglyceride level are smoking-related abnormal findings. In the medical check-up, medical professionals should inform smokers of these data and encourage them to quit smoking.