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

Association of Smoke and Nicotine Product Consumption With Sensorineural Hearing Loss: A Population-Level Analysis

OBJECTIVE

To test the hypothesis that use of cigarettes or other products with either cigarette-like smoke profile or high nicotine content by young populations increases the odds of developing sensorineural hearing loss (SNHL).

STUDY DESIGN

Retrospective cohort study.

SETTING

TriNetX US Collaborative Network (2003-2022).

PATIENTS

Approximately 3.6 million patients at least 18 years old.

INTERVENTION

None.

MAIN OUTCOME MEASURES

The primary outcome of interest was diagnosis of SNHL, defined using medical billing codes ( International Classification of Diseases, Tenth Revision , Current Procedural Terminology , etc.). Cohort inclusion criteria included electronic health record entry after 2003, age 18 to 54 or 55+ years at index, and status of cigarette, noncigarette nicotine, or cannabis use. Covariates were controlled via 1:1 propensity score matching for SNHL-related conditions, including diabetes mellitus and ischemic diseases. Odds for developing SNHL were calculated against control subjects aged 18 to 54 years who have no record of nicotine/cannabis use.

RESULTS

Odds for developing SNHL are higher for people 18 to 54 years old who use any nicotine product (odds ratio [95% confidence interval], 5.91 [5.71-6.13]), cigarettes only (4.00 [3.69-4.33]), chewing tobacco only (9.04 [7.09-11.63]), or cannabis only (3.99 [3.60-4.44]) compared with control. People 55+ years old who use no products also showed increased odds for SNHL (4.73 [4.63-4.85]).

CONCLUSIONS

Both nicotine and smoke exposure seem to be strongly associated with increased odds for developing SNHL, with chewing tobacco having the strongest association.

The Effect of Active and Passive Smoking on Hearing Loss in Noise-Exposed Metal Workers

Background

Many people are exposed to cigarette smoke actively or passively. We aimed to determine the effect of active and passive smoking on hearing thresholds and hearing loss noise-exposed workers.

Methods

This cross-sectional study was conducted on 929 metal workers. We divided the workers into 3 groups according to smoking status-current smokers, nonsmokers, and passive smokers. Audiometric testing was recorded for both ears. Hearing loss was defined by 3 models. The SPSS software Version 24 was used to analyze the collected data. We used an independent t test, chi-square, Fisher exact, and analysis of variance tests and logistic regression, and the significance level was set at P ˂0.05 to interpret the relationships between variables.

Results

The hearing threshold levels at 4000 Hz, high frequencies, and low frequencies were significantly higher in smokers than nonsmokers (P < 0.05). Also, and hearing loss at the 4000 Hz (P = 0.002; odds ratio [OR] = 1.96; 95% CI = 1.27-3.03) and high frequencies (P = 0.001; OR = 2.15; 95% CI = 1.36-3.4) had a significant correlation with smoking. Hearing loss was significantly correlated with passive smoking at 4000 Hz (P < 0.001; OR = 5.87; 95% CI = 3.29-10.47), high frequencies (P < 0.001; OR = 7.16; 95% CI = 3.97-12.89) and low frequencies (P = 0.021; OR = 4.16; 95% CI = 1.12-15.43).

Conclusion

The findings show that active and passive smokers who work in noisy environments are at higher risk for noise-induced hearing loss. Therefore, smoking cessation in smoker workers and reduction of environmental exposure to cigarette smoke is necessary to reduce the exacerbation of hearing loss. Moreover, more attention should be paid to passive smokers and they should be given priority in the same programs.

Association between Statin Use and Sensorineural Hearing Loss in Type 2 Diabetic Patients: A Hospital-Based Study

Statins have emerged as protective agents against sensorineural hearing loss (SNHL) associated with dyslipidemia, but the effects of statins on SNHL are not consistent. The purpose of this study was to investigate the association between statin use and the risk of SNHL using a hospital cohort. This nested case-control study included type 2 diabetic patients over the age of 18 years without a history of hearing loss. Of these, 1379 patients newly diagnosed with SNHL or tinnitus were classified as cases, and 5512 patients matched to the cases based on age, sex, and index year were classified as controls. Chi-squared tests were used to compare categorical variables between the two groups. Odds ratios (ORs) and adjusted odds ratios (AOR) were calculated from univariate and multivariable unconditional logistic regression analyses, respectively. There was a significant difference in the prevalence of statin use between the cases and controls (53.7% vs. 61.2%, respectively; p < 0.001). The use of statins in type 2 diabetic patients significantly reduced the risk of SNHL or tinnitus by 24.8% (95% CI 14.2–34.1%, p < 0.001) after controlling for confounders. Similar results were found for the association between statin use and SNHL (AOR = 0.706; 95% CI 0.616–0.811, p < 0.001). The protective effects of statins against SNHL were consistent regardless of age and sex. The use of statins for type 2 diabetic patients was significantly associated with a reduced risk of SNHL, regardless of age and sex. Further studies are needed, especially large cohort studies, to evaluate the long-term protective effects of statins.

Hearing Loss and Associated Factors Among Noise-Exposed Workers in Palm Oil Mills

Introduction

Almost 90% of the reported occupational diseases in Sabah, Malaysian Borneo were due to hearing loss. The manufacturing industry was the main contributor to this problem. This study aims to identify the prevalence and associated factors for hearing loss among workers in the palm oil manufacturing industry in Sabah.

Material and Methods

A cross-sectional study was done among 312 respondents from five palm oil mills in Sabah from January to April 2019. Audiometric tests, validated questionnaires and sound level meters were used. Chi-square test and independent t-test were conducted to determine the associated factors for hearing loss.

Results

75% (n = 234) of the respondents were diagnosed with hearing loss. Most of them were male (96.2%) with a mean age of 44.4 (SD 9.8) years, mean duration of employment of 16.2 (SD 9.7) years and mean noise exposure of 96.1 (SD 4.8) dB(A). The significant factors associated with hearing loss were older age (p = 0.001), married (p = 0.001), blue-collar jobs (p = 0.003), smoking (p = 0.001), works with noisy machinery (p = 0.005), lower level of noise exposed (p = 0.015), longer duration of employment (p = 0.001), and longer overtime hours per week (p = 0.001).

Conclusion

The prevalence of hearing loss among workers in the noise-exposed palm oil industries was high. Annual audiometry testing and job rotation from noise-exposed workstations were recommended. A smoking cessation program may help but reduction of noise from the source by engineering control is still the best method.

The relationship between chronic exposure to arsenic through drinking water and hearing function in exposed population aged 10-49 years: A cross-sectional study

It has been documented that arsenic has a potential risk to human health and identified as a risk factor for hearing impairment. However, there are few studies that confirm the ototoxic effect of arsenic, especially on the human auditory system. Therefore, the current study was conducted to investigate the correlation between auditory thresholds at different frequencies (0.25, 0.5, 1, 2, 4 and 8 kHz) and arsenic levels in drinking water samples. A total of 240 people, divided into two equal groups: exposed and reference, were selected for the auditory tests. It should be noted that, at frequencies from 0.25 to 1 kHz, no hearing loss was observed in the both groups. Based on the results, no significant correlations (p > 0.05) were found between hearing thresholds and confounding variables including gender and BMI. However, smoking and age are known to be the main variables for hearing loss in univariate regression analysis. In the case of age, the hearing loss risk in the older participants was increased compared with the younger participants (4 kHz (OR =1.09; 95% CI: 1.04, 1.13) and 8 kHz (OR =1.12; 95% CI: 1.06, 1.18)). Smoking habits had significant associations with hearing loss risk at 4 kHz (OR = 3.48; 95% CI: 1.47, 8.22) and 8 kHz (OR = 3.01; 95% CI: 1.14, 7.95). The multivariate regression analysis showed that age, smoking status, and exposure to arsenic were significantly associated with increased risk of hearing loss. Moreover, no statistically significant correlation (p˃0.05) was observed between arsenic exposure and hearing loss in the logistic regression model compared to the reference group. These outcomes suggest that further investigation and cohort studies with a larger number of participants should be conducted to find an association between arsenic exposure and hearing loss in general population.

Explaining better hearing in Norway: a comparison of two cohorts 20 years apart - the HUNT study

Background

The hearing function at a given age seems to have improved in more recent born cohorts in industrialized countries. But the reasons for the improvement have not yet been explained.

Methods

We investigated the extent to which better hearing in Norway is attributed to modifiable risk factors by using representative demographic and audiometric data from two cohorts of the Trøndelag Health Study, HUNT2 (1996–1998) and HUNT4 (2017–2019). We estimated natural indirect effects using causal inference methods in order to assess whether cohort improvement in hearing thresholds (HTs) was mediated by occupational noise exposure, recurrent ear infections, smoking and education.

Results

The improvement in HTs from HUNT2 to HUNT4 was 2.8 and 3.0 dB at low respectively high frequencies. Together all risk factors mediated this improvement by 0.8 dB (95% CI 0.7–0.9) and 0.8 dB (95% CI 0.7–0.9) respectively, corresponding to mediated proportions of 27 and 28%. Substantial mediation was specifically found for occupational noise in men and recurrent ear infections in women (mediated proportions of 11 and 17% at high frequencies, respectively).

Conclusions

Increased education, less occupational noise exposure, ear infections and smoking contributed considerably to better hearing in Norway the last two decades.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10301-1.

Conceptual Model of Hearing Health Inequalities (HHI Model): A Critical Interpretive Synthesis

Hearing loss is a major health challenge that can have severe physical, social, cognitive, economic, and emotional consequences on people's quality of life. Currently, the modifiable factors linked to socioeconomic inequalities in hearing health are poorly understood. Therefore, an online database search (PubMed, Scopus, and Psych) was conducted to identify literature that relates hearing loss to health inequalities as a determinant or health outcome. A total of 53 studies were selected to thematically summarize the existing literature, using a critical interpretive synthesis method, where the subjectivity of the researcher is intimately involved in providing new insights with explanatory power. The evidence provided by the literature can be summarized under four key themes: (a) There might be a vicious cycle between hearing loss and socioeconomic inequalities and lifestyle factors, (b) socioeconomic position may interact with less healthy lifestyles, which are harmful to hearing ability, (c) increasing health literacy could improve the diagnosis and prognosis of hearing loss and prevent the adverse consequences of hearing loss on people's health, and (d) people with hearing loss might be vulnerable to receiving low-quality and less safe health care. This study uses elements from theoretical models of health inequalities to formulate a highly interpretive conceptual model for examining hearing health inequalities. This model depicts the specific mechanisms of hearing health and their evolution over time. There are many modifiable determinants of hearing loss, in several stages across an individual's life span; tackling socioeconomic inequalities throughout the life-course could improve the population's health, maximizing the opportunity for healthy aging.

A systematic review of the impact of cigarettes and electronic cigarettes in otology

BACKGROUND

The detrimental systemic effects of cigarette smoking are well established. Though less pronounced in the field of otology, they are proposed to contribute to the global burden of unaddressed hearing loss. Recently, in efforts to stop smoking, individuals have used electronic cigarettes of which the long-term safety data are largely unknown. This study aimed to conduct a systematic review of cigarette smoking and electronic cigarette effects in the field of otology.

METHOD

Relevant articles were identified by a National Institute for Health and Care Excellence healthcare database literature search and by scanning the references of relevant articles and reviews.

RESULTS

A total of 473 articles were identified, with 43 articles included in the review after trials were excluded.

CONCLUSION

Cigarette smoking is associated with recurrent otitis media, otitis media with effusion and sensorineural hearing loss in children exposed to second-hand smoke. In adults, it is associated with active and aggressive chronic suppurative otitis media, worse tympanoplasty success rates, increased post-operative complications and sensorineural hearing loss that is more pronounced in the long term and at high frequencies. The effects of e-cigarettes in otology are largely unknown.

Longitudinal screening of hearing threshold in navy divers: is diving really a hazard?

INTRODUCTION

Hearing loss (HL) is common in the adult working population. It is widely assumed that diving is a risk factor for HL. However, studies with sufficient follow-up comparing HL in divers to non-divers are limited. This study aimed to assess the hearing threshold (HT) of Royal Netherlands Navy divers who had been diving for more than 15 years and to compare it to the ISO standard 7029:2017 reference table.

METHODS

In this 25-year retrospective cohort study the Royal Netherlands Navy Diving Medical Centre audited the medical records of 1,117 Navy divers. Yearly dive medical assessments were performed according to professional standards, including audiometry. HTs were compared to the ISO 7029:2017 reference table, including Z-distribution, using paired t-tests.

RESULTS

Thirty-five divers were included who had been diving for 15 years or longer. The HT increased significantly in nine of the 16 measured frequencies, while the Z-score decreased significantly in nine of the 16 tested frequencies (eight in both ears). In the 25-year follow-up the pattern was more obvious, with one significantly increased HT, and 10 significantly decreased Z-scores.

DISCUSSION

The absolute HT increases after 15 years of military diving, but less than would be expected from normal age-related deterioration. Moreover, when comparing Z-scores, this sample of divers actually hear better than non-divers. We conclude that military diving is not an increased risk for HL compared to regular occupational hazards and suggest withdrawing the requirement for routine yearly audiometric evaluation as part of a dive medical examination.

Socioeconomic and lifestyle factors associated with hearing loss in older adults: a cross-sectional study of the English Longitudinal Study of Ageing (ELSA)

OBJECTIVES

Aims were (1) to examine whether socioeconomic position (SEP) is associated with hearing loss (HL) among older adults in England and (2) whether major modifiable lifestyle factors (high body mass index, physical inactivity, tobacco consumption and alcohol intake above the low-risk-level guidelines) are associated with HL after controlling for non-modifiable demographic factors and SEP.

SETTING

We used data from the wave 7 of the English Longitudinal Study of Ageing, which is a longitudinal household survey dataset of a representative sample of people aged 50 and older.

PARTICIPANTS

The final analytical sample was 8529 participants aged 50-89 that gave consent to have their hearing acuity objectively measured by a screening audiometry device and did not have any ear infection.

PRIMARY AND SECONDARY OUTCOME MEASURES

HL defined as >35 dBHL at 3.0 kHz (better-hearing ear). Those with HL were further subdivided into two categories depending on the number of tones heard at 3.0 kHz.

RESULTS

HL was identified in 32.1% of men and 22.3% of women aged 50-89. Those in a lower SEP were up to two times more likely to have HL; the adjusted odds of HL were higher for those with no qualifications versus those with a degree/higher education (men: OR 1.87, 95%CI 1.47 to 2.38, women: OR 1.53, 95%CI 1.21 to 1.95), those in routine/manual occupations versus those in managerial/professional occupations (men: OR 1.92, 95%CI 1.43 to 2.63, women: OR 1.25, 95%CI 1.03 to 1.54), and those in the lowest versus the highest income and wealth quintiles (men: OR 1.62, 95%CI 1.08 to 2.44, women: OR 1.36, 95%CI 0.85 to 2.16, and men: OR1.72, 95%CI 1.26 to 2.35, women: OR 1.88, 95%CI 1.37 to 2.58, respectively). All regression models showed that socioeconomic and the modifiable lifestyle factors were strongly associated with HL after controlling for age and gender.

CONCLUSIONS

Socioeconomic and lifestyle factors are associated with HL among older adults as strongly as core demographic risk factors, such as age and gender. Socioeconomic inequalities and modifiable lifestyle behaviours need to be targeted by the health policy strategies, as an important step in designing interventions for individuals that face hearing health inequalities.

Hearing Loss in Agricultural Workers Exposed to Pesticides and Noise

Agricultural workers who have concurrent exposure to pesticides and noise are at increased risk of hearing loss. We recruited 163 Thai conventional and 172 organic farmers to answer our questionnaires about personal demographics, agricultural activities, and pesticide and agricultural machinery use. This information was used to calculate the years of conventional (pesticide use) farming and the years of agricultural noise exposure, and to estimate semiquantitative metrics for pesticide exposure (cumulative intensity score-years) and cumulative noise exposure (dB(A)-years) for each conventional farmer. All participants underwent pure tone audiometric testing. The mean hearing threshold in the low-frequency band (0.5-2 kHz) and high-frequency band (3-6 kHz) were used for analysis. Years involved in conventional farming and years using agricultural machinery were associated with an increase in the average hearing threshold for the high-frequency band after controlling for age, ever exposed to industrial noise and cigarette smoking. The highest category of cumulative insecticide exposure (score-years), cumulative organophosphates exposure (score-years) and cumulative noise exposure (dB(A)-years) were also associated with an increased high-frequency band hearing threshold among conventional farmers. Results from the full cohort and the subcohort of conventional farmers support each other and the hypothesis that pesticide and noise have an additive effect on hearing, since no model interactions were significant.

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 combined effect of cigarette smoking and occupational noise exposure on hearing loss: evidence from the Dongfeng-Tongji Cohort Study

Combined effect of cigarette smoking and occupational noise exposure on hearing loss has rarely been evaluated among Chinese population, especially among females. This cross-sectional study was conducted in 11196 participants of Dongfeng-Tongji cohort study. Smoking status was self-reported through questionnaire and occupational noise exposure was evaluated through workplace noise level and/or the job titles. Hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1, 2, and 4 kHz in both ears. Compared with participants without occupational noise exposure, the risk of hearing loss was significantly higher for noise exposure duration ≥20 (OR = 1.45, 95%CI = 1.28–1.65). The association was particularly evident among individuals who were males (OR = 1.74, 95%CI = 1.45–2.08) and aged ≥ 70 (OR = 1.74, 95%CI = 1.30–2.33). Similarly, the risks increased with the increasing of pack-years in males and all age groups except for those aged <60. As to the combined effect, the hearing loss risk was highest for noise exposure duration ≥20 and pack-years ≥25 (OR = 2.41, 95%CI = 1.78–3.28), especially among males (OR = 2.42, 95%CI = 1.74–3.37) and those aged ≥70 (OR = 2.76, 95%CI = 1.36–5.60). Smoking may be an independent risk factor for hearing loss. And it may synergistically affect hearing when combined with occupational noise exposure, especially among males and older participants.

Comparisons of hearing threshold changes in male workers with unilateral conductive hearing loss exposed to workplace noise: a retrospective cohort study for 8 years

BACKGROUND

The purpose of this study was to investigate hearing threshold changes of workers with unilateral conductive hearing loss who were exposed to workplace noise for 8-years.

METHODS

Among 1819 workers at a shipyard in Ulsan, 78 subjects with an air-bone gap ≥10 dBHL in unilateral ears were selected. Factors that could affect hearing were acquired from questionnaires, physical examinations, and biochemistry examinations. Paired t-test was conducted to compare the hearing threshold changes over time between conductive hearing loss (CHL) ear and sensorineural hearing loss (SNHL) ear.

RESULTS

The study included male subjects aged 48.7 ± 2.9, having worked for 29.8 ± 2.7 years. Hearing thresholds increased significantly in CHL ears and SNHL ears at all frequencies (0.5-6 kHz) during follow-up period (p < 0.05). The threshold change at 4 kHz was 3.2 dBHL higher in SNHL ears which was statistically significant (p < 0.05). When workers were exposed to noise levels of 85 dBA and above, threshold change at 4 kHz was 5.6 dBHL higher in SNHL ears which was statistically significant (p < 0.05). Among workers aged below 50, the threshold change values were lower in low-frequency (0.5-2 kHz) in SNHL ears, with a small range of changes, whereas in high-frequency (3-6 kHz), the range of changes was greater SNHL ears (p < 0.05). Among workers aged 50 and above, SNHL ears showed a wider range of changes in both high- and low-frequency areas (p < 0.05).

CONCLUSIONS

At high-frequencies, particularly at 4 kHz, the range of hearing threshold changes was lower in ears with conductive hearing loss than in contralateral ears. This is suggested as a protective effect against noise exposure.

PON2 and ATP2B2 gene polymorphisms with noise-induced hearing loss

BACKGROUND

Noise-induced hearing loss (NIHL) is a complex disease induced by a combination of genetic and environmental factors. Paraoxonase2 (PON2) gene involved in the regulation of reactive oxygen species, and affecting the vulnerability of cochlea to NIHL, and ATPase, calcium-transporting, plasma membrane 2 (ATP2B2) gene which encodes plasma membrane calcium-transporting ATPase isoform 2 (PMCA2) are the candidate genes relating to the attack of NIHL. In this study, we investigated whether ATP2B2 and PON2 polymorphisms were associated with NIHL in Chinese of Han nationality population.

METHODS

We performed a case-control study between six single nucleotide polymorphisms (SNPs) (rs1719571, rs3209637 and rs4327369 within ATP2B2, rs12026, rs7785846 and rs12704796 within PON2) and NIHL in 454 subjects. All the SNPs were genotypes, using the TaqMan MGB probe assay. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs) with logistic regression analysis to test the level of association for SNPs.

RESULTS

In our study, 221 subjects with hearing loss and 233 subjects without hearing loss were recruited. The frequencies of the CG and CG + GG genotype of rs12026 (PON2) conferred risk factors for NIHL with adjusted OR values of 2.62 (95% CI, 1.69-4.06) and 2.48 (95% CI, 1.63-3.78), respectively. This kind of significance was also found at locus rs7785846, where genotypes CT and CT + TT were the risk types, with adjusted ORs of 2.52 (95% CI, 1.62-3.93) and 2.35 (95% CI, 1.54-3.58), respectively. We performed stratified analysis per noise exposure level, when it came to rs7785846 and rs12026 in the >92 dB(A) noise exposure group, the subjects who carried heterozygote were of significantly (P<0.01) higher susceptibility to NIHL than homozygote carriers. By contrast, no significantly higher risk was found for any rs12704796 genotypes or any genotypes in ATP2B2 (P>0.05), which may suggest that these SNPs did not have significant effects on noise susceptibility across noise exposure.

CONCLUSIONS

Our research suggested that PON2 might play a role in the etiology of NIHL in Chinese of Han nationality population.

Empirical estimation of the grades of hearing impairment among industrial workers based on new artificial neural networks and classical regression methods

Background:

Prediction models are used in a variety of medical domains, and they are frequently built from experience which constitutes data acquired from actual cases. This study aimed to analyze the potential of artificial neural networks and logistic regression techniques for estimation of hearing impairment among industrial workers.

Materials and Methods:

A total of 210 workers employed in a steel factory (in West of Iran) were selected, and their occupational exposure histories were analyzed. The hearing loss thresholds of the studied workers were determined using a calibrated audiometer. The personal noise exposures were also measured using a noise dosimeter in the workstations. Data obtained from five variables, which can influence the hearing loss, were used as input features, and the hearing loss thresholds were considered as target feature of the prediction methods. Multilayer feedforward neural networks and logistic regression were developed using MATLAB R2011a software.

Results:

Based on the World Health Organization classification for the grades of hearing loss, 74.2% of the studied workers have normal hearing thresholds, 23.4% have slight hearing loss, and 2.4% have moderate hearing loss. The accuracy and kappa coefficient of the best developed neural networks for prediction of the grades of hearing loss were 88.6 and 66.30, respectively. The accuracy and kappa coefficient of the logistic regression were also 84.28 and 51.30, respectively.

Conclusion:

Neural networks could provide more accurate predictions of the hearing loss than logistic regression. The prediction method can provide reliable and comprehensible information for occupational health and medicine experts.

Cardiovascular risk factors and hearing loss: The HUNT study

OBJECTIVE

The purpose of the present paper was to examine the association between prospectively and cross-sectionally assessed cardiovascular risk factors and hearing loss.

DESIGN

Hearing was assessed by pure-tone average thresholds at low (0.25-0.5 kHz), middle (1-2 kHz), and high (3-8 kHz) frequencies. Self-reported or measured cardiovascular risk factors were assessed both 11 years before and simultaneously with the audiometric assessment. Cardiovascular risk factors were smoking, alcohol use, physical inactivity, waist circumference, body mass index, resting heart rate, blood pressure, triglycerides, total serum cholesterol, LDL cholesterol, HDL cholesterol, and diabetes.

STUDY SAMPLE

A population-based cohort of 31 547 subjects.

RESULTS

After adjustment for age, sex, level of education, income, recurrent ear infections, and noise exposure, risk factors associated with poorer hearing sensitivity were smoking, diabetes, physical inactivity, resting heart rate, and waist circumference. Smoking was only associated with hearing loss at high frequencies. The effects were very small, in combination explaining only 0.2-0.4% of the variance in addition to the component explained by age and the other cofactors.

CONCLUSION

This cohort study indicates that, although many cardiovascular risk factors are associated with hearing loss, the effects are small and of doubtful clinical relevance.

Analysis of Predisposing Factors for Hearing Loss in Adults

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

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

BACKGROUND

Recently, a positive association has been reported between hypertension and periodontitis. The authors hypothesized that oral hygiene promotion activities could have an effect on hypertension prevention or the degree of hypertension control. Therefore, this study examines the relationship between oral hygiene behaviors and hypertension using data from a nationally representative survey, the Korea National Health and Nutrition Examination Survey (KNHANES).

METHODS

Using data from the KNHANES (2008 to 2010), 19,560 adults with complete data sets were included. The authors analyzed the relationship of the prevalence and control rate of hypertension and numerous variables, including oral hygiene behavior.

RESULTS

As the frequency of toothbrushing increased, the prevalence of hypertension decreased in multivariate analysis after adjusting for various factors, including the presence of periodontitis. In a subgroup analysis, this relationship was also observed in individuals without periodontitis. In particular, systolic blood pressure levels progressively decreased as the frequency of toothbrushing and the number of secondary oral products used increased. The adjusted odds ratio of hypertension prevalence was 1.195 (95% confidence interval 1.033 to 1.383) for individuals who brushed their teeth hardly ever or once daily compared with those who brushed after every meal.

CONCLUSIONS

Individuals with poor oral hygiene behavior are more likely to have a higher prevalence of hypertension, even before periodontitis is shown. Oral hygiene behavior may be considered an independent risk indicator for hypertension, and maintaining good oral hygiene may help to prevent and control hypertension.

The prevalence and factors associated with hearing impairment in the Korean adults: the 2010-2012 Korea National Health and Nutrition Examination Survey (observational study)

There are few studies that have used audiometric testing to gauge the demographic characteristics and associated risk factors for hearing loss at the national-level. Here, we investigated the weighted prevalence and associated factors of hearing impairment in 16,040 Korean adult population. Subjects completed audiometric test and laboratory examination as part of the data from The 2010-2012 Korea National Health and Nutrition Examination Survey (KNHANES). In our respective study, the overall weighted (n = 33,762,584) prevalence of mild hearing impairment among the Korean adult population was 20.5% (95% clearance [CI], 19.6-21.6), whereas moderate-to-profound hearing impairment was 9.2% (95% CI, 8.6-9.9). The weighted prevalence of mild hearing impairment in younger adults (19-39 years' old) was 4.4% (3.5-5.5), in middle-age adults (40-64 years), it was 21.1% (19.8-22.5), and in older adults (≥65 years' old), it was 69.7% (67.8-71.6). Logistic regression analyses were performed for low/mid frequency or high-frequency mild hearing impairment with age, sex, tobacco use, heavy alcohol use, educational background, occupational noise exposure, obesity, hypertension, diabetes, total serum cholesterol, and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m² as covariates. The analyses revealed independent correlations between increased age, tobacco use, education, hypertension, and eGFR <60 mL/min/1.73m², and low/mid frequency and high frequency mild hearing impairment. High frequency mild hearing impairment was positively correlated with male sex, diabetes, and an increase in total serum cholesterol. Taken together, hearing impairment in Korea is highly prevalent with approximately one-fifth of Korean adult reporting mild hearing impairment. This study suggests that individuals with cardiovascular risk factors such as hypertension, diabetes, smoking, increased serum cholesterol, or decreased eGFR are at particular risk of developing hearing impairment. As such, these groups may benefit from hearing loss screening in addition to those groups typically considered to be of elevated risk including geriatrics, those of low socioeconomic status, and those with considerable occupational noise exposure.

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.