Bilateral high-frequency hearing loss is associated with elevated blood pressure and increased hypertension risk in occupational noise exposed workers

Occupational noise and hypertension in Southern Chinese workers: a large occupational population-based study

INTRODUCTION

An increasing number of original studies suggested that occupational noise exposure might be associated with the risk of hypertension, but the results remain inconsistent and inconclusive. In addition, the attributable fraction (AF) of occupational noise exposure has not been well quantified. We aimed to conduct a large-scale occupational population-based study to comprehensively investigate the relationship between occupational noise exposure and blood pressure and different hypertension subtypes and to estimate the AF for hypertension burden attributable to occupational noise exposure.

METHODS

A total of 715,135 workers aged 18-60 years were included in this study based on the Key Occupational Diseases Surveillance Project of Guangdong in 2020. Multiple linear regression was performed to explore the relationships of occupational noise exposure status, the combination of occupational noise exposure and binaural high frequency threshold on average (BHFTA) with systolic and diastolic blood pressure (SBP, DBP). Multivariable logistic regression was used to examine the relationshipassociation between occupational noise exposure status, occupational noise exposure combined with BHFTA and hypertension. Furthermore, the attributable risk (AR) was calculated to estimate the hypertension burden attributed to occupational exposure to noise.

RESULTS

The prevalence of hypertension among occupational noise-exposed participants was 13·7%. SBP and DBP were both significantly associated with the occupational noise exposure status and classification of occupational noise exposure combined with BHFTA in the crude and adjusted models (all P < 0·0001). Compared with workers without occupational noise exposure, the risk of hypertension was 50% greater among those exposed to occupational noise in the adjusted model (95% CI 1·42-1·58). For participants of occupational noise exposed with BHFTA normal, and occupational noise exposed with BHFTA elevated, the corresponding risks of hypertension were 48% (1·41-1·56) and 56% (1·46-1·63) greater than those of occupational noise non-exposed with BHFTA normal, respectively. A similar association was found in isolated systolic hypertension (ISH) and prehypertension. Subgroup analysis by sex and age showed that the positive associations between occupational noise exposure and hypertension remained statistically significant across all subgroups (all P < 0.001). Significant interactions between occupational noise status, classification of occupational noise exposure combined with BHFTA, and age in relation to hypertension risk were identified (all P for interaction < 0.001). The associations of occupational noise status, classification of occupational noise exposure combined with BHFTA and hypertension were most pronounced in the 18-29 age groups. The AR% of occupational noise exposure for hypertension was 28·05% in the final adjusted model.

CONCLUSIONS

Occupational noise exposure was positively associated with blood pressure levels and the prevalence of hypertension, ISH, and prehypertension in a large occupational population-based study. A significantly increased risk of hypertension was found even in individuals with normal BHFTA exposed to occupational noise, with a further elevated risk observed in those with elevated BHFTA. Our findings provide epidemiological evidence for key groups associated with occupational noise exposure and hypertension, and more than one-fourth of hypertension cases would have been prevented by avoiding occupational noise exposure.

Cardiometabolic diseases according to the type and degree of hearing loss in noise-exposed workers

Background

This study aimed to determine the association between cardiometabolic diseases, including metabolic syndrome, hypertension, and diabetes, and the type and degree of hearing loss in noise-exposed workers.

Methods

A total of 237,028 workers underwent air conduction pure tone audiometry in 2015 to assess their health and diagnose cardiometabolic diseases. The study defined metabolic syndrome, hypertension, and diabetes using blood pressure, fasting blood sugar, cholesterol, and triglyceride levels. Mid-frequency hearing loss was defined as ≥ 30 dB at 2,000 Hz, whereas high-frequency hearing loss was ≥ 40 dB at 4,000 Hz. The average air conduction hearing thresholds at these frequencies were used to determine hearing loss degrees.

Results

The odds ratio (OR) of combined exposure to noise and night-shift work in all cardiometabolic diseases was higher than that of noise exposure alone. The risk of cardiometabolic diseases was dose-response, with higher hearing loss causing higher ORs. The ORs of hypertension compared with the normal group were 1.147 (1.098-1.198), 1.196 (1.127-1.270), and 1.212 (1.124-1.306), and those of diabetes were 1.177 (1.119-1.239), 1.234 (1.154-1.319), and 1.346 (1.241-1.459) for mild, moderate, and moderate-severe hearing loss, respectively.

Conclusions

Workers who are exposed to noise tend to demonstrate high risks of hearing loss and cardiometabolic diseases; thus, bio-monitoring of cardiometabolic diseases, as well as auditory observation, is necessary.

MiRNA-92a-3p mediated the association between occupational noise exposure and blood pressure among Chinese adults

Evidence on the association between occupational noise exposure and blood pressure is inconsistent, and the underlying mechanism remains unknown. This study aimed to evaluate the association between occupational noise exposure and blood pressure, and explore the potential role of miRNAs in the association. A total of 894 subjects from two companies in Wuhan, China were included. Occupational noise exposure was assessed using cumulative noise exposure (CNE), and six candidate plasma miRNAs (miR-92a-3p, miR-21-5p, miR-200a-3p, miR-200b-3p, miR-200c-3p, and miR-1-3p) which were not only associated with blood pressure/hypertension but also related to oxidative stress were selected according to previous studies and tested. A linear dose-response relationship was found between occupational noise exposure and blood pressure, including systolic blood pressure (SBP) and diastolic blood pressure (DBP). Each 1-unit increase in CNE levels was significantly associated with a 0.130 (95 % confidence interval [CI] = 0.026, 0.234) unit increase in SBP and a 0.141 (95 % CI = 0.063, 0.219) unit increase in DBP. However, the association between occupational noise and hypertension is not statistically significant (P > 0.05). In the meanwhile, occupational noise exposure was negatively associated with miRNA-92a-3p (β = -0.019, 95 % CI = -0.032, -0.006) and miRNA-21-5p (β = -0.031, 95 % CI = -0.052, -0.010), and miRNA-92a-3p mediated 24.66 % of the association between occupational noise exposure and DBP. In addition, bilateral high-frequency hearing loss was not only positively associated with occupational noise exposure (OR = 1.974, 95 % CI = 1.084, 3.702) but also DBP (β = 2.546, 95 % CI = 0.160, 4.932). Our study suggests that occupational noise exposure is positively associated with SBP and DBP, and miRNA-92a-3p partially mediate the association between occupational noise exposure and DBP.

The Combined Effect of Elevated Blood Pressure and Occupational Noise Exposure on Bilateral High-Frequency Hearing Loss: Evidence From a Large Sample Cross-sectional Study

BACKGROUND

Combined effect of elevated blood pressure and occupational noise exposure on hearing loss have rarely been evaluated among Chinese population.

METHODS

This cross-sectional study was conducted in 242,811 participants. Logistic regression model was performed to estimate the independent and combined associations.

RESULTS

Compared with participants without occupational noise exposure, the risk of bilateral high-frequency hearing loss (BHFHL) was significantly higher for noise exposure 10 years or more (odds ratio [OR] = 1.29, 95% confidence interval [95% CI] = 1.23-1.35). Compared with no hypertension, participants with grade 1 hypertension had higher risk of BHFHL in all age groups (OR, 1.14; 95% CI, 1.09-1.20). As to the combined effect, the highest BHFHL risk was found in males (OR, 1.51; 95% CI, 1.37-1.67), especially among participants with grade 1 hypertension older than 50 years (OR, 1.65; 95% CI, 1.46-1.88).

CONCLUSIONS

Elevated blood pressure may synergistically influence hearing loss combined with occupational noise exposure.

Occupational Noise-Induced Pre-Hypertension and Determinant Factors Among Metal Manufacturing Workers in Gondar City Administration, Northwest Ethiopia

Introduction

Cardiovascular disorders are one of the commonly recognized occupational diseases in the developed world. Individuals chronically exposed to noise at workplaces had a higher risk of developing elevated arterial blood pressure. There are limited studies in Ethiopia regarding this topic and thus this study determined the prevalence and determinant factors of occupational noise-induced pre-hypertension among metal manufacturing workers in Gondar city administration, Northwest Ethiopia.

Methods

An institution-based cross-sectional study design was carried out. In this study, 300 study participants were recruited by census sampling method. A sound level meter was used to measure the working area noise level. A semi-structured pre-tested interviewer-administered questionnaire was used to collect sociodemographic and clinical data. Blood pressure was measured in a quiet room in the morning using a mercurial sphygmomanometer. Both bivariable and multi-variable binary logistic regressions were used to identify factors associated with noise-induced prehypertension. Adjusted odds ratio with 95% confidence interval was reported, and variables with p < 0.05 were considered as statistically associated factors with pre-hypertension.

Results

The prevalence of noise-induced pre-hypertension was 27.7% (95% CI: 22.7-32.7). In multivariable logistic regression, working area noise level (AOR = 3.8, 95% CI: 6.8-8.9), 45-65 years' age (AOR = 9.8, 95% CI: 5.4-12.9), years of work experience ((6-10 years (AOR = 2.8, 95% CI: 1.98-5.90 and >10 years (AOR = 4.8, 95% CI: 7.8-9.75)), being a cigarette smoker (AOR = 3.6, 95% CI: 1.36-9.77), and alcohol consumption (AOR = 2.4, 95% CI: 1.06-1.04) were significantly associated with noise-induced prehypertension.

Conclusion

Workers in metal manufactures who were exposed to noise levels >85 dB developed elevated blood pressure. The odds of having prehypertension were increased by years of work experience, advanced age, smoking, and alcohol consumption. Our findings recommended that the real-world preventive strategies should be taken to lower the risk of noise-induced pre-hypertension hastened by occupational noise exposure.

The Psychosocial Effects of Noise Level in Hydroelectric Power Plants on Employees

Background

This cross-sectional study was conducted to investigate the psychosocial effects of noise on employees in Hydroelectric Power Plants in Turkey.

Methods

The study was conducted in 2018, in operating Hydroelectric Power Plants located in the city of Artvin in Turkey with 110 employees. Data were collected by performing noise measurement, blood pressure measurement and using descriptive characteristics form and Depression, Anxiety and Stress Scale.

Results

The average personal noise of the sample was 72.3±0.8 dB(A). The blood pressure of the employees were within normal limits. There was no significant difference between the noise levels and the sub-dimensions of the scales used.

Conclusion

The measured mean noise of the sample was within normal limits as per the regulations regarding the protection of employees from noise. Measured BP means of employees during working and resting hours were within normal limits. DASS-42 subscale scores exhibited no difference depending on the noise level.

Hearing Loss and Hypertension: A Literature Review

Hypertension is a condition in which there is an abnormal blood pressure with a systolic pressure of more than 140 mmHg and a diastolic pressure of more than 90 mmHg. It has been cited that hypertension can cause hearing loss. To understand the association between hypertension and hearing loss, a systematic review has been carried out in Pubmed Central, Google Scholar, EBSCO, Web of Science, Indian Science Abstracts, J Gate, Proquest, and Shodh Ganga. This review included original articles published on or after 2016 with cross-sectional study design, retrospective study design, and longitudinal design and excluded case reports and letters to the editors. Out of the 11,977 articles, only ten articles were finalized. These 10 articles stated a possible association between hypertension and hearing loss by explaining that Cochlear microcirculation change resulted in tissue hypoxia that caused hearing loss.

Hearing loss and hypertension among noise-exposed workers: a pilot study based on baseline data

This study aimed to assess the prevalence of noise-induced hearing loss (NIHL) and hypertension, and the association between NIHL and hypertension using occupational physical examination data of 42,588 noise-exposed workers from local enterprises in Yangzhou between 2015 and 2017. The average binaural high-frequency threshold on average (BHFTA), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 23.09 ± 11.32 dB, 126.85 ± 15.94 mm Hg and 79.94 ± 11.61 mm Hg. The prevalence of NIHL and hypertension were 24.38% and 25.40%. An increased risk of NIHL and hypertension was observed in the groups of males, aged >35 years, noise exposure time >5 years, noise exposure level >85 dB(A) and smoking. 32.25% NIHL workers had hypertension. NIHL workers were at higher risk of hypertension (adjusted OR = 1.07, 95%CI = 1.02-1.13). This study shows that the noise-exposed workers have high risk of developing NIHL and hypertension.

Investigating the effects of occupational and environmental noise on cardiovascular diseases: a systematic review and meta-analysis

The present study aimed to use a meta-analysis to investigate the relationship between occupational and non-occupational noise exposure expressed in various studies with cardiovascular disease. This is a systematic review and meta-analysis study based on PRISMA checklist. In this study, the researchers searched five international databases of Medline/PubMed, Embase, Scopus, ISI/web of knowledge, and Google Scholar. Search keywords included two categories noise and noise pollution, cardiovascular disease, and hypertension. The Joanna Briggs Institute checklist was used to review and control the quality of the articles. After all screening stage 139 articles entered the final analysis. The results show that except for East African environmental studies and workplace studies in East Asia, Western Asia, and Northern Europe, there was a significant association between noise exposure and cardiovascular disease. Also, there was a significant difference between the intensity of sound and blood pressure in workers (OR = 1.28, CI 95%: 1.15-1.42, P < 0.001). Based on the results of environmental noise, there was a significant difference between ambient noise intensity and blood pressure (OR = 1.55, CI 95%: 1.53-1.57, P < 0.001). It can be concluded that it is very important to study and identify jobs or living environments with less than the recommended noise level and in addition to hearing aids that occur in over-standard exposures, such as cardiovascular disease.

Association of occupational noise exposure, bilateral hearing loss with hypertension among Chinese workers

OBJECTIVE

To evaluate the relationship of occupational noise, bilateral hearing loss with blood pressure and hypertension among a Chinese population.

METHODS

We included 15 422 individuals from a cross-sectional survey of the key occupational diseases in 2017 in Wuhan, Hubei Province, China. Occupational noise exposure was evaluated through workplace noise level and/or the job titles. Hearing loss was defined as a pure-tone average of 25 dB or higher at speech frequency (0.5, 1, 2 kHz) or high frequency (3, 4, 6 kHz) in both ears. Hypertension was defined as blood pressure at least 140/90 mmHg or self-reported current use of antihypertensive medication.

RESULTS

Compared with participants without occupational noise exposure, the prevalence of hypertension was significantly higher for noise exposure duration of 5 to less than 10 years [odds ratio (OR) = 1.13, 95% confidence interval (CI) = 1.04-1.27] and at least 10 years (OR = 1.17, 95% CI = 1.09-1.30). In the sex-specific analysis, the association was significantly pronounced in male (OR = 1.18, 95% CI = 1.06-1.32 for duration of 5 to <10 years; OR = 1.25, 95% CI = 1.12-1.38 for duration ≥10 years), but not in female (OR = 1.01, 95% CI = 0.80-1.11 for duration of 5 to <10 years; OR = 1.06, 95% CI = 0.90-1.20 for duration ≥10 years). In the subsample analyses, bilateral hearing loss was associated with a higher prevalence of hypertension, no matter for speech frequency hearing loss (OR = 1.12, 95% CI = 1.02-1.30 for mild; OR = 1.35, 95% CI = 1.20-1.50 for severe) or for high-frequency hearing loss (OR = 1.24, 95% CI = 1.03-1.50 for mild; OR = 2.40, 95% CI = 1.80-3.17 for severe). The sex-subgroup analysis of hearing loss with hypertension was similar as occupational noise and hypertension.

CONCLUSION

Our study has suggested occupational noise exposure is a potential risk factor for hypertension.

Impact of exposure to noise on the risk of hypertension: A systematic review and meta-analysis of cohort studies

OBJECTIVE

We aimed to synthesize available cohorts about the relationship between various types of noise and hypertension, and to explore the potential dose-response relationship between them in an updated meta-analysis.

METHODS

PubMed and Embase were searched through October 2019 to identify cohort studies that met predetermined inclusion criteria. A random-effects model was used to combine the results of included studies. Dose-response meta-analysis was conducted to examine the potential dose-response relationship.

RESULTS

Eleven cohort studies involving 224,829 participants were included in this systematic review. Pooled result showed that living or working in environment with noise exposure was significantly associated with increased risk of hypertension (RR: 1.18; 95% CI: 1.06 to 1.32), with low heterogeneity (P = 0.098, I² = 42.1%). We found no evidence of a nonlinear association of elevated noise with hypertension risk (P = 0.443). The summary risk ratio of hypertension for an increment of per 10 dB(A) of noise was 1.13 (95% CI: 0.99 to 1.28), with moderate heterogeneity (P = 0.003, I² = 72.1%).

CONCLUSIONS

Integrated evidence from cohort studies supports the hypothesis that exposure to noise may be a risk factor of hypertension.

Increased Risk of Sensorineural Hearing Loss as a Result of Exposure to Air Pollution

Whether exposure to air pollution is associated with developing sensorineural hearing loss (SHL) remains controversial. Using data from the National Health Insurance Research Database, we recruited a total of 75,767 subjects aged older than 20 years with no history of SHL from 1998 to 2010, and they were followed up until SHL was observed, they withdrew from the National Health Insurance program, or the study ended. The subjects were evenly exposed to low-level, mid-level, and high-level carbon monoxide (CO) and nitrogen dioxide (NO₂). The incidence rate ratio of SHL for patients exposed to high-level CO was 1.24 (95% confidence interval (CI) = 1.14–1.36). The NO₂ pollutants increased the incidence rate ratios of SHL in mid-level NO₂ and high-level NO₂ exposures by 1.10 (95% CI = 1.10–1.32) and 1.36 (95% CI = 1.24–1.49) times, respectively. The adjusted hazard ratio (adj. HR) of SHL in patients exposed to high-level CO was 1.45 (95% CI = 1.31–1.59), relative to that of patients exposed to low-level CO. Compared to patients exposed to low-level NO₂, patients exposed to mid-level NO₂ (adj. HR = 1.40, 95% CI = 1.27–1.54) and high-level NO₂ (adj. HR = 1.63, 95% CI = 1.48–1.81) had a higher risk of developing SHL. The increased risk of SHL following the increased concentrations of air pollutants (CO and NO₂) was statistically significant in this study. In conclusion, the subjects’ exposure to air pollution exhibited a significantly higher risk of developing SHL in Taiwan.