Relationship between occupational noise exposure and the risk factors of cardiovascular disease in China: A meta-analysis

Relationship Between Occupational Noise Exposure and Gestational Hypertension in Pregnant Women in Taizhou City: Cross-Sectional Study

OBJECTIVE

In view of the hazards of occupational noise exposure, this study investigated the relationship between occupational noise exposure and gestational hypertension in Taizhou City, Zhejiang Province, China to provide inspiration and reference for reducing the occurrence of gestational hypertension.

METHODS

This cross-sectional study analyzed the clinical data of 316 pregnant women in Taizhou City admitted to Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University from May 2020 to May 2023. In accordance with Acoustic Environment Quality Standards (GB3096-2008), 60 dB was used as the cut-off point. These pregnant women were divided into the low noise group (LNG, n = 161) and high noise group (HNG, n = 155) according to the noise exposure level in the working environment. This also study compared the noise exposure, blood pressure (BP), fasting blood glucose (FBG), blood lipid (BL), fetal size, and heart rate (HR), and analyzed the relationship of noise exposure with BP, FBG, BL, fetal size, HR, and occurrence of gestational hypertension.

RESULTS

The HNG had higher noise exposure level (P < 0.001), BP, FBG, BL and HR (P < 0.001), larger fetal size (P < 0.001) and higher occurrence of gestational hypertension (P < 0.05) compared with the LNG. Correlation analysis showed that noise exposure level was positively correlated with BP, FBG, BL, HR, and fetal size (P < 0.001) and had the strongest association with gestational hypertension.

CONCLUSION

Occupational noise exposure has adverse effects on pregnant women and fetuses. Pregnant women should pay attention to their exposure to occupational noise to prevent gestational hypertension. The results of this study must be further verified and generalized.

Association Between Hearing Loss and Cardiovascular Disease: A Meta-analysis

OBJECTIVE

Hearing loss (HL) has been postulated to be linked to cardiovascular diseases (CVDs) via vascular mechanisms, but epidemiological associations remain unclear. The study aims to clarify the association between HL and stroke, coronary artery disease (CAD), and any CVD.

DATA SOURCES

PubMed, Embase, and SCOPUS from inception until April 27, 2022.

REVIEW METHODS

Three blinded reviewers selected observational studies reporting stroke, CAD, and any CVD in patients with HL, compared to individuals without HL. We extracted data, evaluated study bias using the Newcastle-Ottawa scale, following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and a PROSPERO-registered protocol (CRD42022348648). We used random-effects inverse variance meta-analyses to pool the odds ratios (ORs) for the association of HL with stroke, CAD, and any CVD.

RESULTS

We included 4 cohort studies (N = 940,771) and 6 cross-sectional studies (N = 680,349). Stroke, CAD, and any CVD were all strongly associated with HL. The overall pooled OR of the association between HL and stroke was 1.26 (95% confidence interval [CI] = 1.16-1.37, I2  = 78%), and was 1.33 (95% CI = 1.12-1.58) and 1.29 (95% CI = 1.14-1.45) for low- and high-frequency HL, respectively. Minimal publication bias was observed, with minimal change to pooled effect size following trim and fill. Similarly, the pooled OR of the association between HL and CAD was 1.36 (95% CI = 1.13-1.64, I2  = 96%), while that between HL and any CVD was 1.38 (95% CI = 1.07-1.77, I2  = 99%).

CONCLUSION

Our findings suggest that HL and CVD are closely related. Physicians treating patients with HL should be cognizant of this association and view HL in the broader context of general health and aging.

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.

Is occupational noise associated with arthritis? Cross-sectional evidence from US population

BACKGROUND

The impact of occupational noise exposure on various diseases, including ear and cardiovascular diseases, has been studied extensively. Nevertheless, the connection between osteoarthritis (OA) and rheumatoid arthritis (RA) and occupational noise exposure remains largely unexplored in real-world scenarios. This study assessed the association between occupational noise exposure and the prevalence of two types of arthritis.

METHODS

This study used database data from 2005 to 2012 and 2015-March 2020 from the prepandemic National Health and Nutrition Examination Survey (NHANES) related to occupational noise exposure and arthritis. Multivariate logistic regression analysis was used to estimate the association between occupational noise exposure and RA/OA, adjusting for age, gender, race, education level, marital status, the ratio of family income to poverty, trouble sleeping, smoking status, alcohol consumption, diabetes, hypertension, body mass index (BMI), metabolic equivalents (METs), and thyroid disease.

RESULTS

This study included 11,053 participants. Multivariate logistic regression analysis demonstrated that previous exposure to occupational noise was positively associated with self-reported RA (OR = 1.43, 95% CI = 1.18-1.73) and OA (OR = 1.25, 95% CI = 1.07-1.46). Compared to individuals without a history of occupational noise exposure, those with an exposure duration of 1 year or greater exhibited higher odds of prevalent RA, though there was no apparent exposure response relationship for noise exposure durations longer than 1 year. The results of our subgroup analyses showed a significant interaction between age and occupational noise exposure on the odds of self-reported prevalent OA.

CONCLUSIONS

Our findings suggest an association between occupational noise exposure and the prevalence of RA and OA. Nevertheless, further clinical and basic research is warranted to better explore their associations.

Geo-Demographic and Socioeconomic Determinants of Diagnosed Hypertension among Urban Dwellers in Ibadan, Nigeria: A Community-based Study

Background

The relationship between diagnosed high blood pressure (HBP) and proximity to health facilities and noise sources is poorly understood. We investigated the relationship between proximity to noise sources, sociodemographic and economic factors, and diagnosed HBP in Ibadan, Nigeria.

Methods

We investigated 13,531 adults from the African Rigorous Innovative Stroke Epidemiological Surveillance (ARISES) study in Ibadan. Using a Geographic Information System (GIS), the locations of healthcare facilities, pharmaceutical shops, bus stops, churches, and mosques were buffered at 100m intervals, and coordinates of persons diagnosed with HBP were overlaid on the buffered features. The number of persons with diagnosed HBP living at every 100m interval was estimated. Gender, occupation, marital status, educational status, type of housing, age, and income were used as predictor variables. Analysis was conducted using Spearman rank correlation and binary logistic regression at p<0.05.

Results

There was a significant inverse relationship between the number of persons diagnosed with HBP and distance from pharmaceutical shops (r=-0.818), churches (r=-0.818), mosques (r=-0.893) and major roads (r=-0.667). The odds of diagnosed HBP were higher among the unemployed (AOR=1.58, 95% CI: 1.11-2.24), currently married (AOR=1.45, CI: 1.11-1.89), and previously married (1.75, CI: 1.29-2.38). The odds of diagnosed HBP increased with educational level and age group.

Conclusion

Proximity to noise sources, being unemployed and educational level were associated with diagnosed HBP. Reduction in noise generation, transmission, and exposure could reduce the burden of hypertension in urban settings.

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.

FLUCTUATING HEARING LOSS AS A SYMPTOM OF ACQUIRED PERILYMPHATIC FISTULA (PLF) UNDER EXTERNAL INJURIES FACTOR

OBJECTIVE

The aim: To evaluate the effectiveness of treatment patients with spontaneous PLF and labyrinthine window ruptures by studying the clinical and audiological results.

PATIENTS AND METHODS

Materials and methods: 52 patients after exposure to traumatic factors in the anamnesis were evaluated. The perilymphatic fistula was diagnosed in 18 patients after the complex examination. All patients with PLF underwent surgical treatment.

RESULTS

Results: Vestibular disorders and hearing loss were the predominant symptoms. The fistula test was positive in 11 (61%) patients. Fluctuating hearing loss was determined in 9 (50%) patients. Labyrinthine window ruptures were detected in 16 (88%) patients: oval window membrane rupture was identified in 6 patients, and in another 10 patients round window membrane rupture was found and was detected on CT scan. The surgical treatment included minimally invasive tympanotomy with combined microscopic and endoscopic visualization and sealing techniques. Results were evaluated in 6 months after surgical treatment, patients had a decrease in bone and air conduction thresholds at all evaluated frequencies and a significant decrease in the level of the air-bone interval.

CONCLUSION

Conclusions: Fluctuating hearing loss is considered one of the key symptoms, which suggests the presence of PLF. Determination of PLF and its surgical treatment, by using minimally invasive tympanotomy with sealing technique using optimal combined visualization, allows obtaining a stable functional result, with hearing improvement and vestibular symptoms reducing.

Association of occupational noise exposure with hypertension: A cross-sectional study

The effects of chronic occupational noise exposure on hypertension are debated. We aimed to investigate the association between occupational noise exposure and the prevalence of hypertension. The cross-sectional data were collected from 2017 to 2018 using occupational physical examination data from a local aircraft manufacturing enterprise in Xi'an. We categorized occupational noise exposure as high (≥85 dBA) and low noise exposure (< 85 dBA). Logistic regression analysis was performed to evaluate the association between occupational noise exposure and hypertension, and associations were further evaluated using subgroup analyses for age, sex, and body mass index (BMI). Of the 4746 participants (median age, 43 years; 73.4% men), 9.57% (454/4746) had hypertension and 32.4% (1540/4746) were exposed to high noise. Compared to the participants with low occupational exposure to noise, the adjusted odds ratio (OR) for hypertension prevalence was 1.30 (1.05-1.62) for those with high occupational noise exposure. Subgroup analyses revealed that the noise-hypertension association only existed in young participants (OR, 1.70; 95% CI, 1.21-2.40). This study revealed a harmful association between high occupational noise exposure and hypertension in young adults. The study suggests occupational noise exposure as a target for worksite interventions to prevent hypertension.

Relationship between occupational noise exposure and hypertension: Cross-sectional evidence from real-world

Background

Occupational noise is one of the most common and prevalent occupational hazards worldwide and may induce adverse auditory and/or non-auditory health effects. However, the relationship between occupational noise exposure and hypertension is controversial and has long been debated.

Methods

Based on large sample cross-sectional data from all registered occupational health examination units from 2021 to 2022 (N = 101,605), this study aimed to analyze the prevalence of hearing loss and hypertension and to explore the influencing factors of hypertension of workers in Wuhan. Descriptive statistics, univariate analyses and multivariate analyses were used. Forest plot and nomograms were constructed for the visualization of predictive results. The ROC curve, AUC, C-index and calibration curves were used to assess the predictive accuracy and validity. DCA was performed to evaluate the net benefit that workers could receive.

Results

Higher rate of high-frequency hearing loss (25.3%), speech frequency hearing loss (8.8%), ECG abnormalities (31.9%) and hypertension (21.0%) were found in workers exposed to occupational noise in Wuhan. Occupational noise exposure (OR = 1.09, 95% CI: 1.01-1.18, p = 0.04), growth of age (OR: 1.07, 95% CI: 1.07-1.07, p < 0.001), overweight (OR: 1.82, 95% CI: 1.73-1.92, p < 0.001), obesity (OR: 3.62, 95% CI: 3.42-3.83, p < 0.001), hyperglycemia (OR: 1.84, 95% CI: 1.73-1.96, p < 0.001), hypercholesterolemia (OR = 1.34; 95% CI 1.22-1.48; p < 0.001), ECG abnormalities (OR = 1.11; 95% CI 1.07-1.15; p < 0.001) and family history of hypertension (OR = 1.69; 95% CI 1.58-1.81; p < 0.001) were risk factors of hypertension for workers. Male workers had a relatively higher hypertension risk than female workers (OR = 1.61; 95% CI 1.54-1.69; p < 0.001). Ear protective measures could not reduce the risk of hypertension in workers. Our nomogram has good predictive accuracy and validity. A dynamic nomogram to predict the workers' risk of hypertension was established publicly available online.

Conclusion

Occupational noise exposure may elevate workers' hypertension risk. More effective and relevant prevention measures should be taken. Our nomogram may help identify high-risk workers and facilitate timely interventions.

Relationship Between Occupational Noise and Hypertension in Modern Enterprise Workers: A Case–Control Study

Objective: The association between occupational noise exposure and hypertension is controversial. Thus, we aimed to assess the relationship between occupational noise exposure and hypertension.

Methods: This was a case‒control study, and 509 cases and 1,018 controls from an automobile company were included between July and October 2013. Occupational noise exposure was defined as exposure to noise level ≥80 dB(A) (Lex, 8 h) or cumulative noise exposure (CNE) ≥ 80 dB(A)-years. To assess the associations of noise level and CNE with hypertension, univariate and multivariate logistic regression were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The restricted cubic spline function was used to establish dose‒response curves.

Results: A noise level ≥80 dB (A) (Lex, 8 h) was significantly associated with hypertension (OR 2.48, 95% CI 1.89–3.24). CNE ≥80 dB (A)-years was significantly associated with hypertension (OR 1.53, 95% CI 1.18–2.00). Nonlinear relationships between noise level, CNE and hypertension were found (p- nonlinear<0.05).

Conclusion: Our study suggests that occupational noise exposure is a potential risk factor for hypertension in automobile company workers.

Occupational risk factors for hypertension

The identification and characterization of the modifiable risk factors of hypertension is of great value for public health and clinical medicine to achieve primary prevention. A large amount of literature on the effects of occupational factors on blood pressure and hypertension has been published. In this review, I summarize current evidence regarding the role of occupational factors in hypertension. The results of this review suggest that there is sufficient evidence to support the association between increased risk of hypertension and job stress, shift work, occupational lead exposure, and noise exposure. The association of hypertension with physical inactivity, sedentary behavior, and occupational exposure to mercury, arsenic, cadmium, or carbon disulfide remains inconclusive, although several studies have reported this finding. This review will serve as a step toward future research and provide baseline information for developing strategic interventions to prevent hypertension in the working population.

Assessment of sick building syndrome using visual analog scales

BACKGROUND

Despite there is no recommendations for assessing symptoms of sick building syndrome, the use of visual analog scales (VAS) seems attractive and appropriate. We aimed to demonstrate the benefits of using VAS for evaluating subjective symptoms of sick building syndrome.

METHOD

We compared an exposed group to a control group with a one-year follow-up. To assess chronology of symptoms, employees were asked to complete four VAS at different times: after vacations (time 1), beginning of the week-beginning of the day (time 2), beginning of the week-end of the day (time 3), and end of the week-end of the day (time 4). Measurements were repeated before and after ventilation work for the exposed group and at the same time in the control group without intervention. Confounding factors were assessed.

RESULTS

We included 36 employees (21 in the exposed group and 15 in the control group). Both groups were comparable. Prior to ventilation work, the exposed group had more subjective symptoms than the control group with a chronology of symptoms. After ventilation work, symptoms did not differ between groups, and most symptoms decreased within the exposed group.

PRACTICAL IMPLICATION

The use of VAS provided reliable data for assessing sick building syndrome and showed a dose-response relationship between occupational exposure and symptoms.

The Impact of Occupational Noise on Hypertension Risk: A Case-Control Study in Automobile Factory Personnel

Background

Many epidemiological studies have investigated the relationship between occupational noise and hypertension, but with conflicting findings. This study aimed to assess the relationship between occupational noise exposure and the risk of hypertension.

Methods

A case-control study was conducted to explore hypertension predictors, and then sensitivity analysis was performed based on propensity score matching (PSM). Data were collected from participants' annual physical examinations and occupational noise exposure measurements. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression analysis. A restricted cubic spline (RCS) function was used to fit the dose-effect relationship.

Results

500 cases and 4,356 controls were included in the study. Multivariate logistic regression showed that an increase in the level of occupational noise [range 68–102 dB(A)] of 1 dB(A), corresponded to an increase in hypertension risk of 8.3% (OR: 1.083, 95% CI: 1.058–1.109). Compared to the first quartile, the risk of hypertension in the fourth quartile was 1.742 (95% CI: 1.313–2.310). After applying PSM to minimize bias, we obtained a population of 500 cases and 1,000 controls. Noise level was significantly associated with the risk of hypertension. In addition, the RCS curve showed the risk of hypertension was relatively stable until a predicted noise level of around 80 dB(A) and then started to increase rapidly afterward (Pnonlinear = 0.002).

Conclusions

Occupational noise exposure was significantly associated with hypertension risk and there was a positively correlated dose-response relationship.

Effect of ACE, ACE2 and CYP11B2 gene polymorphisms and noise on essential hypertension among steelworkers in China: a case-control study

Background

Previous studies on the relationship between ACE I/D, ACE2 G8790A and CYP11B2-344T/C gene polymorphisms and essential hypertension (EH) were inconsistent. Moreover, few studies have reported the combined effect of these gene polymorphisms and noise exposure on EH. The purpose of this study was to explore the combined and separate effects of ACE I/D, ACE2 G8790A and CYP11B2-344T/C gene polymorphisms and noise on EH among steelworkers.

Methods

A case–control study was conducted on 725 male workers between March 2014 and July 2014 in the Tangsteel Company, China. The noise exposure of the workers were measured. Logistic regression and crossover analysis were used to analyse the effects of the interactions on the EH among steelworkers. GMDR was used to determine the best combination model of gene–noise interactions.

Results

Multivariate logistic regression showed that noise exposure increased the odds of EH, and the OR is 1.52 (95% CI 1.04–2.22). The risk of having EH for ACE I/D DD genotype carriers was 1.99 times that for II genotype carriers (95% CI 1.14–3.51). There was a negative additive interaction between ACE2 G8790A and CYP11B2-344T/C on EH (U3 =  − 2.221, P = 0.026, and S = 0.128) and a positive multiplicative interaction between ACE I/D and CYP11B2-344T/C on essential hypertension (P = 0.041). In addition, there was no significant gene–noise interaction model through the GMDR method after adjusting the confounders.

Conclusions

The ACE DD genotype may make men susceptible to EH. Simultaneously carrying the DD genotype of ACE I/D and the TC genotype of CYP11B2-344T/C increased the risk of EH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01177-0.

Noise Exposure and Quality of Life Among Nurses

BACKGROUND

The purpose of this study was to describe the relationship between noise exposure, selected health conditions, and well-being among nurses.

METHODS

A secondary analysis was performed on data obtained from 3,818 U.S. nurses who responded to a survey regarding noise exposure, health conditions, stress, professional quality of life, and workplace support.

FINDINGS

Those who reported high noise exposure reported more health conditions, higher stress and burnout scores, and lower supportive environments. High noise exposure was significantly associated with lower professional quality of life.

CONCLUSION/APPLICATION TO PRACTICE

Noise may impact the health and quality of professional life of nurses. Occupational health nurses should advocate for the regular monitoring of nurses' exposure to hazardous noise at work, compare it to OSHA permissible levels, and collaborate with the occupational health team to ensure safe noise levels are maintained. Occupational health nurses should advocate for expanded research on effects of noise on health.

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.

The effect of occupational exposure to noise on ischaemic heart disease, stroke and hypertension: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-Related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large number of individual experts. Evidence from mechanistic data suggests that occupational exposure to noise may cause cardiovascular disease (CVD). In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from CVD that are attributable to occupational exposure to noise, for the development of the WHO/ILO Joint Estimates.

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of any (high) occupational exposure to noise (≥85 dBA), compared with no (low) occupational exposure to noise (<85 dBA), on the prevalence, incidence and mortality of ischaemic heart disease (IHD), stroke, and hypertension.

DATA SOURCES

A protocol was developed and published, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic academic databases for potentially relevant records from published and unpublished studies up to 1 April 2019, including International Trials Register, Ovid MEDLINE, PubMed, Embase, Lilacs, Scopus, Web of Science, and CISDOC. The MEDLINE and Pubmed searches were updated on 31 January 2020. We also searched grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews and included study records; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (<15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of the effect of any occupational exposure to noise on CVD prevalence, incidence or mortality, compared with the theoretical minimum risk exposure level (<85 dBA).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. We prioritized evidence from cohort studies and combined relative risk estimates using random-effect meta-analysis. To assess the robustness of findings, we conducted sensitivity analyses (leave-one-out meta-analysis and used as alternative fixed effects and inverse-variance heterogeneity estimators). At least two review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide tools and approaches adapted to this project.

RESULTS

Seventeen studies (11 cohort studies, six case-control studies) met the inclusion criteria, comprising a total of 534,688 participants (39,947 or 7.47% females) in 11 countries in three WHO regions (the Americas, Europe, and the Western Pacific). The exposure was generally assessed with dosimetry, sound level meter and/or official or company records. The outcome was most commonly assessed using health records. We are very uncertain (low quality of evidence) about the effect of occupational exposure to noise (≥85 dBA), compared with no occupational exposure to noise (<85 dBA), on: having IHD (0 studies); acquiring IHD (relative risk (RR) 1.29, 95% confidence interval (95% CI) 1.15 to 1.43, two studies, 11,758 participants, I² 0%); dying from IHD (RR 1.03, 95% CI 0.93-1.14, four studies, 198,926 participants, I² 26%); having stroke (0 studies); acquiring stroke (RR 1.11, 95% CI 0.82-1.65, two studies, 170,000 participants, I² 0%); dying from stroke (RR 1.02, 95% CI 0.93-1.12, three studies, 195,539 participants, I² 0%); having hypertension (0 studies); acquiring hypertension (RR 1.07, 95% CI 0.90-1.28, three studies, four estimates, 147,820 participants, I² 52%); and dying from hypertension (0 studies). Data for subgroup analyses were missing. Sensitivity analyses supported the main analyses.

CONCLUSIONS

For acquiring IHD, we judged the existing body of evidence from human data to provide "limited evidence of harmfulness"; a positive relationship is observed between exposure and outcome where chance, bias, and confounding cannot be ruled out with reasonable confidence. For all other included outcomes, the bodies of evidence were judged as "inadequate evidence of harmfulness". Producing estimates for the burden of CVD attributable to occupational exposure to noise appears to not be evidence-based at this time.

PROTOCOL IDENTIFIER

10.1016/j.envint.2018.09.040.

PROSPERO REGISTRATION NUMBER

CRD42018092272.

Acute High Level Noise Exposure Can Cause Physiological Dysfunction in Macaque Monkeys: Insight on the Medical Protection for Special Working Environmental Personnel

The high level noise caused by intense acoustic weapons and blasting is a common source of acute acoustic trauma faced by some special environmental personnel. Studies have shown that high level noise can cause auditory and non-auditory effects. However, there are few reports on the biological effects, especially the non-auditory effects of acute high level noise exposure in simulated special working environments, and the great differences between experimental animals and human beings make it difficult to extrapolate from research conclusions. In this study, macaque monkeys were used to detect the effects of acute high level noise exposure on hearing, cognition, and cardiovascular function. Auditory brainstem response, auditory P300, and electrocardiogram (ECG) of macaque monkeys were measured. Results showed that acute high level noise exposure caused permanent hearing threshold shifts; partial hearing loss which couldn’t recover to normal levels in the detection period; pathological changes in T wave and QRS complexes; and large fluctuations in cognitive ability after exposure, which finally recovered to normal. These alterations may be a combination of effects caused by stress-induced neuroendocrine dysfunction and mechanical damage of auditory organs. To elaborate the exact mechanism, further studies are still needed. Meanwhile, positive measures should be taken to reduce the incidence of acute high level noise injury.

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.

Occupational Noise and Hypertension Risk: A Systematic Review and Meta-Analysis

A number of epidemiological studies report an association between occupational noise exposure and arterial hypertension. Existing systematic reviews report conflicting results, so we conducted an updated systematic review with meta-analysis. We registered the review protocol with PROSPERO (registration no.: CRD 42019147923) and searched for observational epidemiological studies in literature databases (Medline, Embase, Scopus, Web of Science). Two independent reviewers screened the titles/abstracts and full texts of the studies. Two reviewers also did the quality assessment and data extraction. Studies without adequate information on recruitment, response, or without a comparison group that was exposed to occupational noise under 80 dB(A) were excluded. The literature search yielded 4583 studies, and 58 studies were found through hand searching. Twenty-four studies were included in the review. The meta-analysis found a pooled effect size (ES) for hypertension (systolic/diastolic blood pressure ≥140/90 mmHg) due to noise exposures ≥80 dB(A) of 1.81 (95% CI 1.51–2.18). There is no substantial risk difference between men and women, but data concerning this question are limited. We found a positive dose-response-relationship: ES = 1.21 (95% CI 0.78–1.87) ≤ 80 dB(A), ES = 1.77 (95% CI 1.36–2.29) > 80–≤85 dB(A), and ES = 3.50 (95% CI 1.56–7.86) > 85–≤90 dB(A). We found high quality of evidence that occupational noise exposure increases the risk of hypertension.

The association between road traffic noise and myocardial infarction: A systematic review and meta-analysis

This systematic review and meta-analysis study aimed to investigate the association between exposure to road traffic noise (RTN) and myocardial infarction (MI). Of 681 studies found by searching in databases, including Scopus, Web of Science, Embase, and PubMed on November 29, 2019, the number of 13 studies, including seven cohort, five case-control, and one cross-sectional studies with 1,626,910 participants and 45,713 cases of MI was included. The pooled relative risk (RR) and 95% confidence interval (CI) of MI were calculated using a random-effect model across studies. Heterogeneity measures by reporting the I-square index. Subgroup analysis according to the designs and sensitivity analysis based on the Jackknife approach was performed. We observed in the eight studies the association was investigated in different noise exposure groups and in the 10 studies (including two conference papers) the risk of MI was provided per specific unit increment of RTN. We ran two independent types of meta-analyses involving a categorical analysis (comparing the highest and the lowest category of noise exposure groups) and an exposure-response analysis (the risk of MI per 10-dB increment of RTN). The pooled RR (95% CI) of MI for the categorical and exposure-response meta-analyses was calculated 1.03 (0.93, 1.13) and 1.02 (1.00, 1.05), respectively. For both types of meta-analyses, subgroup analysis indicates a significant association in the studies with case-control and cross-sectional designs but not cohort studies. For the exposure-response meta-analysis, a significantly greater risk of MI was observed after excluding the two conference papers (RR = 1.03 and 95% CI = 1.00, 1.05) and by further excluding the studies provided originally the risk of MI only for the categorical analysis (RR = 1.02 and 95% CI = 1.01, 1.03). We did not show a significant publication bias across studies. In conclusion, our study suggests a significant odds of association between exposure to RTN and the risk of MI.

Regulation of TGF-β1 on PI3KC3 and its role in hypertension-induced vascular injuries

The aim of the present study was to investigate the expression and role of transforming growth factor (TGF)-β1/phosphatidylinositol 3-kinase catalytic subunit type 3 (PI3KC3) in the peripheral blood in patients with hypertension. A total of 28 patients with primary hypertension and 20 healthy control subjects were included. Peripheral blood samples were collected. The mRNA and protein expression levels were detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Cell counting kit-8 assay, Transwell chamber assay and flow cytometry were performed to detect the cell proliferation, migration ability and cellular apoptosis, respectively. Laser scanning confocal microscopy was used to detect the intracellular autophagosomes. The expression of TGF-β1 was significantly elevated, whereas the expression of PI3KC3 was significantly downregulated in the patients with hypertension compared with controls. There was negative correlation between the TGF-β1 and PI3KC3 expression. Following treatment with TGF-β1, the protein expression of PI3KC3 was significantly decreased in human umbilical vein endothelial cells (HUVECs), and the autophagic activity was significantly decreased. Furthermore, following the treatment of TGF-β1 the proliferation of HUVECs was significantly reduced in the HUVECs, the hypoxia-induced apoptosis rates were significantly elevated and the number of penetrating cells were significantly declined (indicating declined migration ability). However, the overexpression of PI3KC3 significantly ameliorated the proliferation, migration ability and hypoxia tolerance of TGF-β1-treated HUVECs. In conclusion, the present results indicated that TGF-β1 expression was elevated in the peripheral blood in hypertensive patients and negatively correlated with the PI3KC3 expression; and that TGF-β1 regulates the PI3KC3 signaling pathway to inhibit the autophagic activity of vascular endothelial cells, and regulate the cell proliferation, migration and anti-apoptosis ability, thus aggregating the endothelial cell injuries in hypertension. The results of the current study revealed a novel mechanism of TGF-β1 in the regulation of endothelial cell injury in hypertension, which may provide a potential target for disease therapy.