Effects of occupational exposure to respirable quartz dust on acute myocardial infarction

Occupational exposure to respirable crystalline quartz and the risk of incident acute myocardial infarction

We aimed to investigate the association between occupational exposure to respirable crystalline quartz (RCQ) and acute myocardial infarction (AMI) in a Danish register-based cohort (DOC*X Dust, n = 903,415). Through 1976-2017, information on occupation was linked to quantitative exposure estimates of RCQ, obtained from the job-exposure matrix of SYN-JEM. The follow-up period (1996-2018) counted 19,357,326 person-years, where 35,511 first-time AMIs occurred, according to register-based hospital contacts. Incidence rate ratios (IRRs) for AMI based on cumulative, recent, and maximum exposure were computed using Poisson regression adjusted for socio-economic factors, comorbidities, air pollution, and other occupational exposures such as noise, physically demanding work, exposure to diesel exhaust, and job strain. For cumulative exposure, the IRR for AMI in the unadjusted model was highest in the two lowest exposed quartiles (IRR for Q1 = 1.19 (95%CI: 1.13-1.25), IRR for Q2 = 1.12 (95%CI: 1.06, 1.17)). However, in the fully adjusted model, these associations were no longer significant and even inverse for exposed above 25th percentile. The lowest IRR was observed in the highest RCQ exposure quartile (IRR = 0.87, (95%CI: 0.83-0.92)). In general, the RCQ exposure levels in the DOC*X Dust cohort were presumed to be lower than in countries that - contrary to Denmark - have an active mining industry. In conclusion, no increased risk of AMI due to RCQ exposure was observed, but cautious interpretation is warranted because of potential bias from the healthy worker survivor effect.

Unveiling the threat of crystalline silica on the cardiovascular system. A comprehensive review of the current knowledge

Introduction

This paper aims to expose the link between occupational exposure to respirable crystalline silica (SiO2) and cardiovascular diseases (CVDs).

Methods

A comprehensive review of the literature was conducted, focusing on epidemiological studies that assessed the association between silicosis or SiO2 exposure and CVDs. Specific cardiovascular diseases, such as acute myocardial infarction, arrhythmias, pulmonary hypertension and pericarditis, were also pointed. Biomarkers commonly used in both silicosis and cardiovascular diseases were reviewed to underline the common pathological pathways.

Results

Published epidemiological data revealed a higher risk of ischemic heart disease, stroke, and hypertension in silica-exposed workers, even at low exposure levels. SiO2 exposure was linked to an increased risk of myocardial infarction, with potential mechanisms involving inflammation and platelet activation. Elevated risk of arrhythmias, particularly atrial fibrillation, correlated with occupational silica exposure. Consistent with the pathological mechanisms supporting the SiO2 exposure-CVDs relationship, biomarkers related to NLP3 inflammasome activation, reflecting oxidative stress, and revealing fibrosis have been presented.

Conclusion

Actual data support the relationship between occupational SiO2 exposure and various CVDs promoting cardiovascular monitoring in silica-exposed workers. Further studies are needed to identify specific/distinctive biomarkers to improve early detection of CVDs in silica exposed workers.

Occupational exposures and coronary heart disease in the Hamburg City Health Study (HCHS) - a cross-sectional study

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death among adults in Germany. There is evidence that occupational exposure to particulate matter, noise, psychosocial stressors, shift work and high physical workload are associated with CHD. The aim of this study is to identify occupations that are associated with CHD and to elaborate on occupational exposures associated with CHD by using the job exposure matrix (JEM) BAuA-JEM ETB 2018 in a German study population.

METHODS

Cross-sectional data from 8,070 participants, members of the first sub-cohort of the Hamburg City Health Study (HCHS), was used. To classify occupations, we rely on standard occupational titles (ISCO-08). The level of exposure is assigned to each job using a JEM. CHD is measured by self-reported diagnosis. Absolute and relative frequencies were calculated. Using logistic regression, the association of CHD and standard occupation titles via ISCO-08 and the association of CHD and occupational exposures via JEM were calculated and adjusted for potentially confounding covariates. Multiple imputations with chained equations (MICEs) were applied for missing values. Sensitivity analyses were performed.

RESULTS

The CHD prevalence in the study population was 4.6% (95% CI 4.2-5.1). Occupations associated with CHD were Physical and Engineering Science Technicians, Other Health Associate Professionals, General Office Clerks, Secretaries (general), Material Recording and Transport Clerks, Hairdressers, Beauticians and Related Workers, Electronics and Telecommunications Installers and Repairers, Other Craft and Related Workers, Car, Van and Motorcycle Drivers, Mobile Plant Operators and Domestic, Hotel and Office Cleaners and Helpers. Among occupational exposures retrieved from the JEM, Environmental Demands showed an association with CHD in the crude model but not after adjustment. The results remained robust in sensitivity analyses.

CONCLUSIONS

This study is the first to assess the association of a wide range of occupations and occupational exposures with CHD in a German study population. We found no association between occupational exposures and CHD after adjustment, but 11 occupations associated with CHD were identified. The results are limited by cross-sectional design, healthy worker effect (HWE), and small group sizes. Further studies with a larger sample and longitudinal design containing data on occupational history, occupational exposures and time of CHD diagnosis are needed.

Risk of Acute Myocardial Infarction in Pneumoconiosis: Results from a Retrospective Cohort Study

Background: Pneumoconiosis (PCN) has several comorbidities, most notably pulmonary and cardiovascular diseases. However, much is still unknown about the relationship between PCN and acute myocardial infarction (AMI). The present study aimed to clarify the association between PCN and subsequent AMI risk using a retrospective cohort study design. Methods: This was a population-based, retrospective cohort study that used data from Taiwan’s National Health Insurance Database. A total of 7556 newly diagnosed patients with PCN and 7556 individuals without PCN were included in the PCN and comparison cohort (PC and CC), respectively, between 2008 and 2018, with propensity score matching for age, gender, comorbidity, medication, and date of PCN diagnosis. The occurrence of AMI was monitored until the end of 2019, and AMI risk was assessed using Cox proportional hazard regression models. Results: The overall incidence of AMI was 1.34-fold higher in the PC than in the CC (4.33 vs. 3.23 per 1000 person-years, respectively, p < 0.05), with an adjusted hazard ratio (aHR) of 1.36 (95% confidence interval (CI): 1.08–1.72) after controlling for age, gender, comorbidity, and medication. Further analyses showed a higher risk of AMI with increased annual number of emergency department visits among patients with PCN (aHR: 1.30, 95% CI: 1.01–1.66 (<1) and aHR: 1.68, 95% CI: 1.13–2.50 (≥1)). Conclusion: Patients with PCN had a significantly higher risk of developing AMI than those without PCN. Clinicians should pay more attention to prevent AMI episodes in patients with PCN.

Occupational exposure to respirable crystalline silica and acute myocardial infarction among men and women in Sweden

OBJECTIVES

Occupational exposure to respirable crystalline silica (RCS) is common. The study aimed to assess the risk for acute myocardial infarction (AMI) after long-term exposure to RCS and to explore differences in risk between men and women.

METHODS

The cohort included all manual workers identified from the Swedish National Census in 1980 using data on job titles and demography altogether from five censuses from 1960 to 1990, in total 605 246 men and 480 607 women. Information on AMI was obtained from nationwide registers from 1992 to 2006. Exposure to RCS was assessed with a job-exposure matrix. HRs and 95% CIs were estimated by Cox regression, adjusted for age, socioeconomic status and urbanisation index.

RESULTS

Among manual workers ever exposed to RCS, the adjusted risk of AMI was HR 1.29 (95% CI 1.15 to 1.46) in women, and HR 1.02 (95% CI 1.00 to 1.04) in men. In the highest quartile of cumulative exposure, the risk of AMI was HR 1.66 (95% CI 1.27 to 2.18) for women, and HR 1.06 (95% CI 1.03 to 1.10) for men, respectively. The risk of AMI increased with cumulative exposure to RCS both in women (p=0.001) and in men (p=0.016). An interaction analysis showed that the relative risk from exposure to RCS was statistically significantly lower in men than in women at similar exposure levels.

CONCLUSIONS

Occupational exposure to RCS was related to the risk of AMI. Women were more sensitive to exposure to RCS than men.

Incidence of acute myocardial infarction in the workforce: Findings from the Occupational Disease Surveillance System

BACKGROUND

Increased risks of acute myocardial infarction (AMI) may be attributable to the workplace, however, associations are not well-established. Using the Occupational Disease Surveillance System (ODSS), we sought to estimate associations between occupation and industry of employment and AMI risk among workers in Ontario, Canada.

METHODS

The study population was derived by linking provincial accepted lost-time workers' compensation claims data, to inpatient hospitalization records. Workers aged 15-65 years with an accepted non-AMI compensation claim were followed for an AMI event between 2007 and 2016. Adjusted Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for each industry and occupation group, compared to all other workers in the cohort. Sex-stratified analyses were also performed.

RESULTS

In all, 24,514 incident cases of AMI were identified among 1,502,072 Ontario workers. Increased incidence rates of AMI were found across forestry (HR 1.37, 95% CI 1.19-1.58) and wood processing (HR 1.50, 1.27-1.77) job-titles. Elevated rates were also detected within industries and occupations both broadly related to mining and quarrying (HR 1.52, 1.17-1.97), trucking (HR 1.32, 1.27-1.38), construction (HR 1.32, 1.14-1.54), and the manufacturing and processing of metal (HR 1.41, 1.19-1.68), textile (HR 1.41, 1.07-1.88), non-metallic mineral (HR 1.30, 0.82-2.07), and rubber and plastic (HR 1.42, 1.27-1.60) products. Female food service workers also had elevated AMI rates (HR 1.36, 1.23-1.51).

CONCLUSION

This study found occupational variation in AMI incidence. Future studies should examine work-related hazards possibly contributing to such excess risks, like noise, vibration, occupational physical activity, shift work, and chemical and particulate exposures.

Cardiovascular disease in the World Trade Center Health Program General Responder Cohort

BACKGROUND

Over 90,000 rescue and recovery responders to the September 2001 World Trade Center (WTC) attacks were exposed to toxic materials that can impair cardiac function and increase cardiovascular disease (CVD) risk. We examined WTC-related exposures association with annual and cumulative CVD incidence and risk over 17 years in the WTC Health Program (HP) General Responder Cohort (GRC).

METHODS

Post 9/11 first occurrence of CVD was assessed in 37,725 responders from self-reported physician diagnosis of, or current treatment for, coronary artery disease, myocardial infarction, stroke and/or congestive heart failure from WTCHP GRC monitoring visits. Kaplan-Meier estimates of CVD incidence used the generalized Wilcoxon test statistic to account for censored data. Cox proportional hazards regression analyses estimated the CVD hazard ratio associated with 9/11/2001 arrival in responders with and without dust cloud exposure, compared with arrival on or after 9/12/2001. Additional analyses adjusted for comorbidities.

RESULTS

To date, 6.3% reported new CVD. In covariate-adjusted analyses, men's CVD 9/11/2001 arrival risks were 1.40 (95% confidence interval [CI] = 1.26, 1.56) and 1.43 (95% CI = 1.29, 1.58) and women's were 2.16 (95% CI = 1.49, 3.11) and 1.59 (95% CI = 1.11, 2.27) with and without dust cloud exposure, respectively. Protective service employment on 9/11 had higher CVD risk.

CONCLUSIONS

WTCHP GRC members with 9/11/2001 exposures had substantially higher CVD risk than those initiating work afterward, consistent with observations among WTC-exposed New York City firefighters. Women's risk was greater than that of men's. GRC-elevated CVD risk may also be occurring at a younger age than in the general population.

Occupational exposure to silica and risk of heart disease: a systematic review with meta-analysis

OBJECTIVE

To search for evidence of the relationship between occupational silica exposure and heart disease.

DESIGN

A systematic review and meta-analysis.

BACKGROUND

Growing evidence suggests a relationship between occupational silica exposure and heart disease; however, the link between them is less clear.

DATA SOURCES

PubMed, ScienceDirect, Springer and EMBASE were searched for articles published between 1 January 1995 and 20 June 2019. Articles that investigated the effects of occupational silica exposure on the risk of heart disease were considered.

STUDY SELECTION

We included cohort studies, including prospective, retrospective and retroprospective studies.

DATA EXTRACTION AND SYNTHESIS

We extracted data using a piloted data collection form and conducted random-effects meta-analysis and exposure-response analysis. The meta-relative risk (meta-RR), a measure of the average ratio of heart disease rates in those with and without silica exposure, was used as an inverse variance-weighted average of relative risks from the individual studies. The Newcastle-Ottawa Quality Assessment Scale for cohort studies was used for study quality assessment.

OUTCOME MEASURE

We calculated the risk of heart diseases such as pulmonary heart disease, ischaemic heart disease and others.

RESULTS

Twenty cohort studies were included. The results suggest a significant increase in the risk of overall heart disease (meta-RR=1.08, 95% CI 1.03 to 1.13). Stronger evidence of association with pulmonary heart disease was found in the risk estimate of both categories of heart disease (meta-RR=1.24, 95% CI 1.08 to 1.43) and in the exposure-response analysis (meta-RR=1.39, 95% CI 1.19 to 1.62). Our subgroup analyses also revealed that the statistical heterogeneity among studies could be attributed mainly to the diversity in reference group, occupation and study quality score.

CONCLUSIONS

Silica-exposed workers are at an increased risk for overall heart disease, especially pulmonary heart disease. Further research is needed to better clarify the relationship between occupational silica exposure and ischaemic heart disease.

PROSPERO REGISTRATION NUMBER

CRD42019124673.