Chronic obstructive pulmonary disease (COPD) and occupational exposures

Brick kiln pollution and its impact on health: A systematic review and meta-analysis

Brick kiln emissions adversely affect air pollution and the health of workers and individuals living near the kilns; however, evidence of their impacts remains limited. We conducted a systematic review of brick kiln pollution (emissions, source contributions and personal exposures) and its effects on health. We extracted articles from electronic databases and through manual citation searching. We estimated pooled, sample-size-weighted means and standard deviations for personal exposures by job type; computed mean emission factors and pollutant concentrations by brick kiln design; and meta-analyzed differences in means or proportions for health outcomes between brick kiln workers and controls or for participants living near or far away from kilns. We identified 104 studies; 74 were conducted in South Asia. The most evaluated pollutants were particulate matter (PM; n = 48), sulfur dioxide (SO2; n = 24) and carbon monoxide (CO; n = 22), and the most evaluated health outcomes were respiratory health (n = 34) and musculoskeletal disorders (n = 9). PM and CO emissions were higher among traditional than improved brick kilns. Mean respirable silica exposures were only measured in 4 (4%) studies and were as high as 620 μg/m3, exceeding the NIOSH recommended exposure limit by a factor of over 12. Brick kiln workers had consistently worse lung function, more respiratory symptoms, more musculoskeletal complaints, and more inflammation when compared to unexposed participants across studies; however, most studies had a small sample size and did not fully describe methods used for sampling or data collection. On average, brick kiln workers had worse health outcomes when compared to unexposed controls but study quality supporting the evidence was low. Few studies reported silica concentrations or personal exposures, but the few that did suggest that exposures are high. Further research is needed to better understand the relationship between brick kiln pollution and health among workers, and to evaluate exposure mitigation strategies.

Botanical formulation HX110B ameliorates PPE-induced emphysema in mice via regulation of PPAR/RXR signaling pathway

Chronic obstructive pulmonary disease (COPD), an inflammatory lung disease, causes approximately 3 million deaths each year; however, its pathological mechanisms are not fully understood. In this study, we examined whether HX110B, a mixture of Taraxacum officinale, Dioscorea batatas, and Schizonepeta tenuifolia extracts, could suppress porcine pancreatic elastase (PPE)-induced emphysema in mice and its mechanism of action. The therapeutic efficacy of HX110B was tested using a PPE-induced emphysema mouse model and human bronchial epithelial cell line BEAS-2B. In vivo data showed that the alveolar wall and air space expansion damaged by PPE were improved by HX110B administration. HX110B also effectively suppresses the expression levels of pro-inflammatory mediators including IL-6, IL-1β, MIP-2, and iNOS, while stimulating the expression of lung protective factors such as IL-10, CC16, SP-D, and sRAGE. Moreover, HX110B improved the impaired OXPHOS subunit gene expression. In vitro analysis revealed that HX110B exerted its effects by activating the PPAR-RXR signaling pathways. Overall, our data demonstrated that HX110B could be a promising therapeutic option for COPD treatment.

Mortality risk associated with occupational exposures in people with small airways obstruction

BACKGROUND

Small airways obstruction (SAO) has been associated with occupational exposures. Whether exposure to harmful occupational agents impacts the survival of people with SAO is unknown. Our aim was to estimate the mortality risk associated with occupational exposures among people with SAO.

METHODS

We used data from UK Biobank participants with SAO, defined as a ratio of forced expiratory volume in three seconds to forced expiratory volume in six seconds (FEV3/FEV6) below the lower limit of normal. We assigned lifetime occupational exposures to participants with available occupational histories using the ALOHA+ Job Exposure Matrix. Mortality data were provided by the National Death Registries. We used Cox regression to assess the association of all-cause mortality with lifetime occupational exposures (vapours, gases, dusts, fumes-VGDF; solvents; pesticides; metals), adjusting for potential confounders.

RESULTS

The 13,942 participants with SAO had a mean age of 56±7 years, 59% were females and 94.2% were of White ancestry. Overall, there were 457 deaths over a median follow-up of 12.8 years. A greater mortality risk was associated with exposure to VGDF, with hazard ratios of 1.32 (95%CI: 1.04-1.78) for low levels and 1.41 (95%CI: 1.11-1.78) for moderate levels of cumulative exposure. There was no evidence of association for the other occupational exposures.

CONCLUSION

Lifetime occupational exposure to VGDF in people with SAO may have a detrimental effect on their survival. Future respiratory health surveillance programmes of people exposed to VGDF should consider assessment for SAO and focus on primary prevention through adequate exposure control.

Environmental Exposure and Respiratory Health: Unraveling the Impact of Toxic Release Inventory Facilities on COPD Prevalence

This cross-sectional geospatial analysis explores the prevalence of Chronic Obstructive Pulmonary Disease (COPD) concerning the proximity to toxic release inventory (TRI) facilities in Jefferson County, Alabama. Employing the fuzzy analytical hierarchy process (FAHP), the study evaluates COPD prevalence, comorbidities, healthcare access, and individual health assessments. Given the mounting evidence linking environmental pollutants to COPD exacerbations, the research probes the influence of TRI sites on respiratory health, integrating Geographic Information Systems (GIS) to scrutinize the geospatial vulnerability of communities neighboring TRI sites. Socio-demographic disparities, economic conditions, and air pollution are emphasized in the analysis. The EPA's Toxic Release Inventory serves as the cornerstone for assessing the association between TRI proximity and COPD prevalence. The analysis uncovers a notable inverse correlation between distance from TRI sites and COPD prevalence, signaling potential health risks for populations residing closer to these facilities. Moreover, factors such as minority status, low income, and air pollution are associated with higher COPD prevalence, underscoring the imperative of comprehending the interplay between environmental exposure and respiratory health. This study bridges gaps in the literature by addressing the geographical nexus between COPD prevalence and pollution exposure. By leveraging FAHP, the research furnishes a holistic understanding of the multifaceted factors influencing vulnerability to COPD. The findings underscore the necessity for targeted public health interventions and policy measures to redress environmental disparities and alleviate the repercussions of TRI facilities on respiratory health.

Global-, regional- and country-level estimates of the work-related burden of diseases and accidents in 2019

OBJECTIVE

This study provides the global-, regional- and country-level estimates on the work-related burden of diseases and accidents for 2019, including deaths, disability adjusted life years (DALY) and economic losses.

METHODS

Data on occupational illnesses and injuries from international organizations, institutions, and public websites were used. Risk ratios (RR) and population attributable fractions (PAF) for the risk factor-outcome pairs were derived from the literature. Estimated mortality and DALY for a group of seven major diseases covering 120 risk-outcome pairs attributable to work were calculated for 181 countries.

RESULTS

Globally, 2.9 million deaths were attributed to work, with 2.58 million deaths due to work-related diseases and 0.32 million related to occupational injuries. Globally, work-related diseases with a long latency period are increasing, while the number of occupational injuries has decreased. Work-related circulatory diseases were the major cause of 912 000 deaths globally, followed by 843 000 work-related malignant neoplasms. In high-income, American, Eastern European and Western Pacific World Health Organization (WHO) regions, however, work-related malignant neoplasms comprised the biggest disease group. DALY attributable to work were estimated to be 180 million in 2019, with an associated economic loss of 5.8% of global GDP. New estimates of psychosocial factors increased the global loss.

CONCLUSIONS

The burden of work-related diseases and injuries increased by 26% from 2.3 million annual deaths in 2014 to 2.9 million in 2019. The DALY attributable to work have also substantially increased from 123 million in 2014 to 180 million in 2019 (47% increase). We found large regional and country variations.

Cumulative occupational exposure to gases and fumes is associated with impairment in lung function and disease-related quality of life in a German COPD patient cohort

OBJECTIVES

The impact of occupational exposures on lung function impairments and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD) was analysed and compared with that of smoking.

METHODS

Data from 1283 men and 759 women (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1-4 or former grade 0, without alpha-1-antitrypsin deficiency) of the COPD and Systemic Consequences Comorbidities Network cohort were analysed. Cumulative exposure to gases/fumes, biological dust, mineral dust or the combination vapours/gases/dusts/fumes was assessed using the ALOHA job exposure matrix. The effect of both occupational and smoking exposure on lung function and disease-specific QoL (St George's Respiratory Questionnaire) was analysed using linear regression analysis adjusting for age, body mass index, diabetes, hypertension and coronary artery disease, stratified by sex.

RESULTS

In men, exposure to gases/fumes showed the strongest effects among occupational exposures, being significantly associated with all lung function parameters and QoL; the effects were partially stronger than of smoking. Smoking had a larger effect than occupational exposure on lung diffusing capacity (transfer factor for carbon monoxide) but not on air trapping (residual volume/total lung capacity). In women, occupational exposures were not significantly associated with QoL or lung function, while the relationships between lung function parameters and smoking were comparable to men.

CONCLUSIONS

In patients with COPD, cumulative occupational exposure, particularly to gases/fumes, showed effects on airway obstruction, air trapping, gas uptake capacity and disease-related QoL, some of which were larger than those of smoking. These findings suggest that lung air trapping and QoL should be considered as outcomes of occupational exposure to gases and fumes in patients with COPD.

TRIAL REGISTRATION NUMBER

NCT01245933.

Prediction and stratification of longitudinal risk for chronic obstructive pulmonary disease across smoking behaviors

Smoking is the leading risk factor for chronic obstructive pulmonary disease (COPD) worldwide, yet many people who never smoke develop COPD. We perform a longitudinal analysis of COPD in the UK Biobank to derive and validate the Socioeconomic and Environmental Risk Score which captures additive and cumulative environmental, behavioral, and socioeconomic exposure risks beyond tobacco smoking. The Socioeconomic and Environmental Risk Score is more predictive of COPD than smoking status and pack-years. Individuals in the highest decile of the risk score have a greater risk for incident COPD compared to the remaining population. Never smokers in the highest decile of exposure risk are more likely to develop COPD than previous and current smokers in the lowest decile. In general, the prediction accuracy of the Social and Environmental Risk Score is lower in non-European populations. While smoking status is often considered in screening COPD, our finding highlights the importance of other non-smoking environmental and socioeconomic variables.

Occupational Risks and Chronic Obstructive Pulmonary Disease in the Indian Subcontinent: A Critical Review

Chronic obstructive pulmonary disease (COPD) is a significant public health concern in the Indian subcontinent, with high prevalence rates observed in countries like India, Pakistan, Bangladesh, and neighboring nations. This review article critically examines the occupational risks associated with COPD in the region and emphasizes the need for comprehensive preventive strategies. The review begins by providing background on COPD and highlighting its impact on individuals and the economy. It then explores the different occupational hazards that contribute to the development and progression of COPD, including exposure to airborne pollutants and chemicals, occupational dust, and smoking and secondhand smoke in the workplace. The existing occupational health and safety regulations in the Indian subcontinent are assessed, along with an evaluation of their effectiveness in addressing occupational risks for COPD. The review also highlights gaps and challenges in implementing and enforcing these regulations. The impact of COPD on occupational health and the economy is examined, emphasizing the burden it places on affected individuals and their ability to work. The economic implications of COPD-related productivity losses are evaluated, underscoring the importance of addressing occupational risks to improve workforce health and productivity. Prevention and mitigation strategies are explored, including an overview of preventive measures to reduce occupational risks for COPD, the significance of early detection and diagnosis of COPD in the workplace, and the implementation of engineering controls, personal protective equipment, and ventilation systems. The role of education and training programs for workers and employers is also discussed. The review identifies research gaps in the current understanding of occupational risks and COPD in the Indian subcontinent and suggests future research directions to address these gaps. It emphasizes the importance of collaborative efforts between researchers, policymakers, and industry stakeholders to generate evidence, inform policy decisions, and implement effective interventions.

Prediction and stratification of longitudinal risk for chronic obstructive pulmonary disease across smoking behaviors

Smoking is the leading risk factor for chronic obstructive pulmonary disease (COPD) worldwide, yet many people who never smoke develop COPD. We hypothesize that considering other socioeconomic and environmental factors can better predict and stratify the risk of COPD in both non-smokers and smokers. We performed longitudinal analysis of COPD in the UK Biobank to develop the Socioeconomic and Environmental Risk Score (SERS) which captures additive and cumulative environmental, behavioral, and socioeconomic exposure risks beyond tobacco smoking. We tested the ability of SERS to predict and stratify the risk of COPD in current, previous, and never smokers of European and non-European ancestries in comparison to a composite genome-wide polygenic risk score (PGS). We tested associations using Cox regression models and assessed the predictive performance of models using Harrell's C index. SERS (C index = 0.770, 95% CI 0.756 to 0.784) was more predictive of COPD than smoking status (C index = 0.738, 95% CI 0.724 to 0.752), pack-years (C index = 0.742, 95% CI 0.727 to 0.756). Compared to the remaining population, individuals in the highest decile of the SERS had hazard ratios (HR) = 7.24 (95% CI 6.51 to 8.05, P < 0.0001) for incident COPD. Never smokers in the highest decile of exposure risk were more likely to develop COPD than previous and current smokers in the lowest decile with HR=4.95 (95% CI 1.56 to 15.69, P=6.65×10-3) and 2.92 (95%CI 1.51 to 5.61, P=1.38×10-3), respectively. In general, the prediction accuracy of SERS was lower in the non-European populations compared to the European evaluation set. In addition to genetic factors, socioeconomic and environmental factors beyond smoking can predict and stratify COPD risk for both non- and smoking individuals. Smoking status is often considered in screening; other non-smoking environmental and non-genetic variables should be evaluated prospectively for their clinical utility.

Studying the Association Between Occupational Stress and Urinary Levels of Oxidative Stress Biomarkers (8-OHdG and Biopyrrins) in Brickfield Workers

OBJECTIVES

The aims of the study are to measure the prevalence and level of occupational stress (OS) and to explore its association with oxidative stress among some brickfield workers.

METHODS

Eighty-six brickfield workers and 90 administrative controls were assessed using the Arabic validated version of the Occupational Stress Index. The urinary levels of oxidative biomarkers; 8-hydroxy-2'-deoxyguanosine and biopyrrins were also measured.

RESULTS

The prevalence of moderate and severe OS in addition to the urinary levels of both oxidative biomarkers was significantly higher among the brickfield workers compared with their controls. Both biomarkers levels were significantly and positively correlated with scores of Occupational Stress Index, duration of employment, and with each other. The receiver operating characteristic analysis showed significant specificity and sensitivity of both biomarkers for determining the level of OS.

CONCLUSIONS

A significant association between occupational and oxidative stresses was detected in brickfield workers.

Metabolomics for exposure assessment and toxicity effects of occupational pollutants: current status and future perspectives

INTRODUCTION

Work-related exposures to harmful agents or factors are associated with an increase in incidence of occupational diseases. These exposures often represent a complex mixture of different stressors, challenging the ability to delineate the mechanisms and risk factors underlying exposure-disease relationships. The use of omics measurement approaches that enable characterization of biological marker patterns provide internal indicators of molecular alterations, which could be used to identify bioeffects following exposure to a toxicant. Metabolomics is the comprehensive analysis of small molecule present in biological samples, and allows identification of potential modes of action and altered pathways by systematic measurement of metabolites.

OBJECTIVES

The aim of this study is to review the application of metabolomics studies for use in occupational health, with a focus on applying metabolomics for exposure monitoring and its relationship to occupational diseases.

METHODS

PubMed, Web of Science, Embase and Scopus electronic databases were systematically searched for relevant studies published up to 2021.

RESULTS

Most of reviewed studies included worker populations exposed to heavy metals such as As, Cd, Pb, Cr, Ni, Mn and organic compounds such as tetrachlorodibenzo-p-dioxin, trichloroethylene, polyfluoroalkyl, acrylamide, polyvinyl chloride. Occupational exposures were associated with changes in metabolites and pathways, and provided novel insight into the relationship between exposure and disease outcomes. The reviewed studies demonstrate that metabolomics provides a powerful ability to identify metabolic phenotypes and bioeffect of occupational exposures.

CONCLUSION

Continued application to worker populations has the potential to enable characterization of thousands of chemical signals in biological samples, which could lead to discovery of new biomarkers of exposure for chemicals, identify possible toxicological mechanisms, and improved understanding of biological effects increasing disease risk associated with occupational exposure.

Identification of Modifiable Risk Factors of Exacerbations Chronic Respiratory Diseases with Airways Obstruction, in Vietnam

OBJECTIVES

to determine modifiable risk factors of exacerbations in chronic respiratory diseases with airways obstruction (i.e., asthma and COPD) in southern Vietnam.

METHODS

an environmental and health-related behavioural questionnaire was submitted to patients with both chronic respiratory symptoms and airways obstruction. An exacerbation was defined as any acute worsening in clinical symptoms requiring a change in treatment, in a patient receiving prophylactic therapy.

RESULTS

235 patients were evaluated, including 131 (56%) chronic obstructive pulmonary disease (COPD) and 104 (44%) asthmatics. There were 75% males and 69% smokers. Occupational exposure accounted for 66%, mainly among construction and industry workers. Smoking was associated with more severe airways obstruction. Respiratory exacerbations were reported in 56/235 patients (24%). The risk of exacerbation was increased in patients with a lower education level, exposure to occupational pollutants, cumulative smoking ≥ 20 pack year, housing space < 10 m², and poorly ventilated housing. Based on multivariate analysis, the risk of exacerbation remained significantly higher among patients with occupational exposure and low housing space per person.

CONCLUSIONS

besides smoking cessation, more supportive policies, including improvement of occupational environment and housing design for better ventilation, are needed to prevent the severity of chronic respiratory diseases in Vietnam.

Disparities in Healthcare Utilization: Superfund Site vs. Neighboring Comparison Site

Inequities in pollution-attributable health disparities are similar in most urban areas throughout the United States, and appear to encompass racial and socio-demographic differences, thereby suggesting increased health risks for those living in these areas. Individuals residing in close proximity to Superfund sites, predominantly people of color, are increasingly stricken with lung diseases. The prevalence of chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), asthma in children, and lower respiratory tract infections (LRTI), is significantly higher in the affected area compared to the neighboring control area, irrespective of smoking, socio-economic status, or demographics. We conducted a retrospective analysis using data collected from patients who obtained healthcare from the University of Alabama at Birmingham (UAB) Health System. The data were procured from the Enterprise Data Warehouse (UAB Informatics for Integrating Biology and the Bedside (i2b2)). We evaluated healthcare utilization and classification of disease (defined by ICD-10 codes) of patients residing in zip codes: affected (35207, 35217) and neighboring comparison (35214). The results of the analysis may provide evidence that can be used for risk mitigation strategies or outreach education campaign(s) for those who live in the affected area.

High-flow nasal cannula improves respiratory impedance evaluated by impulse oscillometry in chronic obstructive pulmonary disease patients: a randomised controlled trial

Non-pharmacological treatment with high-flow nasal cannula (HFNC) may play a vital role in treatment of patients with chronic obstructive pulmonary disease (COPD). To evaluate the efficacy of HFNC, impulse oscillation system (IOS) is a new noninvasive technique in measuring the impedance of different portions of lungs. It shows higher sensitivity in contrast to conventional pulmonary function tests (PFT). However, whether IOS is an appropriate technique to evaluate the efficacy of HFNC in improving the impedance of small airways or peripheral lung in patients with COPD is still unclear. We enrolled 26 stable COPD participants randomised into two groups receiving HFNC or nasal cannula (NC) for 10 min followed by a 4-week washout period and crossover alternatively. IOS was used to detect the difference of respiratory impedance after HFNC or NC interventions. IOS parameters, PFT results, transcutaneous partial pressure of carbon dioxide, peripheral oxygen saturation, body temperature, respiratory rate, pulse rate, and blood pressure at the time of pre-HFNC, post-HFNC, pre-NC, and post-NC, were collected and analysed using SPSS (version 25.0, IBM, Armonk, NY, USA). The IOS measurement indicated that HFNC significantly improved R5, R5% predicted, R5–R20, X5-predicted, and Fres compared with NC, whereas no significant difference was observed through the PFT measurement. The beneficial effect of HFNC in improving small airway resistance and peripheral lung reactance compared with that of NC in patients with stable COPD was confirmed through IOS measurement.

Trial registration: ClinicalTrials.gov NCT05130112 22/11/2021.

Occupational chronic obstructive pulmonary disorder: prevalence and prevention

INTRODUCTION

Occupational chronic obstructive pulmonary disorder, i.e. work-related asthma (WRA) and occupational chronic obstructive pulmonary disease (COPD), are the most common occupational lung diseases in the last decades worldwide. As in the case of the other occupational disorders, these diseases may be prevented.

AREAS COVERED

WRA is a heterogeneous entity that includes three subtypes, immunologic occupational asthma (OA), irritant-induced asthma (IIA), and work-exacerbated asthma (WEA), depending on the role of occupational exposures as a causing or aggravating factor of the disease. In addition, there is consistent evidence that a substantial proportion of COPD cases can be explained by exposure to noxious particles and gases other than tobacco smoke, such as workplace dusts, gases, fumes, and vapors. The articles cited in this paper were searched by keywords in several databases in the period up to May-July 2021.

EXPERT OPINION

The development of occupational chronic obstructive disorder is a matter of prevention. WRA and occupational COPD contribute significantly to the overall burden of asthma and COPD. Activities and measures targeted to elimination or reduction of harmful workplace exposures, as well as to early detection and early intervention in the course of the lung damage, can significantly reduce the burden caused by these diseases.

Comparison of demographic, clinical, spirometry, and radiological parameters between smoking and non-smoking COPD patients in rural Gujarat, India

Context:

A total of 20% of Chronic Obstructive Pulmonary Disease(COPD) patients are non-smokers due to preventable causes, such as biomass fuel exposure, post tuberculous sequelae, occupational exposure, air pollution, persistent chronic asthma, and genetic predisposition.

Aims:

To compare smokers and non-smokers with COPD.

Settings and Design:

An observational study was conducted at a tertiary care hospital on 60 patients diagnosed with COPD, (GOLD criteria), who were divided into smoker and non-smoker groups.

Subjects and Methods:

Demographic data, clinical profile, smoking history, and radiological data were collected and compared. Exclusion criteria were individuals having active pulmonary tuberculosis and reversible air flow limitations.

Statistical Analysis Used:

Using STATA 14.2, quantitative and qualitative data were presented using descriptive statistics.

Results:

A total of 100% of smokers were male, whereas 70% of non-smokers were female. Compared to non-smokers (16.67%), smokers (26.6%) presented with higher grade of dyspnea. A statistically significant difference was seen with more smokers diagnosed as severe (40%) and very severe (30%) COPD compared to non-smokers with mild (16.67%) and moderate (46.67%) COPD (P < 0.012), Post bronchodilator FEV₁ among smokers (42.63) compared to non-smokers (56.63) (P < 0.01) and decrease in FEV₁ as the grade of dyspnea increased (P < 0.002). Compared to 36.67% in non-smokers, 70% smokers showed emphysematous x-rays.

Conclusions:

In our study we found majority of non-smokers to be female, and smokers had a higher grade of dyspnea, more severe COPD, lower post bronchodilator FEV₁, and more emphysematous changes on x-rays.

Prevalence of COPD among population above 30 years in India: A systematic review and meta-analysis

Background

By 2030, Sustainable Development Goal 3.4 aims to reduce the premature mortality caused by non-communicable diseases through prevention and treatment. Chronic obstructive pulmonary disease is the second leading cause of mortality and disability-adjusted life years in India. This review was conducted to estimate the prevalence of COPD using systematic review and meta-analysis technique.

Method

Search was conducted using six databases for studies on COPD among population above 30 years in India between years 2000 to 2020. Cross-sectional and cohort studies reporting prevalence of COPD and associated risk factors were included in the present review. Screening and data extraction was done by two authors independently. Studies were appraised for quality using the modified New Castle Ottawa scale and reporting quality was assessed using STROBE guidelines.

Result

Our search returned 8973 records, from which 23 records fulfilled the eligibility criteria. Overall, the prevalence of COPD among population aged 30 years and above in India was 7%. Risk factors like active and passive smoking, biomass fuel exposure, environmental tobacco smoke, occupational exposure to dust, indoor and outdoor pollution, and increasing age were reported to have a significant association with COPD among Indian population.

Conclusion

Our findings suggest the need for a multicentric national-level research study to understand COPD burden and its contributing risk factors. The findings also suggest the need for COPD sensitive health literacy program focused on early screening and primary prevention of risk factors for COPD, which may help early initiation of self-management practices, that are crucial for better quality of life.

Challenges in Diagnosing Occupational Chronic Obstructive Pulmonary Disease

Occupational chronic obstructive pulmonary disease (oCOPD) represents 15–20% of the global burden of this disease. Even if industrial bronchitis has long been known, new occupational hazards continue to emerge and enlarge the number of people exposed to risk. This review discusses the challenges related to the early detection of oCOPD, in the context of new exposures and of limited usage of methods for an efficient disease occupational screening. It underlines that a better translation into clinical practice of the new methods for lung function impairment measurements, imaging techniques, or the use of serum or exhaled breath inflammation biomarkers could add significant value in the early detection of oCOPD. Such an approach would increase the chance to stop exposure at an earlier moment and to prevent or at least slow down the further deterioration of the lung function as a result of exposure to occupational (inhaled) hazards.

Bioprinting of Organ-on-Chip Systems: A Literature Review from a Manufacturing Perspective

This review discusses the reported studies investigating the use of bioprinting to develop functional organ-on-chip systems from a manufacturing perspective. These organ-on-chip systems model the liver, kidney, heart, lung, gut, bone, vessel, and tumors to demonstrate the viability of bioprinted organ-on-chip systems for disease modeling and drug screening. In addition, the paper highlights the challenges involved in using bioprinting techniques for organ-on-chip system fabrications and suggests future research directions. Based on the reviewed studies, it is concluded that bioprinting can be applied for the automated and assembly-free fabrication of organ-on chip systems. These bioprinted organ-on-chip systems can help in the modeling of several different diseases and can thereby expedite drug discovery by providing an efficient platform for drug screening in the preclinical phase of drug development processes.

Latent Health Risk Classes Associated with Poor Physical and Mental Outcomes in Workers with COPD from Central Appalachian U.S. States

Adults who work in the Central Appalachian region of the United States (U.S.) are disproportionately affected by Chronic Obstructive Pulmonary Disease (COPD). While there is a socio-demographic profile of adults with COPD who are at increased risk for physical and mental distress, the risk factors that uniquely affect the health-related quality of life (HRQoL) of Central Appalachian workers with COPD are unknown. Therefore, we conducted a latent class analysis of 2016 and 2017 Behavioral Risk Factor Surveillance System data from 1326 currently employed adults with COPD living in four U.S. states (KY, NC, TN, and WV) within the Central Appalachian Region. Drawing from the social ecological model, we identified associations between theoretically informed risk indicators-comorbid health conditions, substance use and abuse, and limited access to healthcare-on three HRQoL variables, including infrequent (0-13 days) or frequent (≥14 days) physical distress, mental distress, and limited activity due to poor health over the past 30 days. Workers at high risk for comorbid conditions reported more frequent physical distress, mental distress, and activity limitations as compared to those at low risk. Workers reporting difficulty accessing healthcare were no more likely to report physical or mental distress when compared to workers with adequate access to healthcare; however, those with limited healthcare access did report more frequent activity limitation due to poor health. Interestingly, workers with COPD at high risk for substance use and abuse were no more likely to report poor HRQoL outcomes compared to those at low risk. Our findings have important implications for addressing indicators of poor health among Central Appalachian workers with COPD, especially those living with multiple comorbidities.

SiO2 prompts host defense against Acinetobacter baumannii infection by mTORC1 activation

Host-pathogen interactions in the setting of chronic pulmonary inflammation remain unclear, and the occurrence of pneumonia is increased in patients with chronic obstructive pulmonary disease who use immunosuppressive drugs. We performed Acinetobacter baumannii infection in mice with chronic pulmonary inflammation after intranasal administration of SiO₂ and found SiO₂ treatment increased host defense against A. baumannii infection. Innate immune responses initiated by NF-κB, type 1 interferon, NLRP3 and AIM2 inflammasomes were dispensable for SiO₂-mediated host defense. SiO₂ treatment activated the mTORC1 signaling, and mTORC1 was crucial for host defense against A. baumannii infection. Our study highlights the protective role of mTORC1 signaling in host defense against bacterial infection, offers novel insights into understanding the mechanisms of immunosuppressive drug-related pneumonia, and provides potential host-directed therapeutics to treat bacterial infections.

Job complexity and hazardous working conditions: How do they explain educational gradient in mortality?

Although education's protective effects on health have been well recognized, specific mechanisms through which higher education is associated with better health are still debated. Occupation, although strongly shaped by education, has rarely been examined as a mediating mechanism. Education attainment is patterned by race in the United States, and the same education does not lead to similar occupations for members of different racial/ethnic groups. Therefore, examining the link from education to jobs to mortality can illuminate potential mechanisms that create racial health disparities. Using a large U.S. national cohort of Black and White men and women, we examined if 2 occupational characteristics, substantive complexity of work and hazardous working conditions, mediate the effect of education on mortality. Data on occupation were collected between 2011 and 2013, and mortality follow-up data up to March 2018 were included in this analysis. The race- and gender-stratified analyses showed that among White men, the association between higher education and lower mortality was mediated by lower hazard on the job. Among Black men and White women, higher complexity of work explained the association between higher education and lower mortality. Among Black women, neither job characteristic mediated the association. These results suggest that occupational characteristics help explain health inequalities not only by education but also by race and gender. Investigating occupation explicitly in the causal chain of health disparities will help us better understand the mechanism of and potential solutions for health inequalities. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Multi-walled carbon nanotubes activate and shift polarization of pulmonary macrophages and dendritic cells in an in vivo model of chronic obstructive lung disease

With substantial progress of nanotechnology, there is rising concern about possible adverse health effects related to inhalation of nanomaterials, such as multi-walled carbon nanotubes (MWCNT). In particular, individuals with chronic respiratory disorders, such as chronic obstructive pulmonary disease (COPD), may potentially be more susceptible to adverse health effects related to inhaled MWCNT. Hazard assessment of such inhaled nanomaterials therefore requires timely clarification. This was assessed in this study using a mouse model of COPD by exposing animals to 0.08 µg/cm² of MWCNT administered by intratracheal instillation. Treatment with MWCNT induced an accumulation of alveolar macrophages (AMφ) in bronchoalveolar lavage fluid (BALF) in COPD mice that increased from 24 h to 7 d. In COPD mice, MWCNT induced a dynamic shift in macrophage polarization as measured by expression of CD38 and CD206, and increased AMφ and lung parenchyma macrophage (LPMΦ) activation with upregulation of co-stimulatory markers CD40 and CD80. Moreover, MWCNT treatment increased the frequencies of pulmonary dendritic cells (DC), leading to an expansion of the CD11b⁺CD103^- DC subset. Although MWCNT did not trigger lung functional or structural changes, they induced an increased expression of the muc5AC transcript in mice with COPD. Our data provide initial evidence that inhaled MWCNT affect the pulmonary mucosal immune system by altering the numbers, phenotype, and activation status of antigen-presenting cell populations. Extrapolating these in vivo mouse findings to human pulmonary MWCNT exposure, caution is warranted in limiting exposure when handling inhalable nanofibers.

Clinical correlates of workplace injury occurrence and recurrence in adults

Objectives

To examine the morbidities associated with workplace injury and to explore how clinical variables modify the risk of injury recurrence.

Methods

A case-control study was designed using Florida’s statewide inpatient, outpatient, and emergency visits data obtained from the Healthcare Cost and Utilization Project. We included adults who were admitted for a workplace injury (WPI) or injury at other places (IOP), and a matched population of random controls without WPI/IOP. The associations between WPI and clinical morbidities were assessed by univariate and multivariable regression, ranking predictors by information gain, area under the receiver operating characteristic (AUROC), and odds ratios. We analyzed WPI recurrence using survival methods (Kaplan-Meier, Cox regression, survival decision trees) and developed prediction models via regularized logistic regression, random forest, and AdTree. Performance was assessed by 10-fold cross-validation comparing AUROC, sensitivity, specificity, and Harrell’s c-index.

Results

A total of 80,712 WPI, 161,424 IOP, and 161,424 control patients were included; 485 distinct clinical diagnostic and 160 procedure codes were analyzed after filtering. Acute bronchitis and bronchiolitis, sprains and strains of shoulder and upper arm, ankle and foot, or other and unspecified parts of back, accidents caused by cutting and piercing instruments or objects, and overexertion and strenuous movements were identified as important consequences of WPI. The prediction models of injury recurrence identified several key factors, such as insurance type and prior injury events, although none of the models exhibited high predictive performance (best AUROC = 0.60, best c-index = 0.62).

Conclusions

WPI is associated to diverse serious physical comorbidity burden. There are demographic, social and clinical comorbidity components associated to the risk of WPI recurrence, although their predictive value is moderate, which warrants future investigation in other information source domains, e.g. deepening into the environmental and societal sphere.

Chronic Obstructive Pulmonary Disease Is an Independent Predictor for 30-Day Complications and Readmissions Following 1- to 2-Level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

To study evidence to assess the impact of chronic obstructive pulmonary disease (COPD) on 30-day outcomes following 1- to 2-level anterior cervical discectomy and fusion (ACDF).

METHODS

The 2015-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using Current Procedural Terminology (CPT) codes 22 551 (single-level) and 22 552 (additional level). Patients undergoing disc arthroplasty, multilevel (>2) fusion, posterior cervical spine surgery, and patients with fracture, tumor, and/or infection were excluded.

RESULTS

Out of 14 835 patients undergoing an elective 1- to 2-level ACDF, 649 (4.4%) had a diagnosis of COPD at the time of the surgery. Following adjusted logistic regression analysis, prior history of COPD was significantly associated with a longer length of stay (odds ratio [OR] 1.25 [95% confidence interval (CI0 1.04-1.52]; P = .019), superficial surgical site infection (OR 2.68 [95% CI 1.06-6.80]; P = .038), discharge destination other than home (OR 1.49 [95% CI 1.05-2.12]; P = .026), pneumonia (OR 4.37 [95% CI 2.42-7.88]; P < .001), ventilator use >48 hours (OR 5.34 [95% CI 1.88-15.15]; P = .002), unplanned reintubation (OR 3.36 [1.48-7.62]; P = .004), and 30-day readmissions (OR 1.69 [95% CI 1.20-2.38]; P = .003).

CONCLUSIONS

The findings of this study show that COPD patients are more likely to have postoperative complications and 30-day readmissions, despite elective ACDF itself being a low-risk surgery in general. Results show that majority of the complications were pulmonary in nature, further stressing the need for accurate medical optimization following surgery in these patients.

Serum Homocysteine Could Be Used as a Predictive Marker for Chronic Obstructive Pulmonary Disease: A Meta-Analysis

Background: Serum homocysteine (Hcy) level is inversely related with concentration of folic acid, which is an essential micronutrient for metabolism and energy homeostasis. Serum concentrations of Hcy have been reported to have strong correlation with smoking, which is a major risk factor for pathogenesis of chronic obstructive pulmonary disease (COPD) irrespective of ethnicity and gender. Therefore, we performed a systematic review based meta-analysis to evaluate the overall contribution of Hcy in COPD. Method: Published literature on association of serum Hcy with COPD were obtained through conventional web search and eligible literature were selected based on stringent inclusion/exclusion criteria. Continuous variable data was presented as mean and standard deviation. The variable data was analyzed using RevMan 5 statistical tool to meta-analyze mean differences (MD) with 95 % CI for case-control studies. Result: Four case-control studies met the inclusion criteria for this study. A total of 145 COPD subjects and 107 healthy controls were analyzed. Elevated serum homocysteine concentration was found to induce risk for COPD (MD = 3.05). Conclusion: Molecular role of Hcy in COPD pathogenesis or prognosis is not clear but existing literature suggests that smoking disturbs folic acid metabolism and promotes Hcy accumulation. This study suggested the contribution of Hcy in COPD pathogenesis. However, large scale prospective cohort study and replication studies with more power are warranted to confirm the results.

Jaboticabin and Related Polyphenols from Jaboticaba ( Myrciaria cauliflora) with Anti-inflammatory Activity for Chronic Obstructive Pulmonary Disease

Myrciaria cauliflora (jaboticaba) is an edible fruit common in Brazil that has been used for treating respiratory diseases, including chronic tonsillitis and asthma. This study explores the distribution of an anti-inflammatory depside, jaboticabin, in different parts of the jaboticaba plant as well as major polyphenols from the wood of jaboticaba, some with biological activity similar to jaboticabin. The peel of the fruit was found to be the major source of jaboticabin. This is the first phytochemical study of the wood of M. cauliflora. The antioxidant-activity-guided fractionation strategy successfully identified 3,3'-dimethylellagic acid-4- O-sulfate from jaboticaba wood. This ellagic acid derivative, in a manner similar to jaboticabin, showed antiradical activity and inhibited the production of the chemokine interleukin-8 after treating the human small airway epithelial cells with cigarette smoke extract. The human intestinal Caco-2 cell studies demonstrated the jaboticabin transport in vitro. The polyphenols, jaboticabin and 3,3'-dimethyellagic acid-4- O-sulfate, from jaboticaba were both found to exhibit anti-inflammatory activities, thus suggesting the potential use of these compounds or even the fruits themselves for chronic obstructive pulmonary disease.

Adenosine Metabolism in COPD: A Study on Adenosine Levels, 5'-Nucleotidase, Adenosine Deaminase and Its Isoenzymes Activity in Serum, Lymphocytes and Erythrocytes

Adenosine is a signaling molecule which is produced in high concentrations during airway inflammation. Airway inflammation is a characteristic feature of COPD. Therefore, the current study was designed to evaluate the changes in adenosine metabolism in COPD and correlate these changes with severity of the disease. The study was conducted on 50 healthy controls (25 healthy non-smokers and 25 healthy smokers) and 46 COPD patients (21 moderate, 15 severe and 10 very severe). The patients were sub-divided into moderate, severe and very severe categories as per the GOLD spirometric classification. Blood was collected from each subject and serum, lymphocytes and erythrocytes were separated. The adenosine levels and activities of 5'-nucleotidase, adenosine deaminase and its isoenzymes were assessed in serum, lymphocytes and erythrocytes. The data were analyzed statistically. A p value < 0.05 was considered as significant. In healthy smokers and COPD patients the adenosine levels increased. In COPD patients 5'-nucleotidase activity increased significantly in serum, lymphocytes and erythrocytes. The activities of ADA and isoenzymes decreased significantly in serum of healthy smokers and COPD patients, in lymphocytes and erythrocytes of very severe COPD patients and of ADA and ADA2 in lymphocytes and erythrocytes of moderate and severe COPD patients. The FEV1 (% of predicted) showed a significant negative correlation with adenosine levels and 5'-nucleotidase activity in serum, lymphocytes and erythrocytes and significant positive correlation with ADA and isoenzymes activity in serum and lymphocytes of COPD patients. We conclude that the adenosine metabolism changes in COPD. The adenosine levels and 5'-nucleotidase activity increase, and ADA activity decreases with severity of the disease.

The role of environmental exposure to non-cigarette smoke in lung disease

Chronic exposure to household indoor smoke and outdoor air pollution is a major contributor to global morbidity and mortality. The majority of these deaths occur in low and middle-income countries. Children, women, the elderly and people with underlying chronic conditions are most affected. In addition to reduced lung function, children exposed to biomass smoke have an increased risk of developing lower respiratory tract infections and asthma-related symptoms. In adults, chronic exposure to biomass smoke, ambient air pollution, and opportunistic exposure to fumes and dust are associated with an increased risk of developing chronic bronchitis, chronic obstructive pulmonary disease (COPD), lung cancer and respiratory infections, including tuberculosis. Here, we review the evidence of prevalence of COPD in people exposed to non-cigarette smoke. We highlight mechanisms that are likely involved in biomass-smoke exposure-related COPD and other lung diseases. Finally, we summarize the potential preventive and therapeutic strategies for management of COPD induced by non-cigarette smoke exposure.

Prevalence of Obstructive Lung Disease in Asymptomatic Gas Field Workers

Introduction Obstructive lung disease, if not managed appropriately and in a timely manner, increases morbidity and mortality. The aim of this study was to see an obstruction on spirometry reports of clinically asymptomatic oil and gas field workers. Methods In this retrospective observational study, spirometry reports performed at the pulmonary function laboratory of Ziauddin Hospital and University, Karachi, were reviewed. All reports were of the clinically asymptomatic employees of an oil and gas company in Pakistan, who presented for their routine assessment. Obstructive impairment was defined as a forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio of less than 0.7. Results Of the total of 199 spirometry reports, 197 (99%) were of male employees. The mean age of the employees was 30.52 ± 8.24 years and 46 (23.1%) employee were smokers. Obstruction was observed in 48 (24.1%) of the reports of the employees with 13 (27.1%) smokers and 35 (72.9%) non-smokers. No statistically significant association between obstruction and gender, age, and smoking was observed. Conclusion In this study, we observed obstructive impairment in around one-fourth of the otherwise clinically asymptomatic oil and gas field workers with no apparent impact of baseline smoking behavior.

Development of a functional airway-on-a-chip by 3D cell printing

We used 3D cell printing to emulate an airway coupled with a naturally-derived blood vessel network in vitro. Decellularized extracellular matrix bioink derived from porcine tracheal mucosa (tmdECM) was used to encapsulate and print endothelial cells and fibroblasts within a designated polycarprolactone (PCL) frame. Providing a niche that emulates conditions in vivo, tmdECM gradually drives endothelial re-orientation, which leads to the formation of a lumen and blood vessel network. A fully-differentiated in vitro airway model was assembled with the printed vascular platform, and collectively reproduced a functional interface between the airway epithelium and the vascular network. The model presented respiratory symptoms including asthmatic airway inflammation and allergen-induced asthma exacerbation in physiological context. Because of the adaptable and automated nature of direct 3D cell printing, we expect that this will have relevance in vivo and high reproducibility for production of high-content platforms for preclinical trials in biomedical research.

Circulatory heavy metals (cadmium, lead, mercury, and chromium) inversely correlate with plasma GST activity and GSH level in COPD patients and impair NOX4/Nrf2/GCLC/GST signaling pathway in cultured monocytes

This study aims to examine the hypothesis that circulatory heavy metals may be associated with lung function decline and lower plasma GST activity and GSH level in COPD patients via activating monocytes mediated by impairing the NOX4/Nrf2/GCLC/GST signaling pathway. Results showed that the blood levels of heavy metals (cadmium, lead, mercury, and chromium) were significantly higher in COPD patients of coal mine site compared to the healthy controls. The levels of heavy metals in COPD patients were significantly and negatively correlated with lung function, GST activity, and GSH level. Using flowcytometry, fluorescence spectroscopy, and immunoblotting studies we have further demonstrated that treatment with individual heavy metals dose-dependently increased the NOX4 protein expression, intracellular ROS production, and decreased the Nrf2, GCLC, and GST protein expression, GST activity, and GSH level in THP-1 monocytes. None of the treatment caused any change in cell viability compared to control. In conclusion, this study suggests that circulatory heavy metals in COPD patients of coal mine site weakened the lung function, decreased the plasma GST activity and GSH level via impairing the NOX4/Nrf2/GCLC/GST signaling pathway in monocytes, which may cause monocyte activation and initiate the COPD pathophysiology.

Changes in the expression level of IL-17A and p53-fibrinolytic system in smokers with or without COPD

COPD is a chronic airway inflammatory disease characterized mainly by neutrophil airway infiltrations. The neutrophil airway inflammation is mainly mediated through a key player like the pro-inflammatory cytokine IL-17A which is involved in the modulation of p53-fibrinolytic system. This study was undertaken to examine the molecular changes for the expressions of IL-17A and p53-fibrinolytic system in smokers with or without COPD. Blood and serum samples were collected from ten patients of smokers having COPD and ten samples from smokers without COPD and ten healthy control subjects. Western blot analyses were performed to evaluate the expressions of IL-17A, p53 and PAI-1. Apoptosis was assessed by immunoblot for cleaved caspase-3. In addition, FEV% was also determined of these patients. qRT-PCR was done to detect the gene expression study from the blood samples on p53-fibrinolytic components. A significant difference was found in the expression levels of IL-17A in smokers with COPD patient when compared to smokers without COPD and the control subjects. Similarly the smokers with COPD showed significant increase in the fibrinolytic component PAI-1 as well as in expression levels of p53 when compared to smokers without COPD and normal subjects. Increased cleaved caspase-3 may also promote apoptosis.The expression pattern of the IL-17A in chronic obstructive pulmonary distress syndrome samples was increased as compared of those of normal samples, and their main role in the regulation of and p53-fibrinolytic system makes these components as a predictive prominent component in smokers with COPD.

Chronic obstructive pulmonary disease is an independent predictor for 30-day readmissions following 1- to 2-level posterior lumbar fusions

Background

Chronic obstructive pulmonary disease (COPD) is a common cause of morbidity and mortality worldwide. Past literature has demonstrated that patients with COPD are at an increased risk of post-operative complications. We assessed the impact of COPD on 30-day outcomes following a 1- to 2-level posterior lumbar fusion (PLF).

Methods

The 2012-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using current procedural terminology (CPT) codes 22612, 22630 and 22633 to identify patients undergoing PLFs. Only patients undergoing a 1- to 2-level PLF for degenerative spine pathologies were included.

Results

In total, 1,123 (4.8%) of 23,481 patients undergoing an elective PLF had a diagnosis of COPD at the time of the surgery. Following adjusted logistic regression analysis, COPD was significantly associated with a longer length of stay of >3 days [odds ratio (OR), 1.40; 95% confidence interval (CI): 1.32-1.48; P=0.008], shorter total operative time (OR, 0.83; 95% CI: 0.73-0.94; P=0.003), discharge to skilled nursing care or rehabilitation facility (OR, 1.28; 95% CI: 1.09-1.51; P=0.002), pneumonia (OR, 2.53; 95% CI: 1.62-3.97; P<0.001) and 30-day readmissions (OR, 1.31; 95% CI: 1.03-1.65; P=0.025).

Conclusions

Patients with COPD are more likely to have a longer length of stay, discharge to nursing care/rehabilitation facility, and higher risk of pneumonia and readmissions within 30-days following 1- and 2-level PLF. Our analysis of a large national cohort of patients highlights the importance of pre-operative and post-operative medical optimization in these high-risk patients.

Mortality and morbidity in populations in the vicinity of coal mining: a systematic review

BACKGROUND

Evidence of the association of coal mining with health outcomes such as increased mortality and morbidity in the general population has been provided by epidemiological studies in the last 25 years. Given the diverse sources of data included to investigate different health outcomes in the exposed populations, the International Classification of Diseases (ICD) can be used as a single classification standard to compare the findings of studies conducted in different socioeconomic and geographic contexts. The ICD classifies diagnoses of diseases and other disorders as codes organized by categories and chapters.

OBJECTIVES

Identify the ICD codes found in studies of morbidity and/or mortality in populations resident or in proximity of coal mining and assess the methods of these studies conducting a systematic review.

METHODS

A systematic database search of PubMed, EMBASE and Scopus following the PRISMA protocol was conducted to assess epidemiological studies from 1990 to 2016. The health outcomes were mapped to ICD codes and classified by studies of morbidity and/or mortality, and the categories and chapters of the ICD.

RESULTS

Twenty-eight epidemiological studies with ecological design from the USA, Europe and China were included. The exposed populations had increased risk of mortality and/or morbidity by 78 ICD diagnosis categories and 9 groups of ICD categories in 10 chapters of the ICD: Neoplasms, diseases of the circulatory, respiratory and genitourinary systems, metabolic diseases, diseases of the eye and the skin, perinatal conditions, congenital and chromosomal abnormalities, and external causes of morbidity. Exposed populations had non-increased risk of 9 ICD diagnosis categories of diseases of the genitourinary system, and prostate cancer.

CONCLUSIONS

There is consistent evidence of the association of coal mining with a wide spectrum of diseases in populations resident or in proximity of the mining activities. The methods of the studies included in this review can be integrated with individual-level and longitudinal studies to provide further evidence of the exposure pathways linked to increased risk in the exposed populations.

Chronic Obstructive Pulmonary Disease in Sweden: An intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy

Socioeconomic, ethnic and gender disparities in Chronic Obstructive Pulmonary Disease (COPD) risk are well established but no studies have applied multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) within an intersectional framework to study this outcome. We study individuals at the first level of analysis and combinations of multiple social and demographic categorizations (i.e., intersectional strata) at the second level of analysis. Here we used MAIHDA to assess to what extent individual differences in the propensity of developing COPD are at the intersectional strata level. We also used MAIHDA to determine the degree of similarity in COPD incidence of individuals in the same intersectional stratum. This leads to an improved understanding of risk heterogeneity and of the social dynamics driving socioeconomic and demographic disparities in COPD incidence. Using data from 2,445,501 residents in Sweden aged 45–65, we constructed 96 intersectional strata combining categories of age, gender, income, education, civil- and migration status. The incidences of COPD ranged from 0.02% for young, native males with high income and high education who cohabited to 0.98% for older native females with low income and low education who lived alone. We calculated the intra-class correlation coefficient (ICC) that informs on the discriminatory accuracy of the categorizations. In a model that conflated additive and interaction effects, the ICC was good (20.0%). In contrast, in a model that measured only interaction effects, the ICC was poor (1.1%) suggesting that most of the observed differences in COPD incidence across strata are due to the main effects of the categories used to construct the intersectional matrix while only a minor share of the differences are attributable to intersectional interactions. We found conclusive interaction effects. The intersectional MAIHDA approach offers improved information to guide public health policies in COPD prevention, and such policies should adopt an intersectional perspective.

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We use multilevel analysis of individual heterogeneity and discriminatory accuracy.

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There is a clear difference in COPD incidence between intersectional strata.

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Intersectionality improves mapping of socioeconomic differences in COPD incidence.

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Preventive measures should be based on intersectional rather than classic analyses.

High Prevalence of Chronic Respiratory Symptoms among Autorickshaw Drivers of Urban Puducherry, South India

Context:

Auto-rickshaw (three wheelers open cabin type of vehicle) drivers are exposed to traffic air pollution. Studies have demonstrated reduced pulmonary function among drivers. However, limited studies have determined the prevalence of chronic respiratory symptoms or chronic obstructive pulmonary disease (COPD) among drivers.

Aims:

Among auto-rickshaw drivers of urban Puducherry to determine prevalence of (i) chronic respiratory symptoms by using Indian Study on Epidemiology of Asthma, Respiratory Symptoms, and Chronic Bronchitis (INSEARCH) questionnaire and (ii) COPD by measuring peak expiratory flow rate (PEFR).

Setting and Designs:

Cross-sectional, descriptive study.

Subjects and Methods:

Cluster random sampling was used to select 297 auto-rickshaw drivers. Subjects were interviewed using the INSEARCH questionnaire. PEFR was measured using Wright's peak flow meter. We also assessed exposure to tobacco smoke.

Statistical Analysis Used:

Prevalence and 95% confidence interval of chronic respiratory symptoms and COPD were calculated.

Results:

All the auto-rickshaw drivers were male, and 75% were in the age group of 31–50 years. They spend most of the time on the roadside either driving or waiting at the auto-stand. Prevalence of nonspecific respiratory symptoms among auto-rickshaw drivers was 76% (breathlessness on exertion 68%, cough at night and phlegm in the morning 22%, wheezing 18% assessed for last 12 months). Around 28% of them had PEFR <80%. The prevalence of tobacco smoking was also high (64%), and 100% had exposure to tobacco smoke at the workplace.

Conclusion:

The nonspecific chronic symptoms were high among auto-rickshaw drivers as compared to the general population noted from a multicentric study done in India. We recommend that auto-rickshaw drivers should use personal protective equipment and would require regular screening and treatment for respiratory impairment.

COPD in individuals with the PiMZ alpha-1 antitrypsin genotype

Since the discovery of severe alpha-1 antitrypsin deficiency as a genetic risk factor for emphysema, there has been ongoing debate over whether individuals with intermediate deficiency with one protease inhibitor Z allele (PiMZ, or MZ) are at some risk for emphysema. This is important, because MZ individuals comprise 2-5% of the general population. In this review we summarise the evidence about the risks of the MZ population to develop emphysema or asthma. We discuss the different study designs that have tried to answer this question. The risk of emphysema is more pronounced in case-control than in population-based studies, perhaps due to inadequate power. Carefully designed family studies show an increased risk of emphysema in MZ smokers. This is supported by the rapid decline in lung function of MZ individuals when compared to the general population after massive environmental exposures. The risk of asthma in MZ subjects is less studied, and more literature is needed before firm conclusions can be made. Augmentation therapy in MZ individuals is not supported by any objective studies. MZ smokers are at increased risk for emphysema that is more pronounced when other environmental challenges are present.

Explaining racial/ethnic differences in all-cause mortality in the Multi-Ethnic Study of Atherosclerosis (MESA): Substantive complexity and hazardous working conditions as mediating factors

Research on racial/ethnic health disparities and socioeconomic position has not fully considered occupation. However, because occupations are racially patterned, certain occupational characteristics may explain racial/ethnic difference in health. This study examines the role of occupational characteristics in racial/ethnic disparities in all-cause mortality. Data are from a U.S. community-based cohort study (n=6342, median follow-up: 12.2 years), in which 893 deaths (14.1%) occurred. We estimated mortality hazard ratios (HRs) for African Americans, Hispanics, and Chinese Americans compared with whites. We also estimated the proportion of the HR mediated by each of two occupational characteristics, substantive complexity of work (e.g., problem solving, inductive/deductive reasoning on the job) and hazardous conditions (e.g., noise, extreme temperature, chemicals), derived from the Occupational Information Network database (O*NET). Analyses were adjusted for age, sex, nativity, working status at baseline, and study sites. African Americans had a higher rate of all-cause death (HR 1.41; 95% confidence interval [CI]: 1.19–1.66) than whites. Chinese-American ethnicity was protective (HR 0.59, CI: 0.40–0.85); Hispanic ethnicity was not significantly different from whites (HR 0.88; CI: 0.67–1.17). Substantive complexity of work mediated 30% of the higher rate of death for African Americans compared with whites. For other groups, mediation was not significant. Hazardous conditions did not significantly mediate mortality in any racial/ethnic group. Lower levels of substantive complexity of work mediate a substantial part of the health disadvantage in African Americans. This job characteristic may be an important factor in explaining racial health disparities.

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Health disparities research rarely considers occupational characteristics.

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Occupation is strongly patterned by race/ethnicity in the United States.

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Different working conditions may explain racial health disparities.

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Complexity of the job explains one-third of black-white mortality difference.

Mortality in Miners with Coal-Workers' Pneumoconiosis in the Czech Republic in the Period 1992-2013

While working underground, miners are exposed to a number of risk factors that have a negative impact on their health and may be a cause of an increased mortality in miners. The aim of the study was to compare total and specific mortality in black coal miners with acknowledged coal-workers’ pneumoconiosis (CWP) and without CWP, and the mortality of the general male population in the Czech Republic in the period 1992–2013. The sample consisted of 3476 coal miners with CWP and 6687 ex-coal miners without CWP, who were removed after achieving the maximum permissible exposure (MPE). The mortality risk differences were analyzed with the use of the standardized mortality ratio (SMR) and 95% confidence interval. Significantly higher total mortality (SMR = 1.10; 95% CI: 1.02–1.17), and mortality from malignant neoplasm (SMR = 1.16; 95% CI: 1.03–1.30), lung cancers (SMR = 1.70; 95% CI: 1.41–2.04), and non-malignant respiratory diseases (SMR = 2.78; 95% CI: 2.32–3.31) were found in the sample of coal miners with CWP. In this sample, the severity of CWP was assessed, and the SMR increased with the severity of CWP. The total (SMR = 0.86; 95% CI: 0.82–0.91) and specific mortality of miners without CWP were not higher compared with the general population. In the case where the miners were removed from underground work after achieving the MPE (without CWP), their mortality was not higher than that of the general population, but the mortality of miners with CWP was higher compared to the general population. This mortality was affected by malignant and non-malignant respiratory diseases.

Occupational Risk Factors for COPD: A Case-Control Study

OBJECTIVES

The aim of this research was to examine the occupational risk factors for Chronic Obstructive Pulmonary Diseases (COPD) in a range of occupations.

METHODS

Eleven occupations involving different types of exposure were observed in this multicenter case-control study. Controls and cases were matched for sex, age and smoking. Multiple logistic regression analyses were used to estimate odds ratios (ORs).

RESULTS

A total of 1,519 participants were initially recruited between September 2004 and September 2012. After matching, 547 pairs were obtained. The mean age was 56.3 +/- 10.4 years. Smelter workers were the only ones with an increased risk of COPD in this study (OR = 7.6, p < 0.0001, 95% CI [4.5, 12.9]). Physical activity was protective (OR = 0.7), while living in the city was a risk (OR = 1.6). The main used metals were cast iron, aluminum and alloys. Molds and cores were mainly made from sand and synthetic resins. Machine maintenance (65.2%), molding (49.6%), finishing (41.1%) and casting (41.0%) were the most common activities. Almost all workers (95.1%) cleaned the floors and machines with a brush or compressed air.

CONCLUSIONS

This study demonstrates the importance of occupational factors in the genesis of COPD, especially among smelter workers. As with the fight against smoking-related disease, the removal or substitution of recognized hazardous agents is the best way of preventing the onset of COPD. This is why it is essential to continue research on its occupational risk factors.

Transcriptional profiling and targeted proteomics reveals common molecular changes associated with cigarette smoke-induced lung emphysema development in five susceptible mouse strains

BACKGROUND

Mouse models are useful for studying cigarette smoke (CS)-induced chronic pulmonary pathologies such as lung emphysema. To enhance translation of large-scale omics data from mechanistic studies into pathophysiological changes, we have developed computational tools based on reverse causal reasoning (RCR).

OBJECTIVE

In the present study we applied a systems biology approach leveraging RCR to identify molecular mechanistic explanations of pathophysiological changes associated with CS-induced lung emphysema in susceptible mice.

METHODS

The lung transcriptomes of five mouse models (C57BL/6, ApoE (-/-) , A/J, CD1, and Nrf2 (-/-) ) were analyzed following 5-7 months of CS exposure.

RESULTS

We predicted 39 molecular changes mostly related to inflammatory processes including known key emphysema drivers such as NF-κB and TLR4 signaling, and increased levels of TNF-α, CSF2, and several interleukins. More importantly, RCR predicted potential molecular mechanisms that are less well-established, including increased transcriptional activity of PU.1, STAT1, C/EBP, FOXM1, YY1, and N-COR, and reduced protein abundance of ITGB6 and CFTR. We corroborated several predictions using targeted proteomic approaches, demonstrating increased abundance of CSF2, C/EBPα, C/EBPβ, PU.1, BRCA1, and STAT1.

CONCLUSION

These systems biology-derived candidate mechanisms common to susceptible mouse models may enhance understanding of CS-induced molecular processes underlying emphysema development in mice and their relevancy for human chronic obstructive pulmonary disease.

Prevalence of chronic obstructive pulmonary disease among US working adults aged 40 to 70 years. National Health Interview Survey data 2004 to 2011

OBJECTIVE

To estimate the prevalence and prevalence odds ratios of chronic obstructive pulmonary disease (COPD) among US workers by major occupational groups.

METHODS

The 2004 to 2011 National Health Interview Survey data for working adults 40 to 70 years old was analyzed to estimate the prevalence of COPD by major occupational groups. Logistic regression models were used to evaluate the associations between COPD (chronic bronchitis or emphysema) and occupations.

RESULTS

The estimated overall COPD prevalence was 4.2% (95% CI, 4.0 to 4.3). The odds of COPD were highest among workers in health care support occupations (prevalence odds ratio, 1.64; 95% CI, 1.25 to 2.14) followed by food preparation and serving-related occupations (prevalence odds ratio, 1.57; 95% CI, 1.20 to 2.06).

CONCLUSIONS

Prevalence varied by occupations, suggesting workplace exposures may contribute to COPD. Preventive measures such as interventions to reduce smoking may reduce the prevalence of COPD.

Impact of chronic obstructive pulmonary disease (COPD) in the Asia-Pacific region: the EPIC Asia population-based survey

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a clinical syndrome encompassing a group of chronic, progressive, and debilitating respiratory conditions, that are characterized by incompletely reversible airflow limitation. Within the Asia-Pacific region, prevalence estimates have been derived using various protocols and study methods, and there is little data on the impact of COPD exacerbations. This study aimed to provide a comprehensive picture of the current prevalence and burden of COPD in this region.

METHODS

A population-based survey was conducted in nine Asia-Pacific territories between 01 February 2012 and 16 May 2012. Overall, 112,330 households were screened to identify eligible subjects (aged ≥40 years, with a physician diagnosis of COPD, chronic bronchitis or emphysema, or with identifiable symptoms of chronic bronchitis). Out of a sample of 69,279 individuals aged ≥40 years, 4,289 subjects with COPD were identified. Data were collected via face-to-face interviews or by fixed-line telephone, using a structured questionnaire. A total of 1,841 completed questionnaires were analyzed.

RESULTS

The overall estimated COPD prevalence was 6.2%, with 19.1% of subjects having severe COPD. In the 12 months prior to the survey, nearly half of all subjects (46%) had experienced exacerbations, and 19% had been hospitalized as a result of their condition. When subjects were asked about the impact of their condition on employment, 23% said their condition kept them from working, and 42% felt that their condition limited their ability to work or their activities. Of those who reported taking prescription drugs, 20% did not know the name of the drugs they were taking. Prescription of oral corticosteroids was common, with 44% of subjects having used these during the previous year to manage their respiratory symptoms; in contrast, inhaler use was low (25%). Only 37% of subjects had taken a lung function test, and the majority (89%) of those tested did not know their test results.

CONCLUSIONS

Across the Asia-Pacific territories surveyed, the prevalence of COPD is high, indicating a substantial socioeconomic burden. Our findings suggest that there is considerable room for improvement in the management of COPD, and highlight a need to enhance patient and physician education in the region.

Work-related COPD after years of occupational exposure

BACKGROUND

Cigarette smoking is known as the most important risk factor of chronic obstructive pulmonary disease (COPD). However, occupational exposure to other substances can result in COPD.

CASE REPORT

A 76-year-old man with occupational exposures to mixtures of silica dust, gas, and fumes for 10 years and with a 25 pack-year smoking history was diagnosed with COPD. His computed tomogram scan revealed some hyperinflation with emphysematous change in both upper lobes. In the pulmonary function tests, his post-bronchodilator forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1/FVC% were 2.20 L (67% of the predicted value), 1.12 L (52% of the predicted value), and 51%, respectively, indicating moderate COPD. This case of COPD was confirmed as a work-related disease by the Occupational Lung Disease Research Institute in Korea Workers' Compensation & Welfare Service.

CONCLUSION

Exposure to various substances such as silica dust, gas, and fumes from furnace and boiler installation was likely the cause of COPD in this patient. Thus, occupational exposure should be considered an important risk factor of COPD.

An estimate of the prevalence of COPD in Africa: a systematic analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is among the leading causes of death globally, accounting for about 3 million deaths worldwide in 2011. We aimed to estimate the prevalence of COPD in Africa in the year 2010 to provide the information that could assist health policy in the region.

METHODS

We conducted a systematic review of Medline, EMBASE and Global Health for studies on COPD published between 1990 and 2012. We included original population based studies providing estimates of the prevalence of COPD. We considered the reported estimates in terms of the mean age of the sample, sex ratio, the year of study and the country of the study as possible covariates. RESULTS from two different types of studies, i.e., based on spirometric and non-spirometric diagnosis of COPD, were further compared. The United Nation Population Division's population figures were used to estimate the number of COPD cases in the year 2010.

RESULTS

Our search returned 243 studies, from which only 13 met our selection criteria and only five were based on spirometry. The difference in the median prevalence of COPD in persons aged 40 years or older based on spirometry data (13.4%; IQR: 9.4%-22.1%) and non-spirometry data (4.0%; IQR: 2.1%-8.9%) was statistically significant (p = 0.001). There was no significant effect of the gender or the year of the study on the reported prevalence of COPD in either set of studies. The prevalence of COPD increased with age in spirometry-based studies (p = 0.017), which is a plausible finding suggesting internal consistency of spirometry-based estimates, while this trend was not observed in studies using other case definitions. When applied to the appropriate age group (40 years or more), which accounted for 196.4 million people in Africa in 2010, the estimated prevalence translates into 26.3 million (18.5-43.4 million) cases of COPD. Comparable figures for the year 2000 based on the same prevalence rates would amount to 20.0 million (14.1-33.1), suggesting an increase of 31.5% over a decade that is attributable to ageing of the African population alone.

CONCLUSION

Our findings suggest that COPD is likely to already represent a very large public health problem in Africa. Moreover, rapidly ageing African population should expect a steady increase in the number of COPD cases in the next decade and beyond. The quantity and quality of available evidence does not match the size of the problem. There is a need for more research on COPD prevalence, but also incidence, mortality and risk factors in Africa. We hope this study will raise awareness of COPD in Africa and encourage further research.