Occupational exposures associated with severe exacerbation of asthma

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

Associations between comorbidities and annual incidence plus frequency of asthma exacerbation hospitalisation during the past year: data from CARN study

Purpose

While asthma comorbidities are associated with higher health care utilisation, lower quality of life and poorer asthma control, the impact of asthma comorbidities on hospitalisation for asthma exacerbation (H-AX) remains less recognised. We aim to analyse the impact of asthma comorbidities on H-AX.

Methods

Based on a national survey on asthma control and disease perception (CARN 2015 study), we analysed the impact of comorbidities on annual incidence and frequency of H-AX in China. Information on demographic characteristics, asthma comorbidities and annual incidence and frequency of H-AX were presented in this study.

Results

Among 3875 ambulatory asthma patients, 75.9% (2941/3875) had comorbidities, and 26.4% (1017/3858) experienced H-AX during past year. After adjusting for confounding factors such as demographic data, smoking status and asthma control, COPD [OR = 2.189, 95% CI (1.673, 2.863)] and coronary heart disease [OR = 1.387, 95% CI (1.032, 1.864)] were associated with higher annual incidence, while allergic rhinitis [OR = 0.692, 95% CI (0.588, 0.815)] was associated with lower annual incidence, of H-AX. In terms of frequency, allergic rhinitis [OR = 1.630, 95% CI (1.214, 2.187)], COPD [OR = 1.472, 95% CI (1.021, 2.122)] and anxiety [OR = 2.609, 95% CI (1.051, 6.477)] showed statistically significant correlation with frequent H-AX.

Conclusions

COPD and coronary heart disease were associated with higher annual incidence, while allergic rhinitis was associated with lower annual incidence of H-AX. Allergic rhinitis, COPD and anxiety were associated with frequent H-AX. Comorbidities may have an important role in the risk and frequency of annual hospitalisations due to asthma exacerbation. The goal of asthma control should rely on a multi-disciplinary treatment protocol.

Progress in Occupational Asthma

Occupational asthma (OA) represents one of the major public health problems due to its high prevalence, important social and economic burden. The aim of this review is to summarize current data about clinical phenotypes, biomarkers, diagnosis and management of OA, a subtype of work-related asthma. Most studies have identified two phenotypes of OA. One is sensitizer-induced asthma, occuring after a latency period and caused by hypersensitivity to high- or low-molecular weight agents. The other is irritant-induced asthma, which can occur after one or more exposures to high concentrations of irritants without latency period. More than 400 agents causing OA have been identified and its list is growing fast. The best diagnostic approach for OA is a combination of clinical history and objective tests. An important tool is a specific inhalation challenge. Additional tests include assessments of bronchial hyperresponsiveness to methacholine/histamine in patients without airflow limitations, monitoring peak expiratory flow at- and off-work, sputum eosinophil count, exhaled nitric oxide measurement, skin prick tests with occupational allergens and serum specific IgE. Treatment of OA implies avoidance of exposure, pharmacotherapy and education. OA is a heterogeneous disease. Mechanisms of its different phenotypes, their diagnosis, role of new biomarkers and treatment require further investigation.

Occupational asthma: clinical phenotypes, biomarkers, and management

PURPOSE OF REVIEW

This review focuses on new findings in the clinical and inflammatory aspects that can help to better identify the different phenotypes of work-related asthma and the development of specific biomarkers useful in diagnosis and follow-up.

RECENT FINDINGS

Studies on phenotyping of occupational asthma, a subtype of work-related asthma, have mainly compared the clinical, physiological, and inflammatory patterns associated with the type of agent causing occupational asthma, namely, high-molecular-weight and low-molecular-weight agents. Most of this research has found that patients with occupational asthma due to high-molecular-weight agents have an associated presence of rhinitis, conjunctivitis, atopy, and a pattern of early asthmatic reactions during specific inhalation challenge. The inflammatory profile (blood eosinophils, sputum cell count, or exhaled nitric oxide) may be similar when occupational asthma is caused by either type of agent. In some studies, severity of asthma and exacerbations have been associated with exposure to low-molecular-weight agents. The most reliable biomarkers in diagnosis and follow-up are eosinophilia in induced sputum and exhaled nitric oxide.

SUMMARY

There are several phenotypes, characterized by its pathogenesis and inflammatory profile. Avoidance of the causative agents does not warrant complete recovery of occupational asthma. Treatment with biologic agents may be considered in severe occupational asthma.

Development of an Asthma-Specific Job Exposure Matrix for Use in the United States

INTRODUCTION

Existing asthma-specific job-exposure matrices (JEMs) do not necessarily reflect current working conditions in the USA and do not directly function with occupational coding systems commonly used in the USA. We initiated a project to modify an existing JEM to address these limitations, and to apply the new JEM to the entire US employed population to estimate quantitatively the extent of probable work-related asthma exposures nationwide.

METHODS

We started with an asthma-specific JEM that was developed for northern Europe (the N-JEM) and modified it to function with the 2010 US Standard Occupational Classification (SOC-2010) codes and to reflect working conditions in the USA during the post-2000 period. This involved cross walking from the 1988 International Standard Classification of Occupations (ISCO-88) codes used in the N-JEM to the SOC-2010 codes, transferring the N-JEM exposure assignments to the SOC-2010 codes, and modifying those assignments to reflect working conditions in the USA. The new US asthma JEM (USA-JEM) assigns exposures to 19 agents organized into five categories. The USA-JEM and N-JEM were applied to the same sample of working adults with asthma to compare how they performed, and the USA-JEM was also applied to the entire 2015 US working population to estimate the extent of occupational asthma exposures nationally.

RESULTS

The USA-JEM assigns at least one asthma-related probable exposure to 47.5% and at least one possible exposure to 14.9% of the 840 SOC-2010 detailed occupations, and 9.0% of the occupations have both probable exposure to at least one agent and possible exposure to at least one other agent. The USA-JEM has greater sensitivity for cleaning products, highly reactive disinfectants and sterilants, and irritant peak exposures than the N-JEM. When applied to the entire 2015 US working population, the USA-JEM determined that 42.6% of workers had probable exposure to at least one type of occupational asthma agent.

DISCUSSION

A new asthma-specific JEM for application in the USA was developed. Additional work is needed to compare its performance to similar JEMs and, if possible, to exposure assessments generated on a case-by-case basis.

High exposure mining occupations are associated with obstructive lung disease, National Health Interview Survey (NHIS), 2006-2015

BACKGROUND

The association between mining occupation categories and obstructive lung disease (OLD) has not been well explored in the United States.

METHODS

National Health Interview Survey (NHIS) data from 2006 to 2015 was used to determine the relationship between mining occupations and diagnosis of chronic bronchitis, emphysema, chronic obstructive pulmonary disease (COPD), and asthma. We classified occupations into low, moderate, high, and very high dust exposure groups. Extraction workers were categorized as very high dust exposure.

RESULTS

We found 4.5% of miners had chronic bronchitis, 3.3% had emphysema, 6.2% had COPD, and 9.9% had asthma. In fully adjusted models, extraction workers had significantly increased odds of having chronic bronchitis (OR = 2.18 [95%CI: 1.02, 4.64]), emphysema (OR = 7.85 [95%CI: 1.70, 36.27]), and COPD (OR = 2.56 [95%CI: 1.29, 5.12]) compared to lower exposure occupations.

CONCLUSIONS

Occupation is an important predictor of OLD in the mining industry.

Correlates of employment status in individuals with asthma: a cross-sectional survey

Background

This study aims to elucidate factors that among adults with asthma are associated with working full-time.

Methods

This cross-sectional survey of 2613 working-age adults with asthma included questions on asthma history, symptoms and use of asthma medication, socioeconomic factors and health behavior. Full-time workers were compared to groups according to employment status: unemployed, work disability and retired due to age.

Results

Adults with asthma working full time were younger and more often nonmanual workers, experienced less asthma symptoms, used less asthma medication and smoked less than subjects with work disability. After adjusting for age, gender, smoking and professional status, having frequent symptoms of asthma during last month was associated with an increase in the risk of unemployment (OR 2.3, 95% CI 1.3–4.2) and with an increase in the risk of work disability (OR 4.4, 95% CI 2.3–8.2).

Conclusions

Among adults with asthma, full-time work was associated with younger age, less symptomatic asthma despite of less medication, nonmanual work and less smoking. Having more severe symptoms of asthma was associated with undesirable employment status such as unemployment or work disability. Possibilities to change from manual to nonmanual work may be important in preventing work disability and early exit from work.

Electronic supplementary material

The online version of this article (doi:10.1186/s12995-017-0165-6) contains supplementary material, which is available to authorized users.

Work-related asthma in a sample of subjects with established asthma

OBJECTIVE

To assess the impact of occupational exposure to irritants or sensitizers on the occurrence, recrudescence and worsening of asthma and to identify unrecognized cases of work related asthma (WRA) including Work-Exacerbated Asthma (WEA) and Occupational Asthma (OA), in a general asthma clinic population sample.

SETTING, DESIGN AND PARTICIPANTS

The study was a population-based cross sectional survey. 1289 asthmatic subjects (from 15 to 46 yrs old) living in a vast district of Tuscany (Italy) were identified from the Medical Reimbursement Register of the National Health System. 893 subjects agreed to take part in the study. Subjects who were currently working or had worked in past were classified in different categories of occupational risk exposure (No, Low or High) according to the italian standard classification for industries and job titles, associated with the judgment of occupational hygiene experts.

RESULTS

41% of subjects worked in industries and in job titles at risk for exposure to airway irritants and/or sensitizers, 48.6% reported an occupational exposure to gases, dust and fumes, more males than females. Prevalence of WEA and OA was higher in subjects who worked at higher risk exposure; these subjects reported a higher prevalence of markers of asthma severity (asthma control, level of treatment, FEV1) than subjects without WRA. Risk of WEA was significantly associated to female gender, older age, and self-reported exposure, while risk of OA was associated to job title with higher exposure risk to occupational asthmogens.

CONCLUSIONS

Our study shows a high prevalence of WRA (especially WEA) associated with employment in industries and job titles at risk for airways sensitizers and/or irritants; data also support a role for occupational exposure in determining a poor asthma control and a higher level of asthma severity.

Association of respiratory symptoms and asthma with occupational exposures: findings from a population-based cross-sectional survey in Telemark, Norway

OBJECTIVES

The aim of this study was to estimate the prevalence of respiratory symptoms and physician-diagnosed asthma and assess the impact of current occupational exposure.

DESIGN

Cross-sectional analyses of the prevalence of self-reported respiratory health and association with current occupational exposure in a random sample of the general population in Telemark County, Norway.

SETTINGS

In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16-50, in Telemark, Norway. The overall response rate was 33%, comprising 16 099 responders.

OUTCOME MEASURES

The prevalence for respiratory symptoms and asthma, and OR of respiratory symptoms and asthma for occupational groups and exposures were calculated. Occupational exposures were assessed using self-reported exposure and an asthma-specific job-exposure matrix (JEM).

RESULTS

The prevalence of physician-diagnosed asthma was 11.5%. For the occupational groups, the category with agriculture/fishery workers and craft/related trade workers was associated with wheezing and asthma attack in the past 12 months, showing OR 1.3 (1.1 to 1.6) and 1.9 (1.2 to 2.8), respectively. The group including technicians and associated professionals was also associated with wheezing OR 1.2 (1.0 to 1.3) and asthma attack OR 1.4 (1.1 to 1.9). The JEM data show that exposure to flour was associated with wheezing OR 3.2 (1.4 to 7.3) and woken with dyspnoea OR 3.5 (1.3 to 9.5), whereas exposures to diisocyanates, welding/soldering fumes and exposure to vehicle/motor exhaust were associated with dyspnoea OR 2.9 (1.5 to 5.7), 3.2 (1.6 to 6.4) and 1.4 (1.0 to 1.8), respectively.

CONCLUSIONS

The observed prevalence of physician-diagnosed asthma was 11.5%. The 'manual' occupations were associated with respiratory symptoms. Occupational exposure to flour, diisocyanates, welding/soldering fumes and vehicle/motor exhaust was associated with respiratory symptoms in the past 12 months and use of asthma medication. However, prospective data are needed to confirm the observed associations.

Impact of occupational exposures on exacerbation of asthma: a population-based asthma cohort study

Background

Asthma is a prevalent chronic disease and occupation contributes to approximately 15 % of cases among adults. However, there are still few studies on risk factors for work-exacerbated asthma. The current study investigated the association between asthma exacerbations and occupational exposures.

Methods

The study comprised all currently working adults (n = 1356) who reported ever asthma in prior population-based cohorts. All subjects completed a questionnaire about exposures, occupations and exacerbations of asthma. Exposure to high and low molecular weight agents, irritating agents and asthmagens were classified using the asthma-specific job exposure matrix for northern Europe (N-JEM). Severe exacerbation of asthma was defined as sought emergency care at a hospital, admitted to a hospital overnight, or made an urgent visit to a primary care physician or district medical office due to breathing problems during the last 12 months. Moderate exacerbation was defined as both being not severe exacerbation and an additional visit to a primary care physician or district medical office, or had extra treatments with corticosteroid tablets. Mild exacerbation was defined as being neither severe nor moderate exacerbation, and increasing usage of inhaled corticosteroids.

Multiple logistic regression was applied to investigate the association between exacerbation of asthma and occupational exposures while adjusting for potential confounders.

Results

Approximately 26 % of the working asthmatics reported exacerbation, and more than two-thirds of them had moderate or severe exacerbation. From 23 to 49 % of the asthmatics reported occupational exposure to a variety of different types of agents. Exposure to any gas, smoke or dust (OR 1.7[95 % CI 1.2–2.6]) was associated with severe exacerbation of asthma, as were organic dust (OR 1.7[1.2–2.5]), dampness and mold (OR 1.8[1.2–2.7]), cold conditions (OR 1.7[1.1–2.7]), and a physically strenuous job (OR 1.6[1.03–2.3]). Asthmagens and low molecular weight agents classified by the N-JEM were associated with mild exacerbation, with OR 1.6[1.1–2.5] and OR 2.2[1.1–4.4], respectively.

Conclusions

Self-reported exposure to any gas, smoke or dust, organic dust, dampness and mold, cold conditions and physically strenuous work, and jobs handling low molecular weight agents were associated with exacerbation of asthma. Reduction of these occupational exposures may help to reduce exacerbation of asthma.

Does industry take the susceptible subpopulation of asthmatic individuals into consideration when setting derived no-effect levels?

Asthma, a chronic respiratory disease, can be aggravated by exposure to certain chemical irritants. The objectives were first to investigate the extent to which experimental observations on asthmatic subjects are taken into consideration in connection with the registration process under the EU REACH regulation, and second, to determine whether asthmatics are provided adequate protection by the derived no-effect levels (DNELs) for acute inhalation exposure. We identified substances for which experimental data on the pulmonary functions of asthmatics exposed to chemicals under controlled conditions are available. The effect concentrations were then compared with DNELs and other guideline and limit values. As of April 2015, only 2.6% of 269 classified irritants had available experimental data on asthmatics. Fourteen of the 22 identified substances with available data were fully registered under REACH and we retrieved 114 reliable studies related to these. Sixty-three of these studies, involving nine of the 14 substances, were cited by the REACH registrants. However, only 17 of the 114 studies, involving four substances, were regarded as key studies. Furthermore, many of the DNELs for acute inhalation were higher than estimated effect levels for asthmatics, i.e., lowest observed adverse effect concentrations or no-observed adverse effect concentrations, indicating low or no safety margin. We conclude that REACH registrants tend to disregard findings on asthmatics when deriving these DNELs. In addition, we found examples of DNELs, particularly among those derived for workers, which likely do not provide adequate protection for asthmatics. Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

Workplace secondhand smoke exposure: a lingering hazard for young adults in California

OBJECTIVE

To examine occupational differences in workplace exposure to secondhand smoke (SHS) among young adults in California.

METHODS

Data are taken from the 2014 Bay Area Young Adult Health Survey, a probabilistic multimode cross-sectional household survey of young adults, aged 18-26, in Alameda and San Francisco Counties. Respondents were asked whether they had been exposed to SHS 'indoors' or 'outdoors' at their workplace in the previous 7 days and also reported their current employment status, industry and occupation. Sociodemographic characteristics and measures of health perception and behaviour were included in the final model.

RESULTS

Young adults employed in service (p<0.001), construction and maintenance (p<0.01), and transportation and material moving (p<0.05) sectors were more likely to report workplace SHS exposure while those reporting very good or excellent self-rated health were less likely (p<0.001).

CONCLUSIONS

Despite California's clean indoor air policy, 33% of young adults in the San Francisco Bay Area still reported workplace SHS exposure in the past week, with those in lower income occupations and working in non-office environments experiencing the greatest exposure. Closing the gaps that exempt certain types of workplaces from the Smoke-Free Workplace Act may be especially beneficial for young adults.

Health challenges in South African automotive companies: Wellness in the workplace

Orientation: In South Africa, workplace programmes in the automotive industry focus predominantly on occupational health and safety and HIV and AIDS. The implementation of focused workplace interventions might be hampered when companies are not convinced that the condition (i.e. HIV and AIDS) is the main negative health influencing factor responsible for increased production costs.Research purpose: The study investigated the health influencing conditions perceived to negatively impact company production costs and related interventions.Motivation for the study: Apart from HIV and AIDS, little information is available about the health challenges in the South African workplace and focused HIV and AIDS programmes might only partly respond to the key health challenges of workplaces. The inter-relatedness of various risky lifestyle factors linked to health conditions necessitates a comprehensive health promotion approach.Research approach, design and method: A cross-sectional survey was conducted amongst 74 companies selected through stratified random sampling. Non-parametric tests were conducted to investigate the health influencing factors perceived to impact production costs, the monitoring thereof, extent of containment and the implementation of interventions in terms of company size and ownership.Main findings: The health factors perceived to have a moderate to large impact were HIV and AIDS, smoking, alcohol use, stress, back and neck ache and tuberculosis, also reported to be better monitored and managed by medium and large organisations. Small organisations reported a smaller impact, fewer efforts and less success. HIV and AIDS programmes were more evident in large companies and those with wellness programmes (52%). Workplace programmes enabled better monitoring and managing of impacting health conditions. Smaller organisations were not convinced of the benefits of interventions in addressing health challenges.Practical/managerial implications: As the impacting health conditions seemed linked, comprehensive and integrated wellness programmes are required to address the health issues and ensure organisations’ competitiveness.Contribution: The results contribute to a better understanding of the perceived salient health influencing factors that impact on production costs. Data support the inter-relationships between the identified health concerns and call for more holistic wellness programmes.