Relations between respiratory symptoms and spirometric values in young adults: the European community respiratory health study

Deployment-related Cigarette Smoking Behaviors and Pulmonary Function Among U.S. Veterans

INTRODUCTION

The effects of smoking on lung function among post-9/11 Veterans deployed to environments with high levels of ambient particulate matter are incompletely understood.

MATERIALS AND METHODS

We analyzed interim data (04/2018-03/2020) from the Veterans Affairs (VA) Cooperative Studies Program #595, "Service and Health Among Deployed Veterans". Veterans with ≥1 land-based deployments enrolled at 1 of 6 regional Veterans Affairs sites completed questionnaires and spirometry. Multivariable linear regression models assessed associations between cigarette smoking (cumulative, deployment-related and non-deployment-related) with pulmonary function.

RESULTS

Among 1,836 participants (mean age 40.7 ± 9.6, 88.6% male), 44.8% (n = 822) were ever-smokers (mean age 39.5 ± 9.5; 91.2% male). Among ever-smokers, 86% (n = 710) initiated smoking before deployment, while 11% (n = 90) initiated smoking during deployment(s). Smoking intensity was 50% greater during deployment than other periods (0.75 versus 0.50 packs-per-day; P < .05), and those with multiple deployments (40.4%) were more likely to smoke during deployment relative to those with single deployments (82% versus 74%). Total cumulative pack-years (median [IQR] = 3.8 [1, 10]) was inversely associated with post-bronchodilator FEV1%-predicted (-0.82; [95% CI] = [-1.25, -0.50] %-predicted per 4 pack-years) and FEV1/FVC%-predicted (-0.54; [95% CI] = [-0.78, -0.43] %-predicted per 4 pack-years). Deployment-related pack-years demonstrated similar point estimates of associations with FEV1%-predicted (-0.61; [95% CI] = [-2.28, 1.09]) and FEV1/FVC%-predicted (-1.09; [95% CI] = [-2.52, 0.50]) as non-deployment-related pack-years (-0.83; [95% CI] = [-1.26, -0.50] for FEV1%-predicted; -0.52; [95% CI] = [-0.73, -0.36] for FEV1/FVC%-predicted).

CONCLUSIONS

Although cumulative pack-years smoking was modest in this cohort, an inverse association with pulmonary function was detectable. Deployment-related pack-years had a similar association with pulmonary function compared to non-deployment-related pack-years.

Chronic respiratory symptoms following deployment-related occupational and environmental exposures among US veterans

OBJECTIVES

Characterise inhalational exposures during deployment to Afghanistan and Southwest Asia and associations with postdeployment respiratory symptoms.

METHODS

Participants (n=1960) in this cross-sectional study of US Veterans (Veterans Affairs Cooperative Study 'Service and Health Among Deployed Veterans') completed an interviewer-administered questionnaire regarding 32 deployment exposures, grouped a priori into six categories: burn pit smoke; other combustion sources; engine exhaust; mechanical and desert dusts; toxicants; and military job-related vapours gas, dusts or fumes (VGDF). Responses were scored ordinally (0, 1, 2) according to exposure frequency. Factor analysis supported item reduction and category consolidation yielding 28 exposure items in 5 categories. Generalised linear models with a logit link tested associations with symptoms (by respiratory health questionnaire) adjusting for other covariates. OR were scaled per 20-point score increment (normalised maximum=100).

RESULTS

The cohort mean age was 40.7 years with a median deployment duration of 11.7 months. Heavy exposures to multiple inhalational exposures were commonly reported, including burn pit smoke (72.7%) and VGDF (72.0%). The prevalence of dyspnoea, chronic bronchitis and wheeze in the past 12 months was 7.3%, 8.2% and 15.6%, respectively. Burn pit smoke exposure was associated with dyspnoea (OR 1.22; 95% CI 1.06 to 1.47) and chronic bronchitis (OR 1.22; 95% CI 1.13 to 1.44). Exposure to VGDF was associated with dyspnoea (OR 1.29; 95% CI 1.14 to 1.58) and wheeze (OR 1.18; 95% CI 1.02 to 1.35).

CONCLUSION

Exposures to burn pit smoke and military occupational VGDF during deployment were associated with an increased odds of chronic respiratory symptoms among US Veterans.

Respiratory Health after Military Service in Southwest Asia and Afghanistan. An Official American Thoracic Society Workshop Report

Since 2001, more than 2.7 million U.S. military personnel have been deployed in support of operations in Southwest Asia and Afghanistan. Land-based personnel experienced elevated exposures to particulate matter and other inhalational exposures from multiple sources, including desert dust, burn pit combustion, and other industrial, mobile, or military sources. A workshop conducted at the 2018 American Thoracic Society International Conference had the goals of: 1) identifying key studies assessing postdeployment respiratory health, 2) describing emerging research, and 3) highlighting knowledge gaps. The workshop reviewed epidemiologic studies that demonstrated more frequent encounters for respiratory symptoms postdeployment compared with nondeployers and for airway disease, predominantly asthma, as well as case series describing postdeployment dyspnea, asthma, and a range of other respiratory tract findings. On the basis of particulate matter effects in other populations, it also is possible that deployers experienced reductions in pulmonary function as a result of such exposure. The workshop also gave particular attention to constrictive bronchiolitis, which has been reported in lung biopsies of selected deployers. Workshop participants had heterogeneous views regarding the definition and frequency of constrictive bronchiolitis and other small airway pathologic findings in deployed populations. The workshop concluded that the relationship of airway disease, including constrictive bronchiolitis, to exposures experienced during deployment remains to be better defined. Future clinical and epidemiologic research efforts should address better characterization of deployment exposures; carry out longitudinal assessment of potentially related adverse health conditions, including lung function and other physiologic changes; and use rigorous histologic, exposure, and clinical characterization of patients with respiratory tract abnormalities.

Assessment of asthma severity in adults with ever asthma: A continuous score

BACKGROUND

In epidemiological studies, continuous measures of asthma severity should be used to catch the heterogeneity of phenotypes. This study aimed at developing and validating continuous measures of asthma severity in adult patients with ever asthma from the general population, to be used in epidemiological studies.

METHODS

Respiratory symptoms, anti-asthmatic treatment and lung function were measured on 520 patients with ever asthma aged 20-64 years from the general Italian population (GEIRD study; 2007/2010). The variables that represent the same dimension of asthma severity were identified through an exploratory factor analysis and were summarized through a multiple factor analysis.

RESULTS

Only respiratory symptoms and anti-asthmatic treatment were summarized in a continuous score (STS). STS ranges from 0 (no symptoms/treatment) to 10 (maximum symptom frequency and treatment intensity). STS was positively correlated with the Global Initiative for Asthma classification of asthma severity computed on the 137 cases with a doctor's diagnosis (Spearman's coefficient = 0.61, p-value<0.0001) (concurrent validity). Furthermore, using a cohort of 1,097 European asthmatics (ECRHS II study; 1999/2002), increasing STS levels at baseline (1991/1993) were positively associated with long-term outcomes (hospitalization and lost workdays for breathing problems, asthma attack frequency and use of asthma controllers) (predictive validity). Finally, the STS scores computed from the GEIRD and ECRHS II data were comparable (Lin's coefficient = 0.95, p-value<0.0001) (replication analysis).

CONCLUSIONS

STS is a valid and replicable measure of asthma severity in adults, which could be used in association studies.

No convincing association between genetic markers and respiratory symptoms: results of a GWA study

BACKGROUND

Respiratory symptoms are associated with accelerated lung function decline, and increased hospitalization and mortality rates in the general population. Although several environmental risk factors for respiratory symptoms are known, knowledge on genetic risk factors is lacking. We aim to identify genetic variants associated with respiratory symptoms by genome-wide association (GWA) analyses.

METHODS

We conducted the first GWA study on cough, dyspnea and phlegm among 7,976 participants in the LifeLines I cohort and used the LifeLines II cohort (n = 5,260) and the Vlagtwedde-Vlaardingen cohort (n = 1,529) for replication.

RESULTS

We identified 50 SNPs that were assessed for replication. Rs16918212, located in the alpha-2-macroglobulin pseudogene 1 (A2MP1), was associated with cough in both the identification (odds ratio (OR) = 0.72, p = 5.41 × 10^-5) and the meta-analyzed replication cohorts (OR = 0.83, p = 0.033). No other significant replicated associations were found.

CONCLUSIONS

Given that only 1 out of 50 SNPs showed significant replication (i.e. 2%) we conclude that we did not find a convincing association between genetic markers and respiratory symptoms. Since, environmental exposures are important risk factors for respiratory symptoms, the next step is to perform a genome-wide interaction (GWI) study to identify genetic susceptibility loci for respiratory symptoms in interaction with known harmful environmental exposures.

Gastroesophageal dysmotility is associated with the impairment of cough-specific quality of life in patients with cough variant asthma

BACKGROUND

Gastroesophageal reflux disease (GERD) is known as a common comorbidity of asthma and chronic cough. The impact of GERD symptoms on cough-specific quality of life (QoL) in patients with asthmatic cough is poorly understood. The aim of this study is to determine the association of GERD symptoms with cough-specific quality of life in patients with cough variant asthma (CVA) using the Leicester Cough Questionnaire (LCQ).

METHODS

A total of 172 consecutive patients (121 females) with mean cough duration of 45.1 months (range 2-480 months) completed the Japanese version of the LCQ. The Frequency Scale for the Symptoms of Gastroesophageal reflux was administered to assess symptoms of acid-reflux and dysmotility. A range of clinical variables that may determine cough-specific QoL (LCQ) were estimated.

RESULTS

The mean LCQ scores was 12.9 (SD 3.5), consistent with severe impairment in QoL. Female gender, symptoms of gastroesophageal dysmotility, sensitization to allergens (house dust and Japanese cedar pollen) and the number of sensitized allergens were associated with lower LCQ scores (i.e. impaired cough-specific QoL) in univariate regression analysis. Acid-reflux symptoms, airway hyperresponsiveness, fractional exhaled nitric oxide, and sensitization to molds were unrelated to the LCQ score. After adjustment for gender, symptoms of gastroesophageal dysmotility was the only significant determinant of impaired cough-specific QoL accounting for 23% of the variance.

CONCLUSIONS

Cough-specific QoL is severely impaired in patients with CVA. Symptoms of gastroesophageal dysmotility are an independent predictor of cough-specific QoL of patients with CVA.

Predictors of dyspnoea prevalence: results from the BOLD study

Dyspnoea is a cardinal symptom for cardiorespiratory diseases. No study has assessed worldwide variation in dyspnoea prevalence or predictors of dyspnoea. We used cross-sectional data from population-based samples in 15 countries of the Burden of Obstructive Lung Disease (BOLD) study to estimate prevalence of dyspnoea in the full sample, as well as in an a priori defined low-risk group (few risk factors or dyspnoea-associated diseases). Dyspnoea was defined by the modified Medical Research Council questions. We used ordered logistic regression analysis to study the association of dyspnoea with site, sex, age, education, smoking habits, low/high body mass index, self-reported disease and spirometry results. Of the 9484 participants, 27% reported any dyspnoea. In the low-risk subsample (n=4329), 16% reported some dyspnoea. In multivariate analyses, all covariates were correlated to dyspnoea, but only 13% of dyspnoea variation was explained. Females reported more dyspnoea than males (odds ratio ∼2.1). When forced vital capacity fell below 60% of predicted, dyspnoea was much more likely. There was considerable geographical variation in dyspnoea, even when we adjusted for known risk factors and spirometry results. We were only able to explain 13% of dyspnoea variation.

Pulmonary function predicting confirmed recovery from lower-respiratory symptoms in World Trade Center-exposed firefighters, 2001 to 2010

BACKGROUND

We examined the relationship between pulmonary function (FEV 1 ) and confirmed recovery from three lower-respiratory symptoms (LRSs) (cough, dyspnea, and wheeze) up to 9 years after symptom onset.

METHODS

The study included white and black male World Trade Center (WTC)-exposed firefighters who reported at least one LRS on a medical monitoring examination during the fi rst year after September 11, 2001. Confirmed recovery was defined as reporting no LRSs on two consecutive and all subsequent examinations. FEV 1 was assessed at the fi rst post-September 11, 2001, examination and at each examination where symptom information was ascertained. We used stratified Cox regression models to analyze FEV 1 , WTC exposure, and other variables in relation to confirmed symptom recovery.

RESULTS

A total of 4,368 fi refighters met inclusion criteria and were symptomatic at year 1, of whom1,592 (36.4%) experienced confirmed recovery. In univariable models, fi rst post-September 11,2001, concurrent, and difference between fi rst post-September 11, 2001, and concurrent FEV 1 values were all significantly associated with confirmed recovery. In adjusted analyses, both fi rst post-September 11, 2001, FEV 1 (hazard ratio [HR], 1.07 per 355-mL difference; 95% CI, 1.04-1.10) and FEV 1 % predicted (HR, 1.08 per 10% predicted difference; 95% CI, 1.04-1.12) predicted confirmed recovery. WTC exposure had an inverse association with confirmed recovery in the model with FEV 1 , with the earliest arrival group less likely to recover than the latest arrival group (HR, 0.73;95% CI, 0.58-0.92).

CONCLUSIONS

Higher FEV 1 and improvement in FEV 1 after September 11, 2001, predicted confirmed LRS recovery, supporting a physiologic basis for recovery and highlighting consideration of spirometry as part of any postexposure respiratory health assessment.

What can we learn about asthma and allergy from the follow-up of the RHINE and the ECRHS studies?

OBJECT

The international population-based studies RHINE and ECRHS have provided new insight in the epidemiology and management of asthma, allergy and rhinitis in young adults. The aim of the present review is to focus on longitudinal results with regard incidence and net change of asthma and asthma-like symptoms, risk factors and management of asthma, with special reference to the Nordic-Baltic countries.

RESULTS

Asthma and rhinitis are common conditions that are important in a public health perspective. There are gender differences in incidence and remission. A socio-economic gradient that non-atopic asthma is more strongly related to poverty seems to have developed in the last decade. These findings will challenge our welfare states in the future. In addition, occupational, as well as indoor and outdoor environmental exposures, influenced the onset of asthma. The population-attributable risk for adult asthma because of occupational exposures is equivalent to an incidence of new-onset asthma of 250-300 cases per million per year. Genetic factors, allergic sensitisation, gastro-oesophageal reflux, habitual snoring, diet and other factors may also contribute to the onset of asthma and rhinitis. Even though management of asthma has improved, there are still great variations throughout Europe. These findings highlight the key role doctors and nurses play in educating and reviewing management of patients.

Association between respiratory symptom score and 30-year cause-specific mortality and lung cancer incidence

INTRODUCTION

Respiratory symptoms are among the main reasons why patients make contact with healthcare professionals and they are associated with several diseases.

OBJECTIVE

The aim of this study was to investigate the relationship between respiratory symptoms reported at one time and 30 years cause-specific mortality and incidence of lung cancer in an urban Norwegian population.

MATERIALS AND METHODS

A total of 19 998 men and women, aged 15-70 years, were in 1972 selected from the general population of Oslo. They received a postal respiratory questionnaire (response rate 89%). All were followed for 30 years for end-point mortality and for lung cancer. The association between respiratory symptoms, given as a symptom load, and end point of interest were investigated separately for men and women by multivariable analyses, with adjustment for age, occupational exposure to air pollution and smoking habits.

RESULTS

A total of 6710 individuals died during follow-up. Obstructive lung diseases (OLDs) and pneumonia accounted for 250 and 293 of the total deaths, respectively. Ischaemic heart disease (IHD) accounted for 1572; stroke accounted for 653 of all deaths. Lung cancer developed in 352 persons during follow-up. The adjusted hazard ratio for mortality from OLD and pneumonia, IHD and stroke increased in a dose-response manner with symptom score, more strongly for OLD and IHD than for pneumonia and stroke.

CONCLUSIONS

Respiratory symptoms were positively associated with mortality from OLD, pneumonia, IHD and stroke, and incidence of lung cancer. This association was significant for mortality from OLD and IHD.

Public facility workers' immunological characteristics involved with development of respiratory allergic diseases in Korea

We evaluated the immuno-pulmonary status of employees working at public facilities to determine whether they are at greater risk of developing respiratory allergies. Fifty-two employees from child daycare centers, elderly nursing homes, subway stations, and hypermarkets, and 17 office workers were recruited. All were subjected to a skin prick test (SPT) for 25 aeroallergens and the methacholine bronchial challenge test. Various immunological parameters, including plasma IgE and IgG4 levels, hematology parameters, and in vitro cytokine production from peripheral T cells, were assessed. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were also determined. Of the facility employees, 54% responded to the SPT, and house dust mite induced positive skin reactions most frequently. Compared to the SPT-negative facility employees and the office workers, the SPT-positive facility employees had upregulated plasma IgE levels and eosinophil frequency in their peripheral blood. Their peripheral T cells also showed elevated IL-4 production relative to IFNgamma production. Four public facility employees who reacted to the methacholine challenge test had elevated eosinophil frequencies, increased plasma IgE levels, and lowered FEV1/FVC values. This study suggests that workers at public facilities could show greater risk towards the development of respiratory allergic diseases.

Respiratory symptoms and lung function in 30-year-old individuals with alpha-1-antitrypsin deficiency

INTRODUCTION

Individuals with severe alpha-1-antitrypsin (AAT) deficiency have a well-known risk of developing emphysema but it is not known at which age the first symptoms occur and lung function declines. The aim of this study was to examine the prevalence of smoking, respiratory symptoms and lung function at the age of 30 in AAT-deficient individuals (PiZ and PiSZ) identified by neonatal screening.

MATERIAL AND METHODS

One hundred and seven PiZ, 45 PiSZ and 197 control subjects (PiMM) filled in a questionnaire regarding smoking habits and symptoms. Ninety PiZ, 40 PiSZ and 84 control subjects underwent spirometry including FEV(1) and FVC.

RESULTS

Twenty-one percent of PiZ, 23% of PiSZ and 34% of PiMM subjects had smoked at some time (p<0.05). Sixty-five percent of PiZ, 55% of PiSZ and 35% of PiMM ever-smokers reported shortness of breath on exertion (p<0.05 PiZ vs PiMM). The mean FEV(1) was 101% predicted (95% CI 98-104) in PiZ, 101% predicted (95% CI 97-106) in PiSZ, and 96% predicted (95% 93-98) in PiMM individuals (p<0.05). There was no difference in mean FEV(1) when comparing ever- and neversmokers in the different Pi groups separately.

CONCLUSION

At the age of 30, the AAT-deficient individuals in this cohort report more symptoms than the control subjects. Smoking is less common in the cohort compared to controls. Their lung function is normal.

Assessing future need for acute care in adult asthmatics: the Profile of Asthma Risk Study: a prospective health maintenance organization-based study

STUDY OBJECTIVES

To develop simple clinical tools predictive of acute asthma care and to identify modifiable risk factors.

DESIGN

Prospective cohort study.

SETTING

A large health maintenance organization (430,000 members).

PATIENTS/PARTICIPANTS

Adult members (18 to 55 years old) with asthma.

INTERVENTIONS

Data from a questionnaire, skin-prick testing for inhalant allergens, and spirometry were collected at the baseline visit. Acute care utilization data were obtained from administrative databases for a subsequent 30-month period.

METHODS

This two-phase study first identified and performed a split-sample validation on three clinical tools to determine their predictive ability by employing data from a questionnaire, questionnaire plus spirometry, and questionnaire plus spirometry and skin-prick testing. Second, it identified modifiable independent risk factors.

MEASUREMENTS AND RESULTS

The 554 study participants generated 173 episodes of acute care over 1,258 person-years of follow-up (0.14 episodes per person per year). Of these, 101 participants had at least one episode, and one third of this group had two or more episodes. Clinical scoring into risk groups was done by reverse stepwise regression analyses. Using relative risks (RRs) as a guide, high-risk, moderate-risk, and low-risk groups were identified. The high-risk groups, 13 to 21% of the validation sample, had a 7- to 11-fold increased risk for hospital care compared to the low-risk groups. The moderate-risk groups, 46 to 50% of the validation sample, had a twofold- to fourfold-increased risk. FEV(1) was the most significant predictor (RR, 4.33). Of the four potentially modifiable risk factors identified, current cigarette smoke exposure (RR, 1.6) and ownership and skin-prick test positivity to cat or dog (RR, 1.5) were the most significant.

CONCLUSIONS

These models stratify asthma patients at risk for acute care. Patients with lower FEV(1) values are at significantly higher risk, underscoring the importance of spirometry in asthma care.

Feasible and simple exclusion criteria for pulmonary reference populations

BACKGROUND

International guidelines recommend that pulmonary reference populations consist of never-smokers without respiratory diseases or symptoms, but the diseases and symptoms are not clearly specified. The present study aimed to identify simple exclusion criteria for defining pulmonary reference populations.

METHODS

Based on a random sample from a general population (the parent population), 2,358 subjects aged 26-82 years performed spirometric tests. From this sample, subjects were stepwise excluded according to self-reported obstructive lung diseases, symptoms and smoking history. Four increasingly more healthy respiratory reference populations were formed. Prediction equations for the median and lower limit of normal lung function were derived using quantile regression analysis.

RESULTS

Subjects without self-reported obstructive lung diseases or the cardinal respiratory symptoms of breathlessness, cough or wheeze (population B), never-smokers without cardinal symptoms (population C) and never-smokers without any respiratory symptoms (population D) constituted 50% (n = 1,184), 23% (n = 539) and 14% (n = 331) of the parent population (population A), respectively. The largest discrepancy between prediction equations was found between the parent population and the population without cardinal respiratory symptoms (population B) (p<0.05). Minor changes in the reference equations were also seen when excluding ever-smokers (population C). There was no additional change with exclusion of other respiratory symptoms (population D). Age-related decline in lung function was steepest in the parent population.

CONCLUSIONS

Obstructive lung diseases, smoking history, breathlessness, cough and wheeze are optimal exclusion criteria for a pulmonary reference population. Further validation of the exclusion criteria identified in this study is recommended with identical wording in other and larger multinational populations.

Asthma score: predictive ability and risk factors

BACKGROUND

Definition of asthma as a continuous score is a promising tool for population studies that has not yet been fully evaluated.

OBJECTIVE

We assessed (i) the predictive ability of an asthma score against the occurrence of different asthma-related outcomes and (ii) the risk factors identified when using an asthma score.

METHODS

The European Community Respiratory Health Study II included subjects from the general population randomly studied during 1991-1993 who were followed up in the years 1998-2001, from 29 centres in 14 countries. A total of 8956 subjects were included. The asthma score consisted of a simple sum of the positive answers to five respiratory symptoms.

RESULTS

Asthma score at baseline showed a linear relationship with incidence of asthma, the occurrence of asthma attacks, use of asthma medication and bronchial reactivity at the end of the follow-up. Asthma score at the end of follow-up was associated with known risk factors at baseline such as IgE to grass, rhinitis or body mass index, in addition to passive smoking in men [average score ratio (RR) = 1.30; 95% confidence interval (CI) 1.09-1.50] or changes in body mass index (RR = 1.27; 95% CI 1.05-1.27, per each kg/m(2)).

CONCLUSION

The asthma score had good predictive ability against outcomes related with asthma and also good ability to detect risk factors. This encourages the use of the score as a measure of asthma in epidemiological studies on aetiology of asthma.

Respiratory symptoms and 30 year mortality from obstructive lung disease and pneumonia

BACKGROUND

As little is known about the long term relationship between respiratory symptoms and mortality from non-malignant respiratory diseases, a study was undertaken to investigate the predictive value of respiratory symptoms and symptom load for mortality from obstructive lung disease (OLD) and pneumonia in the long term in a Norwegian population.

METHODS

In 1972, 19 998 persons aged 15-70 years living in Oslo were randomly selected for a respiratory survey. The response rate was 89%. All were followed for 30 years. The association between cough, asthma-like symptoms, two levels of dyspnoea on exercise, a symptom score, and mortality from OLD and pneumonia were investigated separately for men and women by multivariable analyses, with adjustment for age, occupational exposure to air pollution, and smoking habits.

RESULTS

OLD accounted for 43% and pneumonia for 50% of all deaths from respiratory causes. In men the hazard ratio for mortality from OLD varied from 4.0 (95% confidence interval (CI) 2.4 to 6.5) for cough to 9.6 (95% CI 5.1 to 18.3) for severe dyspnoea, and in women from 5.1 (95% CI 2.3 to 11.3) for moderate dyspnoea to 13.0 (95% CI 6.0 to 28.3) for severe dyspnoea. The symptom score was strongly predictive of death from OLD in a dose-response manner.

CONCLUSIONS

There is a significant, positive, strong association between respiratory symptoms and 30 year mortality from OLD. The association between respiratory symptoms and mortality from pneumonia is weaker and not significant.

Lung Function Decline, Chronic Bronchitis, and Occupational Exposures in Young Adults

RATIONALE

Occupational exposures to vapors, gas, dust, or fumes have been shown to be a risk factor of airway obstruction in cross-sectional studies in the general population.

OBJECTIVES

Our aim was to study the relationships between specific occupations and occupational exposures during a 9-yr follow-up period and changes in lung function and symptoms of chronic bronchitis.

METHODS

Subjects from the general population aged 20 to 45 yr were randomly selected in 1991-1993 within the European Community Respiratory Health Survey. Follow-up took place from 1998 to 2002 among 4,079 males and 4,461 females in 27 study centers. A total of 3,202 men and 3,279 women twice completed lung function measurements. Job history during follow-up was linked to a job exposure matrix and consequently translated into cumulative exposure estimates.

MAIN RESULTS

Individuals exposed to dusts, gases, and fumes during the period of follow-up did not have a steeper decline of FEV1 than did individuals with consistently white-collar occupations without occupational exposures (relative change among men and women, + 1.4 and -3.1 ml/yr, respectively; p > 0.2), nor an increase of prevalence or incidence of airway obstruction defined as an FEV1/FVC ratio of less than 0.7. The incidence of chronic phlegm increased in men exposed to mineral dust (relative risk, 1.94 [1.29-2.91]) and gases and fumes (relative risk, 1.53 [0.99-2.36]), which was not modified by smoking.

CONCLUSION

Occupational exposures to dusts, gases, and fumes occurring during the 1990s are associated with incidence of chronic bronchitis, although these did not impair lung function in a population of relatively young age.