Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Prevalence of COPD and Tobacco Smoking in Tunisia - Results from the BOLD Study

In Tunisia, there is a paucity of population-based data on Chronic Obstructive Pulmonary Disease (COPD) prevalence. To address this problem, we estimated the prevalence of COPD following the Burden of Lung Disease Initiative. We surveyed 807 adults aged 40+ years and have collected information on respiratory history and symptoms, risk factors for COPD and quality of life. Post-bronchodilator spirometry was performed and COPD and its stages were defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Six hundred and sixty one (661) subjects were included in the final analysis. The prevalence of GOLD Stage I and II or higher COPD were 7.8% and 4.2%, respectively (Lower Limit of Normal modified stage I and II or higher COPD prevalence were 5.3% and 3.8%, respectively). COPD was more common in subjects aged 70+ years and in those with a BMI < 20 kg/m(2). Prevalence of stage I+ COPD was 2.3% in <10 pack years smoked and 16.1% in 20+ pack years smoked. Only 3.5% of participants reported doctor-diagnosed COPD. In this Tunisian population, the prevalence of COPD is higher than reported before and higher than self-reported doctor-diagnosed COPD. In subjects with COPD, age is a much more powerful predictor of lung function than smoking

Growth and characterization of cubic GaN grown on GaAs (110) substrate by MOVPE

International audienceGaN layers were grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on GaAs (110) substrate at temperature varying in the range of 750–900 °C. 50 nm-thick GaN layer grown at low temperature (550 °C) was used as buffer layer. Scanning electron microscopy (SEM), atomic force microscopy (AFM), high resolution X-ray diffraction (HRXRD) and room temperature cathodoluminescence (RT-CL) studies were carried out and showed a large dependence of the crystalline and optical properties of GaN layer with the growth temperature. A mixture of cubic and hexagonal GaN phases is evidenced by the 2θ/ω spectra which are dominated by a broad peak associated to c-GaN (220) and h-GaN (11.0) reflections. The cubic GaN phase is maximal for a growth temperature of 850 °C. At this temperature, morphological observations by AFM showed the presence of c-GaN islands and RT-CL spectra showed only c-GaN (3.23 eV) emission whereas both emissions of c-GaN (3.23 eV) and h-GaN (3.39 eV) were observed at 900 °C

Prevalence of COPD and tobacco smoking in Tunisia - Results from the BOLD study.

In Tunisia, there is a paucity of population-based data on Chronic Obstructive Pulmonary Disease (COPD) prevalence. To address this problem, we estimated the prevalence of COPD following the Burden of Lung Disease Initiative. We surveyed 807 adults aged 40+ years and have collected information on respiratory history and symptoms, risk factors for COPD and quality of life. Post -bronchodilator spirometry was performed and COPD and its stages were defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Six hundred and sixty one (661) subjects were included in the final analysis. The prevalence of GOLD Stage I and II or higher COPD were 7.8% and 4.2%, respectively (Lower Limit of Normal modified stage I and II or higher COPD prevalence were 5.3% and 3.8%, respectively). COPD was more common in subjects aged 70+ years and in those with a BMI &lt; 20 kg/m2. Prevalence of stage I+ COPD was 2.3% in &lt;10 pack years smoked and 16.1% in 20+ pack years smoked. Only 3.5% of participants reported doctor-diagnosed COPD. In this Tunisian population, the prevalence of COPD is higher than reported before and higher than self-reported doctor-diagnosed COPD. In subjects with COPD, age is a much more powerful predictor of lung function than smoking

COPD in nonsmokers: Reports from the Tunisian population-based burden of obstructive lung disease study

Background It’s currently well known that smoking and increasing age constitute the most important risk factors for chronic obstructive pulmonary disease (COPD). However, little is known about COPD among nonsmokers. The present study aimed to investigate prevalence, risk factors and the profiles of COPD among nonsmokers based on the Tunisian Burden of Obstructive Lung Disease (BOLD) study. Methods 807 adults aged 40 years+ were randomly selected from the general population. We collected information about history of respiratory disease, risk factors for COPD and quality of life. Post-bronchodilator spirometry was performed for assessment of COPD. COPD diagnostic was based on the post-bronchodilator FEV1/FVC ratio, according to the Global Initiative for Obstructive Lung Disease (GOLD) guidelines. The lower limit of normal (LLN) was determined as an alternative threshold for the FEV1/FVC ratio. Results and Conclusions Among 485 nonsmokers, 4.7% met the criteria for GOLD grade I and higher COPD. These proportions were similar even when the LLN was used as a threshold. None of the nonsmokers with COPD reported a previous doctor diagnosis of COPD compared to 7.1% of smokers. Nonsmokers accounted for 45.1% of the subjects fulfilling the GOLD spirometric criteria of COPD. Nonsmokers were predominately men and reported more asthma problems than obstructed smokers. Among nonsmokers significantly more symptoms and higher co-morbidity were found among those with COPD. Increasing age, male gender, occupational exposure, lower body mass index and a previous diagnosis of asthma are associated with increased risk for COPD in nonsmokers. This study confirms previous evidence that nonsmokers comprise a substantial proportion of individuals with COPD. Nonsmokers with COPD have a specific profile and should, thus, receive far greater attention to prevent and treat chronic airway obstruction.</p