Pulmonary changes on HRCT scans in nonsmoking females with COPD due to wood smoke exposure

Association between biomass exposure and COPD occurrence in Fez, Morocco: results from the BOLD study

OBJECTIVE

To investigate the association between biomass exposure and chronic obstructive pulmonary disease (COPD) in a representative sample of adults from the Moroccan population METHODS: A cross-sectional study was conducted in Fez as part of the Burden of Obstructive Lung Disease (BOLD) study, which included apparently healthy subjects aged 40 years and above. Biomass exposure was defined as self-report use of various biomass types for heating or cooking. The Wood Heating Exposure Index, and the Cooking Biomass Exposure Index were used to assess biomass exposure. Participants underwent post-bronchodilator spirometry and COPD was defined as having a forced expiratory volume in 1 s/forced vital capacity ratio <0.7. Descriptive, univariate and multivariable statistical analyses adjusting for potential confounders including age, sex, smoking, education level, Mokken scale (wealth index) and occupational dust exposure were performed for the general population and separately for men and women.

RESULTS

A total of 760 subjects were included, comprising 350 men and 410 women. In the multivariable analyses, we found a statistically significant association between a higher Wood Heating Exposure Index and COPD in men (adjusted OR=3.8; 95% CI: 1.4 to 10.4). While for women, a high Cooking Biomass Exposure Index was the main factor potentially linked to the increased risk of COPD (adjusted OR=7.2; 95% CI: 1.7 to 30.0).

CONCLUSION

This study suggests that biomass exposure is a significant risk factor for COPD development in both men and women, independently of the smoking status which is known as its main risk factor.

Occupational lung disease: when should I think of it and why is it important?

Exposure to toxic inhalants in the workplace has the potential to cause (in susceptible individuals) almost any major type of lung disease, such as asthma, COPD and interstitial lung diseases. Patients with occupational lung disease will often present to or will be managed by respiratory specialists without training in occupational respiratory medicine, and patients (or their clinicians) may not identify a link between their disease and their current or a past job. Without an awareness of the range of different occupational lung diseases that exist, their similarity to their non-occupational counterparts, and without directed questioning, these conditions may go unidentified. Patients with occupational lung diseases are often in lower paid work and are disproportionally affected by health inequality. Both clinical and socioeconomic outcomes generally improve if cases are identified early. This allows appropriate advice to be given about the risks of ongoing exposure, clinical management, occupational mobility and, in some cases, eligibility for legal compensation. As respiratory professionals, it is important that these cases are not missed, and if needed, are discussed with a physician with specialised expertise. Here we describe some of the most common occupational lung diseases and outline the diagnostic and treatment approach.

Residential radon and characteristics of chronic obstructive pulmonary disease

It is not known whether residential radon exposure may be linked to the development of chronic obstructive pulmonary disease (COPD) and/or have an influence on the functional characteristics or exacerbations of COPD. The aim of this study was therefore to ascertain whether there might be an association between residential radon concentrations and certain characteristics of COPD. We analyzed COPD cases drawn from a case-control study conducted in an area of high radon exposure. Data were collected on spirometric pulmonary function variables, hospital admissions, and smoking. Radon measurements were taken using alpha-track-type CR-39 detectors individually placed in patients' homes. All statistical analyses were performed using the IBM SPSS v22 computer software program. The study included 189 COPD cases (79.4% men; median age 64 years). The median radon concentration was 157 Bq/m3. No differences were found between radon concentration and sex, age or severity of breathing obstruction as measured by FEV1%. It should be noted, however, that 48.1% of patients with FEV1% < 50 had radon concentrations below 100 Bq/m3, as compared to 35.6% with the same severity of obstruction who had over 300 Bq/m3. COPD cases with radon concentrations higher than > 600 Bq/m3 exhibited no different characteristics in lung function. Exposure to radon does not appear to have an influence on the clinical characteristics of smokers and ex-smokers with COPD. As exposure to residential radon increases, there is no trend towards a worsening of FEV1%. Further studies are thus needed to analyze this possible association in never-smokers with COPD.

The "Slow Horse Racing Effect" on Lung Function in Adult Life in Chronic Obstructive Pulmonary Disease Associated to Biomass Exposure

Although different trajectories in lung function decline have been identified in patients with COPD associated to tobacco exposure (TE-COPD), genetic, environmental, and infectious factors affecting lung function throughout life have not been fully elucidated in patients with COPD associated to biomass (BE-COPD). In this review, we present current epidemiological findings and notable advances in the natural history of lung decline in BE-COPD, as well as conditions modeling the FEV₁ trajectory, such as health insults, during the first years of childhood. Evidence shows that women exposed to biomass smoke reach adult life with a lower FEV₁ than expected. However, in contrast to the “horse racing effect” predicting an excessive lung-function decline in forthcoming years, as observed in smokers, this decline is slower in non-smokers, and no rapid decliners are observed. Accordingly, BE-COPD might be considered another phenotype of COPD based on assessments of lung function decline. Likewise, other functional and clinical aspects described in this review suggest that this condition might be similar to TE-COPD. More research is needed to fully characterize this subgroup of variants of COPD.

Exposure to the use of firewood for cooking in Brazil and its relation with the health problems of the population

Indoor air pollution is exacerbated by the burning of firewood in rustic stoves and poorly ventilated environments. Exposure to the pollutants emitted by this type of fuel results in increased morbidity and mortality. In Brazil, studies and estimates regarding these conditions are scarce. In order to understand this problem, the objective of this work was to investigate the use of firewood using the data series of government agencies to estimate the number of exposed people. The results indicated that firewood is the second most used fuel for cooking, being used by a significant portion of the population, more than 30 million Brazilians. A decisive factor in the increased use of this fuel is the socioeconomic level of the population associated with the price of liquefied petroleum gas (LPG). The studies carried out in the country recorded high concentrations of particles during firewood burning, exceeding the limits suggested by the World Health Organization (WHO). Associations were also observed between the exposure to the pollutants generated by the burning and the aggravation of health problems, among them respiratory diseases and cancer. Replacing fuelwood and other solid fuels with cleaner fuels should be the government's goal to minimize health costs.

Biomass smoke COPD has less tomographic abnormalities but worse hypoxemia compared with tobacco COPD

Special attention has emerged towards biomass smoke-induced chronic obstructive pulmonary disease (COPD), providing new knowledge for prevention and therapeutic approach of non-smoker COPD patients. However, the understanding of biomass smoke COPD is still limited and somewhat controversial. The aim of the present study was to compare COPD exclusively caused by tobacco smoking with COPD exclusively caused by environmental or occupational exposures. For this cross-sectional study, COPD patients were recruited from outpatient clinics and formed two groups: non-smoker COPD group (n=16) with exposure to biomass smoke who did not smoke cigarette and tobacco smoker COPD group (n=15) with people who did not report biomass smoke exposure. Subjects underwent pulmonary function tests, thoracic high-resolution computed tomography, 6-min walk test, and sputum induction. The non-smoker COPD group had biomass smoke exposure of 133.3±86 hour-years. The tobacco COPD group smoked 48.5±27.4 pack-years. Women were 62.5 and 66.7%, respectively, of non-smokers and smokers. The non-smoker COPD group showed higher prevalence of dyspnea, lower arterial oxygen tension (PaO2), and lower arterial oxygen saturation (SaO2%) with similar spirometry results, lung volumes, and diffusion capacity. Regarding inflammatory biomarkers, differences were detected in sputum number of lymphomononuclear cells and in sputum concentrations of interleukin (IL)-6 and IL-8 with higher values in the smoker group. Emphysema was more prevalent in the tobacco smoker group, which also showed higher relative bronchial wall thickness and lower lung density by quantitative analysis. Biomass smoke induced more hypoxemia compared to tobacco in COPD patients with similar severity.

Chronic Obstructive Pulmonary Disease in Latin America

The PLATINO and PREPOCOL population-based studies documented the prevalence of chronic obstructive pulmonary disease (COPD) in several Latin American (Mexico City, Sao Paulo, Montevideo, Santiago and Caracas) and Colombian (Medellin, Bogota, Barranquilla, Bucaramanga and Cali) cities. COPD ranged between 6.2 and 19.6% in individuals ≥40 years of age, with substantial rates of underdiagnosis (up to 89%) but also overdiagnosis, mostly due to the lack of spirometric confirmation. The main risk factor was tobacco smoking, but male gender and age were also associated with COPD. COPD in never smokers represented about one third of the cases and was associated with previous history of tuberculosis or a diagnosis of asthma. COPD associated with biomass smoke exposure was a common clinical phenotype in Latin America, found as a risk factor in PREPOCOL and other observational studies in the region. Smoking has been decreasing in Latin America and efforts have been made to implement cleaner biomass stoves. Unfortunately, treatment of COPD in Latin America remains highly variable with low rates of smoking cessation counselling, low use of inhaled bronchodilators and influenza vaccination. A primary-care approach to COPD, particularly in the form of integrated programs is lacking but would be critical to improving rates of diagnosis and treatment of COPD.

Increased Airway Wall Thickness is Associated with Adverse Longitudinal First-Second Forced Expiratory Volume Trajectories of Former World Trade Center workers

RATIONALE

Occupational exposures at the WTC site after September 11, 2001 have been associated with several presumably inflammatory lower airway diseases. In this study, we describe the trajectories of expiratory air flow decline, identify subgroups with adverse progression, and investigate the association of a quantitative computed tomography (QCT) imaging measurement of airway wall thickness, and other risk factors for adverse progression.

METHODS

We examined the trajectories of expiratory air flow decline in a group of 799 former WTC workers and volunteers with QCT-measured (with two independent systems) wall area percent (WAP) and at least 3 periodic spirometries. We calculated individual regression lines for first-second forced expiratory volume (FEV₁), identified subjects with rapidly declining and increasing ("gainers"), and compared them to subjects with normal and "stable" FEV₁ decline. We used multivariate logistic regression to model decliner vs. stable trajectories.

RESULTS

The mean longitudinal FEV₁slopes for the entire study population, and its stable, decliner, and gainer subgroups were, respectively, - 35.8, - 8, - 157.6, and + 173.62 ml/year. WAP was associated with "decliner" status (OR_adj 1.08, 95% CI 1.02, 1.14, per 5% increment) compared to stable. Age, weight gain, baseline FEV₁ percent predicted, bronchodilator response, and pre-WTC occupational exposures were also significantly associated with accelerated FEV₁ decline. Analyses of gainers vs. stable subgroup showed WAP as a significant predictor in unadjusted but not consistently in adjusted analyses.

CONCLUSIONS

The apparent normal age-related rate of FEV₁ decline results from averaging widely divergent trajectories. WAP is significantly associated with accelerated air flow decline in WTC workers.

Comparative analysis of COPD associated with tobacco smoking, biomass smoke exposure or both

Background

Exposure to noxious gases and particles contained in both tobacco smoking (TS) and biomass smoke (BS) are well recognized environmental risk factors for chronic obstructive pulmonary disease (COPD). COPD is characterized by an abnormal inflammatory response, both in the pulmonary and systemic compartments. The differential effects of TS, BS or their combined exposure have not been well characterized yet. This study sought to compare the lung function characteristics and systemic inflammatory response in COPD patients exposed to TS, BS or their combination.

Methods

Sociodemographic, clinical and lung functional parameters were compared across 49 COPD patients with a history of smoking and no BS exposure (TS COPD), 31 never-smoker COPD patients with BS exposure (BS COPD), 46 COPD patients with a combined exposure (TS + BS COPD) and 52 healthy controls (HC) who have never been exposed neither to TS or BS. Blood cell counts, C-reactive protein (CRP), fibrinogen and immunoglobulin E (IgE) levels were quantified in all four groups.

Results

TS + BS COPD patients exhibited significantly lower oxygen saturation than the rest of groups (p < 0.01). Spirometry and diffusing capacity were significantly higher in BS than in TS or TS + BS patients. CRP levels were significantly higher in TS COPD patients than in BS COPD group (p < 0.05), whereas fibrinogen was raised in COPD patients with a history of smoking (TS and TS + BS) when compared to control subjects (p < 0.01). Finally, COPD patients with BS exposure (BS and BS + TS groups) showed higher IgE levels than TS and HC (p < 0.05).

Conclusions

There are significant physiological and inflammatory differences between COPD patients with TS, BS and TS + BS exposures. The latter had worse blood oxygenation, whereas the raised levels of IgE in BS exposed patients suggests a differential Th2 systemic inflammatory pattern triggered by this pollutant.

Review of biomarkers to assess the effects of switching from cigarettes to modified risk tobacco products

Context: One approach to reducing the harm caused by cigarette smoking, at both individual and population level, is to develop, assess and commercialize modified risk alternatives that adult smokers can switch to. Studies to demonstrate the exposure and risk reduction potential of such products generally involve the measuring of biomarkers, of both exposure and effect, sampled in various biological matrices.Objective: In this review, we detail the pros and cons for using several biomarkers as indicators of effects of changing from conventional cigarettes to modified risk products.Materials and methods: English language publications between 2008 and 2017 were retrieved from PubMed using the same search criteria for each of the 25 assessed biomarkers. Nine exclusion criteria were applied to exclude non-relevant publications.Results: A total of 8876 articles were retrieved (of which 7476 were excluded according to the exclusion criteria). The literature indicates that not all assessed biomarkers return to baseline levels following smoking cessation during the study periods but that nine had potential for use in medium to long-term studies.Discussion and conclusion: In clinical studies, it is important to choose biomarkers that show the biological effect of cessation within the duration of the study.

Thorax Computed Tomography Findings in Patients with Erectile Dysfunction

Objective:

Diabetes mellitus, smoking, dyslipidemia, and obesity play an important role in the etiology of erectile dysfunction, particularly in cases with vascular insufficiency. These risk factors also target the lungs due to their systemic effects.

Materials and Methods:

Patients with penile vascular insufficiency determined at Doppler ultrasonography and undergoing thoracic computerized tomography for various reasons were included in this study. A history of acute thoracic trauma, pneumonic consolidation, or pelvic surgery and trauma were regarded as exclusion criteria.

Results:

Thirty-seven male patients with identified vascular insufficiency (age 54.48 ± 13.62 years) were enrolled. Mass lesions with a malignant morphology were present in two patients. The most common mediastinal/vascular pathology was atherosclerosis, while the most common parenchymal lesion was emphysematous aeration. Other findings included parenchymal fibrotic bands, atelectasis, interstitial thickening, bronchiectasis, air trapping, aortic aneurysm, a dilated pulmonary artery, hiatal hernia, and pericardial effusion.

Conclusion:

Erectile dysfunction may be an early sign of cardiovascular diseases. Care must be taken in terms of existing or potential pulmonary pathologies in these patients due to their sharing common risk factors with systemic effects.

Is Chronic Obstructive Pulmonary Disease Caused by Wood Smoke a Different Phenotype or a Different Entity?

Around 40% of the world's population continue using solid fuel, including wood, for cooking or heating their homes. Chronic exposure to wood smoke is a risk factor for developing chronic obstructive pulmonary disease (COPD). In some regions of the world, this can be a more important cause of COPD than exposure to tobacco smoke from cigarettes. Significant differences between COPD associated with wood smoke (W-COPD) and that caused by smoking (S-COPD) have led some authors to suggest that W-COPD should be considered a new COPD phenotype. We present a review of the differences between W-COPD and S-COPD. On the premise that wood smoke and tobacco smoke are not the same and the physiopathological mechanisms they induce may differ, we have analyzed whether W-COPD can be considered as another COPD phenotype or a distinct nosological entity.

The chronic bronchitis phenotype in chronic obstructive pulmonary disease: features and implications

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is a major public health problem that is projected to rank fifth worldwide in terms of disease burden and third in terms of mortality. Chronic bronchitis is associated with multiple clinical consequences, including hastening lung function decline, increasing risk of exacerbations, reducing health-related quality of life, and possibly raising all-cause mortality. Recent data suggest greater elucidation on the risk factors, radiologic characteristics, and treatment regimens. Our goal was to review the literature on chronic bronchitis that has been published in the past few years.

RECENT FINDINGS

A growing body of literature that more carefully describes environmental risk factors, epidemiology, and genetics associated with chronic bronchitis. In addition, as computed tomography technology continues to improve, the radiologic phenotype associated with chronic bronchitis is better understood.

SUMMARY

With these new data, the clinician can recognize the newly described risk factors and the associated phenotype for chronic bronchitis and entertain new treatment options for this high-risk population.

Pathogenic mechanisms in chronic obstructive pulmonary disease due to biomass smoke exposure

Chronic obstructive pulmonary disease (COPD) mortality and morbidity have increased significantly worldwide in recent decades. Although cigarette smoke is still considered the main risk factor for the development of the disease, estimates suggest that between 25% and 33% of COPD patients are non-smokers. Among the factors that may increase the risk of developing COPD, biomass smoke has been proposed as one of the most important, affecting especially women and children in developing countries. Despite the epidemiological evidence linking exposure to biomass smoke with adverse health effects, the specific cellular and molecular mechanisms by which this pollutant can be harmful for the respiratory and cardiovascular systems remain unclear. In this article we review the main pathogenic mechanisms proposed to date that make biomass smoke one of the major risk factors for COPD.

Clinical Characteristics of Patients With Biomass Smoke-Associated COPD and Chronic Bronchitis, 2004-2014

Individuals with chronic obstructive pulmonary disease (COPD) associated with biomass smoke inhalation tend to be women born in rural areas with lifelong exposure to open fires while cooking, but can also include persons with prenatal and childhood exposure. Compared with individuals with COPD due to tobacco smoking, individuals exposed to biomass smoke uncommonly have severe airflow obstruction, low diffusing capacity of the lung for carbon monoxide (DLCO) or emphysema in high-resolution computed tomography (HRCT) but cough, phlegm and airway thickening and air trapping are very common. Autopsies of patients with COPD from biomass smoke exposure show increased pulmonary artery small vessel intimal thickening which may explain pulmonary hypertension, in addition to emphysema and airway disease. Research on similarities and differences in lung damage produced by exposure to biomass fuel smoke while cooking vs. smoking tobacco may provide new insights on COPD. As a public health problem, COPD caused by inhalation of smoke from burning solid fuel is as relevant as COPD caused by smoking tobacco but mainly affects women and children from disadvantaged areas and countries and requires an organized effort for its control. Improved vented biomass stoves are currently the most feasible intervention, but even more efficient stoves are necessary to reduce the biomass smoke exposure and reduce incidence of COPD among this population.