COPD in never smokers: results from the population-based burden of obstructive lung disease study

The association between psoriasis and chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

Psoriasis is a chronic T-cell-mediated inflammatory and proliferative skin disease. Chronic obstructive pulmonary disease (COPD) is an inflammatory disease of the airways. COPD has been studied as a comorbidity of psoriasis, but the association needs further study, hence the objective of this study.

EVIDENCE ACQUISITION

A systematic review was performed using the database PubMed and 155 records were found including the ones found through references. Seven records were found eligible for this study including six observational studies and one experimental study with a total of 229,075 participants. The odds ratio of COPD in patients with psoriasis and healthy subjects was analysed using a random effects model.

EVIDENCE SYNTHESIS

The pooled data showed a significant association (OR=1.77, 95% CI [1.32; 2.39]) between psoriasis and COPD with high inter-study heterogeneity (I2=96%). Sub-analyses of the different types of studies (cohort study: OR=2.53 [2.43; 2.63], case-control study: OR=1.6 [0.03; 100.96] and cross-sectional study: OR=1.57 [0.58; 4.22]) and smoking status (OR=1.7 [0.69; 4.14]) were also performed to further examine the association.

CONCLUSIONS

There is a significant association between psoriasis and COPD, but the underlying mechanism and how smoking status affects the results remain unclear and need further study. Physicians should be aware of the risk and its seriousness to provide better and more targeted treatment.

Application of the Lancet Commission COPD classification to COPD Cohort Population in South Korea

The Lancet Commissions on COPD recommended a new classification based on five main risk factors. Patients with COPD were prospectively enrolled in a Korean COPD subgroup study cohort between April 2012 and June 2022. Patients were classified according to the etiologies (Type 1: Genetically determined (COPD-G), Type 2: Abnormal lung development (COPD-D), Type 3: Infections (COPD-I), Type 4: Cigarette smoking (COPD-C), Type 5: Biomass and pollution (COPD-P)). The database enrolled 3476 patients. Among 3392 patients, 52 (2 %), 1339 (39 %), 2930 (86 %), and 2221 (65 %) were compatible with type 2 (COPD-D), 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Most patients (71 %, 2405) had multiple risk factors contributing to their COPD. However, 93, 712, and 182 patients had only type 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Type 3 (COPD-I) only patients were significantly younger, more often female, and had lower lung function. Both the rate and frequency of severe exacerbations were significantly higher in type 3 (COPD-I) only patients (p = 0.038 and p = 0.048, respectively). Compared with type 5 (COPD-P) only, type 3 (COPD-I) only was significantly associated with the risk of severe exacerbation (Odds ratio, 5.7 [95 % CI, 1.0-32.4]; P = 0.049, incident rate ratio, 8.7 [95 % CI, 1.7-44.0]; P = 0.009). Many patients were affected by multiple factors. Therefore, it is important to consider not only smoking history, but also other potential risk factors when evaluating patients with COPD. Further research is needed to explore the implications of this new COPD classification system for clinical practice and treatment strategies.

Availability of Receptors for Advanced Glycation End-Products (RAGE) Influences Differential Transcriptome Expression in Lungs from Mice Exposed to Chronic Secondhand Smoke (SHS)

The receptor for advanced glycation end-products (RAGE) has a central function in orchestrating inflammatory responses in multiple disease states including chronic obstructive pulmonary disease (COPD). RAGE is a transmembrane pattern recognition receptor with particular interest in lung disease due to its naturally abundant pulmonary expression. Our previous research demonstrated an inflammatory role for RAGE following acute exposure to secondhand smoke (SHS). However, chronic inflammatory mechanisms associated with RAGE remain ambiguous. In this study, we assessed transcriptional outcomes in mice exposed to chronic SHS in the context of RAGE expression. RAGE knockout (RKO) and wild-type (WT) mice were delivered nose-only SHS via an exposure system for six months and compared to control mice exposed to room air (RA). We specifically compared WT + RA, WT + SHS, RKO + RA, and RKO + SHS. Analysis of gene expression data from WT + RA vs. WT + SHS showed FEZ1, Slpi, and Msln as significant at the three-month time point; while RKO + SHS vs. WT + SHS identified cytochrome p450 1a1 and Slc26a4 as significant at multiple time points; and the RKO + SHS vs. WT + RA revealed Tmem151A as significant at the three-month time point as well as Gprc5a and Dynlt1b as significant at the three- and six-month time points. Notable gene clusters were functionally analyzed and discovered to be specific to cytoskeletal elements, inflammatory signaling, lipogenesis, and ciliogenesis. We found gene ontologies (GO) demonstrated significant biological pathways differentially impacted by the presence of RAGE. We also observed evidence that the PI3K-Akt and NF-κB signaling pathways were significantly enriched in DEGs across multiple comparisons. These data collectively identify several opportunities to further dissect RAGE signaling in the context of SHS exposure and foreshadow possible therapeutic modalities.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BACKGROUND

Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.

METHODS

The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.

RESULTS

High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.

CONCLUSIONS

PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

The Role of Nutrition in the Development and Management of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a prevalent lung condition associated with significant morbidity and mortality. The management of COPD classically involves pulmonary rehabilitation, bronchodilators, and corticosteroids. An aspect of COPD management that is currently lacking in the literature is nutritional management, despite the prevalence of inadequate nutritional status in patients with COPD. In addition, certain nutritional imbalances have been reported to increase the risk of COPD development. This review summarizes the current literature on the role diet and nutrients may play in the risk and management of COPD development.

Particulate matter-induced metabolic recoding of epigenetics in macrophages drives pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a group of illnesses associated with unresolved inflammation in response to toxic environmental stimuli. Persistent exposure to PM is a major risk factor for COPD, but the underlying mechanism remains unclear. Using our established mouse model of PM-induced COPD, we find that repeated PM exposure provokes macrophage-centered chronic inflammation and COPD development. Mechanistically, chronic PM exposure induces transcriptional downregulation of HAAO, KMO, KYNU, and QPRT in macrophages, which are the enzymes of de novo NAD+ synthesis pathway (kynurenine pathway; KP), via elevated chromatin binding of the CCCTC-binding factor (CTCF) near the transcriptional regulatory regions of the enzymes. Subsequent reduction of NAD+ and SIRT1 function increases histone acetylation, resulting in elevated expression of pro-inflammatory genes in PM-exposed macrophages. Activation of SIRT1 by nutraceutical resveratrol mitigated PM-induced chronic inflammation and COPD development. In agreement, increased levels of histone acetylation and decreased expression of KP enzymes were observed in pulmonary macrophages of COPD patients. We newly provide an evidence that dysregulated NAD+ metabolism and consecutive SIRT1 deficiency significantly contribute to the pathological activation of macrophages during PM-mediated COPD pathogenesis. Additionally, targeting PM-induced intertwined metabolic and epigenetic reprogramming in macrophages is an effective strategy for COPD treatment.

Blood-based Transcriptomic and Proteomic Biomarkers of Emphysema

Rationale: Emphysema is a chronic obstructive pulmonary disease phenotype with important prognostic implications. Identifying blood-based biomarkers of emphysema will facilitate early diagnosis and development of targeted therapies. Objectives: To discover blood omics biomarkers for chest computed tomography-quantified emphysema and develop predictive biomarker panels. Methods: Emphysema blood biomarker discovery was performed using differential gene expression, alternative splicing, and protein association analyses in a training sample of 2,370 COPDGene participants with available blood RNA sequencing, plasma proteomics, and clinical data. Internal validation was conducted in a COPDGene testing sample (n = 1,016), and external validation was done in the ECLIPSE study (n = 526). Because low body mass index (BMI) and emphysema often co-occur, we performed a mediation analysis to quantify the effect of BMI on gene and protein associations with emphysema. Elastic net models with bootstrapping were also developed in the training sample sequentially using clinical, blood cell proportions, RNA-sequencing, and proteomic biomarkers to predict quantitative emphysema. Model accuracy was assessed by the area under the receiver operating characteristic curves for subjects stratified into tertiles of emphysema severity. Measurements and Main Results: Totals of 3,829 genes, 942 isoforms, 260 exons, and 714 proteins were significantly associated with emphysema (false discovery rate, 5%) and yielded 11 biological pathways. Seventy-four percent of these genes and 62% of these proteins showed mediation by BMI. Our prediction models demonstrated reasonable predictive performance in both COPDGene and ECLIPSE. The highest-performing model used clinical, blood cell, and protein data (area under the receiver operating characteristic curve in COPDGene testing, 0.90; 95% confidence interval, 0.85-0.90). Conclusions: Blood transcriptome and proteome-wide analyses revealed key biological pathways of emphysema and enhanced the prediction of emphysema.

COPD and Smoking Status - It Does Matter: Characteristics and Prognosis of COPD According to Smoking Status

Background

Chronic obstructive pulmonary disease is a chronic, often progressive disease, which in most patients is caused by tobacco smoking. Our study focuses on differences in COPD-related outcomes between never smokers, former smokers, and current smokers.

Methods

A nationwide, population-based cohort study utilizing Danish health registries. Clinical and socioeconomic variables including smoking status, comorbidities, and dyspnea were obtained. Poisson and Cox Regression were used to calculate the impact of these clinical parameters on the risk of moderate and severe exacerbations and mortality during 12 months of follow-up.

Results

A total of 49,826 patients ≥40 years of age, with a hospital diagnosis of COPD in 2008-2017, were identified (mean age 69.2 years, 52% females). A total of 2127 (4%) were never smokers, 29,854 (60%) were former smokers and 17,845 (36%) current smokers. Compared to former and current smokers, never smokers reported a lower modified Medical Research Council score and had a milder COPD stage according to the Global Initiative for Chronic Obstructive Lung Disease classification. During follow-up, never smokers had a significantly lower risk of severe exacerbations (hazard ratio 0.87, 95% confidence interval [CI] 0.78-0.97) and a lower rate of death (mortality ratio 0.75, 95% CI 0.70-0.81) compared to patients with a smoking history.

Discussion

Our nationwide study showed that COPD in never smokers is characterized by a lower level of dyspnea, milder lung function impairment, and a lower risk of exacerbations and death. At the same time, we found active smokers to have the highest risk. These findings highlight the need for campaigns to prevent smoking and may help general practitioners as well as other health care professionals to motivate patients with COPD to stop smoking.

COPD in Never-Smokers: BOLD Australia Study

Purpose

Tobacco smoking is the major risk factor for COPD, and it is common for other risk factors in never-smokers to be overlooked. We examined the prevalence of COPD among never-smokers in Australia and identified associated risk factors.

Methods

We used data from the Australia Burden of Obstructive Lung Disease (BOLD) study, a cross-section of people aged ≥40 years from six sites. Participants completed interviews and post-bronchodilator spirometry. COPD was primarily defined as an FEV1/FVC ratio <0.70 and secondarily as the ratio less than the lower limit of normal (LLN).

Results

The prevalence of COPD in the 1656 never-smokers who completed the study was 10.5% (95% CI: 9.1-12.1%) [ratio

Conclusion

COPD was prevalent in this population of never-smokers aged 40 years and over. This finding highlights the significance of risk factors other than smoking in the development of COPD.

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Key Words

• BOLD
• LLN
• burden of obstructive lung disease
• lower limit of normal
• non-smokers
• prevalence
• spirometry

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MESH Headings

• Female
• Male
• Humans
• Adult
• Middle Aged
• Child
• Smokers
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Asthma
• Odds Ratio
• Australia/epidemiology

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Grants

• National Health and Medical Research Council (NHMRC) of Australia
• Thoracic Society of Australia and New Zealand
• Robert Pierce Grant-in-Aid for Indigenous Lung Health
• Air Liquide, AstraZeneca; GlaxoSmithKline; and Boehringer Ingelheim

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Affiliation(s)

Marsha A Ivey School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia School of Medicine, Faculty of Medical Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
Sheree M Smith School of Nursing and Midwifery, Campbelltown Campus, Western Sydney University, Penrith, NSW, 2751, Australia Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
Geza Benke School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
Brett G Toelle Respiratory and Environmental Epidemiology Group, Woolcock Institute of Medical Research, Sydney, NSW, 2037, Australia Sydney Local Health District, Sydney, NSW, 2050, Australia
Michael L Hunter School of Population and Global Health, University of Western Australia, Perth, WA, 6009, Australia
Alan L James Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital and Medical School, University of Western Australia, Perth, WA, 6009, Australia
Graeme P Maguire Curtin Medical School, Curtin University, Perth, WA, 6102, Australia
Richard Wood-Baker School of Medicine, University of Tasmania, Hobart, TAS, 7000, Australia
David P Johns Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
Guy B Marks Respiratory and Environmental Epidemiology Group, Woolcock Institute of Medical Research, Sydney, NSW, 2037, Australia School of Clinical Medicine, University of New South Wales, Sydney, NSW, 2052, Australia
Michael J Abramson School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia

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Sex differences in chronic obstructive pulmonary disease characteristics: the Korea National Health and Nutrition Examination Survey 2007-2018

BACKGROUND/AIMS

Chronic obstructive pulmonary disease (COPD) is less prevalent in females than males, but it affects mortality in females. There may be sex differences in the clinical characteristics of COPD.

METHODS

We analyzed the Korea National Health and Nutrition Examination Survey dataset from 2007 to 2018. We compared the clinical characteristics and comorbidities in subjects with COPD according to sex. We adjusted the multivariate logistic regression of lung cancer prevalence according to COPD and sex by age and smoking amount.

RESULTS

Females with COPD tended to be older than males with COPD (64.1 ± 0.4 yr vs. 62.3 ± 0.2 yr, respectively, p < 0.001). Approximately 89% of males with COPD had a smoking history, while 86% of females with COPD were non-smokers (p < 0.001). Household income was lower (p < 0.001) and asthma and overall malignancy were more prevalent in females with COPD than males with COPD (25.5 vs. 11.6%, respectively, p < 0.001; (6.3 vs. 5.4%, respectively, p < 0.001). However, lung cancer was more common in males with COPD than females with COPD (0.9 vs. 0.1%, respectively, p < 0.001). Lung cancer prevalence increased in males with moderate COPD compared to subjects without COPD (OR, 4.409; 95% CI, 1.741-9.419).

CONCLUSION

Females with COPD had a lower smoking rate, household income, and lung cancer prevalence than males with COPD. More active COPD screening is needed for women of low socioeconomic status, even if they do not smoke.

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.

RETRO-POPE: A Retrospective, Multicenter, Real-World Study of All-Cause Mortality in COPD

Purpose

The Phenotypes of COPD in Central and Eastern Europe (POPE) study assessed the prevalence and clinical characteristics of four clinical COPD phenotypes, but not mortality. This retrospective analysis of the POPE study (RETRO-POPE) investigated the relationship between all-cause mortality and patient characteristics using two grouping methods: clinical phenotyping (as in POPE) and Burgel clustering, to better identify high-risk patients.

Patients and Methods

The two largest POPE study patient cohorts (Czech Republic and Serbia) were categorized into one of four clinical phenotypes (acute exacerbators [with/without chronic bronchitis], non-exacerbators, asthma-COPD overlap), and one of five Burgel clusters based on comorbidities, lung function, age, body mass index (BMI) and dyspnea (very severe comorbid, very severe respiratory, moderate-to-severe respiratory, moderate-to-severe comorbid/obese, and mild respiratory). Patients were followed-up for approximately 7 years for survival status.

Results

Overall, 801 of 1,003 screened patients had sufficient data for analysis. Of these, 440 patients (54.9%) were alive and 361 (45.1%) had died at the end of follow-up. Analysis of survival by clinical phenotype showed no significant differences between the phenotypes (P=0.211). However, Burgel clustering demonstrated significant differences in survival between clusters (P<0.001), with patients in the "very severe comorbid" and "very severe respiratory" clusters most likely to die. Overall survival was not significantly different between Serbia and the Czech Republic after adjustment for age, BMI, comorbidities and forced expiratory volume in 1 second (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.65-0.99; P=0.036 [unadjusted]; HR 0.88, 95% CI 0.7-1.1; P=0.257 [adjusted]). The most common causes of death were respiratory-related (36.8%), followed by cardiovascular (25.2%) then neoplasm (15.2%).

Conclusion

Patient clusters based on comorbidities, lung function, age, BMI and dyspnea were more likely to show differences in COPD mortality risk than phenotypes defined by exacerbation history and presence/absence of chronic bronchitis and/or asthmatic features.

Lower Airway Dysbiosis Augments Lung Inflammatory Injury in Mild-to-Moderate Chronic Obstructive Pulmonary Disease

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with high morbidity, mortality, and healthcare costs. Cigarette smoke is a causative factor; however, not all heavy smokers develop COPD. Microbial colonization and infections are contributing factors to disease progression in advanced stages. Objectives: We investigated whether lower airway dysbiosis occurs in mild-to-moderate COPD and analyzed possible mechanistic contributions to COPD pathogenesis. Methods: We recruited 57 patients with a >10 pack-year smoking history: 26 had physiological evidence of COPD, and 31 had normal lung function (smoker control subjects). Bronchoscopy sampled the upper airways, lower airways, and environmental background. Samples were analyzed by 16S rRNA gene sequencing, whole genome, RNA metatranscriptome, and host RNA transcriptome. A preclinical mouse model was used to evaluate the contributions of cigarette smoke and dysbiosis on lower airway inflammatory injury. Measurements and Main Results: Compared with smoker control subjects, microbiome analyses showed that the lower airways of subjects with COPD were enriched with common oral commensals. The lower airway host transcriptomics demonstrated differences in markers of inflammation and tumorigenesis, such as upregulation of IL-17, IL-6, ERK/MAPK, PI3K, MUC1, and MUC4 in mild-to-moderate COPD. Finally, in a preclinical murine model exposed to cigarette smoke, lower airway dysbiosis with common oral commensals augments the inflammatory injury, revealing transcriptomic signatures similar to those observed in human subjects with COPD. Conclusions: Lower airway dysbiosis in the setting of smoke exposure contributes to inflammatory injury early in COPD. Targeting the lower airway microbiome in combination with smoking cessation may be of potential therapeutic relevance.

An explainable artificial intelligence framework for risk prediction of COPD in smokers

BACKGROUND

Since the inconspicuous nature of early signs associated with Chronic Obstructive Pulmonary Disease (COPD), individuals often remain unidentified, leading to suboptimal opportunities for timely prevention and treatment. The purpose of this study was to create an explainable artificial intelligence framework combining data preprocessing methods, machine learning methods, and model interpretability methods to identify people at high risk of COPD in the smoking population and to provide a reasonable interpretation of model predictions.

METHODS

The data comprised questionnaire information, physical examination data and results of pulmonary function tests before and after bronchodilatation. First, the factorial analysis for mixed data (FAMD), Boruta and NRSBoundary-SMOTE resampling methods were used to solve the missing data, high dimensionality and category imbalance problems. Then, seven classification models (CatBoost, NGBoost, XGBoost, LightGBM, random forest, SVM and logistic regression) were applied to model the risk level, and the best machine learning (ML) model's decisions were explained using the Shapley additive explanations (SHAP) method and partial dependence plot (PDP).

RESULTS

In the smoking population, age and 14 other variables were significant factors for predicting COPD. The CatBoost, random forest, and logistic regression models performed reasonably well in unbalanced datasets. CatBoost with NRSBoundary-SMOTE had the best classification performance in balanced datasets when composite indicators (the AUC, F1-score, and G-mean) were used as model comparison criteria. Age, COPD Assessment Test (CAT) score, gross annual income, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), anhelation, respiratory disease, central obesity, use of polluting fuel for household heating, region, use of polluting fuel for household cooking, and wheezing were important factors for predicting COPD in the smoking population.

CONCLUSION

This study combined feature screening methods, unbalanced data processing methods, and advanced machine learning methods to enable early identification of COPD risk groups in the smoking population. COPD risk factors in the smoking population were identified using SHAP and PDP, with the goal of providing theoretical support for targeted screening strategies and smoking population self-management strategies.

Inflammatory Cytokine Elaboration Following Secondhand Smoke (SHS) Exposure Is Mediated in Part by RAGE Signaling

The receptor for advanced glycation end products (RAGE) is a key contributor to immune and inflammatory responses in myriad diseases. RAGE is a transmembrane pattern recognition receptor with a special interest in pulmonary anomalies due to its naturally abundant pulmonary expression. Our previous studies demonstrated an inflammatory role for RAGE following acute 30-day exposure to secondhand smoke (SHS), wherein immune cell diapedesis and cytokine/chemokine secretion were accentuated in part via RAGE signaling. However, the chronic inflammatory mechanisms associated with RAGE have yet to be fully elucidated. In this study, we address the impact of long-term SHS exposure on RAGE signaling. RAGE knockout (RKO) and wild-type (WT) mice were exposed to SHS using a nose-only delivery system (Scireq Scientific, Montreal, Canada) for six months. SHS-exposed animals were compared to mice exposed to room air (RA) only. Immunoblotting was used to assess the phospho-AKT and phospho-ERK activation data, and colorimetric high-throughput assays were used to measure NF-kB. Ras activation was measured via ELISAs. Bronchoalveolar lavage fluid (BALF) cellularity was quantified, and a mouse cytokine antibody array was used to screen the secreted cytokines. The phospho-AKT level was decreased, while those of phospho-ERK, NF-kB, and Ras were elevated in both groups of SHS-exposed mice, with the RKO + SHS-exposed mice demonstrating significantly decreased levels of each intermediate compared to those of the WT + SHS-exposed mice. The BALF contained increased levels of diverse pro-inflammatory cytokines in the SHS-exposed WT mice, and diminished secretion was detected in the SHS-exposed RKO mice. These results validate the role for RAGE in the mediation of chronic pulmonary inflammatory responses and suggest ERK signaling as a likely pathway that perpetuates RAGE-dependent inflammation. Additional characterization of RAGE-mediated pulmonary responses to prolonged exposure will provide a valuable insight into the cellular mechanisms of lung diseases such as chronic obstructive pulmonary disease.

Chronic Obstructive Pulmonary Disease in Cameroon: Prevalence and Predictors-A Multisetting Community-Based Study

Objective

Little is known concerning chronic obstructive pulmonary disease (COPD) in Sub-Saharan Africa (SSA), where the disease remains underdiagnosed. We aimed to estimate its prevalence in Cameroon and look for its predictors.

Methods

Adults aged 19 years and older were randomly selected in 4 regions of Cameroon to participate in a cross-sectional community-based study. Data were collected in the participant's home or place of work. Spirometry was performed on selected participants. COPD was defined as the postbronchodilator forced expiratory volume in 1 second/forced vital capacity ratio (FEV1/FVC) < lower limit of normal, using the global lung initiative (GLI) equations for Black people. Binomial logistic regression was used to seek COPD-associated factors. The strength of the association was measured using the adjusted odds ratio (aOR).

Results

A total of 5055 participants (median age (25th-75th percentile) = 43 (30-56) years, 54.9% of women) were enrolled. COPD prevalence (95% confidence interval (95% CI)) was 2.9% (2.4, 3.3)%. Independent predictors of COPD (aOR (95% CI)) were a high educational level (4.7 (2.0, 11.1)), living in semiurban or rural locality (1.7 (1.4, 3.0)), tobacco smoking (1.7 (1.1, 2.5)), biomass fuel exposure (1.9 (1.1, 3.3)), experience of dyspnea (2.2 (1.4, 3.5)), history of tuberculosis (3.6 (1.9, 6.7)), and history of asthma (6.3 (3.4, 11.6)). Obesity was protective factor (aOR (95%CI) = 0.3 (0.2, 0.5)).

Conclusion

The prevalence of COPD was relatively low. Alternative risk factors such as biomass fuel exposure, history of tuberculosis, and asthma were confirmed as predictors.

Endoplasmic reticulum stress: a vital process and potential therapeutic target in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a chronic and progressive disease characterized by persistent respiratory symptoms and progressive airflow obstruction, has attracted extensive attention due to its high morbidity and mortality. Although the understanding of the pathogenesis of COPD has gradually increased because of increasing evidence, many questions regarding the mechanisms involved in COPD progression and its deleterious effects remain unanswered. Recent advances have shown the potential functions of endoplasmic reticulum (ER) stress in causing airway inflammation, emphasizing the vital role of unfolded protein response (UPR) pathways in the development of COPD.

METHODS

A comprehensive search of major databases including PubMed, Scopus, and Web of Science was conducted to retrieve original research articles and reviews related to ER stress, UPR, and COPD.

RESULTS

The common causes of COPD, namely cigarette smoke (CS) and air pollutants, induce ER stress through the generation of reactive oxygen species (ROS). UPR promotes mucus secretion and further plays a dual role in the cell apoptosis-autophagy axis in the development of COPD. Existing drug research has indicated the potential of UPR as a therapeutic target for COPD.

CONCLUSIONS

ER stress and UPR activation play significant roles in the etiology, pathogenesis, and treatment of COPD and discuss whether related genes can be used as biomarkers and therapeutic targets.

High Prevalence and Burden of Physical and Psychological Symptoms in a Chronic Obstructive Pulmonary Disease Population in Primary Care Settings in South Africa

Background

Many deaths globally are attributable to non-communicable disease, and four-fifths of these deaths are in low- and middle-income countries. Globally, COPD is currently the third leading cause of mortality.

Research Question

1) To determine the prevalence and burden of symptoms and concerns, and 2) determine predicting factors of symptom burden among patients with COPD.

Methods

A cross-sectional survey was conducted at eight primary care sites in Western Cape. We collected socio-demographic data (age, gender, smoking status, number of missed doses of prescribed medication in the last seven days) and clinical data (PEF and KPS). The Memorial Symptom Assessment Scale (MSAS), the Medical Outcomes Study, Social Support Survey (MOS-SSS), the London Chest Activity of Daily Living Scale (LCADLS) and the COPD Assessment Test (CAT) (impairment on person's life) were administered to patients. We conducted ordered logistic regression analysis to assess factors associated with the burden of symptoms. MSAS subscales: 1) Global symptom distress index, 2) physical symptom distress and 3) psychological symptom distress were dependent outcomes. We constructed three ordinal logistic regression models for each of the three subscales. Covariates were MOS-SSS, LCADLS, CAT, demographic and clinical variables.

Results

We recruited n=387 patients, mean age 59.5 years, 53.0% female. In multivariate analysis, each of the three models (ie, global, psychological and physical symptom distress) was positively associated with impairment on person's life p<0.001, difficulty to perform activities of daily living p<0.001, and low social support p<0.001. Old age was associated with lower global symptom distress (p=0.004), psychological and (0.014) physical distress (0.005). Missing 1 or more doses of medication was associated with higher levels of global (0.004) and physical (0.005) symptom distress.

Interpretation

The high prevalence and burden of physical and psychological symptoms provides strong evidence of the need for integrating person-centred assessment and management of symptoms in primary care settings.

Prevalence and determinants of chronic respiratory diseases in adults in rural Sudan

BACKGROUND: Chronic respiratory diseases (CRDs) greatly contribute to worldwide mortality. Despite new data emerging from Africa, prevalence estimates and determinants of CRDs in rural settings are limited. This study sought to extend the existing research conducted in urban Sudan by conducting a rural comparison.METHODS: Participants aged ≥18 years (n = 1,850), living in rural Gezira State completed pre-and post-bronchodilator spirometry and a questionnaire. Prevalence of respiratory symptoms and spirometric abnormalities were reported. Regression analyses were used to identify risk factors for CRDs.RESULTS: Prevalence of chronic airflow obstruction (CAO) was 4.1% overall and 5.5% in those aged ≥40 years. Reversibility was seen in 6.4%. Low forced vital capacity (FVC) was seen in 58.5%, and at least one respiratory symptom was present in 40.7% of the participants. CAO was more common among people aged 60-69 years (OR 2.07, 95% CI 1.13-3.82) and less common among highly educated participants (OR 0.50, 95% CI 0.27-0.93). Being underweight was associated with lower FVC (OR 3.07, 95% CI 2.24-4.20).CONCLUSIONS: A substantial burden of CRD exists among adults in rural Sudan. Investment in CRD prevention and management strategies is needed.

Phenotyping asthma with airflow obstruction in middle-aged and older adults: a CADSET clinical research collaboration

BACKGROUND

The prevalence and clinical profile of asthma with airflow obstruction (AO) remain uncertain. We aimed to phenotype AO in population- and clinic-based cohorts.

METHODS

This cross-sectional multicohort study included adults ≥50 years from nine CADSET cohorts with spirometry data (N=69 789). AO was defined as ever diagnosed asthma with pre-BD or post-BD FEV1/FVC <0.7 in population-based and clinic-based cohorts, respectively. Clinical characteristics and comorbidities of AO were compared with asthma without airflow obstruction (asthma-only) and chronic obstructive pulmonary disease (COPD) without asthma history (COPD-only). ORs for comorbidities adjusted for age, sex, smoking status and body mass index (BMI) were meta-analysed using a random effects model.

RESULTS

The prevalence of AO was 2.1% (95% CI 2.0% to 2.2%) in population-based, 21.1% (95% CI 18.6% to 23.8%) in asthma-based and 16.9% (95% CI 15.8% to 17.9%) in COPD-based cohorts. AO patients had more often clinically relevant dyspnoea (modified Medical Research Council score ≥2) than asthma-only (+14.4 and +14.7 percentage points) and COPD-only (+24.0 and +5.0 percentage points) in population-based and clinic-based cohorts, respectively. AO patients had more often elevated blood eosinophil counts (>300 cells/µL), although only significant in population-based cohorts. Compared with asthma-only, AO patients were more often men, current smokers, with a lower BMI, had less often obesity and had more often chronic bronchitis. Compared with COPD-only, AO patients were younger, less often current smokers and had less pack-years. In the general population, AO patients had a higher risk of coronary artery disease than asthma-only and COPD-only (OR=2.09 (95% CI 1.26 to 3.47) and OR=1.89 (95% CI 1.10 to 3.24), respectively) and of depression (OR=1.41 (95% CI 1.19 to 1.67)), osteoporosis (OR=2.30 (95% CI 1.43 to 3.72)) and gastro-oesophageal reflux disease (OR=1.68 (95% CI 1.06 to 2.68)) than COPD-only, independent of age, sex, smoking status and BMI.

CONCLUSIONS

AO is a relatively prevalent respiratory phenotype associated with more dyspnoea and a higher risk of coronary artery disease and elevated blood eosinophil counts in the general population compared with both asthma-only and COPD-only.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Sex matters: the frequently overlooked importance of considering sex in computational models

Personalised medicine and the development of a virtual human or a digital twin comprises visions of the future of medicine. To realise these innovations, an understanding of the biology and physiology of all people are required if we wish to apply these technologies at a population level. Sex differences in health and biology is one aspect that has frequently been overlooked, with young white males being seen as the "average" human being. This has not been helped by the lack of inclusion of female cells and animals in biomedical research and preclinical studies or the historic exclusion, and still low in proportion, of women in clinical trials. However, there are many known differences in health between the sexes across all scales of biology which can manifest in differences in susceptibility to diseases, symptoms in a given disease, and outcomes to a given treatment. Neglecting these important differences in the development of any health technologies could lead to adverse outcomes for both males and females. Here we highlight just some of the sex differences in the cardio-respiratory systems with the goal of raising awareness that these differences exist. We discuss modelling studies that have considered sex differences and touch on how and when to create sex-specific models. Scientific studies should ensure sex differences are included right from the study planning phase and results reported using sex as a biological variable. Computational models must have sex-specific versions to ensure a movement towards personalised medicine is realised.

Clinical characteristics of chronic obstructive pulmonary disease in never-smokers: A systematic review

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) is the third cause of death worldwide. While tobacco smoking is a key risk factor, COPD also occurs in never-smokers (NS). However, available evidence on risk factors, clinical characteristics, and natural history of the disease in NS is scarce. Here, we perform a systematic review of the literature to better describe the characteristics of COPD in NS.

METHODS

We searched different databases following the PRISMA guidelines with explicit inclusion and exclusion criteria. A purpose-designed quality scale was applied to the studies included in the analysis. It was not possible to pool the results due to the high heterogeneity of the studies included.

RESULTS

A total of 17 studies that met the selection criteria were included, albeit only 2 of them studied NS exclusively. The total number of participants in these studies were 57,146 subjects,25,047 of whom were NS and 2655 of the latter had NS-COPD. Compared to COPD in smokers, COPD in NS is more frequent in women and older ages, and is associated with a slightly higher prevalence of comorbidities. There are not enough studies to understand if COPD progression and clinical symptoms in NS are different to that of ever-smokers.

CONCLUSIONS

There is a significant knowledge gap on COPD in NS. Given that COPD in NS account for about a third of all COPD patients in the world, particularly in low-middle income countries, and the decrease in tobacco consumption in high income countries, understanding COPD in NS constitutes a public-health priority.

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.

Clinical Profile and Quality of Life of Patients With Post-pulmonary Tuberculosis Sequelae Presenting to a Tertiary Care Hospital

Background and objective There is a dearth of studies on the clinical presentation of patients with post-pulmonary tuberculosis (PTB) sequelae and its impact on their quality of life (QoL). In light of this, we conducted this study to analyze the clinical profile and QoL in patients with post-PTB sequelae. Methods Patients with a history of treated PTB and evidence of radiological damage were enrolled prospectively from November 2018 till June 2020 to study their clinical profile and QoL as per the eligibility criteria. A detailed clinical history was taken along with posteroanterior-view chest X-rays and CT scans of the thorax with bronchial angiography in patients with hemoptysis. QoL was assessed using the Hindi version of St. George's Respiratory Questionnaire (SGRQ) for which permission was obtained from the St. George's University of London. SGRQ scores were calculated using score calculation algorithms (Microsoft Excel-based) and missing data imputation as recommended by its developer. Results A total of 174 patients were included in the analysis. The analyzed population was relatively younger (mean age: 44.27 years) with BMIs leaning toward the lower side of normal (median: 19.6 kg/m²); the majority of the patients were males (59%) and non-smokers (77%). PTB had been diagnosed clinico-radiologically in the majority (68%) of patients with non-compliance to antitubercular treatment (ATT) being reported by only 9% of patients. Multiple courses of ATT were received by about one-third of patients, mainly on a clinico-radiologic basis. Systemic hypertension (HTN) (11%) and diabetes mellitus (DM) (9%) were the most common comorbidities. The most common symptom complex found was cough, expectoration, and dyspnea (n=102, 59%). At least one incidence of massive hemoptysis was reported by 20% of patients. Bronchial artery embolization (BAE) was performed for moderate to massive hemoptysis in 26% of patients with a success rate of >90%. One-fifth of the study participants required hospitalization for exacerbation of respiratory symptoms with more than half of these (59%) requiring ventilatory support. Health-related QoL was significantly impaired as reflected by a median SGRQ total score of 45.53. The most affected domain of QoL was the activity domain (mean score: 45.47). Females had worse QoL as compared to males (p=0.0062), and so did underweight patients (p=0.048). The prolonged duration of the illness also significantly impaired the QoL (p<0.001, r=0.313). Conclusion The sequelae of PTB are under-recognized even among physicians and are frequently misdiagnosed as active PTB. The QoL is more severely affected due to residual damage. This study highlights the clinical profile of this patient population and underscores the need to recognize post-PTB sequelae as a separate entity. An important remedy to mitigate its long-term consequences is its inclusion and recognition in national and international TB guidelines to facilitate its early identification and promote further research to address its evidence-based management.

Pathophysiology, Therapeutic Targets, and Future Therapeutic Alternatives in COPD: Focus on the Importance of the Cholinergic System

Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by airway limitation and changes in airway structure. It has a high global burden of mortality and morbidity. The etiology of COPD is complex, but exposure to tobacco smoke and other inhaled lung oxidants are major risk factors. Both pharmacological and non-pharmacological approaches are used to manage COPD, but there remains an urgent unmet need for drugs that can modify the course of the disease. This review focuses on the role of acetylcholine and other components of the pulmonary cholinergic system in the pathogenesis of COPD, and the inhaled pharmacological agents that target it. In addition to its role as a neurotransmitter, acetylcholine regulates diverse aspects of COPD pathogenesis including bronchoconstriction, airway remodeling, mucus secretion and inflammation. Inhaled antimuscarinic drugs are a key component of therapy for COPD, as monotherapy or in combination with inhaled β2 agonists or corticosteroids. We review the evidence supporting the use of current anticholinergic agents in COPD and preview novel drugs targeting the cholinergic system and agents from other classes in clinical development, such as phosphodiesterase-4 inhibitors and monoclonal antibodies targeting inflammatory mediators.

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

Exposure to occupational risk factors is associated with the severity and progression of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) results from a complex interaction between genes and the environment, and occupational exposures are an underappreciated risk factor. Until now, little research attention has been paid to the potential impact of occupational risk factor exposure on the COPD in China. The aim of this retrospective study was to analyze the role of occupational risk factor exposure on the severity and progression of COPD for exploring new prevention strategies for this disease. This study adopted a random cluster-sampling method. Five grade-A tertiary hospitals that met the inclusion criteria were selected as the survey sites, and patients with COPD hospitalized in these hospitals from January 1, 2019, to December 31, 2019, were selected as the research subjects. Data of the patients diagnosed with COPD met the Global Initiative for Chronic Obstructive Lung Disease (2019) criteria and were collected from the computerized medical record databases. Among 4082 investigated COPD patients, 1063 (26%) were found to have occupational risk factor exposure history. The top 3 industries with a large COPD case number and a history of occupational risk factor exposure ranked in the order of agriculture (including farming, forestry, animal husbandry, and fishery), manufacturing, and mining. Further multivariate logistic regression analysis indicated that when setting a low exposure level as a reference, medium and high exposure levels were correlated with the severity of COPD (odds ratio values were 2.837 and 6.201, respectively, P < .05). Linear regression analysis showed that cumulative exposure to occupational risk factors was negatively correlated with the forced expiratory volume in 1-second percentage of COPD patients, with a correlation coefficient of 0.68. Our results indicated that occupational risk factor exposure levels were related to the severity of COPD significantly. The incubation period of COPD in the exposure group was significantly shorter than that in the non-exposure group. To prevent worked-related COPD, special attention and control efforts should be taken to reduce the level of occupational risk factors such as organic dust, irritating chemicals, etc in the work environments, especially in the industries of agriculture, forestry, animal husbandry and fishery, manufacturing, and mining.

Is telerehabilitation an effective maintenance strategy for patients with chronic obstructive pulmonary diseases: a systematic review

BACKGROUND

Pulmonary rehabilitation (PR) has proven to improve the physical and psychosocial function in patients with chronic obstructive pulmonary disease (COPD). However, the gains achieved during pulmonary rehabilitation diminish over time without an effective maintenance strategy. With several factors affecting access to pulmonary rehabilitation, calls for innovative models were made, which saw the emergence of studies exploring telerehabilitation (TR) as an alternative to traditional pulmonary rehabilitation models. Although there are current reviews exploring the effectiveness of telerehabilitation as an alternative for conventional PR, no review has considered telerehabilitation effectiveness in the long term. Hence, this review aims at examining the effectiveness of telerehabilitation following to pulmonary rehabilitation in patients with chronic obstructive pulmonary disease.

MAIN BODY

A systematic review of the literature using CINAHL, MEDLINE, SCOPUS, Web of science PEDRO, AMED and EMBASE databases was conducted to assess the effectiveness of telerehabilitation following PR in patients with COPD. Health-related quality of life (HRQoL) and exercise capacity was maintained within 6-12 months of a TR maintenance programme. However, there was no significant increase in HRQoL and exercise capacity between the intervention and control groups in 6-12 months.

CONCLUSIONS

This review suggests that a TR maintenance strategy effectively maintains benefits gained and may improve HRQoL and exercise capacity within 6-12 months for patients with COPD. Nonetheless, it is impossible to extrapolate the findings to the general population due to the paucity of included studies. Further high quality randomised controlled trials examining TR in the long-term is required in the future.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s42269-023-00980-8.

Early Origins of Chronic Obstructive Pulmonary Disease: Prenatal and Early Life Risk Factors

The main risk factor for chronic obstructive pulmonary disease (COPD) is active smoking. However, a considerable amount of people with COPD never smoked, and increasing evidence suggests that adult lung disease can have its origins in prenatal and early life. This article reviews some of the factors that can potentially affect lung development and lung function trajectories throughout the lifespan from genetics and prematurity to respiratory tract infections and childhood asthma. Maternal smoking and air pollution exposure were also analyzed among the environmental factors. The adoption of preventive strategies to avoid these risk factors since the prenatal period may be crucial to prevent, delay the onset or modify the progression of COPD lung disease throughout life.

Differences of Clinical Characteristics and Drug Prescriptions between Men and Women with COPD in China

BACKGROUND

Sex differences in symptoms exist in patients with COPD. Our aim is to measure the differences between men and women with COPD, focusing on risk factors, symptoms, quality of life and drug prescriptions.

METHODS

In this cross-sectional observational study, patients with COPD were collected in China; demographic characteristics, smoking history, occupational exposure, biomass exposure, lung function, dyspnea, quality of life, and prescriptions for inhaled medications were collected. The nearest neighbor algorithm was used to match female and male patients (ratio 2:1) on age, body mass index, and lung function.

RESULTS

Compared with 1462 men, the 731 women generally had lower educational levels and were married less (both p < 0.001). A total of 576 (90.0%) women did not smoke cigarettes. More men were exposed to occupational dust (539 (36.9%) vs. 84 (11.5%), p = 0.013), while more women were exposed to biomass smoke (330 (45.1%) vs. 392 (26.8%), p = 0.004). Except for phlegm and chest tightness, women had more complaints than men for cough, breathlessness, activities, confidence, sleep and energy (p < 0.05). In addition, more women were prescribed triple therapy than men (236 (36.3%) vs. 388 (31.0%), p = 0.020).

CONCLUSIONS

There are obvious discrepancies in the quality of life and use of inhaled medications between male and female patients with COPD.

Incidence and Risk of Lung Cancer in Tuberculosis Patients, and Vice Versa: A Literature Review of the Last Decade

Background

The incidence and risk of both lung cancer (LC) and tuberculosis (TB) are increasing rapidly. These two diseases frequently exist together and can influence the incidence and risk of each other. The aim of the current review was to summarize the incidence and risk of LC in TB patients, and vice versa, short out research gap, and contemplate future research perspectives. Methodology. PubMed and Scopus databases, and Google Scholar search engine were searched for epidemiological studies that investigated the incidence and risk of TB and LC, published since January 2011 to April 2022, and written in English. We used the searching keyword "tuberculosis" combined with "lung cancer" and associated medical subject heading (MeSH) to retrieve eligible research articles. We retrieved information's regarding the diagnosis of TB and LC, confounders, the associations of TB and LC, and incidence and risks of each other.

Results

We found higher incidence rate and risks (1.64 to 6 times higher) of LC in TB patients in comparison to non-TB participants. However, the incidence rate and risks of TB in LC patients were comparatively low. Male patients were exhibited higher risks than female. The medical comorbidities, smoking habits, and age can also influence the associations and risks of LC in TB patients or vice versa.

Conclusion

Our summarized studies might suggest that existing active TB may increase the incidence and risk of LC. However, large prospective cohort study is warranted to explore the real scenario worldwide.

Basilar Predominant Emphysema: Thinking beyond Alpha-1-Antitrypsin Deficiency

Basilar predominant emphysema, or disproportionate emphysematous involvement of the lung bases compared to the apices, is an uncommon radiographic pattern of emphysema traditionally associated with alpha-1-antitrypsin deficiency (AATD). We present a case of a 59-year-old female with 41 pack-year tobacco use, Stage IV COPD with supplemental oxygen, and bibasilar predominant emphysema who successfully underwent bronchoscopic lung volume reduction. She presented with recurrent hospitalizations for frequent exacerbations. After lung reduction, the patient displayed improvement in functional status without hospitalizations at the 15-month follow-up. Careful history taking is essential for any patients diagnosed with lower lobe emphysema to elucidate the underlying etiology. This case challenges the notion that basilar emphysema is sensitive or specific for AATD and emphasizes that this pattern of emphysema has a broad differential diagnosis and alternative etiologies should be considered. Our patient was ultimately diagnosed with smoking-related emphysema, with atypical bibasilar involvement. Furthermore, basilar predominant emphysema should be considered a separate entity from its apical predominant counterpart.

Sex Differences in Airways at Chest CT: Results from the COPDGene Cohort

Background The prevalence of chronic obstructive pulmonary disease (COPD) in women is fast approaching that in men, and women experience greater symptom burden. Although sex differences in emphysema have been reported, differences in airways have not been systematically characterized. Purpose To evaluate whether structural differences in airways may underlie some of the sex differences in COPD prevalence and clinical outcomes. Materials and Methods In a secondary analyses of a multicenter study of never-, current-, and former-smokers enrolled from January 2008 to June 2011 and followed up longitudinally until November 2020, airway disease on CT images was quantified using seven metrics: airway wall thickness, wall area percent, and square root of the wall thickness of a hypothetical airway with internal perimeter of 10 mm (referred to as Pi10) for airway wall; and lumen diameter, airway volume, total airway count, and airway fractal dimension for airway lumen. Least-squares mean values for each airway metric were calculated and adjusted for age, height, ethnicity, body mass index, pack-years of smoking, current smoking status, total lung capacity, display field of view, and scanner type. In ever-smokers, associations were tested between each airway metric and postbronchodilator forced expiratory volume in 1 second (FEV1)-to-forced vital capacity (FVC) ratio, modified Medical Research Council dyspnea scale, St George's Respiratory Questionnaire score, and 6-minute walk distance. Multivariable Cox proportional hazards models were created to evaluate the sex-specific association between each airway metric and mortality. Results In never-smokers (n = 420), men had thicker airway walls than women as quantified on CT images for segmental airway wall area percentage (least-squares mean, 47.68 ± 0.61 [standard error] vs 45.78 ± 0.55; difference, -1.90; P = .02), whereas airway lumen dimensions were lower in women than men after accounting for height and total lung capacity (segmental lumen diameter, 8.05 mm ± 0.14 vs 9.05 mm ± 0.16; difference, -1.00 mm; P < .001). In ever-smokers (n = 9363), men had greater segmental airway wall area percentage (least-squares mean, 52.19 ± 0.16 vs 48.89 ± 0.18; difference, -3.30; P < .001), whereas women had narrower segmental lumen diameter (7.80 mm ± 0.05 vs 8.69 mm ± 0.04; difference, -0.89; P < .001). A unit change in each of the airway metrics (higher wall or lower lumen measure) resulted in lower FEV1-to-FVC ratio, more dyspnea, poorer respiratory quality of life, lower 6-minute walk distance, and worse survival in women compared with men (all P < .01). Conclusion Airway lumen sizes quantified at chest CT were smaller in women than in men after accounting for height and lung size, and these lower baseline values in women conferred lower reserves against respiratory morbidity and mortality for equivalent changes compared with men. © RSNA, 2022 Online supplemental material is available for this article.

Hedgehog-interacting protein acts in the habenula to regulate nicotine intake

Hedgehog-interacting protein (HHIP) sequesters Hedgehog ligands to repress Smoothened (SMO)-mediated recruitment of the GLI family of transcription factors. Allelic variation in HHIP confers risk of chronic obstructive pulmonary disease and other smoking-related lung diseases, but underlying mechanisms are unclear. Using single-cell and cell-type-specific translational profiling, we show that HHIP expression is highly enriched in medial habenula (MHb) neurons, particularly MHb cholinergic neurons that regulate aversive behavioral responses to nicotine. HHIP deficiency dysregulated the expression of genes involved in cholinergic signaling in the MHb and disrupted the function of nicotinic acetylcholine receptors (nAChRs) through a PTCH-1/cholesterol-dependent mechanism. Further, CRISPR/Cas9-mediated genomic cleavage of the Hhip gene in MHb neurons enhanced the motivational properties of nicotine in mice. These findings suggest that HHIP influences vulnerability to smoking-related lung diseases in part by regulating the actions of nicotine on habenular aversion circuits.

Does the asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) exist? A narrative review from epidemiology and practice

Asthma and chronic obstructive pulmonary disease (COPD) have traditionally been approached as separate entities that must be researched and treated separately. There is growing recognition, however, that a substantial proportion of patients with obstructive lung disease have characteristics of both asthma and COPD (termed the asthma-COPD overlap syndrome (ACOS)). Lung disease experts have difficulty defining ACOS, and many still resist accepting the possibility that asthma and COPD may be linked. It is likely that practicing clinicians may be equally confused about how to identify and treat ACOS. This narrative review aims to clarify concepts of ACOS definition, argues that the best way to understand ACOS is to view the chronic lung disease process longitudinally rather than cross-sectionally, and presents evidence that ACOS can be the end result of the natural history of severe asthma. The review also points out the serious gaps in knowledge regarding therapy for ACOS and presents emerging data supporting the intracellular respiratory pathogen Chlamydia pneumoniae as a possible common etiologic agent in severe asthma and ACOS.

Association between pregnancy and pregnancy loss with COPD in Chinese women: The China Kadoorie Biobank study

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by airflow blockage. Pregnancy and pregnancy loss may be related to an elevated risk of COPD, although studies have yet to report on this association. Hence, this study aims to investigate the association between pregnancy and pregnancy loss with the risk of COPD among Chinese women.

Methods

Data on 302,510 female participants from the China Kadoorie Biobank were utilized for this study. Multivariable logistic regression, stratified by sociodemographic and lifestyle factors, was employed to obtain the odds ratio (ORs) and 95% confidence intervals (CIs) for the association between pregnancy and pregnancy loss with COPD.

Results

Pregnancy loss was significantly associated with increased risk of COPD (OR 1.19, 95% CI 1.13-1.25), specifically, spontaneous (OR 1.19, 95% CI 1.11-1.29) and induced abortion (OR 1.18, 95% CI 1.12-1.25). Stillbirth, however, was not significantly associated with the risk of COPD (OR 1.09, 95% CI 0.99-1.20). Increasing number of pregnancy losses was associated with increasing risk of COPD (one pregnancy loss: OR 1.14, 95% CI 1.07-1.21, two or more pregnancy loss: OR 1.25, 95% CI 1.17-1.32, and each additional pregnancy loss: OR 1.06, 95% CI 1.03-1.09). A single pregnancy was significantly associated with reduced risk of COPD (OR 0.75, 95% CI 0.59-0.97), although each additional pregnancy was significantly associated with increased risk of COPD (OR 1.03, 95% CI 1.01-1.04).

Conclusion

Pregnancy loss, in particular, spontaneous and induced abortions are associated with increased risk of COPD among Chinese women. A single pregnancy, however, demonstrated protective effects.

Prevalence and Characteristics of Chronic Obstructive Pulmonary Disease in Dairy Farmers

Objective: To assess the prevalence and characteristics of chronic obstructive pulmonary disease (COPD) in dairy farmers, and evaluate the role of job exposure and smoking as predictors for respiratory health impairment. Methods: A cross-sectional study was performed, including 83 dairy farmers (mean age: 52.6±8.7 years; mean exposure duration: 23.7±7.6 years) and 80 office workers as a control group (mean age: 52.7±8.2 years) matched for age, smoking habits, and socioeconomic status. Methods for evaluation of study participants included a questionnaire on respiratory symptoms in the last 12 months, baseline spirometry and bronchodilator reversibility testing, and diagnostic criteria for COPD. Results: The mean post-bronchodilator values of spirometric parameters are significantly lower in subjects among EG with negative bronchodilator test compared to those in CG, while the mean post-bronchodilator values of spirometric parameters are lower in dairy farmers with negative BD tests exposed more than 20 years compared to those with exposure less than 20 years, being statistically significant for FEV1/FVC%, MEF25, MEF50 and MEF75. The COPD prevalence is non-significantly higher in dairy farmers compared to controls, and is significantly associated with age over 40 years in dairy farmers (P=0.035). The risk for COPD development in dairy farmers is about 36 fold higher in subjects exposed more than 20 years (OR = 36.00 (1.21-37.77) CI 95%) compared to those with exposure duration less than 20 years, and is about 6 fold higher in dairy farmers who are current smokers (OR = 6.12 (0.95-37.77) CI 95%). COPD is significantly associated with smoking duration among smokers in both groups, while combined effect of smoking, smoking duration, and number of cigarettes smoked daily has a significant impact on COPD development in dairy farmers. According to the GOLD classification, depending on the degree of airflow limitation, mild and moderate types of COPD are detected in dairy farmers, and only mild type in controls, showing no significant difference between the two groups. Conclusion: The study findings recognized the role of farming exposure, and smoking as well, as predictors for respiratory health impairment, and furthermore confirmed their potential to be a predictive factor in the COPD development. These facts should be helpful in detection of critical points for action, indicate the need of adverse occupational exposures reduction through adequate preventive measures and regular health examinations, implementation of relevant engineering controls, smoking cessation programs, and complete and efficient respiratory health assessment.

Epidemiological evidence for associations between variants in CHRNA genes and risk of lung cancer and chronic obstructive pulmonary disease

Background

Genetic studies have previously reported that single-nucleotide polymorphisms (SNPs) in CHRNA genes (such as CHRNA3, CHRNA4, CHRNA5, or CHRNA3-CHRNA5-CHRNB4 clusters) are linked to the risk of neoplastic and non-neoplastic diseases. However, these conclusions were controversial and no systematic research synopsis has been available. We aimed to synthesize current knowledge of variants in the CHRNA genes on the risk of diseases.

Methods

We systematically searched for publications using PubMed, Medline, and Web of Science on or before 25 August 2021. A total of 1,818 publications were identified, of which 29 were deemed eligible for inclusion that could be used to perform meta-analysis based on at least three data sources to assess whether the morbidity associated with neoplastic and non-neoplastic diseases can be attributed to SNPs in CHRNA genes. To further evaluate the authenticity of cumulative evidence proving significant associations, the present study covered the Venice criteria and false-positive report probability tests. Through the Encyclopedia of DNA Elements (ENCODE) project, we created functional annotations for strong associations.

Results

Meta-analyses were done for nine genetic variants with two diseases {chronic obstructive pulmonary disease (COPD) and lung cancer (LC)}that had at least three data sources. Interestingly, eight polymorphisms were significantly related to changes in the susceptibility COPD and LC (p < 0.05). Of these, strong evidence was assigned to six variants (28 significant associations): CHRNA3 rs1051730, CHRNA3 rs6495309, and CHRNA5 rs16969968 with COPD risk, and CHRNA3 rs1051730, CHRNA3 rs578776, CHRNA3 rs6495309, CHRNA3 rs938682, CHRNA5 rs16969968, and CHRNA5 rs588765 with LC risk; moderate evidence was assigned to five SNPs (12 total associations) with LC or COPD risk. Data from ENCODE and other public databases showed that SNPs with strong evidence may be located in presumptive functional regions.

Conclusions

Our study summarized comprehensive evidence showing that common mutations in CHRNA genes are strongly related to LC and COPD risk. The study also elucidated the vital function of CHRNA genes in genetic predispositions to human diseases.

Association of tobacco product use with chronic obstructive pulmonary disease (COPD) prevalence and incidence in Waves 1 through 5 (2013-2019) of the Population Assessment of Tobacco and Health (PATH) Study

BACKGROUND

We examined the association of non-cigarette tobacco use on chronic obstructive pulmonary disease (COPD) risk in the Population Assessment of Tobacco and Health (PATH) Study.

METHODS

There were 13,752 participants ≥ 40 years with Wave 1 (W1) data for prevalence analyses, including 6945 adults without COPD for incidence analyses; W1-5 (2013-2019) data were analyzed. W1 tobacco use was modeled as 12 mutually-exclusive categories of past 30-day (P30D) single and polyuse, with two reference categories (current exclusive cigarette and never tobacco). Prevalence and incidence ratios of self-reported physician-diagnosed COPD were estimated using weighted multivariable Poisson regression.

RESULTS

W1 mean (SE) age was 58.1(0.1) years; mean cigarette pack-years was similar for all categories involving cigarettes and exclusive use of e-cigarettes (all > 20), greater than exclusive cigar users (< 10); and COPD prevalence was 7.7%. Compared to P30D cigarette use, never tobacco, former tobacco, and cigar use were associated with lower COPD prevalence (RR = 0.33, (95% confidence interval-CI) [0.26, 0.42]; RR = 0.57, CI [0.47, 0.70]; RR = 0.46, CI [0.28, 0.76], respectively); compared to never tobacco use, all categories except cigar and smokeless tobacco use were associated with higher COPD prevalence (RR former = 1.72, CI [1.33, 2.23]; RR cigarette = 3.00, CI [2.37, 3.80]; RR e-cigarette = 2.22, CI [1.44, 3.42]; RR cigarette + e-cigarette = 3.10, CI [2.39, 4.02]; RR polycombusted = 3.37, CI [2.44, 4.65]; RR polycombusted plus noncombusted = 2.75, CI]1.99, 3.81]). COPD incidence from W2-5 was 5.8%. Never and former tobacco users had lower COPD risk compared to current cigarette smokers (RR = 0.52, CI [0.35, 0.77]; RR = 0.47, CI [0.32, 0.70], respectively). Compared to never use, cigarette, smokeless, cigarette plus e-cigarette, and polycombusted tobacco use were associated with higher COPD incidence (RR = 1.92, CI [1.29, 2.86]; RR = 2.08, CI [1.07, 4.03]; RR = 1.99, CI [1.29, 3.07]; RR = 2.59, CI [1.60, 4.21], respectively); exclusive use of e-cigarettes was not (RR = 1.36, CI [0.55, 3.39]).

CONCLUSIONS

E-cigarettes and all use categories involving cigarettes were associated with higher COPD prevalence compared to never use, reflecting, in part, the high burden of cigarette exposure in these groups. Cigarette-but not exclusive e-cigarette-use was also strongly associated with higher COPD incidence. Compared to cigarette use, only quitting tobacco was protective against COPD development.

The association of chronic bronchitis and airflow obstruction with lifetime and current farm activities in a sample of rural adults in Iowa

OBJECTIVE

Farmers have an increased risk for chronic bronchitis and airflow obstruction. The objective of this study was to investigate the association of these health outcomes with farm activities.

METHODS

We evaluated the Keokuk County Rural Health Study (KCRHS) enrollment data for farm activities and the two health outcomes chronic bronchitis based on self-reported symptoms and airflow obstruction based on spirometry. We used logistic regression to model the health outcomes, yielding an odds ratio (OR) and 95% confidence interval (95% CI) for farm activities while adjusting for potential confounders and other risk factors.

RESULTS

Of the 1234 farmers, 104 (8.4%) had chronic bronchitis, 75 (6.1%) fulfilled the criteria for airflow obstruction, and the two outcomes overlapped by 18 participants. Chronic bronchitis without airflow obstruction (n = 86) had a statistically significant association with crop storage insecticides (OR 3.1, 95% CI 1.6, 6.1) and a low number of years (≤ 3) worked with turkeys (OR 3.3, 95% CI 1.2, 9.4). The latter result should be interpreted with caution because it is based on a small number of cases (n = 5). Airflow obstruction with or without chronic bronchitis (n = 75) was significantly associated with ever working in a hog or chicken confinement setting (OR 2.2, 95% CI 1.0, 4.5).

CONCLUSIONS

These results suggest that work with crop storage insecticides or turkeys may increase the risk for chronic bronchitis and work in hog or chicken confinement may increase the risk for airflow obstruction.

Impact of Previous Occupational Exposure on Outcomes of Chronic Obstructive Pulmonary Disease

Occupational exposures have been regarded as a risk factor for the development of chronic obstructive pulmonary disease (COPD). However, there is little knowledge regarding the effect of occupational exposure on the treatment outcomes of COPD. Therefore, the aim of this study was to evaluate the question of whether occupational exposure can have a potential impact on COPD outcomes. Methods: Information regarding self-reported occupational exposure for 312 patients with COPD from the Korean Obstructive Lung Disease (KOLD) Cohort were included. A comparison of the rate of acute exacerbation, annual lung function change, and quality of life according to the presence or absence of occupational exposure was performed. Results: Seventy-six patients (24.4%) had experienced occupational exposure; chemical materials were most common. At enrollment, a higher COPD-specific version of the St. George Respiratory Questionnaire total score (39.7 ± 18.8 vs. 33.1 ± 17.6, p = 0.005) and a higher exacerbation history in the past year (30.3% vs. 17.5%, p = 0.017) were observed for patients with occupational exposure compared to those without occupational exposure. Furthermore, in the follow-up period, after adjusting for potential confounders, a higher frequency of acute exacerbation (odd ratio, 1.418; 95% confidence interval, 1.027–1.956; p = 0.033) and a more rapid decline in forced expiratory volume in 1 s (p = 0.009) was observed for COPD patients with occupational exposure compared to those without occupational exposure. Conclusions: In the KOLD cohort, worse outcomes in terms of exacerbation rate and change in lung function were observed for COPD patients with occupational exposure compared to those without occupational exposure. These findings suggest that occupational exposure not only is a risk factor for COPD but also might have a prognostic impact on COPD.

Clinical course of COPD in patients with Arg16Gly (rs1042713) polymorphism of <em>ADRB2</em> gene

The ADBR2 gene has been studied for its possible relationship with the development and clinical course of chronic obstructive pulmonary disease (COPD), including response to beta-2 agonists, with existing data being contentious on the subject. So, the purpose of this study was to look into the potential impact of the arginine-16-glycine (Arg16Gly) polymorphism on the clinical course and drug utilization in COPD patients. Data show that patients with Arg16Arg have a lower number of hospital admissions for exacerbations (p=0.048), but only in the total number of exacerbations, including those treated out-patients (p=0.086). Each glycine (Gly) copy was associated with a higher number of exacerbations (OR: 0.25; 95% CI: 0.00-055; p=0.048). The number of exacerbations after LABA/LAMA treatment was similar across groups, indicating that all ADRB2 variants responded well to the treatment. Furthermore, there were no statistically significant differences in mMRC and CAT values across all study visits. Interestingly, groups differed in their use of antibiotics (AB) at all visits, with Arg16Arg being associated with the least amount of AB use. There was also a link discovered between clycine copies and increased use of glucocorticoids. As a result, Arg16Gly is involved in the clinical course of COPD as well as the utilization of drug groups. Based on the findings, we can speculate that the cross-talk between the ADRB2 gene and the corticosteroid receptor is altered in patients with the Gly16Gly genotype.

Novel Lung Growth Strategy with Biological Therapy Targeting Airway Remodeling in Childhood Bronchial Asthma

Anti-inflammatory therapy, centered on inhaled steroids, suppresses airway inflammation in asthma, reduces asthma mortality and hospitalization rates, and achieves clinical remission in many pediatric patients. However, the spontaneous remission rate of childhood asthma in adulthood is not high, and airway inflammation and airway remodeling persist after remission of asthma symptoms. Childhood asthma impairs normal lung maturation, interferes with peak lung function in adolescence, reduces lung function in adulthood, and increases the risk of developing chronic obstructive pulmonary disease (COPD). Early suppression of airway inflammation in childhood and prevention of asthma exacerbations may improve lung maturation, leading to good lung function and prevention of adult COPD. Biological drugs that target T-helper 2 (Th2) cytokines are used in patients with severe pediatric asthma to reduce exacerbations and airway inflammation and improve respiratory function. They may also suppress airway remodeling in childhood and prevent respiratory deterioration in adulthood, reducing the risk of COPD and improving long-term prognosis. No studies have demonstrated a suppressive effect on airway remodeling in childhood severe asthma, and further clinical trials using airway imaging analysis are needed to ascertain the inhibitory effect of biological drugs on airway remodeling in severe childhood asthma. In this review, we describe the natural prognosis of lung function in childhood asthma and the risk of developing adult COPD, the pathophysiology of allergic airway inflammation and airway remodeling via Th2 cytokines, and the inhibitory effect of biological drugs on airway remodeling in childhood asthma.

Acute exacerbations of chronic obstructive pulmonary disease in a cohort of Chinese never smokers goes along with decreased risks of recurrent acute exacerbation, emphysema and comorbidity of lung cancer as well as decreased levels of circulating eosinophils and basophils

Acute exacerbations show a significant impact on disease morbidity and mortality in chronic obstructive pulmonary disease (COPD). In contrast to stable COPD, the association of smoking status with clinical and laboratory characteristics in patients with acute exacerbations of COPD (AECOPD) has not been well studied. In this retrospective study, we compared never smokers and ever smokers on their demographic, clinical, and laboratory characteristics in a Chinese clinical cohort of AECOPD. In this cohort comprising 1,034 consecutive patients with AECOPD, never smokers were older (75 vs 70.5 years, padjusted &lt; 0.001) and had a higher body mass index than smokers (21.1 ± 4.0 vs 20.3 ± 3.4, padjusted = 0.028). Furthermore, never smokers showed a decreased risk of recurrent acute exacerbation (13.0 vs 21.8%, padjusted = 0.029), a lower risk of development of emphysema (77.8 vs 89.1%, padjusted &lt; 0.001), a lower prevalence of the co-morbidity of lung cancer (0.5 vs 6.6%, padjusted &lt; 0.001), lower levels of circulating eosinophils (EO; 0.04 × 109/L vs 0.10 × 109/L, padjusted = 0.007) and basophils (BA; 0.02 × 109/L vs 0.03 × 109/L, padjusted = 0.019), and a higher plasma levels of D-dimer (0.62 μg/ml vs 0.51 μg/ml, padjusted = 0.02). Furthermore, multivariate logistic regression analysis identified several risk factor for the recurrent acute exacerbation, such as smoking [odds ratio (OR) = 1.84, 95% CI: 1.03–3.40, p = 0.044], urban residential area (OR = 1.43, 95% CI: 1.01–2.05, p = 0.045), and the presence of emphysema (OR = 2.31, 95% CI: 1.25–4.69, p = 0.012). In conclusion, this study demonstrates that the smoking status of patients is associated with recurrent acute exacerbations, emphysema, lung cancer, and levels of circulating EO and BA in AECOPD. Identification of cigarette smoking as a risk factor for recurrent acute exacerbation supports behavioral intervention of smoking cessation in the management of patients with AECOPD.

Causal Path of COPD Progression-Associated Genes in Different Biological Samples

Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory disease with pulmonary and extra-pulmonary complications. Due to the disease's systemic nature, many investigations investigated the genetic alterations in various biological samples. We aimed to infer causal genes in COPD's pathogenesis in different biological samples using elastic-net logistic regression and the Structural Equation Model. Samples of small airway epithelial cells, bronchoalveolar lavage macrophages, lung tissue biopsy, sputum, and blood samples were selected (135, 70, 235, 143, and 226 samples, respectively). Elastic-net Logistic Regression analysis was implemented to identify the most important genes involved in COPD progression. Thirty-three candidate genes were identified as essential factors in the pathogenesis of COPD and regulation of lung function. Recognized candidate genes in small airway epithelial (SAE) cells have the highest area under the ROC curve (AUC = 97%, SD = 3.9%). Our analysis indicates that macrophages and epithelial cells are more influential in COPD progression at the transcriptome level.