Sex-specific features of emphysema among current and former smokers with COPD

Uncertainty-aware quantitative CT evaluation of emphysema and mortality risk from variable radiation dose images

OBJECTIVE

To develop an automated method for the joint and consistent evaluation of emphysema and mortality risk that provides quantification of data and model uncertainty.

MATERIALS AND METHODS

Participants from the prospective COPDGene study who underwent both full radiation dose (FD) and reduced radiation dose (RD) chest CT scans at 5-year follow-up were included and divided into training (80%), validation (10%), and testing (10%) datasets. We trained a multi-task Bayesian neural network (BNN) to estimate the FD volume-adjusted lung density (ALD) regardless of acquisition protocol, in addition to the 5-year mortality risk. The data and model uncertainty were quantified in the testing dataset. Our deep learning ALD (DL-ALD) was compared to the conventional ALD.

RESULTS

In total, 1350 participants (mean age 64.4 years ± 8.7; 659 female) were included. Compared to conventional ALD, DL-ALD was more consistent between FD and RD CT images (mean difference: 1 g/L ± 3.1 versus 14.8 g/L ± 5.3, p < 0.001). The predicted 5-year mortality was similar between image protocols (mean difference: 0.0007 ± 0.02, p = 0.76). The uncertainty associated with image variability when quantifying DL-ALD was lower in participants with severe emphysema (Pearson's rho = 0.79, p < 0.001), and the model uncertainty for mortality risk was lower both for severe and early-stage participants compared to other participants (p < 0.001).

CONCLUSION

The presented multi-task BNN provides an increased robustness to imaging protocol compared to conventional methods for CT evaluation of emphysema. Additionally, it provides direct measurements of uncertainty for its generalization to diverse imaging protocols and patient populations.

KEY POINTS

Question Quantitative CT evaluation of emphysema is highly sensitive to CT protocol, which increases uncertainty in disease evaluation and impacts the clinical utility of traditional metrics. Findings Uncertainty-aware deep learning improved consistency in emphysema quantification between fixed and reduced dose CT scans compared to traditional histogram analysis. Clinical relevance CT evaluation of emphysema severity and mortality risk using uncertainty-aware deep learning methods is more consistent across variable radiation dose protocols compared to conventional methods while also providing measurement reliability metrics, improving the evaluation of COPD using CT.

Sex Differences in Chronic Obstructive Pulmonary Disease: Implications for Pathogenesis, Diagnosis, and Treatment

Chronic obstructive pulmonary disease (COPD) is a leading chronic disease worldwide, with significant healthcare utilization, morbidity, and mortality. Irreversible airflow obstruction identified on spirometry establishes the diagnosis of COPD, but the disease entity encompasses a heterogeneous collection of lung diseases, including chronic bronchitis and emphysema. Despite the enormous burden of COPD, there are no pharmacological therapies that slow its progression or reduce mortality, indicating the need for a deeper understanding. There are sex differences concerning COPD prevalence, pathology, and symptoms. Historically thought to primarily affect males, its effect on females has increased significantly over time due to a rising prevalence of smoking and exposure to harmful pollutants among females. Over the past decade, the age-adjusted prevalence of COPD has been consistently higher in females than in males. Despite this, the impacts of biological sex continue to be confusing and poorly defined. The primary goal of this review is to organize and collate sex-dependent factors that may contribute to disease differences in males and females, thereby identifying future research questions in this area.

Sex, Gender, and COPD

Sex and gender have emerged as critical considerations relevant to chronic obstructive pulmonary disease (COPD). Sex differences in lung development and physiologic response to hormones and environmental exposures influence COPD susceptibility, progression, severity, morbidity, and mortality. Gender has been poorly measured in the context of COPD, and gendered exposures further impact biology. The hormonal milieu is critical to study across the life course. Differences in immunity and inflammation likely impact sex- and gender-related features of COPD. Emerging evidence from multiple types of omics data is revealing new genes and pathways to consider as relevant to sex- and gender-divergent features of COPD. Much research to date has focused on autosomes, but the growing awareness of a role for allosomes is highlighting knowledge gaps. Reproductive aging impacts lung function and requires more investigation. Network medicine holds promise as an approach to sex and gender omics to uncover drivers of COPD in men and women.

Temporal trends, gender, and ethnoracial disparities in mortality from pulmonary emphysema: A retrospective nationwide analysis

Emphysema, a significant global health issue, involves abnormal lung enlargement and wall destruction, affecting 9% to 12% of people worldwide. In the United States (US), 2 million people live with emphysema, with numbers expected to rise. Data on mortality trends and disparities associated with demographic factors is limited, underscoring our study's focus on analyzing these patterns in US adults. This study examined death certificates from the CDC WONDER database for individuals aged 25 and older who died with emphysema (J43) between 1999 and 2020. Age-adjusted mortality rates (AAMRs) and annual percent change were calculated by year, gender, age group, race/ethnicity, geographic region, and urbanization status. Between 1999 and 2020, there were 484,095 reported deaths among emphysema patients. The overall AAMR decreased from 18.5 to 7.2 per 100,000 population, with an annual decrease of 8% from 2008 to 2015, followed by a slight recent increase. Analyzing by age groups, older adults had the highest AAMR of 42. Men had significantly higher AAMRs than women (13.4 vs 7.8). By race, non-Hispanic (NH) White patients had the highest AAMRs (11.3), followed by NH American Indian or Alaska Native (8.2), NH Black (7.7), Hispanic (3.9), and NH Asian or Pacific Islander patients (3.1). Nonmetropolitan areas had higher AAMRs compared to metropolitan areas (11.7 vs 9.8). Emphysema mortality has decreased overall but recently increased slightly. Higher rates are seen among older adults, men, NH White patients, and nonmetropolitan residents. Policies are needed to continue reducing these death rates and to address these disparities.

Exploring Gender Differences in the Association Between TyG Index and COPD: A Cross-Sectional Study from NHANES 1999-2018

Purpose

This study examined gender differences in the association of Triglyceride-Glucose (TyG) index with the prevalence of chronic obstructive pulmonary disease (COPD), particularly in a non-diabetic population.

Methods

The study leveraged data from the National Health and Nutrition Examination Survey (NHANES), spanning from 1999 to 2018, with a cohort of 23,456 participants. Logistic regression and restricted cubic spline analyses were employed to explore the relationship between the TyG index and COPD prevalence.

Results

Statistical analyses revealed a significant positive association between the TyG index and COPD prevalence among non-diabetic women after adjustment for all covariates (OR=1.50; 95% CI, 1.08-2.08), supported by a linear relationship (P for non-linearity=0.298). No equivalent significant association was found in non-diabetic men (OR=1.00; 95% CI, 0.67-1.48). Within the diabetic group, the TyG index did not show a significant association with COPD prevalence, regardless of gender.

Conclusion

Our study reveals a significant positive correlation between the TyG index and COPD prevalence in the non-diabetic population, marked by notable gender differences.

Sex-specific emphysematous changes evaluated by a three-dimensional computed tomography volumetric analysis among patients with smoking histories who underwent resection for lung cancer

PURPOSE

The present study evaluated the sex-specific susceptibility to the development of emphysema in patients with smoking histories who underwent lung cancer surgeries.

METHODS

Lung cancer patients with smoking histories who underwent lung resection at the University of Tsukuba Hospital, Japan, were enrolled. Radiologic emphysematous changes were analyzed using three-dimensional computed tomography (3D-CT). The volume proportion of emphysematous lung per unit of smoking and the relationship between emphysematous change and clinicopathologic factors were evaluated.

RESULTS

Radiologic emphysematous changes analyzed using 3D-CT per pack-year smoked, defined as the Smoking-Emphysema Index (SEI), were greater in females than males. The difference was more profound in adenocarcinoma patients than in non-adenocarcinoma patients (0.70 ± 2.30 vs. 0.21 ± 0.28, P = 0.037).

CONCLUSION

Female lung cancer patients are more susceptible to smoking-induced emphysema than males. The SEI may be an effective indicator for evaluating smoking-induced emphysema.

Sex-Specific Genetic Determinants of Asthma-COPD Phenotype and COPD in Middle-Aged and Older Canadian Adults: An Analysis of CLSA Data

The etiology of sex differences in the risk of asthma-COPD phenotype and COPD is still not completely understood. Genetic and environmental risk factors are commonly believed to play an important role. This study aims to identify sex-specific genetic markers associated with asthma-COPD phenotype and COPD using the Canadian Longitudinal Study on Aging (CLSA) Baseline Comprehensive and Genomic data. There were a total of 1,415 COPD cases. Out of them, 504 asthma-COPD phenotype cases were identified. 20,524 participants without a diagnosis of asthma and COPD served as controls. We performed genome-wide SNP-by-sex interaction analysis. SNPs with an interaction p-value < 10^-5 were included in a sex-stratified multivariable logistic regression for asthma-COPD phenotype and COPD outcomes. 18 and 28 SNPs had a significant interaction term p-value < 10^-5 with sex in the regression analyses of asthma-COPD phenotype and COPD outcomes, respectively. Sex-stratified multivariable analysis of asthma-COPD phenotype showed that 7 SNPs in/near SMYD3, FHIT, ZNF608, RIMBP2, ZNF133, BPIFB1, and S100B loci were significant in males. Sex-stratified multivariable analysis of COPD showed that 8 SNPs in/near MAGI1, COX18, OSTC, ELOVL5, C7orf72 FGF14, and NKAIN4 were significant in males, and 4 SNPs in/near genes CAMTA1, SATB2, PDE10A, and LINC00908 were significant in females. An SNP in the ZPBP gene was associated with COPD in both males and females. Identification of sex-specific loci associated with asthma-COPD phenotype and COPD may offer valuable evidence toward a better understanding of the sex-specific differences in the pathophysiology of the diseases.

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.

The utility of quantitative computed tomography in cohort studies of chronic obstructive pulmonary disease: a narrative review

Background and Objective

Chronic obstructive pulmonary disease (COPD) is a significant contributor to global morbidity and mortality. Quantitative computed tomography (QCT), a non-invasive imaging modality, offers the potential to assess lung structure and function in COPD patients. Amidst the coronavirus disease 2019 (COVID-19) pandemic, chest computed tomography (CT) scans have emerged as a viable alternative for assessing pulmonary function (e.g., spirometry), minimizing the risk of aerosolized virus transmission. However, the clinical application of QCT measurements is not yet widespread enough, necessitating broader validation to determine its usefulness in COPD management.

Methods

We conducted a search in the PubMed database in English from January 1, 2013 to April 20, 2023, using keywords and controlled vocabulary related to QCT, COPD, and cohort studies.

Key Content and Findings

Existing studies have demonstrated the potential of QCT in providing valuable information on lung volume, airway geometry, airway wall thickness, emphysema, and lung tissue density in COPD patients. Moreover, QCT values have shown robust correlations with pulmonary function tests, and can predict exacerbation risk and mortality in patients with COPD. QCT can even discern COPD subtypes based on phenotypic characteristics such as emphysema predominance, supporting targeted management and interventions.

Conclusions

QCT has shown promise in cohort studies related to COPD, since it can provide critical insights into the pathogenesis and progression of the disease. Further research is necessary to determine the clinical significance of QCT measurements for COPD management.

Contribution of adaptive immunity to human COPD and experimental models of emphysema

The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction.

Machine learning reveals sex differences in clinical features of acute exacerbation of chronic obstructive pulmonary disease: A multicenter cross-sectional study

Introduction

Intrinsically, chronic obstructive pulmonary disease (COPD) is a highly heterogonous disease. Several sex differences in COPD, such as risk factors and prevalence, were identified. However, sex differences in clinical features of acute exacerbation chronic obstructive pulmonary disease (AECOPD) were not well explored. Machine learning showed a promising role in medical practice, including diagnosis prediction and classification. Then, sex differences in clinical manifestations of AECOPD were explored by machine learning approaches in this study.

Methods

In this cross-sectional study, 278 male patients and 81 female patients hospitalized with AECOPD were included. Baseline characteristics, clinical symptoms, and laboratory parameters were analyzed. The K-prototype algorithm was used to explore the degree of sex differences. Binary logistic regression, random forest, and XGBoost models were performed to identify sex-associated clinical manifestations in AECOPD. Nomogram and its associated curves were established to visualize and validate binary logistic regression.

Results

The predictive accuracy of sex was 83.930% using the k-prototype algorithm. Binary logistic regression revealed that eight variables were independently associated with sex in AECOPD, which was visualized by using a nomogram. The AUC of the ROC curve was 0.945. The DCA curve showed that the nomogram had more clinical benefits, with thresholds from 0.02 to 0.99. The top 15 sex-associated important variables were identified by random forest and XGBoost, respectively. Subsequently, seven clinical features, including smoking, biomass fuel exposure, GOLD stages, PaO2, serum potassium, serum calcium, and blood urea nitrogen (BUN), were concurrently identified by three models. However, CAD was not identified by machine learning models.

Conclusions

Overall, our results support that the clinical features differ markedly by sex in AECOPD. Male patients presented worse lung function and oxygenation, less biomass fuel exposure, more smoking, renal dysfunction, and hyperkalemia than female patients with AECOPD. Furthermore, our results also suggest that machine learning is a promising and powerful tool in clinical decision-making.

Clinical characteristics, management, and outcome of eosinophilic pneumonia associated with daptomycin

OBJECTIVE

The association between daptomycin exposure and eosinophilic pneumonia (EP) is mainly based on case reports. The purpose of this study was to evaluate the clinical characteristics and provide more evidence for better identify and management of daptomycin-induced eosinophilic pneumonia in clinical practice.

METHODS

Literature from 1991 to October 31, 2021 on EP induced by daptomycin were collected for retrospective analysis.

RESULTS

A total of 47 patients (40 male and 7 female) from 35 studies were included. The median age was 67 years (range 28-89), and 78.7% of patients were ≥60 years. Daptomycin was mainly used in patients undergoing osteoarticular infections (63.8%). Typical initial symptoms were fever (91.5%), cough (55.3%) and dyspnea (59.6%). The median onset time of symptom was 3 weeks. EP recurred in 14.9% of patients after the re-administration of daptomycin, and 57.1% of EP recurred within 24h. Most cases were accompanied by marked accumulation of eosinophils in peripheral (41 cases) and/or bronchoalveolar lavage fluid (27 cases). The main radiological features were pulmonary infiltration, ground glass opacity or consolidation in CT/CXR. All patients had symptom resolution after discontinuation of daptomycin except for one patient died due to the progression of the primary disease, the median time to symptoms relief was 3 days. Corticosteroids have been shown to help symptoms relief in some cases (59.6%).

CONCLUSION

Daptomycin-induced eosinophilic pneumonia is a rare and serious complication. Physicians should consider eosinophilic pneumonia as a differential diagnosis when receiving daptomycin therapy, particularly in elderly male patients.

X chromosome associations with chronic obstructive pulmonary disease and related phenotypes: an X chromosome-wide association study

BACKGROUND

The association between genetic variants on the X chromosome to risk of COPD has not been fully explored. We hypothesize that the X chromosome harbors variants important in determining risk of COPD related phenotypes and may drive sex differences in COPD manifestations.

METHODS

Using X chromosome data from three COPD-enriched cohorts of adult smokers, we performed X chromosome specific quality control, imputation, and testing for association with COPD case-control status, lung function, and quantitative emphysema. Analyses were performed among all subjects, then stratified by sex, and subsequently combined in meta-analyses.

RESULTS

Among 10,193 subjects of non-Hispanic white or European ancestry, a variant near TMSB4X, rs5979771, reached genome-wide significance for association with lung function measured by FEV₁/FVC ([Formula: see text] 0.020, SE 0.004, p 4.97 × 10^-08), with suggestive evidence of association with FEV₁ ([Formula: see text] 0.092, SE 0.018, p 3.40 × 10^-07). Sex-stratified analyses revealed X chromosome variants that were differentially trending in one sex, with significantly different effect sizes or directions.

CONCLUSIONS

This investigation identified loci influencing lung function, COPD, and emphysema in a comprehensive genetic association meta-analysis of X chromosome genetic markers from multiple COPD-related datasets. Sex differences play an important role in the pathobiology of complex lung disease, including X chromosome variants that demonstrate differential effects by sex and variants that may be relevant through escape from X chromosome inactivation. Comprehensive interrogation of the X chromosome to better understand genetic control of COPD and lung function is important to further understanding of disease pathology. Trial registration Genetic Epidemiology of COPD Study (COPDGene) is registered at ClinicalTrials.gov, NCT00608764 (Active since January 28, 2008). Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints Study (ECLIPSE), GlaxoSmithKline study code SCO104960, is registered at ClinicalTrials.gov, NCT00292552 (Active since February 16, 2006). Genetics of COPD in Norway Study (GenKOLS) holds GlaxoSmithKline study code RES11080, Genetics of Chronic Obstructive Lung Disease.

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.

Haploinsufficiency of Col5a1 causes intrinsic lung and respiratory changes in a mouse model of classical Ehlers-Danlos syndrome

The Ehlers-Danlos syndromes (EDS) are inherited connective tissue diseases with primary manifestations that affect the skin and the musculoskeletal system. However, the effects of EDS on the respiratory system are not well understood and are described in the literature as sporadic case reports. We performed histological, histomorphometric, and the first in-depth characterization of respiratory system function in a mouse model of classical EDS (cEDS) with haploinsufficiency of type V collagen (Col5a1+/-). In young adult male and female mice, lung histology showed reduced alveolar density, reminiscent of emphysematous-like changes. Respiratory mechanics showed a consistent increase in respiratory system compliance accompanied by increased lung volumes in Col5a1+/- compared to control mice. Flow-volume curves, generated to mimic human spirometry measurements, demonstrated larger volumes throughout the expiratory limb of the flow volume curves in Col5a1+/- compared to controls. Some parameters showed a sexual dimorphism with significant changes in male but not female mice. Our study identified a clear respiratory phenotype in the Col5a1+/- mouse model of EDS and indicated that intrinsic respiratory and lung changes may exist in cEDS patients. Their potential impact on the respiratory function during lung infections, other respiratory disease processes, or insults may be significant and justify further clinical evaluation.

Differences Between Men and Women with Chronic Obstructive Pulmonary Disease

There are many differences between men and women in risk factor vulnerability and impact, symptom development, presentation, clinical manifestations, and outcomes of chronic obstructive pulmonary disease (COPD). These differences have been inadequately explored, which is of particular concern in view of the delay in diagnosis and treatment that occurs for both men and women, and the need to use all therapies in a targeted and tailored way for best clinical gain and least harm. Women are generally underrepresented in randomized trials, as are non-tobacco-related phenotypes of COPD. We must garner the information available to better describe optimal treatment approaches.

Progression of Emphysema and Small Airways Disease in Cigarette Smokers

BACKGROUND

Little is known about factors associated with emphysema progression in cigarette smokers. We evaluated factors associated with change in emphysema and forced expiratory volume in 1 second (FEV1) in participants with and without chronic obstructive pulmonary disease (COPD).

METHODS

This retrospective study included individuals participating in the COPD Genetic Epidemiology study who completed the 5-year follow-up, including inspiratory and expiratory computed tomography (CT) and spirometry. All paired CT scans were analyzed using micro-mapping, which classifies individual voxels as emphysema or functional small airway disease (fSAD). Presence and progression of emphysema and FEV1 were determined based on comparison to nonsmoker values. Logistic regression analyses were used to identify clinical parameters associated with disease progression.

RESULTS

A total of 3088 participants were included with a mean ± SD age of 60.7±8.9 years, including 72 nonsmokers. In all Global initiative for chronic Obstructive Lung Disease (GOLD) stages, the presence of emphysema at baseline was associated with emphysema progression (odds ratio [OR]: GOLD 0: 4.32; preserved ratio-impaired spirometry [PRISm]; 5.73; GOLD 1: 5.16; GOLD 2: 5.69; GOLD 3/4: 5.55; all p ≤0.01). If there was no emphysema at baseline, the amount of fSAD at baseline was associated with emphysema progression (OR for 1% increase: GOLD 0: 1.06; PRISm: 1.20; GOLD 1: 1.7; GOLD 3/4: 1.08; all p ≤ 0.03).In 1735 participants without spirometric COPD, progression in emphysema occurred in 105 (6.1%) participants and only 21 (1.2%) had progression in both emphysema and FEV1.

CONCLUSIONS

The presence of emphysema is an important predictor of emphysema progression. In patients without emphysema, fSAD is associated with the development of emphysema. In participants without spirometric COPD, emphysema progression occurred independently of FEV1 decline.

Metabolomic Profiling Reveals Sex Specific Associations with Chronic Obstructive Pulmonary Disease and Emphysema

Susceptibility and progression of lung disease, as well as response to treatment, often differ by sex, yet the metabolic mechanisms driving these sex-specific differences are still poorly understood. Women with chronic obstructive pulmonary disease (COPD) have less emphysema and more small airway disease on average than men, though these differences become less pronounced with more severe airflow limitation. While small studies of targeted metabolites have identified compounds differing by sex and COPD status, the sex-specific effect of COPD on systemic metabolism has yet to be interrogated. Significant sex differences were observed in 9 of the 11 modules identified in COPDGene. Sex-specific associations by COPD status and emphysema were observed in 3 modules for each phenotype. Sex stratified individual metabolite associations with COPD demonstrated male-specific associations in sphingomyelins and female-specific associations in acyl carnitines and phosphatidylethanolamines. There was high preservation of module assignments in SPIROMICS (SubPopulations and InteRmediate Outcome Measures In COPD Study) and similar female-specific shift in acyl carnitines. Several COPD associated metabolites differed by sex. Acyl carnitines and sphingomyelins demonstrate sex-specific abundances and may represent important metabolic signatures of sex differences in COPD. Accurately characterizing the sex-specific molecular differences in COPD is vital for personalized diagnostics and therapeutics.

Gender modifies the effect of body mass index on lung function decline in mild-to-moderate COPD patients: a pooled analysis

Background

Low body weight is associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). However, it is not known whether gender modifies this relationship.

Methods

We pooled data of 8686 COPD patients from 7 studies with a median length of 36-months of follow up. Using a longitudinal natural cubic spline regression model, we examined the dose–response relationship between body mass index (BMI) and the rate of decline in forced expiratory volume in one second (FEV₁) in patients with GOLD 1 and 2 disease, stratified by gender and adjusted for age, smoking status, and cohort effects.

Results

There was an inverse linear relationship between BMI and the rate of FEV₁ decline in GOLD Grades 1 and 2, which was modified by gender (p < 0.001). In male patients, an increase of BMI by 1 kg/m² reduced FEV₁ decline by 1.05 mL/year (95% CI 0.96, 1.14). However, in female patients, BMI status did not have a clinically meaningful impact on FEV₁ decline: an increase of baseline BMI by 1 kg/m² reduced FEV₁ decline by 0.16 ml/year (95% CI 0.11, 0.21). These gender-modified relationships were similar between GOLD 1 and 2 patients, and between current and former smokers.

Conclusion

In mild to moderate COPD, higher BMI was associated with a less rapid decline of FEV₁ in male patients whereas this association was minimal in females patients. This gender-specific BMI effect was independent of COPD severity and smoking status.

Chronic hypoxaemia and gender status modulate adiponectin plasmatic level and its multimer proportion in severe COPD patients: new endotypic presentation?

BACKGROUND

Disease progression in COPD patient is associated to lung function decline, leading to a higher risk of hypoxaemia and associated comorbidities, notably cardiovascular diseases (CVD). Adiponectin (Ad) is an adipokine with cardio-protective properties. In COPD patients, conflicting results were previously reported regarding Ad plasmatic (Adpl) level, probably because COPD is a heterogeneous disease with multifactorial influence. Among these factors, gender and hypoxaemia could interact in a variety of ways with Ad pathway. Therefore, we postulated that these components could influence Adpl level and its multimers in COPD patients and contribute to the appearance of a distinct endotype associated to an altered CVD risk.

METHODS

One hundred COPD patients were recruited: 61 were men and 39 were women. Patients who were not severely hypoxemic were allocated to non-hypoxemic group which included 46 patients: 27 men and 19 women. Hypoxemic group included 54 patients: 34 men and 20 women. For all patients, Adpl level and proportion of its different forms were measured. Differences between groups were evaluated by Rank-Sum tests. The relationship between these measures and BMI, blood gas analysis (PaO2, PaCO2), or lung function (FEV1, FEV1/FVC, TLCO, TLC, RV) were evaluated by Pearson correlation analysis.

RESULTS

Despite similar age, BMI and obstruction severity, women had a higher TLC and RV (median: TLC = 105%; RV = 166%) than men (median: TLC = 87%; RV = 132%). Adpl level was higher in women (median = 11,152 ng/ml) than in men (median = 10,239 ng/ml) and was negatively associated with hyperinflation (R = - 0,43) and hypercapnia (R = - 0,42). The proportion of the most active forms of Ad (HMW) was increased in hypoxemic women (median = 10%) compared with non-hypoxemic women (median = 8%) but was not modulated in men.

CONCLUSION

COPD pathophysiology seemed to be different in hypoxemic women and was associated to Ad modulations. Hyperinflation and air-trapping in association with hypercapnia and hypoxaemia, could contribute to a modulation of Adpl level and of its HMW forms. These results suggest the development of a distinct endotypic presentation, based on gender.

Impact of gender on chronic obstructive pulmonary disease outcomes: a propensity score-matched analysis of a prospective cohort study

BACKGROUND/AIMS

Despite increasing awareness of the burden of chronic obstructive pulmonary disease (COPD) in women, knowledge regarding gender differences in COPD outcomes is limited. Therefore, we aimed to evaluate whether COPD outcomes, including exacerbations, lung function, and symptoms differ by gender.

METHODS

We recruited patients with COPD from two Korean multicenter prospective cohorts. After propensity score matching, the main outcome, the incidence of moderate or severe exacerbations was analyzed using a negative binomial regression model. We also assessed changes in lung function and symptom scores including the St. George's respiratory questionnaire for COPD (SGRQ-C), COPD assessment test (CAT), and the modified Medical Research Council (mMRC) dyspnea score.

RESULTS

After propensity score matching, 74 women and 74 men with COPD were included. The incidence rates of exacerbations in women and men were not significantly different (incidence rate ratio, 1.49; 95% confidence interval [CI], 0.88 to 2.54). There was no significant difference in the incidence rates adjusted for medication possession ratios of long-acting muscarinic antagonists, long-acting β-agonists, and inhaled corticosteroids during the follow-up period (incidence rate ratio, 1.47; 95% CI, 0.86 to 2.52). Rates of decline in post-bronchodilator forced expiratory volume in 1 second and forced vital capacity did not differ between women and men during 48 months of follow-up. The changes in scores on the SGRQ-C, CAT, and mMRC Questionnaire in women were also similar to those in men.

CONCLUSION

We observed no gender differences in the rate of exacerbations of COPD in a prospective longitudinal study. Further studies are needed to confirm these findings in the general COPD population.

Host, Gender, and Early-Life Factors as Risks for Chronic Obstructive Pulmonary Disease

Although smoking results in lung pathology in many, still not all smokers develop chronic obstructive pulmonary disease (COPD). Roughly a quarter of patients with COPD have never smoked. An understanding of both host and environmental factors beyond smoking that contribute to disease development remain critical to understanding disease prevention and ultimately effectively intervene. In this article, we summarize host factors, including genetics and gender, as well as early-life events that contribute to the development of COPD.

Sex and gender: modifiers of health, disease, and medicine

Clinicians can encounter sex and gender disparities in diagnostic and therapeutic responses. These disparities are noted in epidemiology, pathophysiology, clinical manifestations, disease progression, and response to treatment. This Review discusses the fundamental influences of sex and gender as modifiers of the major causes of death and morbidity. We articulate how the genetic, epigenetic, and hormonal influences of biological sex influence physiology and disease, and how the social constructs of gender affect the behaviour of the community, clinicians, and patients in the health-care system and interact with pathobiology. We aim to guide clinicians and researchers to consider sex and gender in their approach to diagnosis, prevention, and treatment of diseases as a necessary and fundamental step towards precision medicine, which will benefit men's and women's health.

Recent advances in chronic obstructive pulmonary disease pathogenesis: from disease mechanisms to precision medicine

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease with a high personal and societal burden. Exposure to toxic particles and gases, including cigarette smoke, is the main risk factor for COPD. Together with smoking cessation, current treatment strategies of COPD aim to improve symptoms and prevent exacerbations, but there is no disease-modifying treatment. The biggest drawback of today's COPD treatment regimen is the 'one size fits all' pharmacological intervention, mainly based on disease severity and symptoms and not the individual's disease pathology. To halt the worrying increase in the burden of COPD, disease management needs to be advanced with a focus on personalized treatment. The main pathological feature of COPD includes a chronic and abnormal inflammatory response within the lungs, which results in airway and alveolar changes in the lung as reflected by (small) airways disease and emphysema. Here we discuss recent developments related to the abnormal inflammatory response, ECM and age-related changes, structural changes in the small airways and the role of sex-related differences, which are all relevant to explain the individual differences in the disease pathology of COPD and improve disease endotyping. Furthermore, we will discuss the most recent developments of new treatment strategies using biologicals to target specific pathological features or disease endotypes of COPD. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Chronic Obstructive Pulmonary Disease in Women: A Biologically Focused Review with a Systematic Search Strategy

Purpose

Evidence suggests that chronic obstructive pulmonary disease (COPD) symptoms and progression may differ between men and women. However, limited information is currently available on the pathophysiological and biological factors that may underlie these sex-related differences. The objective of this review is to systematically evaluate reports of potential sex-related differences, including genetic, pathophysiological, structural, and other biological factors, that may influence COPD development, manifestation, and progression in women.

Patients and Methods

A PubMed literature search was conducted from inception until January 2020. Original reports of genetic, hormonal, and physiological differences, and biological influences that could contribute to COPD development, manifestation, and progression in women were included.

Results

Overall, 491 articles were screened; 29 articles met the inclusion criteria. Results from this analysis demonstrated between-sex differences in inflammatory, immune, genetic, structural, and physiological factors in patients with COPD.

Conclusion

Various biological differences are observed between men and women with COPD including differences in inflammatory and metabolic pathways related to obesity and fat distribution, immune cell function and autophagy, extent and distribution of emphysema and airway wall remodeling. An enhanced understanding of these differences has the potential to broaden our understanding of how COPD develops and progresses, thereby providing an opportunity to ultimately improve diagnosis, treatment, and monitoring of COPD in both men and women.

COPD and lung cancer incidence in the Women's Health Initiative Observational Study: A brief report

OBJECTIVES

Lung cancer is the leading cause of cancer mortality in both men and women in the United States. COPD is associated with lung cancer independently of cigarette smoking, but remains understudied in women. Utilizing data from the Women's Health Initiative Observational Study (WHI-OS), this report investigates the association between COPD and development of lung cancer, with a focus on ethnicity and cancer subtype.

MATERIALS AND METHODS

The WHI-OS, part of the larger Women's Health Initiative (WHI), is comprised of postmenopausal women between ages 50 and 79 years old at enrollment. Self-administered questionnaires were utilized to gather baseline demographic, socioeconomic, and behavioral information from participants. For this analysis, COPD status was determined at study entry (baseline) and on annual survey (incident). Information on the primary outcome of interest, diagnosis of lung cancer, was also collected annually.

RESULTS AND CONCLUSION

Of the 92,789 women examined, 1,536 developed lung cancer. Overall, women with COPD were 1.64 times more likely to develop lung cancer than those without COPD, after adjusting for smoking status and intensity, ethnicity, education, body mass index, and income (HR = 1.64, 95 % CI: 1.43, 1.89). The relationship between COPD and lung cancer was not found to be significantly different between ethnic groups (p-value = 0.697). The associations between COPD and lung cancer was similar across subtypes (HR range 1.31-2.16), after adjusting for smoking status and intensity. COPD increases risk of lung cancer in women, thus they may benefit from more intensive surveillance compared to similar women without COPD.

Clinical Features Of Women With COPD: Sex Differences In A Cross-Sectional Study In Spain ("The ESPIRAL-ES Study")

Aim

This cross-sectional multicenter study was performed aimed at describing the clinical characteristics of women with COPD attended in routine daily practice in Spain.

Methods and results

Of a total of 1610 consecutive patients diagnosed with COPD recruited in primary care centers and pneumology services throughout Spain over a 90-day period, 17.9% (n=286) were women, with a median age of 62 years. Differences in COPD phenotypes by sex were statistically significant (P = 0.002). Males as compared with females showed a higher prevalence of non-exacerbator (47.9% vs 42.2%) and exacerbator with chronic bronchitis (22.9% vs 18.8%) phenotypes, whereas the ACOS phenotype was more common among females (21.7% vs 12.9%). The mean (SD) CAT score was similar in men than in women (20.8 [9.0] vs 21.2 [8.7], P = 0.481), as well as the impact of the disease on the quality of life according to CAT scores of <5 (no impact), 5–9 (low), 10–20 (medium), >20 (high), and >30 (very high). Sex-related differences according to smoking status were statistically significant (P < 0.001), with a higher percentage of men as compared with women in the groups of current smokers and ex-smokers; never-smokers were higher in women (9.1%) than in men (0.6%). The mean number of comorbidities was 2.01 (1.43) (95% CI 1.93–2.09) in males and 1.99 (1.42) (95% CI 1.83–2.16) (P = 0.930) in females, but cardiovascular diseases (hypertension, ischemic heart disease, chronic heart failure) were more frequent in men, whereas metabolic disorders (osteoporosis) were more frequent in women.

Conclusion

This study highlights the impact of COPD in women and the importance of continuing sex-based research in tobacco-related respiratory diseases.

[Vulnerability of women to tobacco: The broncho-pulmonary consequences (asthma, COPD)]

Smoking remains common, with an exposure that begins early during pregnancy. It induces epigenetic changes, with a trans-generational transmission. Smoking increases the risk of uncontrolled asthma during childhood and adult life. Asthma is also associated with increased risk of a decline of lung function and chronic obstructive pulmonary disease (COPD). Women are more at risk of developing early and severe COPD. The mechanisms are currently poorly known.

Clinical Epidemiology of COPD: Insights From 10 Years of the COPDGene Study

The Genetic Epidemiology of COPD (COPDGene) study is a noninterventional, multicenter, longitudinal analysis of > 10,000 subjects, including smokers with a ≥ 10 pack-year history with and without COPD and healthy never smokers. The goal was to characterize disease-related phenotypes and explore associations with susceptibility genes. The subjects were extensively phenotyped with the use of comprehensive symptom and comorbidity questionnaires, spirometry, CT scans of the chest, and genetic and biomarker profiling. The objective of this review was to summarize the major advances in the clinical epidemiology of COPD from the first 10 years of the COPDGene study. We highlight the influence of age, sex, and race on the natural history of COPD, and the impact of comorbid conditions, chronic bronchitis, exacerbations, and asthma/COPD overlap.

Sex-specific differences in emphysema using a murine antisense oligonucleotide model of α-1 antitrypsin deficiency

α-1 Antitrypsin (AAT) deficiency is the leading genetic cause of emphysema; however, until recently, no genuine animal models of AAT deficiency existed, hampering the development of new therapies. This shortcoming is now addressed by both AAT-null and antisense oligonucleotide mouse models. The goal of this study was to more fully characterize the antisense oligonucleotide model. Both liver AAT mRNA and serum AAT levels were lower in anti-AAT versus control oligonucleotide-treated mice after 6, 12, and 24 wk. Six and twelve weeks of anti-AAT oligonucleotide therapy induced emphysema that was worse in female than male mice: mean linear intercept 73.4 versus 62.5 μm (P = 0.000003). However, at 24 wk of treatment, control oligonucleotide-treated mice also developed emphysema. After 6 wk of therapy, anti-AAT male and female mice demonstrated a similar reduction serum AAT levels, and there were no sex or treatment-specific alterations in inflammatory, serine protease, or matrix metalloproteinase mRNAs, with the exception of chymotrypsin-like elastase 1 (Cela1), which was 7- and 9-fold higher in anti-AAT versus control male and female lungs, respectively, and 1.6-fold higher in female versus male anti-AAT-treated lungs (P = 0.04). While lung AAT protein levels were reduced in anti-AAT-treated mice, lung AAT mRNA levels were unaffected. These findings are consistent with increased emphysema susceptibility of female patients with AAT-deficiency. The anti-AAT oligonucleotide model of AAT deficiency is useful for compartment-specific, in vivo molecular biology, and sex-specific studies of AAT-deficient emphysema, but it should be used with caution in studies longer than 12-wk duration.

Lung alveolar tissue destruction and protein citrullination in diesel exhaust-exposed mouse lungs

Humanity faces an increasing impact of air pollution worldwide, including threats to human health. Air pollutants prompt and promote chronic inflammation, tumourigenesis, autoimmune and other destructive processes in the human body. Post-translational modification of proteins, for example citrullination, results from damaging attacks of pollutants, including smoking, air pollution and others, rendering host tissues immunogenic. Citrullinated proteins and citrullinating enzymes, deiminases, are more prevalent in patients with COPD and correlate with ongoing inflammation and oxidative stress. In this study, we installed an in-house-designed diesel exhaust delivery and cannabidiol vaporization system where mice were exposed to relevant, urban traffic-related levels of diesel exhaust for 14 days and assessed integrity of alveolar tissue, gene expression shifts and changes in protein content in the lungs and other tissues of exposed mice. Systemic presence of modified proteins was also tested. The protective effect of phytocannabinoids was investigated as well. Data obtained in our study show subacute effects of diesel exhaust on mouse lung integrity and protein content. Emphysematous changes are documented in exposed mouse lungs. In parallel, increased levels of citrulline were detected in the alveolar lung tissue and peripheral blood of exposed mice. Pre-treatment with vaporized cannabidiol ameliorated some damaging effects. Results reported hereby provide new insights into subacute lung tissue changes that follow diesel exhaust exposure and suggest possible dietary and/or other therapeutic interventions for maintaining lung health and healthy ageing.

Dynamic changes in lung responses after single and repeated exposures to cigarette smoke in mice

Cigarette smoke is well recognized to cause injury to the airways and the alveolar walls over time. This injury usually requires many years of exposure, suggesting that the lungs may rapidly develop responses that initially protect it from this repetitive injury. Our studies tested the hypotheses that smoke induces an inflammatory response and changes in mRNA profiles that are dependent on sex and the health status of the lung, and that the response of the lungs to smoke differs after 1 day compared to 5 days of exposure. Male and female wildtype (WT) and Scnn1b-transgenic (βENaC) mice, which have chronic bronchitis and emphysematous changes due to dehydrated mucus, were exposed to cigarette smoke or sham air conditions for 1 or 5 days. The inflammatory response and gene expression profiles were analyzed in lung tissue. Overall, the inflammatory response to cigarette smoke was mild, and changes in mediators were more numerous after 1 than 5 days. βENaC mice had more airspace leukocytes than WT mice, and smoke exposure resulted in additional significant alterations. Many genes and gene sets responded similarly at 1 and 5 days: genes involved in oxidative stress responses were upregulated while immune response genes were downregulated. However, certain genes and biological processes were regulated differently after 1 compared to 5 days. Extracellular matrix biology genes and gene sets were upregulated after 1 day but downregulated by 5 days of smoke compared to sham exposure. There was no difference in the transcriptional response to smoke between WT and βENaC mice or between male and female mice at either 1 or 5 days. Taken together, these studies suggest that the lungs rapidly alter gene expression after only one exposure to cigarette smoke, with few additional changes after four additional days of repeated exposure. These changes may contribute to preventing lung damage.

Imaging Advances in Chronic Obstructive Pulmonary Disease. Insights from the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) Study

The Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) study, which began in 2007, is an ongoing multicenter observational cohort study of more than 10,000 current and former smokers. The study is aimed at understanding the etiology, progression, and heterogeneity of chronic obstructive pulmonary disease (COPD). In addition to genetic analysis, the participants have been extensively characterized by clinical questionnaires, spirometry, volumetric inspiratory and expiratory computed tomography, and longitudinal follow-up, including follow-up computed tomography at 5 years after enrollment. The purpose of this state-of-the-art review is to summarize the major advances in our understanding of COPD resulting from the imaging findings in the COPDGene study. Imaging features that are associated with adverse clinical outcomes include early interstitial lung abnormalities, visual presence and pattern of emphysema, the ratio of pulmonary artery to ascending aortic diameter, quantitative evaluation of emphysema, airway wall thickness, and expiratory gas trapping. COPD is characterized by the early involvement of the small conducting airways, and the addition of expiratory scans has enabled measurement of small airway disease. Computational advances have enabled indirect measurement of nonemphysematous gas trapping. These metrics have provided insights into the pathogenesis and prognosis of COPD and have aided early identification of disease. Important quantifiable extrapulmonary findings include coronary artery calcification, cardiac morphology, intrathoracic and extrathoracic fat, and osteoporosis. Current active research includes identification of novel quantitative measures for emphysema and airway disease, evaluation of dose reduction techniques, and use of deep learning for phenotyping COPD.

Office-Based Sedation/General Anesthesia for COPD Patients, Part II

The safe treatment of patients with chronic obstructive pulmonary disease (COPD) in dental office office-based settings can be quite complex without a current understanding of the etiology, course, severity, and current treatment modalities of the disease. The additional concerns of providing sedation and/or general anesthesia to patients with COPD in settings outside of a hospital demand thorough investigation of individual patient presentation and realistic development of planned treatment that patients suffering from this respiratory condition can tolerate. Along with other co-morbidities, such as advanced age and potential significant cardiovascular compromise, the dental practitioner providing sedation or general anesthesia must tailor any treatment plan to address multiple organ systems and mitigate risks of precipitating acute respiratory failure from inadequate pain and/or anxiety control. Part I of this article covered the epidemiology, etiology, and pathophysiology of COPD. Patient considerations in the preoperative period were also reviewed. Part II will cover which patients are acceptable for sedation/general anesthesia in the dental office-based setting as well as sedation/general anesthesia techniques that may be considered. Postoperative care will also be reviewed.

Emphysema extent on computed tomography is a highly specific index in diagnosing persistent airflow limitation: a real-world study in China

Objective

The diagnostic value of emphysema extent in consistent air flow limitation remains controversial. Therefore, we aimed to assess the value of emphysema extent on computed tomography (CT) on the diagnosis of persistent airflow limitation. Furthermore, we developed a diagnostic criterion for further verification.

Materials and methods

We retrospectively enrolled patients who underwent chest CT and lung function test. To be specific, 671 patients were enrolled in the derivation group (Group 1.1), while 479 patients were in the internal validation group (Group 1.2). The percentage of lung volume occupied by low attenuation areas (LAA%) and the percentile of the histogram of attenuation values were calculated.

Results

In patients with persistent airflow limitation, the LAA% was higher and the percentile of the histogram of attenuation values was lower, compared with patients without persistent airflow limitation. Using LAA% with a threshold of −950 HU >1.4% as the criterion, the sensitivity was 44.3% and 47.2%, and the specificity was 95.2% and 95.7%, in Group 1.1 and Group 1.2, respectively. The specificity was influenced by the coexistence of interstitial lung disease, pneumothorax, and post-surgery, rather than the coexistence of pneumonia, nodule, or mass. Multivariable models were also developed.

Conclusion

The emphysema extent on CT is a highly specific marker in the diagnosis of persistent airflow limitation.

Symptom clusters in chronic obstructive pulmonary disease: A systematic review

AIM

To conduct a comprehensive literature review to identify symptom clusters commonly present in Chronic obstructive pulmonary disease (COPD) patients.

BACKGROUND

COPD is the fourth leading cause of death worldwide. Substantial research has been studied regarding single symptoms that burden patients with this disease and the profound impacts that these symptoms can have on physical and psychological health. However, these symptoms rarely occur in isolation and limited research has been conducted identifying clinically significant relationships or clusters of symptoms associated with COPD afflicted patients.

METHODS

PubMed, Web of Science, and Embase databases were used to identify potential articles limited to records published between 2005 and 2018 with human-conducted trials on adults with COPD, examining symptom clusters in this population. Only 5 studies met inclusion criteria.

RESULTS

Across the five studies, 596 participants were included with a mean age of 70.49. Two themes emerged including psychological symptom clusters and respiratory-related symptom clusters. Anxiety-related symptoms appeared to be a common theme among psychological symptom clusters and varied greatly based on instrument selection. Inconsistent results were found in respiratory-related symptom clusters, but included difficulty breathing as a common symptom component. Only one study examined for stability of symptoms over time.

CONCLUSION

There were inconsistent results across all studies which may be contributed to the heterogeneity amongst patients, instruments administered, and statistical approach. Future research should be conducted to further elucidate COPD related symptom clusters, their effects on somatic and cognitive health, and the stability of these symptom clusters over time.

Childhood asthma is associated with COPD and known asthma variants in COPDGene: a genome-wide association study

BACKGROUND

Childhood asthma is strongly influenced by genetics and is a risk factor for reduced lung function and chronic obstructive pulmonary disease (COPD) in adults. This study investigates self-reported childhood asthma in adult smokers from the COPDGene Study. We hypothesize that childhood asthma is associated with decreased lung function, increased risk for COPD, and that a genome-wide association study (GWAS) will show association with established asthma variants.

METHODS

We evaluated current and former smokers ages 45-80 of non-Hispanic white (NHW) or African American (AA) race. Childhood asthma was defined by self-report of asthma, diagnosed by a medical professional, with onset at < 16 years or during childhood. Subjects with a history of childhood asthma were compared to those who never had asthma based on lung function, development of COPD, and genetic variation. GWAS was performed in NHW and AA populations, and combined in meta-analysis. Two sets of established asthma SNPs from published literature were examined for association with childhood asthma.

RESULTS

Among 10,199 adult smokers, 730 (7%) reported childhood asthma and 7493 (73%) reported no history of asthma. Childhood asthmatics had reduced lung function and increased risk for COPD (OR 3.42, 95% CI 2.81-4.18). Genotype data was assessed for 8031 subjects. Among NHWs, 391(7%) had childhood asthma, and GWAS identified one genome-wide significant association in KIAA1958 (rs59289606, p = 4.82 × 10- 8). Among AAs, 339 (12%) had childhood asthma. No SNPs reached genome-wide significance in the AAs or in the meta-analysis combining NHW and AA subjects; however, potential regions of interest were identified. Established asthma SNPs were examined, seven from the NHGRI-EBI database and five with genome-wide significance in the largest pediatric asthma GWAS. Associations were found in the current childhood asthma GWAS with known asthma loci in IL1RL1, IL13, LINC01149, near GSDMB, and in the C11orf30-LRRC32 region (Bonferroni adjusted p < 0.05 for all comparisons).

CONCLUSIONS

Childhood asthmatics are at increased risk for COPD. Defining asthma by self-report is valid in populations at risk for COPD, identifying subjects with clinical and genetic characteristics known to associate with childhood asthma. This has potential to improve clinical understanding of asthma-COPD overlap (ACO) and enhance future research into ACO-specific treatment regimens.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00608764 (Active since January 28, 2008).

Office-Based Sedation/General Anesthesia for COPD Patients, Part I

The safe treatment of patients with chronic obstructive pulmonary disease (COPD) in dental office-based settings can be quite complex without a current understanding of the etiology, course, severity, and treatment modalities of the disease. The additional concerns of providing sedation and/or general anesthesia to patients with COPD in settings outside of a hospital demand thorough investigation of individual patient presentation and realistic development of planned treatment that patients suffering from this respiratory condition can tolerate. Along with other comorbidities, such as advanced age and potential significant cardiovascular compromise, the dental practitioner providing sedation or general anesthesia must tailor any treatment plan to address multiple organ systems and mitigate risks of precipitating acute respiratory failure from inadequate pain and/or anxiety control. Part I of this article will cover the epidemiology, etiology, and pathophysiology of COPD. Patient evaluation in the preoperative period will also be reviewed. Part II will cover which patients are acceptable for sedation/general anesthesia in the dental office-based setting as well as sedation/general anesthesia techniques that may be considered.

Female mice lacking Pald1 exhibit endothelial cell apoptosis and emphysema

Paladin (Pald1, mKIAA1274 or x99384) was identified in screens for vascular-specific genes and is a putative phosphatase. Paladin has also been proposed to be involved in various biological processes such as insulin signaling, innate immunity and neural crest migration. To determine the role of paladin we have now characterized the Pald1 knock-out mouse in a broad array of behavioral, physiological and biochemical tests. Here, we show that female, but not male, Pald1 heterozygous and homozygous knock-out mice display an emphysema-like histology with increased alveolar air spaces and impaired lung function with an obstructive phenotype. In contrast to many other tissues where Pald1 is restricted to the vascular compartment, Pald1 is expressed in both the epithelial and mesenchymal compartments of the postnatal lung. However, in Pald1 knock-out females, there is a specific increase in apoptosis and proliferation of endothelial cells, but not in non-endothelial cells. This results in a transient reduction of endothelial cells in the maturing lung. Our data suggests that Pald1 is required during lung vascular development and for normal function of the developing and adult lung in a sex-specific manner. To our knowledge, this is the first report of a sex-specific effect on endothelial cell apoptosis.

Sex-Based Genetic Association Study Identifies CELSR1 as a Possible Chronic Obstructive Pulmonary Disease Risk Locus among Women

Chronic obstructive pulmonary disease (COPD) is a complex disease with strong environmental and genetic influences and sexually dimorphic features. Although genetic risk factors for COPD have been identified, much of the heritability remains unexplained. Sex-based genetic association studies may uncover additional COPD genetic risk factors. We studied current and former smokers from COPD case-control cohorts (COPDGene non-Hispanic whites and African Americans, Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-Points, and Genetics of Chronic Obstructive Lung Disease). COPD was defined as post-bronchodilator forced expiratory volume in 1 second/forced vital capacity less than 0.70 and forced expiratory volume in 1 second percent predicted less than 80. Testing was performed across all cohorts and combined in a meta-analysis adjusted for age, pack-years, and genetic ancestry. We first performed genome-wide single-nucleotide polymorphism (SNP)-by-sex interaction testing on the outcome of COPD affection status. We performed sex-stratified association testing for SNPs with interaction P less than 10^-6. We examined over 8 million SNPs in four populations, including 6,260 subjects with COPD (40.6% female) and 5,269 smoking control subjects (47.3% female). The SNP rs9615358 in the cadherin gene CELSR1 approached genome-wide significance for an interaction with sex (P = 1.24 × 10^-7). In the sex-stratified meta-analysis, this SNP was associated with COPD among females (odds ratio, 1.37 [95% confidence interval, 1.25-1.49]; P = 3.32 × 10^-7) but not males (odds ratio, 0.90 [95% confidence interval, 0.79-1.01]; P = 0.06). CELSR1 is involved in fetal lung development. In a human fetal lung tissue dataset, we observed greater CELSR1 expression in female compared with male samples. This SNP-by-sex genome-wide association analysis identified the fetal lung development gene, CELSR1, as a potential sex-specific risk factor for COPD. Identifying sex-specific genetic risk factors may reveal new insights into sexually dimorphic features of COPD.

Characteristic plethysmographic findings in a guinea pig model of COPD

AIM OF THE STUDY

Long-term exposure to cigarette smoke generates chronic obstructive pulmonary disease (COPD) in guinea pigs, but a comprehensive evaluation of changes in lung function, as assessed by barometric whole body plethysmography (WBP), is lacking.

MATERIALS AND METHODS

Female guinea pigs were exposed to the smoke of 20 cigarettes/day, 5 days/week, during 10 weeks (COPD group, n = 8), and were compared with unexposed female guinea pigs of the same age (control group, n = 8). WBP was performed in both groups, followed by lung histology.

RESULTS

At the end of the exposure period, guinea pigs in the COPD group had higher respiratory frequency, while duty cycle (Ti/Ttot) was unaffected. There was a trend toward minute ventilation (MV) and expiratory flow at the mid-tidal volume (EF50) to be higher in the COPD group. Enhanced pause (Penh) was lower, while time of braking (TB) and time to PEF relative to Te (Rpef) were higher in the COPD group. All guinea pigs exposed to tobacco smoke developed emphysematous lesions in their lungs and gained less body weight than controls.

CONCLUSIONS

In this COPD model, exposure to cigarette smoke produced changes in WBP characterized by a shallow breathing pattern with decreased Penh and a trend toward increasing EF50 (probably due to decreased elastic recoil), increased TB (suggesting dynamic laryngeal narrowing), and a trend of increasing MV (probably due to a higher metabolic rate). Many of these functional changes resemble those observed in patients with COPD and corroborate the suitability of this guinea pig model for the study of COPD.