• Humans
• Male
• Female
• Tomography, X-Ray Computed/methods
• Middle Aged
• Asthma/diagnostic imaging
• Asthma/physiopathology
• Asthma/complications
• Pulmonary Disease, Chronic Obstructive/diagnostic imaging
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Pulmonary Disease, Chronic Obstructive/complications
• Respiratory Function Tests
• Aged
• Adult
• Severity of Illness Index
• Radiation Dosage
• Lung/diagnostic imaging
• Lung/physiopathology

• Bronchiectasis
• Chronic obstructive
• Cohort studies
• Forced expiratory volume
• Pulmonary disease
• Pulmonary emphysema
• Respiratory function tests

• Chronic obstructive pulmonary disease (COPD)
• asthma-COPD overlap (ACO)
• exacerbation
• wheezing

• body plethysmography
• chronic obstructive pulmonary disease
• computed tomography
• diagnostic accuracy
• impulse oscillometry
• pulmonary emphysema
• pulmonary function test

• CT
• LAA
• emphysema
• mortality
• prognosis
• surgery

• COPD
• future
• phased approach
• precision medicine
• treatable traits strategy

• Asthma/therapy
• Humans
• Phenotype
• Precision Medicine
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/therapy

• Bial and provided all necessary scientific bibliography and funded medical writing support and publishing charges

Lung emphysema is an important phenotype of chronic obstructive pulmonary disease (COPD), and CT scanning is strongly recommended to establish the diagnosis. This study aimed to identify criteria by which physicians with limited technical resources can improve the diagnosis of emphysema.

We studied 436 COPD patients with prospective CT scans from the COSYCONET cohort. All items of the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ), the modified Medical Research Council (mMRC) scale, as well as data from spirometry and CO diffusing capacity, were used to construct binary decision trees. The importance of parameters was checked by the Random Forest and AdaBoost machine learning algorithms.

When relying on questionnaires only, items CAT 1 & 7 and SGRQ 8 & 12 sub-item 3 were most important for the emphysema- versus airway-dominated phenotype, and among the spirometric measures FEV₁/FVC. The combination of CAT item 1 (≤ 2) with mMRC (> 1) and FEV₁/FVC, could raise the odds for emphysema by factor 7.7. About 50% of patients showed combinations of values that did not markedly alter the likelihood for the phenotypes, and these could be easily identified in the trees. Inclusion of CO diffusing capacity revealed the transfer coefficient as dominant measure. The results of machine learning were consistent with those of the single trees.

Selected items (cough, sleep, breathlessness, chest condition, slow walking) from comprehensive COPD questionnaires in combination with FEV₁/FVC could raise or lower the likelihood for lung emphysema in patients with COPD. The simple, parsimonious approach proposed by us might help if diagnostic resources regarding respiratory diseases are limited.

Trial registration ClinicalTrials.gov, Identifier: NCT01245933, registered 18 November 2010, https://clinicaltrials.gov/ct2/show/record/NCT01245933.

The online version contains supplementary material available at 10.1186/s12931-021-01837-2.

• Adaboost
• COPD phenotypes
• CT scan
• Decision trees
• Emphysema
• Random forest

To determine the predictive factors for treatment responsiveness in patients with chronic obstructive pulmonary disease (COPD) at 1-year follow-up by performing quantitative analyses of baseline CT scans.

COPD patients (n = 226; 212 men, 14 women) were recruited from the Korean Obstructive Lung Disease cohort. Patients received a combination of inhaled long-acting beta-agonists and corticosteroids twice daily for 3 months and subsequently received medications according to the practicing clinician's decision. The emphysema index, air-trapping indices, and airway parameter (Pi10), calculated using both full-width-half-maximum and integral-based half-band (IBHB) methods, were obtained with baseline CT scans. Clinically meaningful treatment response was defined as an absolute increase of ≥ 0.225 L in the forced expiratory volume in 1 second (FEV₁) at the one-year follow-up. Multivariate logistic regression analysis was performed to investigate the predictors of an increase in FEV₁, and receiver operating characteristic (ROC) analysis was performed to evaluate the performance of the suggested models.

Treatment response was noted in 47 patients (20.8%). The mean FEV₁ increase in responders was 0.36 ± 0.10 L. On univariate analysis, the air-trapping index (ATI) obtained by the subtraction method, ATI of the emphysematous area, and IBHB-measured Pi10 parameter differed significantly between treatment responders and non-responders (p = 0.048, 0.042, and 0.002, respectively). Multivariate analysis revealed that the IBHB-measured Pi10 was the only independent variable predictive of an FEV₁ increase (p = 0.003). The adjusted odds ratio was 1.787 (95% confidence interval: 1.220–2.619). The area under the ROC curve was 0.641.

Measurement of standardized airway dimensions on baseline CT by using a recently validated quantification method can predict treatment responsiveness in COPD patients.

• Airway
• Chronic obstructive pulmonary disease
• Computed tomography
• Forced expiratory volume in 1 s
• Quantification
• Treatment response

In patients with COPD, acute exacerbation (AE) is not only an important determinant of prognosis, but also an important factor in choosing therapeutic agents. In this study, we evaluated the usefulness of COPD subtypes identified through cluster analysis to predict the first AE.

Among COPD patients in the Korea COPD Subgroup Study (KOCOSS) cohort, 1,195 who had follow-up data for AE were included in our study. We selected seven variables for cluster analysis – age, body mass index, smoking status, history of asthma, COPD assessment test (CAT) score, post-bronchodilator (BD) FEV₁ % predicted, and diffusing capacity of carbon monoxide % predicted.

K-means clustering identified four clusters for COPD that we named putative asthma-COPD overlap (ACO), mild COPD, moderate COPD, and severe COPD subtypes. The ACO group (n=196) showed the second-best post-BD FEV₁ (75.5% vs 80.9% [mild COPD, n=313] vs 52.4% [moderate COPD, n=345] vs 46.7% [severe COPD, n=341] predicted), the longest 6-min walking distance (424 m vs 405 m vs 389  m vs 365 m), and the lowest CAT score (12.2 vs 13.7 vs 15.6 vs 17.5) among the four groups. ACO group had greater risk for first AE compared to the mild COPD group (HR, 1.683; 95% CI, 1.175–2.410). The moderate COPD and severe COPD group HR values were 1.587 (95% CI, 1.145–2.200) and 1.664 (95% CI, 1.203–2.302), respectively. In addition, St. George’s Respiratory Questionnaire score (HR: 1.019; 95% CI, 1.014–1.024) and gastroesophageal reflux disease were independent factors associated with the first AE (HR: 1.535; 95% CI, 1.116–2.112).

Our cluster analysis revealed an exacerbator subtype of COPD independent of FEV₁. Since these patients are susceptible to AE, a more aggressive treatment strategy is needed in these patients.

• asthma-COPD overlap
• clustering
• comorbidity
• exacerbation
• phenotype
• prognosis

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.

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.

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.

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

• computed tomography
• emphysema
• lung function test
• persistent airflow limitation

• Chronic obstructive pulmonary disease
• airways
• computed tomography
• spirometry
• variability

• Aged
• Bronchi/diagnostic imaging
• Bronchi/physiopathology
• Female
• Humans
• Male
• Middle Aged
• Pulmonary Disease, Chronic Obstructive/diagnostic imaging
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Spirometry
• Time Factors
• Tomography, X-Ray Computed

This study was conducted in order to investigate the diversity of respiratory physiology, including the respiratory impedance and reversibility of airway obstruction, based on quantitative computed tomography (CT) in patients with COPD.

Medical records of 174 stable COPD patients were retrospectively reviewed to obtain the patients’ clinical data, including the pulmonary function and imaging data. According to the software-based quantification of the degree of emphysema and airway wall thickness, the patients were classified into the “normal by CT” phenotype, the airway-dominant phenotype, the emphysema-dominant phenotype, and the mixed phenotype. The pulmonary function, including the respiratory impedance evaluated by using the forced oscillation technique (FOT) and the reversibility of airway obstruction in response to inhaled short-acting β₂-agonists, was then compared among the four phenotypes.

The respiratory system resistance at 5 and 20 Hz (R5 and R20) was significantly higher, and the respiratory system reactance at 5 Hz (X5) was significantly more negative in the airway-dominant and mixed phenotypes than in the other phenotypes. The within-breath changes of X5 (ΔX5) were significantly greater in the mixed phenotype than in the “normal by CT” and emphysema-dominant phenotypes. The FOT parameters (R5, R20, and X5) were significantly correlated with indices of the degree of airway wall thickness and significantly but weakly correlated with the reversibility of airway obstruction. There was no significant correlation between the FOT parameters (R5, R20, and X5) and the degree of emphysema.

There is a diversity of respiratory physiology, including the respiratory impedance and reversibility of airway obstruction, based on quantitative CT in patients with COPD. The FOT measurements may reflect the degree of airway disease and aid in detecting airway remodeling in patients with COPD.

• AWT-Pi10
• FOT
• MostGraph
• respiratory impedance

• Computed tomography
• adenocarcinoma
• epidermal growth factor receptor
• lung cancer

• Chronic obstructive pulmonary disease
• high resolution computed tomography
• spirometry

• Adolescent
• Adult
• Aged
• Female
• Forced Expiratory Volume
• Humans
• Lung/diagnostic imaging
• Lung/physiopathology
• Male
• Middle Aged
• Phenotype
• Pulmonary Disease, Chronic Obstructive/diagnostic imaging
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Respiratory Function Tests
• Severity of Illness Index
• Smoking/adverse effects
• Spirometry/methods
• Tomography, X-Ray Computed/methods
• Young Adult

Chronic obstructive pulmonary disease (COPD) has a high prevalence rate in Germany and a further increase is expected within the next years. Although risk factors on an individual level are widely understood, only little is known about the spatial heterogeneity and population-based risk factors of COPD. Background knowledge about broader, population-based processes could help to plan the future provision of healthcare and prevention strategies more aligned to the expected demand. The aim of this study is to analyze how the prevalence of COPD varies across northeastern Germany on the smallest spatial-scale possible and to identify the location-specific population-based risk factors using health insurance claims of the AOK Nordost.

To visualize the spatial distribution of COPD prevalence at the level of municipalities and urban districts, we used the conditional autoregressive Besag–York–Mollié (BYM) model. Geographically weighted regression modelling (GWR) was applied to analyze the location-specific ecological risk factors for COPD.

The sex- and age-adjusted prevalence of COPD was 6.5% in 2012 and varied widely across northeastern Germany. Population-based risk factors consist of the proportions of insurants aged 65 and older, insurants with migration background, household size and area deprivation. The results of the GWR model revealed that the population at risk for COPD varies considerably across northeastern Germany.

Area deprivation has a direct and an indirect influence on the prevalence of COPD. Persons ageing in socially disadvantaged areas have a higher chance of developing COPD, even when they are not necessarily directly affected by deprivation on an individual level. This underlines the importance of considering the impact of area deprivation on health for planning of healthcare. Additionally, our results reveal that in some parts of the study area, insurants with migration background and persons living in multi-persons households are at elevated risk of COPD.

CT is able to precisely define the pathological process in COPD. There are a number of previous articles discussing the distribution of emphysema and its connection with pulmonary function tests. However, the results obtained by the researchers are not identical.

To assess relationships between emphysema and pulmonary function test parameters in COPD patients.

Fifty-nine patients diagnosed to have COPD underwent chest CT examinations and pulmonary function tests.

For the quantitative assessment, percentages of low attenuation volume LAV _{950 HU} (%) of a both lungs, the right lung, the left lung, and each lobe were obtained. Quantitative CT measurements were compared with forced expiratory volume in 1 s (FEV₁), the ratio of FEV₁ to forced vital capacity (FEV₁/FVC), the diffusing capacity for carbon monoxide (DLco) and total lung capacity (TLC).

Except for the right middle lobe and the right upper lobe, respectively, all the quantitative CT measurements showed weak to moderate negative correlations with diffusing capacity (DLco) (r = –0.35 to –0.61, p < 0.05) and weak positive correlations with TLC (r = 0.34 to 0.44, p < 0.05). Group analysis indicated that LAV_{–950 HU} (%) values of both lungs, right lung, left lung, and each lobe, except for right middle lobe, were increased in patients with GOLD stages 3 and 4 of COPD compared to GOLD stages 1 and 2 (p < 0.05).

CT measurements of emphysema are significantly related to pulmonary function tests results, particularly DLco.

• COPD
• emphysema
• pulmonary function
• quantitative computed tomography (CT)

• Computed tomography
• Emphysema
• Epidermal growth factor receptor
• GGO
• Shadow disappearance rate

• asthma
• chronic obstructive pulmonary disease
• overlap

The pathophysiology of chronic obstructive pulmonary disease (COPD) and Alpha one antitrypsin deficiency is increasingly recognised as complex such that lung function alone is insufficient for early detection, clinical categorisation and dictating management. Quantitative imaging techniques can detect disease earlier and more accurately, and provide an objective tool to help phenotype patients into predominant airways disease or emphysema. Computed tomography provides detailed information relating to structural and anatomical changes seen in COPD, and magnetic resonance imaging/nuclear imaging gives functional and regional information with regards to ventilation and perfusion. It is likely imaging will become part of routine clinical practice, and an understanding of the implications of the data is essential. This review discusses technical and clinical aspects of quantitative imaging in obstructive airways disease.

• Chronic obstructive pulmonary disease
• Alpha one antitrypsin deficiency
• Computed tomography
• Densitometry
• Phenotype
• Spirometry
• Magnetic resonance imaging

• Adult
• Aged
• Aged, 80 and over
• Canada/epidemiology
• Cohort Studies
• Female
• Humans
• Male
• Middle Aged
• Odds Ratio
• Outcome Assessment, Health Care
• Population Surveillance
• Prevalence
• Pulmonary Disease, Chronic Obstructive/diagnostic imaging
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Respiratory Function Tests
• Self Report
• Severity of Illness Index
• Tomography, X-Ray Computed

• canadian respiratory research network ( CRRN)
• AstraZeneca Canada
• Boehringer Ingelheim (US)
• GlaxoSmithKline canada
• Novartis
• CIHR
• respiratory health network of the FRSQ
• almirall
• Merck (canada)
• nycomed
• pfizer canada limted
• theratechnologies
• Forest Laboratories
• Amgen Foundation
• Roche
• CSL Behring
• Grifols
• genetech
• kamada

• ACOS
• FOT
• MostGraph
• respiratory impedance

• Administration, Inhalation
• Adrenergic beta-2 Receptor Agonists/administration & dosage
• Aged
• Airway Resistance
• Asthma/diagnosis
• Asthma/drug therapy
• Asthma/physiopathology
• Bronchodilator Agents/administration & dosage
• Female
• Forced Expiratory Volume
• Humans
• Lung/diagnostic imaging
• Lung/drug effects
• Lung/physiopathology
• Male
• Medical Records
• Metered Dose Inhalers
• Peak Expiratory Flow Rate
• Phenotype
• Procaterol/administration & dosage
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/drug therapy
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Pulmonary Emphysema/diagnosis
• Pulmonary Emphysema/drug therapy
• Pulmonary Emphysema/physiopathology
• Retrospective Studies
• Spirometry
• Syndrome
• Tomography, X-Ray Computed

Computed tomography (CT) phenotypic characterization helps in understanding the clinical diversity of chronic obstructive pulmonary disease (COPD) patients, but its clinical relevance and its relationship with functional features are not clarified. Volumetric capnography (VC) uses the principle of gas washout and analyzes the pattern of CO₂ elimination as a function of expired volume. The main variables analyzed were end-tidal concentration of carbon dioxide (ETCO₂), Slope of phase 2 (Slp2), and Slope of phase 3 (Slp3) of capnogram, the curve which represents the total amount of CO₂ eliminated by the lungs during each breath.

To investigate, in a group of patients with severe COPD, if the phenotypic analysis by CT could identify different subsets of patients, and if there was an association of CT findings and functional variables.

Sixty-five patients with COPD Gold III–IV were admitted for clinical evaluation, high-resolution CT, and functional evaluation (spirometry, 6-minute walk test [6MWT], and VC). The presence and profusion of tomography findings were evaluated, and later, the patients were identified as having emphysema (EMP) or airway disease (AWD) phenotype. EMP and AWD groups were compared; tomography findings scores were evaluated versus spirometric, 6MWT, and VC variables.

Bronchiectasis was found in 33.8% and peribronchial thickening in 69.2% of the 65 patients. Structural findings of airways had no significant correlation with spirometric variables. Air trapping and EMP were strongly correlated with VC variables, but in opposite directions. There was some overlap between the EMP and AWD groups, but EMP patients had signicantly lower body mass index, worse obstruction, and shorter walked distance on 6MWT. Concerning VC, EMP patients had signicantly lower ETCO2, Slp2 and Slp3. Increases in Slp3 characterize heterogeneous involvement of the distal air spaces, as in AWD.

Visual assessment and phenotyping of CT in COPD patients is feasible and may help identify functional and clinically different subsets of patients. VC may provide useful information about the heterogeneous involvement of lung structures in COPD.

• bronchiectasis
• chronic obstructive lung disease
• computed tomography
• emphysema
• volumetric capnography

It is increasingly recognized that both asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases with a large inter-individual variability with respect to their clinical expression, disease progression, and responsiveness to the available treatments. The introduction of asthma–COPD overlap syndrome (ACOS) may lead to a better clinical characterization and improved treatment of patients with obstructive airways disease. However, it is still in its early phase and several improvements will have to be made. First, a clear definition of ACOS and preferably also its sub-phenotypes, eg, asthma–ACOS and COPD–ACOS, is urgently needed. That would also allow researchers to design clinical studies in well-defined patients. The latter is important since the interpretation of clinical studies performed so far is hampered by the use of many different definitions of ACOS. Second, future studies are needed to investigate the role of state-of-the-art techniques such as computed tomography, genetics, and genomics in the phenotyping of patients with obstructive airways disease, ie, asthma, COPD, and ACOS. Third, longitudinal studies are now needed to better define the clinical implications of ACOS with respect to the long-term outcome and treatment of ACOS and its sub-phenotypes compared to only asthma or COPD.

• ACOS
• COPD
• asthma
• inflammation
• overlap phenotype
• remodeling

• COPD
• Comorbidities
• Exacerbations
• Modifiable risk factors
• Phenotypes
• Risk factors
• Severity
• Symptoms

• COPD
• eosinophils
• periostin

• Administration, Inhalation
• Adrenal Cortex Hormones/administration & dosage
• Adrenergic beta-2 Receptor Agonists/administration & dosage
• Aged
• Biomarkers/blood
• Blood Cell Count
• Bronchodilator Agents/administration & dosage
• Cell Adhesion Molecules/blood
• Drug Monitoring
• Drug Therapy, Combination/methods
• Eosinophils
• Female
• Forced Expiratory Volume/drug effects
• Forced Expiratory Volume/physiology
• Humans
• Male
• Middle Aged
• Pulmonary Disease, Chronic Obstructive/blood
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/drug therapy
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Statistics as Topic
• Treatment Outcome

• chronic obstructive pulmonary disease (COPD)
• gender
• high-resolution computed tomography (HRCT)
• pulmonary function test (PFT)

• Humans
• Phenotype
• Precision Medicine/methods
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/pathology

• Disease Progression
• Forced Expiratory Volume
• Pulmonary Disease, Chronic Obstructive

• Adrenal Cortex Hormones/therapeutic use
• Adrenergic beta-2 Receptor Agonists/therapeutic use
• Bronchodilator Agents/therapeutic use
• Budesonide/therapeutic use
• Drug Therapy, Combination
• Female
• Fluticasone/therapeutic use
• Forced Expiratory Volume/drug effects
• Forced Expiratory Volume/physiology
• Formoterol Fumarate/therapeutic use
• Humans
• Male
• Pulmonary Disease, Chronic Obstructive/drug therapy
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Recurrence
• Republic of Korea
• Salmeterol Xinafoate/therapeutic use
• Smoking
• Spirometry
• Treatment Outcome

• airway disease
• ct scan
• diabetes mellitus
• emphysema
• spirometry

• Age Factors
• Aged
• Comorbidity
• Diabetes Mellitus/epidemiology
• Exercise Tolerance
• Female
• Forced Expiratory Volume
• Humans
• Male
• Middle Aged
• Pulmonary Disease, Chronic Obstructive/diagnostic imaging
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Pulmonary Emphysema/diagnostic imaging
• Pulmonary Emphysema/epidemiology
• Quality of Life
• Severity of Illness Index
• Tomography, X-Ray Computed
• United States/epidemiology

• R01 HL089897 NHLBI NIH HHS
• R01HL089856 NHLBI NIH HHS
• T32 ES007142 NIEHS NIH HHS
• R01 HL089856 NHLBI NIH HHS
• R01 NR013377 NINR NIH HHS
• U01 HL089856 NHLBI NIH HHS
• R01HL094635 NHLBI NIH HHS
• P01 HL105339 NHLBI NIH HHS
• R01NR013377 NINR NIH HHS
• S21 MD000101 NIMHD NIH HHS
• P01HL105339 NHLBI NIH HHS
• R01HL089897 NHLBI NIH HHS
• U01 HL089897 NHLBI NIH HHS
• R01 HL094635 NHLBI NIH HHS

• COPD
• CPFE
• dynamic hyperinflation
• respiratory impedance

• Aged
• Female
• Forced Expiratory Volume
• Humans
• Lung/diagnostic imaging
• Lung/physiopathology
• Male
• Phenotype
• Predictive Value of Tests
• Pulmonary Diffusing Capacity
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Pulmonary Emphysema/diagnosis
• Pulmonary Emphysema/physiopathology
• Pulmonary Fibrosis/diagnosis
• Pulmonary Fibrosis/physiopathology
• Retrospective Studies
• Severity of Illness Index
• Spirometry
• Syndrome
• Tomography, X-Ray Computed
• Vital Capacity