Asthma-like Features and Clinical Course of Chronic Obstructive Pulmonary Disease. An Analysis from the Hokkaido COPD Cohort Study

Exacerbation rates in Japanese patients with obstructive lung disease: A subanalysis of the prospective, observational NOVELTY study

BACKGROUND

Although clinical trials including asthma and COPD patients have revealed much about exacerbation frequencies, most studies are limited in that they recruited patients only with a clear diagnosis of one disease or the other, based on conventional diagnostic criteria, which may exclude many real-world patients with mixed symptoms.

METHODS

NOVELTY is a global prospective observational study of patients with asthma and/or COPD from real-world practice. In this subanalysis, we compared patient characteristics of obstructive pulmonary diseases between the Japanese population (n = 820) and the overall population excluding Japanese patients (n = 10,406).

RESULTS

The Japanese population had fewer exacerbations than the overall population across most of the physician-assessed disease severities and all diagnoses. The difference in exacerbation frequencies was more prominent in patients with COPD and asthma + COPD. The Japanese population was older, had higher former smoking rates, lower BMI, fewer respiratory symptoms, and better health-related quality of life compared with the overall population across all diagnoses.

CONCLUSIONS

We clarified differences in patient characteristics among patients with asthma and/or COPD in Japan compared with non-Japanese patients. Importantly, we found that Japanese patients with asthma and/or COPD had significantly fewer exacerbations compared with patients overall. The results from our study may contribute to the development of precision medicine and guidelines specific to Japan.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Apoptosis inhibitor of macrophage (AIM)/CD5L is involved in the pathogenesis of COPD

BACKGROUND

Alveolar macrophages (AMs) and AM-produced matrix metalloprotease (MMP)-12 are known to play critical roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). The apoptosis inhibitor of the macrophages (AIM)/CD5 molecule-like (CD5L) is a multifunctional protein secreted by the macrophages that mainly exists in the blood in a combined form with the immunoglobulin (Ig)M pentamer. Although AIM has both facilitative and suppressive roles in various diseases, its role in COPD remains unclear.

METHODS

We investigated the role of AIM in COPD pathogenesis using porcine pancreas elastase (PPE)-induced and cigarette smoke-induced emphysema mouse models and an in vitro model using AMs. We also analyzed the differences in the blood AIM/IgM ratio among nonsmokers, healthy smokers, and patients with COPD and investigated the association between the blood AIM/IgM ratio and COPD exacerbations and mortality in patients with COPD.

RESULTS

Emphysema formation, inflammation, and cell death in the lungs were attenuated in AIM-/- mice compared with wild-type (WT) mice in both PPE- and cigarette smoke-induced emphysema models. The PPE-induced increase in MMP-12 was attenuated in AIM-/- mice at both the mRNA and protein levels. According to in vitro experiments using AMs stimulated with cigarette smoke extract, the MMP-12 level was decreased in AIM-/- mice compared with WT mice. This decrease was reversed by the addition of recombinant AIM. Furthermore, an analysis of clinical samples showed that patients with COPD had a higher blood AIM/IgM ratio than healthy smokers. Additionally, the blood AIM/IgM ratio was positively associated with disease severity in patients with COPD. A higher AIM/IgM ratio was also associated with a shorter time to the first COPD exacerbation and higher all-cause and respiratory mortality.

CONCLUSIONS

AIM facilitates the development of COPD by upregulating MMP-12. Additionally, a higher blood AIM/IgM ratio was associated with poor prognosis in patients with COPD.

TRIAL REGISTRATION

This clinical study, which included nonsmokers, healthy smokers, and smokers with COPD, was approved by the Ethics Committee of the Hokkaido University Hospital (012-0075, date of registration: September 5, 2012). The Hokkaido COPD cohort study was approved by the Ethics Committee of the Hokkaido University School of Medicine (med02-001, date of registration: December 25, 2002).

Eosinophil Subtypes in Adults with Asthma and Adults with Chronic Obstructive Pulmonary Disease

Rationale: There is a differential response to eosinophilic modulation between patients with asthma and those with chronic obstructive pulmonary disease (COPD). There is also evidence of different subtypes of eosinophils in murine models. However, no study has compared eosinophil subtypes in individuals with COPD and in those with asthma. Objectives: Study the differences in eosinophils subtypes based in the surface protein expression in COPD patients and asthmatic patients. Methods: We studied 10 stable subjects in each of four groups: subjects with COPD, subjects with asthma, smokers without COPD, and healthy volunteers. Subjects with COPD and those with asthma were matched by age, sex, and FEV1% predicted. The following variables were determined: anthropometrics, smoking, exacerbation history, medication use, lung function, and comorbidities. Using flow cytometry and confocal microscopy from blood samples, we determined differences in eosinophil surface proteins and classified them as 1) resident eosinophils (Siglec-8+CD62L+IL-3Rlo) or 2) inflammatory eosinophils (iEos; Siglec-8+CD62LloIL-3Rhi). IL-5 receptor was also determined. Findings were validated in 59 patients with COPD and in 17 patients with asthma. Measurements and Main Results: Patients with asthma had a higher proportion of iEos (25 ± 15%) compared with those with COPD (0.5 ± 1%), smokers without COPD (0.14 ± 0.24%), and healthy volunteers (0.67 ± 1.72%). In patients with asthma, the proportion of iEos was independent of total eosinophil number. iEos had more IL-5 receptors than resident eosinophils (777.02 ± 124.55 vs. 598.35 ± 318.69; P < 0.01). In patients with COPD, there was no relation between iEos number and inhaled corticosteroid use, disease severity, or exacerbations rate. The findings in patients with COPD and those with asthma were confirmed in validation cohorts. Conclusions: There are differences in the subtypes of circulating eosinophils between patients with asthma and those with COPD. This could have clinical implications in the interpretation of eosinophil significance and the approach to therapy in these patients.

Clinical characteristics and natural course of chronic obstructive pulmonary disease and/or asthma in Japanese patients: a summary report of two Hokkaido-based cohort studies

Chronic obstructive pulmonary disease (COPD) and asthma are the most common chronic airway diseases and are characterized by chronic airway inflammation and airflow limitation. Japanese patients with COPD or asthma have characteristics different from those of Westerners. Therefore, understanding the characteristics and clinical course of Japanese patients with COPD and those with asthma, particularly severe asthma, is critical for their management and appropriate treatment. The Hokkaido COPD cohort and Hokkaido-based Investigative Cohort Analysis for Refractory Asthma (Hi-CARAT) are high-quality cohort studies of COPD and asthma in the Japanese population and provide valuable data. This report summarizes the clinical findings from the two cohort studies and provides data for more appropriate management of Japanese patients with COPD and/or asthma. Overall, 279 patients with COPD were followed up for up to 10 years in the Hokkaido COPD cohort study, and 127 with severe asthma were followed up for up to 6 years in the Hi-CARAT study. Seventy-nine patients with mild-to-moderate asthma provided baseline data for the Hi-CARAT study. In each disease, several distinct factors, including systemic status and non-pulmonary factors, were associated with important clinical outcomes, such as lung function decline, exacerbations, impaired quality of life, and mortality. Therefore, multifaceted evaluation based on the characteristics of the Japanese population is necessary for the management of COPD and asthma.

Efficacy and safety of once-daily single-inhaler triple therapy for mild-to-moderate chronic obstructive pulmonary disease: a study protocol for a randomised and interventional study

INTRODUCTION

Bronchodilators, including long-acting muscarinic antagonists (LAMA) and long-acting beta 2 agonists (LABA), are the main treatments for chronic obstructive pulmonary disease (COPD). The efficacy of triple therapy (inhaled corticosteroids/LAMA/LABA) has also been reported. However, the effect of triple therapy on patients with mild-to-moderate COPD has not yet been clarified. This study aims to investigate the safety and efficacy of triple therapy, compared with LAMA/LABA combination therapy, for lung function and health-related quality of life in patients with mild-to-moderate COPD and identify baseline characteristics and biomarkers to predict responders and non-responders to triple therapy.

METHODS AND ANALYSIS

This is a multicentre, prospective, open-label, randomised, parallel-group study. Mild-to-moderate patients with COPD will be randomised to receive fluticasone furoate/umeclidinium/vilanterol or umeclidinium/vilanterol for 24 weeks. A total of 668 patients will be enrolled from March 2022 to September 2023 from 38 sites in Japan. The primary endpoint is the change in the trough forced expiration volume in 1 s after 12 weeks of treatment. Secondary endpoints are responder rates based on the COPD assessment test score and the St. George's Respiratory Questionnaire total score after 24 weeks of treatment. The safety endpoint is the occurrence of any adverse events. We will also investigate safety in terms of changes in microbial colonisation in sputum and antimycobacterium avium complex antibodies.

ETHICS AND DISSEMINATION

The study protocol and informed consent documents were approved by the Saga University Clinical Research Review Board (approval number: CRB7180010). Written informed consent will be obtained from all patients. Recruitment of the patients began in March 2022. The results will be disseminated through scientific peer-reviewed publications and domestic and international medical conferences.

TRIAL REGISTRATION NUMBERS

UMIN000046812 and jRCTs031190008.

Subtyping emphysematous COPD by respiratory volume change distributions on CT

BACKGROUND

There is considerable heterogeneity among patients with emphysematous chronic obstructive pulmonary disease (COPD). We hypothesised that in addition to emphysema severity, ventilation distribution in emphysematous regions would be associated with clinical-physiological impairments in these patients.

OBJECTIVE

To evaluate whether the discordance between respiratory volume change distributions (from expiration to inspiration) in emphysematous and non-emphysematous regions affects COPD outcomes using two cohorts.

METHODS

Emphysema was quantified using a low attenuation volume percentage on inspiratory CT (iLAV%). Local respiratory volume changes were calculated using non-rigidly registered expiratory/inspiratory CT. The Ventilation Discordance Index (VDI) represented the log-transformed Wasserstein distance quantifying discordance between respiratory volume change distributions in emphysematous and non-emphysematous regions.

RESULTS

Patients with COPD in the first cohort (n=221) were classified into minimal emphysema (iLAV% <10%; n=113) and established emphysema with high VDI and low VDI groups (n=46 and 62, respectively). Forced expiratory volume in 1 s (FEV₁) was lower in the low VDI group than in the other groups, with no difference between the high VDI and minimal emphysema groups. Higher iLAV%, more severe airway disease and hyperventilated emphysematous regions in the upper-middle lobes were independently associated with lower VDI. The second cohort analyses (n=93) confirmed these findings and showed greater annual FEV₁ decline and higher mortality in the low VDI group than in the high VDI group independent of iLAV% and airway disease on CT.

CONCLUSION

Lower VDI is associated with severe airflow limitation and higher mortality independent of emphysema severity and airway morphological changes in patients with emphysematous COPD.

Real-World Evidence on the Diagnostic and Clinical Characteristics of Asthma in Japanese Patients with COPD: The ACO Japan Cohort Study

Introduction

The ACO Japan Cohort Study, a multicenter observational study, investigated the proportion of patients with chronic obstructive pulmonary disease (COPD) who met the Japanese Respiratory Society (JRS) asthma-COPD overlap (ACO) diagnostic criteria, characteristics of ACO and non-ACO patients, and the patient transitions between ACO/non-ACO diagnosis over 2 years.

Patients and Methods

Patients with COPD were consecutively enrolled between June and December 2018 and followed up continuously for 2 years. All participating study sites were medical institutions where respiratory specialists routinely conducted medical examinations/tests required for ACO diagnosis.

Results

Among 708 patients with COPD, 101 (14.3%), 118 (16.7%), and 125 (17.7%) were diagnosed with ACO at registration, 1 year, and 2 years, respectively. In total, 22.6% of patients lacked the data necessary for ACO diagnosis throughout the 2 years. Among patients who had the necessary data for ACO diagnosis, 24.7% were diagnosed with ACO at 2 years. More ACO patients had moderate or severe exacerbations in the past year than non-ACO patients at registration (15.8% vs 6.3%, p = 0.049) and 1 year (19.4% vs 7.6%, p = 0.025). ACO patients had a greater decrease in mean forced expiratory volume in one second over 2 years than non-ACO patients (-92.0 vs 43.4 mL). Among patients diagnosed with ACO at registration, 21.4% transitioned to non-ACO after 1 year. Conversely, almost all non-ACO patients at registration remained non-ACO after 1 year.

Conclusion

COPD patients with ACO determined by the JRS criteria had a high risk of exacerbations and a rapid decline in respiratory function, indicating that the JRS criteria for ACO are useful for identifying high-risk COPD patients. Testing necessary for ACO diagnosis is insufficiently performed even in real-world clinical practice of COPD specialists.

Heterogeneity of asthma-chronic obstructive pulmonary disease (COPD) overlap from a cohort of patients with severe asthma and COPD

BACKGROUND

A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma-COPD overlap (ACO).

OBJECTIVES

The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria.

DESIGN

We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort.

METHODS

We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio <0.7.

RESULTS

The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22-10.95 or aOR: 2.15, 95% CI: 0.59-7.85].

CONCLUSION

The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk.

Measurement of Blood Eosinophils in Asthma and Chronic Obstructive Pulmonary Disease

Eosinophils are important effector cells in airway inflammation, as pleiotropy and heterogeneity can be linked to various pathophysiologies in asthma and chronic obstructive pulmonary disease (COPD). Sputum eosinophils can reflect the heterogeneity of airway inflammation, and owing to their traits, blood eosinophils can be a surrogate and potential biomarker for managing both conditions. Blood eosinophils are activated via the stimulation of type 2 cytokines, such as interleukin (IL)-5, IL-4/13, granulocyte-macrophage colony-stimulating factor, IL-33, and thymic stromal lymphopoietin. There is sufficient evidence to support the relationship between the blood eosinophil count and clinical outcomes, including pulmonary function decline, exacerbations, all-cause mortality, and treatment response to inhaled corticosteroids and biologics. Thus, there is growing interest in the use of blood eosinophils for the management of these diseases. Compiling recent evidence, we herein review the significance of measuring blood eosinophils in asthma and COPD.

Blood eosinophil count variability in chronic obstructive pulmonary disease and severe asthma

BACKGROUND

Blood eosinophils are essential biomarkers that vary substantially over time in patients with COPD and asthma. However, no study has identified the changes and effects in the changes of the blood eosinophil counts over time in both diseases. This study aimed to demonstrate blood eosinophil variability in patients with COPD and severe asthma based on these backgrounds.

METHODS

A total of 172 patients with COPD from the Hokkaido COPD cohort study and 96 patients with severe asthma from the Hokkaido Severe Asthma Cohort Study, whose blood eosinophil counts were measured annually over a 3-year period, were analyzed. The factors contributing to consistently high or low blood eosinophil counts were examined in each cohort. The stability of the eosinophil classification (<150, 150-299, ≥300 cells/μL) was compared based on the number of asthma-like features in patients with COPD and the smoking status in patients with severe asthma.

RESULTS

Among all the patients, the most stable range of baseline blood eosinophil counts differed between the two diseases, with <150 cells/μL in COPD and ≥300 cells/μL in severe asthma. In COPD, the number of asthma-like features (bronchodilator reversibility, blood eosinophilia, and atopy) affects the blood eosinophil count variation patterns. In severe asthma, smoking status did not affect the blood eosinophil count variation patterns.

CONCLUSIONS

We identified variations in the blood eosinophil counts and their contributing factors in patients with COPD and severe asthma.

Stability of Blood Eosinophils in COPD with Multiple Acute Exacerbations Within 1 Year and Its Relationship with Prognosis

Background

The relationship between increased blood eosinophils (EOS) and the prognosis of patients with chronic obstructive pulmonary disease (COPD) remains controversial. We aimed to explore the stability of blood eosinophils in patients with multiple hospitalizations for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) over a 1-year period and its relationship with readmission rates and mortality.

Methods

Prospectively include patients with at least 2 hospitalizations for AECOPD in 1 year between June 2019 and December 2021. Using 150 cells/ul as the cut-off value, the study population was divided into EOS, non-EOS, and fluctuating groups based on the longitudinal stability of blood EOS. The relationship between blood EOS and readmission rate and mortality was analyzed according to the 6-month follow-up after hospital discharge.

Results

A total of 202 patients were included. 48, 108, and 46 patients were in the EOS, non-EOS, and fluctuating groups, respectively. The stability of blood EOS at 1 year was 77.2%. The risk of death was lower in the EOS group compared to the non-EOS group (HR=0.323, 95% CI 0.113-0.930, P =0.036). The risk of readmission was lower in both the EOS group (HR=0.486, 95% CI 0.256-0.923, P =0.027) and the non-EOS group (HR=0.575, 95% CI 0.347-0.954, P = 0.032) than in the fluctuating group.

Conclusion

The blood EOS of COPD patients is relatively stable over 1 year. Patients with consistently high blood EOS had a lower risk of all-cause mortality after discharge; patients with fluctuating blood EOS had a higher risk of readmission.

Comparison of therapeutic response between asthma, COPD, and ACOS patients by evaluation of spirometric findings

Asthma and Chronic obstructive pulmonary disease (COPD ) both are a common public health problem that affects a large portion of population. Nearly 20% of patients with obstructive lung disease have features of both asthma and COPD called ACOS that GOLD_GINA guidelines defines as persistent airflow limitation with several features of asthma and several features of COPD. Yet there is a little data available about diagnosis and treatment of this entity and current study aimed to compare therapeutic response between asthma, COPD and Asthma-COPD overlap syndrome (ACOS) subjects through spirometric data. In the present cross-sectional study, 30 known patients with mild to moderate asthma, 30 known patients with mild to moderate COPD and 30 known patients with mild to moderate ACOS according to GOLD_GINA guidelines were enrolled. We assessed post bronchodilator the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (fev1) and the forced expiratory volume in the first one second to the forced vital capacity of the lungs (fev1/fvc) in all patients. Then they took standard treatment for 2 months and after this period spirometry was repeated. Spirometric data's changes was compared between the three groups by SPSS26 statistical software. Fev1 changes in response to treatment did not differ significantly between three groups (p > 0.05) but fev1/fvc changes differed significantly and this parameter in asthma was more than ACOS and in COPD was least. (In asthma, spirometric symbolized therapeutic response is more significant than ACOS, and in ACOS, it is more important than COPD in terms of fev1/fvc changes) and there was not any difference between the three groups regarding to FEV1 changes.

Evaluation of asthma-chronic obstructive pulmonary disease overlap using a mouse model of pulmonary disease

BACKGROUND

Features of asthma and chronic obstructive pulmonary disease (COPD) can coexist in the same patient, in a condition termed asthma- chronic obstructive pulmonary disease overlap (ACO). ACO is heterogeneous condition exhibiting various combinations of asthma and COPD features. No clinically acceptable experimental model of ACO has been established. We aimed to establish an animal model of ACO.

METHODS

We generated two phenotypes of ACO by administering ovalbumin and porcine pancreatic elastase in combination, and papain. The proinflammatory cytokines and cell types in bronchoalveolar lavage fluid (BALF) were investigated, and lung function parameters were measured using the FlexiVent system.

RESULTS

Greater airway inflammation was observed in the asthma and both ACO models, and emphysema was found in the COPD and both ACO models. The proportion of eosinophils in BALF was elevated in the asthma and ACO-a model. Type 2 inflammatory cytokine levels were highest in the ACO-a model, and the neutrophil gelatinase-associated lipocalin level was elevated in the asthma and ACO-a model. Of lung function parameters, compliance was greater in the COPD and ACO-b model, in which elastance was lower than in the asthma model. Airway resistance increased with the methacholine concentration in the asthma and both ACO models, but not in the control or COPD model.

CONCLUSION

We established two murine models of ACO that exhibit features of asthma and COPD. We validated the clinical relevance of the ACO models based on changes in cytokine profiles and lung function. These models will be useful in further studies of the pathogenesis of, and therapeutic targets for ACO.

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

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

Functional Predictors Discriminating Asthma-COPD Overlap (ACO) from Chronic Obstructive Pulmonary Disease (COPD)

Background

A significant proportion of patients with obstructive lung disease have clinical and functional features of both asthma and chronic obstructive pulmonary disease (COPD), referred to as the asthma–COPD overlap (ACO). The distinction of these phenotypes, however, is not yet well-established due to the lack of defining clinical and/or functional criteria. The aim of our investigations was to assess the discriminating power of various lung function parameters on the assessment of ACO.

Methods

From databases of 4 pulmonary centers, a total of 540 patients (231 males, 309 females), including 372 patients with asthma, 77 patients with ACO and 91 patients with COPD, were retrospectively collected, and gradients among combinations of explanatory variables of spirometric (FEV₁, FEV₁/FVC, FEF_25-75), plethysmographic (sR_eff, sG_eff, the aerodynamic work of breathing at rest; sWOB), static lung volumes, including trapped gases and measurements of the carbon monoxide transfer (DL_CO, K_CO) were explored using multiple factor analysis (MFA). The discriminating power of lung function parameters with respect to ACO was assessed using linear discriminant analysis (LDA).

Results

LDA revealed that parameters of airway dynamics (sWOB, sR_eff, sG_eff) combined with parameters of static lung volumes such as functional residual capacity (FRC_pleth) and trapped gas at FRC (V_TG^FRC) are valuable and potentially important tools discriminating between asthma, ACO and COPD. Moreover, sWOB significantly contributes to the diagnosis of obstructive airway diseases, independent from the state of pulmonary hyperinflation, whilst the diffusion capacity for carbon monoxide (DL_CO) significantly differentiates between the 3 diagnostic classes.

Conclusion

The complexity of COPD with its components of interaction and their heterogeneity, especially in discrimination from ACO, may well be differentiated if patients are explored by a whole set of target parameters evaluating, interactionally, flow limitation, airway dynamics, pulmonary hyperinflation, small airways dysfunction and gas exchange disturbances assessing specific functional deficits.

Self-Reported Physician Diagnosed Asthma with COPD is Associated with Higher Mortality than Self-Reported Asthma or COPD Alone - A Prospective 24-Year Study in the Population of Helsinki, Finland

Asthma and COPD are common chronic obstructive respiratory diseases. COPD is associated with increased mortality, but for asthma the results are varying. Their combination has been less investigated, and the results are contradictory. The aim of this prospective study was to observe the overall mortality in obstructive pulmonary diseases and how mortality was related to specific causes using postal questionnaire data. This study included data from 6,062 participants in the FinEsS Helsinki Study (1996) linked to mortality data during a 24-year follow-up. According to self-reported physician diagnosed asthma, COPD, or smoking status, the population was divided into five categories: combined asthma and COPD, COPD alone and asthma alone, ever-smokers without asthma or COPD and never-smokers without asthma or COPD (reference group). For the specific causes of death both the underlying and contributing causes of death were used. Participants with asthma and COPD had the highest hazard of mortality 2.4 (95% CI 1.7-3.5). Ever-smokers without asthma or COPD had a 9.5 (3.7-24.2) subhazard ratio (sHR) related to lower respiratory tract disease specific causes. For asthma, COPD and combined, the corresponding figures were 10.8 (3.4-34.1), 25.0 (8.1-77.4), and 56.1 (19.6-160), respectively. Ever-smokers without asthma or COPD sHR 1.7 (95% CI 1.3-2.5), and participants with combined asthma and COPD 3.5 (1.9-6.3) also featured mortality in association with coronary artery disease. Subjects with combined diseases had the highest hazard of overall mortality and combined diseases also showed the highest hazard of mortality associated with lower respiratory tract causes or coronary artery causes.Abbreviations: CigCigaretteCOPDChronic obstructive pulmonary diseaseCVDCardiovascular diseaseFEV₁Forced Expiratory Volume in one secondFVCForced Vital CapacityFinEsSFinland, Estonia, and Sweden study on chronic obstructive pulmonary diseasesHRHazard RatiosHRSubhazard RatioICD-10International Statistical Classifications of Diseases and Related Health Problems (Version 10).

The association between transfer coefficient of the lung and the risk of exacerbation in asthma-COPD overlap: an observational cohort study

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) patients experience exacerbations more frequently than those with asthma or COPD alone. Since low diffusing capacity of the lung for carbon monoxide (DLCO) is known as a strong risk factor for severe exacerbation in COPD, DLCO or a transfer coefficient of the lung for carbon monoxide (KCO) is speculated to also be associated with the risk of exacerbations in ACO.

METHODS

This study was conducted as an observational cohort survey at the National Hospital Organization Fukuoka National Hospital. DLCO and KCO were measured in 94 patients aged ≥ 40 years with a confirmed diagnosis of ACO. Multivariable-adjusted hazard ratios (HRs) for the exacerbation-free rate over one year were estimated and compared across the levels of DLCO and KCO.

RESULTS

Within one year, 33.3% of the cohort experienced exacerbations. After adjustment for potential confounders, low KCO (< 80% per predicted) was positively associated with the incidence of exacerbation (multivariable-adjusted HR = 3.71 (95% confidence interval 1.32-10.4)). The association between low DLCO (< 80% per predicted) and exacerbations showed similar trends, although it failed to reach statistical significance (multivariable-adjusted HR = 1.31 (95% confidence interval 0.55-3.11)).

CONCLUSIONS

Low KCO was a significant risk factor for exacerbations among patients with ACO. Clinicians should be aware that ACO patients with impaired KCO are at increased risk of exacerbations and that careful management in such a population is mandatory.

Blood eosinophil counts in the general population and airways disease: a comprehensive review and meta-analysis

BACKGROUND

The clinical context for using blood eosinophil (EOS) counts as treatment-response biomarkers in asthma and COPD requires better understanding of EOS distributions and ranges. We describe EOS distributions and ranges published in asthma, COPD, control (non-asthma/COPD) and general populations.

METHODS

We conducted a comprehensive literature review and meta-analysis of observational studies (January 2008 to November 2018) that included EOS counts in asthma, severe asthma, COPD, control and general populations. Excluded studies had total sample sizes <200, EOS as inclusion criterion, hospitalised population only and exclusively paediatric participants.

RESULTS

Overall, 91 eligible studies were identified, most had total-population-level data available: asthma (39 studies), severe asthma (12 studies), COPD (23 studies), control (seven studies) and general populations (14 studies); some articles reported data for multiple populations. Reported EOS distributions were right-skewed (seven studies). Reported median EOS counts ranged from 157-280 cells·µL-1 (asthma, 22 studies); 200-400 cells·µL-1 (severe asthma, eight studies); 150-183 cells·µL-1 (COPD, six studies); and 100-160 cells·µL-1 (controls, three studies); and 100-200 cells·µL-1 (general populations, six studies). The meta-analysis showed that observed variability was mostly between studies rather than within studies. Factors reportedly associated with higher blood EOS counts included current smoking, positive skin-prick test, elevated total IgE, comorbid allergic rhinitis, age ≤18 years, male sex, spirometric asthma/COPD diagnosis, metabolic syndrome and adiposity.

CONCLUSION

EOS distribution and range varied by study population, and were affected by clinical factors including age, smoking history and comorbidities, which, regardless of severity, should be considered during treatment decision-making.

Racial Differences in Prevalence and Clinical Characteristics of Asthma-Chronic Obstructive Pulmonary Disease Overlap

Background: This study examined the differences in the prevalence and clinical features of asthma–chronic obstructive pulmonary disease (COPD) overlap (ACO) with identical diagnostic criteria by race and ethnicity in two nationwide cohorts of COPD.

Methods: We used data from the Korean COPD Subgroup Study (KOCOSS) and phase I of the US Genetic Epidemiology of COPD (COPDGene) study. We defined ACO by satisfying bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ≥300/μl.

Results: The prevalences of ACO according to ethnicity were non-Hispanic white (NHW), 21.4%; African American (AA), 17.4%; and Asian, 23.8%. Asian patients with ACO were older, predominantly male, with fewer symptoms, more severe airflow limitation, and fewer comorbidities than NHW and AA patients. During 1-year follow-up, exacerbations occurred in 28.2, 22.0, and 48.4% of NHW, AA, and Asian patients with ACO, respectively. Compared to patients with non-ACO from the same racial group, the risk for exacerbation was significantly higher in NHW and Asian patients with ACO [adjusted incident rate ratio (aIRR), 1.17; 95% CI, 1.01–1.36, and aIRR, 1.37; 95% CI, 1.09–1.71 for NHW and Asian patients with ACO, respectively]. Inhaled corticosteroid (ICS) reduced the risk for future exacerbation in total patients with ACO but the effect was not significant in each racial group.

Conclusions: The prevalence of ACO was similar in the two cohorts using the same diagnostic criteria. The risk for future exacerbation was significantly higher in ACO, and the use of ICS reduced the risk for exacerbation in total patients with ACO.

Annual Body Weight Change and Prognosis in Chronic Obstructive Pulmonary Disease

Purpose

Low body mass index (BMI) has been reported to be associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). In contrast, a detailed analysis of the association between body weight change over time and prognosis is not sufficient, particularly in Japanese patients with COPD who have been reported to be much thinner compared to Westerners. This study aimed to investigate the relationship between annual body weight change and long-term prognosis in Japanese patients with COPD in two independent cohorts.

Patients and Methods

We analyzed 279 patients with COPD who participated in the Hokkaido COPD cohort study as a discovery cohort. We divided participants into three groups according to quartiles of annual body weight change calculated by the data from the first 5 years: weight loss group (<-0.17 kg/year), no change group (−0.17 to ≤0.20 kg/year), and weight gain group (>0.20 kg/year). The association between annual body weight change and prognosis was replicated in the Kyoto University cohort (n = 247).

Results

In the Hokkaido COPD cohort study, the weight loss group had significantly worse mortality than the other groups, whereas there was no difference in BMI at baseline. In the multivariate analysis, annual body weight change was an independent risk factor for all-cause mortality, which was confirmed in the Kyoto University cohort.

Conclusion

Annual body weight loss is associated with poor prognosis in Japanese patients with COPD, independent of baseline BMI. Longitudinal assessment of body weight is important for the management of COPD.

Current Status of Studies Investigating Asthma-Chronic Obstructive Pulmonary Disease Overlap in Korea: A Review

There is a considerable number of individuals who exhibit features of both asthma and chronic obstructive pulmonary disease (COPD), defined as asthma-COPD overlap (ACO). Many studies have reported that these patients have a greater burden of symptoms, including cough and dyspnea, and experience more exacerbations and hospitalizations than those with non-ACO COPD or asthma. Although diagnostic criteria for ACO have not yet been clearly established, their clinical significance remains to be determined. As interest in ACO grows, related studies have been conducted in South Korea as well. The present review summarizes ACO-related studies in South Korea to better understand Korean ACO patients and guide further research. Several cohort studies of asthma and COPD and population-based studies for ACO were reviewed and the key results from demographics, clinical features, lung function, biomarkers, treatment, and prognosis were summarized.

Management of acute exacerbations of airways disease: advice for the non-respiratory physician

Airways disease encompasses a number of conditions including asthma and chronic obstructive pulmonary disorder (COPD). In this article we describe the management of patients with acute exacerbations of airways disease.

Large-scale plasma proteomics can reveal distinct endotypes in chronic obstructive pulmonary disease and severe asthma

BACKGROUND

Chronic airway diseases including chronic obstructive pulmonary disease (COPD) and asthma are heterogenous in nature and endotypes within are underpinned by complex biology. This study aimed to investigate the utility of proteomic profiling of plasma combined with bioinformatic mining, and to define molecular endotypes and expand our knowledge of the underlying biology in chronic respiratory diseases.

METHODS

The plasma proteome was evaluated using an aptamer-based affinity proteomics platform (SOMAscan®), representing 1238 proteins in 34 subjects with stable COPD and 51 subjects with stable but severe asthma. For each disease, we evaluated a range of clinical/demographic characteristics including bronchodilator reversibility, blood eosinophilia levels, and smoking history. We applied modified bioinformatic approaches used in the evaluation of RNA transcriptomics.

RESULTS

Subjects with COPD and severe asthma were distinguished from each other by 365 different protein abundancies, with differential pathway networks and upstream modulators. Furthermore, molecular endotypes within each disease could be defined. The protein groups that defined these endotypes had both known and novel biology including groups significantly enriched in exosomal markers derived from immune/inflammatory cells. Finally, we observed associations to clinical characteristics that previously have been under-explored.

CONCLUSION

This investigational study evaluating the plasma proteome in clinically-phenotyped subjects with chronic airway diseases provides support that such a method can be used to define molecular endotypes and pathobiological mechanisms that underpins these endotypes. It provided new concepts about the complexity of molecular pathways that define these diseases. In the longer term, such information will help to refine treatment options for defined groups.

Asthma-COPD Overlap: What Are the Important Questions?

Asthma-COPD overlap (ACO) is a heterogeneous condition that describes patients who show persistent airflow limitation with clinical features that support both asthma and COPD. Although no single consensus definition exists to diagnose this entity, common major criteria include a strong bronchodilator reversibility or bronchial hyperreactivity, a physician diagnosis of asthma, and a ≥ 10-pack-year cigarette smoking history. The prevalence of ACO ranges from 0.9% to 11.1% in the general population, depending on the diagnostic definition used. Notably, patients with ACO experience greater symptom burden, worse quality of life, and more frequent and severe respiratory exacerbations than those with asthma or COPD. The underlying pathophysiologic features of ACO have been debated. Although emerging evidence supports the role of environmental and inhalational exposures in its pathogenesis among patients with a pre-existing airway disease, biomarker profiling and genetic analyses suggest that ACO may be a heterogeneous condition, but with definable characteristics. Early-life factors including childhood-onset asthma and cigarette smoking may interact to increase the risk of airflow obstruction later in life. For treatment options, the population with ACO historically has been excluded from therapeutic trials; therefore strong, evidence-based recommendations are lacking beyond first-line inhaler therapies. Advanced therapies in patients with ACO are selected according to disease phenotypes and are based on extrapolated data from asthma and COPD. Research focused on defining biomarkers and evidence-based treatment options for ACO is needed urgently.

Suppressor of variegation 3-9 homologue 1 impairment and neutrophil-skewed systemic inflammation are associated with comorbidities in COPD

BACKGROUND

Systemic manifestations and comorbidities are characteristics of chronic obstructive pulmonary disease (COPD) and are probably due to systemic inflammation. The histone methyltransferase SUV39H1 controls the Th1/Th2 balance. We previously reported that reduced SUV39H1 expression contributed to abnormal inflammation in COPD. Here, we aimed to determine whether impaired SUV39H1 expression in COPD patients associated with neutrophilic/eosinophilic inflammation responses and comorbidities.

METHODS

A total of 213 COPD patients and 13 healthy controls were recruited from the Shuang Ho Hospital, Taipei Medical University. SUV39H1 levels in peripheral blood mononuclear cells (PBMCs) from 13 healthy and 30 COPD participants were measured by immunoblotting. We classified the patients into two groups based on low (fold change, FC < 0.5) and high SUV39H1 expression (FC ≥ 0.5) compared to normal controls. Clinical outcomes including neutrophil or eosinophil counts associated with SUV39H1-related inflammation were evaluated by Chi square analyses or Mann-Whitney U test. The correlations between the percentage of neutrophils and number of COPD comorbidities or Charlson Comorbidity Index (CCI) scores were performed by Spearman's rank analysis.

RESULTS

Low SUV39H1 expression group had high neutrophil counts relative to high SUV39H1expression group. In the COPD cohort, the high comorbidity group (≥ 2 comorbidities) had higher counts of whole white blood cell (WBC) and neutrophil, and lower proportion of eosinophil and eosinophil/neutrophil, as compared with low comorbidity group (0 and 1 comorbidities). The quantity of neutrophils was associated with COPD comorbidities (Spearman's r = 0.388, p < 0.001), but not with CCI scores. We also found that the high comorbidity group had more exacerbations per year compared with low comorbidity group (1.5 vs. 0.9 average exacerbations, p = 0.005). However, there were no significant differences between groups with these non-frequent (0-1 exacerbation) and frequent exacerbations per year (> 1 exacerbation) in numbers of WBC and proportion of neutrophils, eosinophils or eosinophil/neutrophil. Finally, patients with high comorbidities had lower SUV39H1 levels in their PBMCs than did those with low comorbidities.

CONCLUSION

Blood neutrophil counts are associated with comorbidities in COPD patients. Impaired SUV39H1 expression in PBMCs from COPD patients are correlated with neutrophilic inflammation and comorbidities.

Current Knowledge of Asthma-COPD Overlap (ACO) Genetic Risk Factors, Characteristics, and Prognosis

Asthma-COPD overlap (ACO) is a newly identified phenotype of chronic obstructive airway diseases with shared asthma and COPD features. Patients with ACO are poorly defined, and some evidence suggests that they have worse health outcomes and greater disease burden than patients with COPD or asthma. Generally, there is no evidence-based and universal definition for ACO; several consensus documents have provided various descriptions of the phenotype. In addition, the mechanisms underlying the development of ACO are not fully understood. Whether ACO is a distinct clinical entity with its particular discrete genetic determinant different from asthma and COPD alone or an intermediate phenotype with overlapping genetic markers within asthma and COPD spectrum of obstructive airway disease remains unproven. This review summarizes the current knowledge of the genetic risk factors, characteristics, and prognosis of ACO.

Bronchodilator Response in Patients with COPD, Asthma-COPD-Overlap (ACO) and Asthma, Evaluated by Plethysmographic and Spirometric z-Score Target Parameters

BACKGROUND

Airflow reversibility criteria in COPD are still debated - especially in situations of co-existing COPD and asthma. Bronchodilator response (BDR) is usually assessed by spirometric parameters. Changes assessed by plethysmographic parameters such as the effective, specific airway conductance (sGeff), and changes in end-expiratory resting level at functional residual capacity (FRCpleth) are rarely appreciated. We aimed to assess BDR by spirometric and concomitantly measured plethysmographic parameters. Moreover, BDR on the specific aerodynamic work of breathing (sWOB) was evaluated.

METHODS

From databases of 3 pulmonary centers, BDR to 200 g salbutamol was retrospectively evaluated by spirometric (∆FEV1 and ∆FEF25-75), and plethysmographic (∆sGeff, ∆FRCpleth, and ∆sWOB) parameters in a total of 843 patients diagnosed as COPD (478 = 57%), asthma-COPD-overlap (ACO) (139 = 17%), or asthma (226 = 27%), encountering 1686 BDR-measurement-sets (COPD n = 958; ACO n = 276; asthma n = 452).

RESULTS

Evaluating z-score improvement taking into consideration the whole pre-test z-score range, highest BDR was achieved by combining ∆sGeff and ∆FRC detecting BDR in 62.2% (asthma: 71.4%; ACO: 56.7%; COPD: 59.8%), by ∆sGeff in 53.4% (asthma: 69.1%; ACO: 51.6%; COPD: 47.4%), whereas ∆FEV1 only distinguished in 10.6% (asthma: 21.8%; ACO: 18.6%; COPD: 4.2%). Remarkably, ∆sWOB detected BDR in 49.4% (asthma: 76.2%; ACO: 47.8%; COPD: 46.9%).

CONCLUSION

BDR largely depends on the pre-test functional severity and, therefore, should be evaluated in relation to the pre-test conditions expressed as ∆z-scores, considering changes in airway dynamics, changes in static lung volumes and changes in small airway function. Plethysmographic parameters demonstrated BDR at a significant higher rate than spirometric parameters.

Parenchymal destruction in asthma: Fixed airflow obstruction and lung function trajectory

BACKGROUND

Fixed airflow obstruction (FAO) in asthma, particularly in nonsmokers, is generally believed to be caused by airway remodeling. However, parenchymal destruction may also contribute to FAO and longitudinal decline in forced expiratory volume in 1 second (FEV₁).

OBJECTIVES

To evaluate parenchymal destruction, we used emphysema indices, exponent D, and low-attenuation area percentage (LAA%) on computed tomography (CT), and test whether the parenchymal destruction and airway disease are independently associated with FAO and FEV₁ decline in both smoking and nonsmoking asthma.

METHODS

Exponent D, LAA%, wall area percentage at segmental airways, and airway fractal dimension (AFD) in those with asthma were measured on inspiratory CT and compared to those in patients with chronic obstructive pulmonary disease (COPD).

RESULTS

Exponent D was lower and LAA% was higher in COPD (n = 42) and asthma with FAO (n = 101) than in asthma without FAO (n = 88). The decreased exponent D and increased LAA% were associated with FAO regardless of smoking status or asthma severity. In multivariable analysis, decreased exponent D and increased LAA% were associated with an increased odds ratio of FAO and decreased FEV₁, irrespective of wall area percentage and airway fractal dimension. Moreover, decreased exponent D affected the longitudinal decline in FEV₁ in those with severe asthma, independent of smoking status.

CONCLUSIONS

Patients with asthma with FAO showed parenchymal destruction regardless of smoking status and asthma severity. Parenchymal destruction was associated with an accelerated FEV₁ decline, suggesting the involvements of both airway and parenchyma in the pathophysiology of a subgroup of asthma.

Machine Learning Methods for the Diagnosis of Chronic Obstructive Pulmonary Disease in Healthy Subjects: Retrospective Observational Cohort Study

BACKGROUND

Airflow limitation is a critical physiological feature in chronic obstructive pulmonary disease (COPD), for which long-term exposure to noxious substances, including tobacco smoke, is an established risk. However, not all long-term smokers develop COPD, meaning that other risk factors exist.

OBJECTIVE

This study aimed to predict the risk factors for COPD diagnosis using machine learning in an annual medical check-up database.

METHODS

In this retrospective observational cohort study (ARTDECO [Analysis of Risk Factors to Detect COPD]), annual medical check-up records for all Hitachi Ltd employees in Japan collected from April 1998 to March 2019 were analyzed. Employees who provided informed consent via an opt-out model were screened and those aged 30 to 75 years without a prior diagnosis of COPD/asthma or a history of cancer were included. The database included clinical measurements (eg, pulmonary function tests) and questionnaire responses. To predict the risk factors for COPD diagnosis within a 3-year period, the Gradient Boosting Decision Tree machine learning (XGBoost) method was applied as a primary approach, with logistic regression as a secondary method. A diagnosis of COPD was made when the ratio of the prebronchodilator forced expiratory volume in 1 second (FEV₁) to prebronchodilator forced vital capacity (FVC) was <0.7 during two consecutive examinations.

RESULTS

Of the 26,101 individuals screened, 1213 met the exclusion criteria, and thus, 24,815 individuals were included in the analysis. The top 10 predictors for COPD diagnosis were FEV₁/FVC, smoking status, allergic symptoms, cough, pack years, hemoglobin A_1c, serum albumin, mean corpuscular volume, percent predicted vital capacity, and percent predicted value of FEV₁. The areas under the receiver operating characteristic curves of the XGBoost model and the logistic regression model were 0.956 and 0.943, respectively.

CONCLUSIONS

Using a machine learning model in this longitudinal database, we identified a number of parameters as risk factors other than smoking exposure or lung function to support general practitioners and occupational health physicians to predict the development of COPD. Further research to confirm our results is warranted, as our analysis involved a database used only in Japan.

Update on Asthma-COPD Overlap (ACO): A Narrative Review

Although chronic obstructive pulmonary disease (COPD) and asthma are well-characterized diseases, they can coexist in a given patient. The term asthma-COPD overlap (ACO) was introduced to describe patients that have clinical features of both diseases and may represent around 25% of COPD patients and around 20% of asthma patients. Despite the increasing interest in ACO, there are still substantial controversies regarding its definition and its position within clinical guidelines for patients with obstructive lung disease. In general, most definitions indicate that ACO patients must present with non-reversible airflow limitation, significant exposure to smoking or other noxious particles or gases, together with features of asthma. In patients with a primary diagnosis of COPD, the identification of ACO has therapeutic implication because the asthmatic component should be treated with inhaled corticosteroids and some studies suggest that the most severe patients may respond to biological agents indicated for severe asthma. This manuscript aims to summarize the current state-of-the-art of ACO. The definitions, prevalence, and clinical manifestations will be reviewed and some innovative aspects, such as genetics, epigenetics, and biomarkers will be addressed. Lastly, the management and prognosis will be outlined as well as the position of ACO in the COPD and asthma guidelines.

Real-world effectiveness of early intervention with fixed-dose tiotropium/olodaterol vs tiotropium in Japanese patients with COPD: a high-dimensional propensity score-matched cohort analysis

Background

Escalation to triple therapy (long-acting muscarinic antagonist/β₂-agonist, inhaled corticosteroid [ICS]) in chronic obstructive pulmonary disorder (COPD) is recommended for patients on LAMA/LABA combinations with frequent exacerbations and severe symptoms. An extended time-to-escalation to triple therapy suggests patients are in a stable condition and is an indicator of treatment effectiveness. No studies in Japanese clinical practice have compared the effectiveness of LAMA/LABA fixed-dose combination therapies with LAMA monotherapy in terms of time-to-escalation to triple therapy. The primary objective of this real-world study in Japan was to compare time-to-escalation to triple therapy among new users of tiotropium/olodaterol or tiotropium monotherapy for COPD without asthma.

Methods

In this active-comparator cohort study, new users of tiotropium/olodaterol (n = 1436) and tiotropium monotherapy (n = 5352) were identified from a large Japanese hospital-based database (Medical Data Vision Co., Ltd., Tokyo; prespecified study period: 1 April 2015 to 31 March 2019); patients in each group were matched 1:1 using high-dimensional propensity scores (hdPS). The primary outcome was time-to-escalation to triple therapy.

Results

For the prespecified study period in the hdPS-matched cohort, escalation to triple therapy was infrequent among new users of tiotropium/olodaterol (n = 1302, 7 escalation events) and tiotropium monotherapy (n = 1302, 8 escalation events). The difference in time-to-escalation to triple therapy between groups was not statistically significant (median [interquartile range]: 28 days [15.0–139.2] for tiotropium monotherapy vs 193 days [94.5–302.0] for tiotropium/olodaterol; hazard ratio: 0.89; 95% CI: 0.32–2.46). Similar findings (hazard ratio: 0.71; 95% Cl: 0.36–1.40) were observed in a post hoc analysis, which extended the study period by 1 year to 31 March 2020. Risks of first moderate and/or severe COPD exacerbation were lower for tiotropium/olodaterol than tiotropium monotherapy (between-group differences not significant). There were no significant between-group differences for the risks of all-cause inpatient mortality, major adverse cardiovascular events, and first use of home oxygen therapy.

Conclusions

ICS monotherapy or ICS/LABA added to tiotropium or tiotropium/olodaterol is limited in Japanese clinical settings. The number of escalations to triple therapy was very limited in the dataset and there was insufficient power to detect differences between the treatment groups in the primary hdPS-matched cohort.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01776-y.

Narrative review of current COPD status in Japan

Chronic obstructive pulmonary disease (COPD) causes morbidity and mortality worldwide. Due to the improvement in environmental sanitation and medical care, the general life span has increased in the past decades in Japan. However, many older patients with COPD develop a wide range of comorbidities, and the impairments in the activities of daily living result in frailty and increase social and economic burdens. Population-based studies have shown that the prevalence of COPD is approximately 10% among subjects aged ≥40 years, but more than 80% of COPD patients are underdiagnosed. The Ministry of Health, Labour, and Welfare in Japan proposed the National Health Promotion in the 21st century, termed Health Japan 21 (the second term), in 2013 to prevent the onset and progression of noncommunicable diseases (NCDs), including COPD. The government, medical society, and community have been attempting to increase the recognition of COPD and promote smoking cessation. Additionally, Japanese cohorts have revealed distinct clinical features in Japanese patients with COPD, including lower rates of patient-reported exacerbations, less frequent coexisting cardiovascular disease and metabolic syndrome, and lower use of inhaled corticosteroids in Japan compared to the Western countries. Moreover, the poor adherence to inhaled medications is found in approximately 20% of subjects, and rehabilitation is performed in 26% of hospitalized patients with COPD. Therefore, more efforts should be made to improve adherence and access to pulmonary rehabilitation. Overall, Japanese COPD patients share common clinical and social features with COPD patients in other countries. Further international corroboration may help establish better comprehensive management of the disease.

High eosinophil counts predict decline in FEV1: results from the CanCOLD study

INTRODUCTION

The aim of this study was to examine the association between blood eosinophil levels and the decline in lung function in individuals aged >40 years from the general population.

METHODS

The study evaluated the eosinophil counts from thawed blood in 1120 participants (mean age 65 years) from the prospective population-based Canadian Cohort of Obstructive Lung Disease (CanCOLD) study. Participants answered interviewer-administered respiratory questionnaires and performed pre-/post-bronchodilator spirometric tests at 18-month intervals; computed tomography (CT) imaging was performed at baseline. Statistical analyses to describe the relationship between eosinophil levels and decline in forced expiratory volume in 1 s (FEV₁) were performed using random mixed-effects regression models with adjustments for demographics, smoking, baseline FEV₁, ever-asthma and history of exacerbations in the previous 12 months. CT measurements were compared between eosinophil subgroups using ANOVA.

RESULTS

Participants who had a peripheral eosinophil count of ≥300 cells·µL^-1 (n=273) had a greater decline in FEV₁ compared with those with eosinophil counts of <150 cells·µL^-1 (n=430; p=0.003) (reference group) and 150-<300 cells·µL^-1 (n=417; p=0.003). The absolute change in FEV₁ was -32.99 mL·year^-1 for participants with eosinophil counts <150 cells·µL^-1; -38.78 mL·year^-1 for those with 150-<300 cells·µL^-1 and -67.30 mL·year^-1 for participants with ≥300 cells·µL^-1. In COPD, higher eosinophil count was associated with quantitative CT measurements reflecting both small and large airway abnormalities.

CONCLUSION

A blood eosinophil count of ≥300 cells·µL^-1 is an independent risk factor for accelerated lung function decline in older adults and is related to undetected structural airway abnormalities.

A Comparative Evaluation of Computed Tomography Images for the Classification of Spirometric Severity of the Chronic Obstructive Pulmonary Disease with Deep Learning

Recently, deep learning applications in medical imaging have been widely applied. However, whether it is sufficient to simply input the entire image or whether it is necessary to preprocess the setting of the supervised image has not been sufficiently studied. This study aimed to create a classifier trained with and without preprocessing for the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification using CT images and to evaluate the classification accuracy of the GOLD classification by confusion matrix. According to former GOLD 0, GOLD 1, GOLD 2, and GOLD 3 or 4, eighty patients were divided into four groups (n = 20). The classification models were created by the transfer learning of the ResNet50 network architecture. The created models were evaluated by confusion matrix and AUC. Moreover, the rearranged confusion matrix for former stages 0 and ≥1 was evaluated by the same procedure. The AUCs of original and threshold images for the four-class analysis were 0.61 ± 0.13 and 0.64 ± 0.10, respectively, and the AUCs for the two classifications of former GOLD 0 and GOLD ≥ 1 were 0.64 ± 0.06 and 0.68 ± 0.12, respectively. In the two-class classification by threshold image, recall and precision were over 0.8 in GOLD ≥ 1, and in the McNemar–Bowker test, there was some symmetry. The results suggest that the preprocessed threshold image can be possibly used as a screening tool for GOLD classification without pulmonary function tests, rather than inputting the normal image into the convolutional neural network (CNN) for CT image learning.

One-year clinically important deterioration and long-term clinical course in Japanese patients with COPD: a multicenter observational cohort study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with a complex progression of many clinical presentations, and clinically important deterioration (CID) has been proposed in the Western studies as a composite endpoint of disease progression. The aim of this study was to investigate the relationships between 1-year CID and the following long-term clinical outcomes in Japanese patients with COPD who have been reported to have different characteristics compared to the Westerners.

METHODS

Among Japanese patients with COPD enrolled in the Hokkaido COPD cohort study, 259 patients who did not drop out within the first year were analyzed in this study. Two definitions of CID were used. Definition 1 comprised ≥ 100 mL decrease in forced expiratory volume in 1 s (FEV₁), ≥ 4-unit increase in St George's Respiratory Questionnaire (SGRQ) score from baseline, or moderate or severe exacerbation. For Definition 2, the thresholds for the FEV₁ and SGRQ score components were doubled. The presence of CID was evaluated within the first year from enrollment, and analyzed the association of the presence of CID with following 4-year risk of exacerbations and 9-year mortality.

RESULTS

Patients with CID using Definition 1, but not any single CID component, during the first year had a significantly worse mortality compared with those without CID. Patients with CID using Definition 2 showed a similar trend on mortality, and had a shorter exacerbation-free survival compared with those without CID.

CONCLUSIONS

Adoption of CID is a beneficial and useful way for the assessment of long-term disease progression and clinical outcomes even in Japanese population with COPD. The definition of CID might be optimized according to the characteristics of COPD population and the observation period for CID.

Characteristics of chronic obstructive pulmonary disease patients with robust progression of emphysematous change

Emphysema is a major pathological change in chronic obstructive pulmonary disease (COPD). However, the annual changes in the progression of emphysematous have not been investigated. We aimed to determine possible baseline predicting factors of the change in emphysematous progression in a subgroup of COPD patients who demonstrated rapid progression. In this observational study, we analyzed patients with COPD who were followed up by computed tomography (CT) at least two times over a 3-year period (n = 217). We divided the annual change in the low attenuation area percentage (LAA%) into quartiles and defined a rapid progression group (n = 54) and a non-progression group (n = 163). Predictors of future changes in emphysematous progression differed from predictors of high LAA% at baseline. On multivariate logistic regression analysis, low blood eosinophilic count (odds ratio [OR], 3.22; P = 0.04) and having osteoporosis (OR, 2.13; P = 0.03) were related to rapid changes in emphysematous progression. There was no difference in baseline nutritional parameters, but nutritional parameters deteriorated in parallel with changes in emphysematous progression. Herein, we clarified the predictors of changes in emphysematous progression and concomitant deterioration of nutritional status in COPD patients.

The coexistence of asthma and COPD: risk factors, clinical history and lung function trajectories

RATIONALE

Patients with concomitant features of asthma and chronic obstructive pulmonary disease (COPD) have a heavy disease burden.

OBJECTIVES

Using data collected prospectively in the European Community Respiratory Health Survey, we compared the risk factors, clinical history, and lung function trajectories from early adulthood to the late sixties of middle aged subjects having asthma+COPD (n=179), past (n=263) or current (n=808) asthma alone, COPD alone (n=111), or none of these (n=3477).

METHODS

Interview data and prebronchodilator FEV₁ and FVC were obtained during three clinical examinations in 1991-1993, 1999-2002, and 2010-2013. Disease status was classified in 2010-2013, when the subjects were aged 40-68, according to the presence of fixed airflow obstruction (postbronchodilator FEV₁/FVC below the lower limit of normal), a lifetime history of asthma, and cumulative exposure to tobacco or occupational inhalants. Previous lung function trajectories, clinical characteristics, and risk factors of these phenotypes were estimated.

MAIN RESULTS

Subjects with asthma+COPD reported maternal smoking (28.2%) and respiratory infections in childhood (19.1%) more frequently than subjects with COPD alone (20.9 and 14.0%, respectively). Subjects with asthma+COPD had an impairment of lung function at age 20 that tracked over adulthood, and more than half of them had asthma onset in childhood. Subjects with COPD alone had the highest lifelong exposure to tobacco smoking and occupational inhalants, and they showed accelerated lung function decline during adult life.

CONCLUSIONS

The coexistence between asthma and COPD seems to have its origins earlier in life compared to COPD alone. These findings suggest that prevention of this severe condition, which is typical at older ages, should start in childhood.

Efficacy of mepolizumab in elderly patients with severe asthma and overlapping COPD in real-world settings: A retrospective observational study

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) are the most common respiratory diseases, presenting overlapping prevalence with age. Mepolizumab is a humanized monoclonal antibody targeting interleukin-5. In major randomized clinical trials, this antibody reportedly reduced the circulating eosinophil count, exacerbation rate, and oral corticosteroid (OCS) dosage in patients with severe eosinophilic asthma. However, data regarding the efficacy of mepolizumab in elderly patients with asthma and overlapping COPD are limited.

METHODS

This was a single-center, retrospective, observational study. Elderly patients (age ≥65 years) administered mepolizumab between August 2016 and March 2019 were enrolled and the effects of mepolizumab on the eosinophil level, exacerbation numbers, OCS dosage, and lung functions were assessed. We compared treatment responses in patients with asthma and COPD overlap (ACO) with responses observed in patients with severe asthma alone. Adverse events were also evaluated.

RESULTS

Twenty patients (10 men and 10 women), with a mean age of 77.5 ± 1.3 years, were included. Mepolizumab significantly reduced the blood eosinophil count, as well as significantly decreased clinically significant exacerbation, in both populations. The OCS dosage was significantly reduced in patients treated receiving maintenance OCS therapy. However, mepolizumab did not improve lung function in either population, and no significant difference was observed in treatment responses between patients with asthma alone and ACO.

CONCLUSIONS

Mepolizumab may be effective in elderly patients with eosinophilic asthma and ACO.

Central airway and peripheral lung structures in airway disease-dominant COPD

The concept that the small airway is a primary pathological site for all COPD phenotypes has been challenged by recent findings that the disease starts from the central airways in COPD subgroups and that a smaller central airway tree increases COPD risk. This study aimed to examine whether the computed tomography (CT)-based airway disease-dominant (AD) subtype, defined using the central airway dimension, was less associated with small airway dysfunction (SAD) on CT, compared to the emphysema-dominant (ED) subtype.

COPD patients were categorised into mild, AD, ED and mixed groups based on wall area per cent (WA%) of the segmental airways and low attenuation volume per cent in the Kyoto–Himeji (n=189) and Hokkaido COPD cohorts (n=93). The volume per cent of SAD regions (SAD%) was obtained by nonrigidly registering inspiratory and expiratory CT.

The AD group had a lower SAD% than the ED group and similar SAD% to the mild group. The AD group had a smaller lumen size of airways proximal to the segmental airways and more frequent asthma history before age 40 years than the ED group. In multivariable analyses, while the AD and ED groups were similarly associated with greater airflow limitation, the ED, but not the AD, group was associated with greater SAD%, whereas the AD, but not the ED, group was associated with a smaller central airway size.

The CT-based AD COPD subtype might be associated with a smaller central airway tree and asthma history, but not with peripheral lung pathologies including small airway disease, unlike the ED subtype.

This study shows that airway disease-dominant COPD, defined using central airway dimension on CT, is associated with a smaller central airway tree, less small airway dysfunction and slower lung function decline than the emphysema-dominant COPDhttps://bit.ly/3nNwxIC

Blood Eosinophil Levels and Prognosis of Hospitalized Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUD

Studies about the clinical significance of high eosinophil levels in chronic obstructive pulmonary disease (COPD) are conflicting, and it has been less studied in hospitalized patients with acute exacerbation of COPD (AECOPD).This study was to examine blood eosinophil levels in relation to the prognosis of hospitalized patients with AECOPD.

METHODS

This was a retrospective cohort study of patients with AECOPD as their primary diagnosis and admitted to Beijing Shijitan Hospital, Capital Medical University, from January 2010 to December 2016. The patients were assigned according to the count of eosinophil in peripheral blood at their first hospitalization. Patients were grouped as ≤100, 100-300, and ≥300 eosinophils/µL of peripheral blood. The use of glucocorticoids, duration of hospitalization, in-hospital mortality, and re-hospitalization were examined.

RESULTS

Compared with the 100-300 eosinophils/µL group, the ≤100 eosinophils/µL group showed higher frequencies of fever, respiratory failure, and the use of systemic glucocorticoids. Eosinophil counts were not associated with in-hospital mortality and duration of hospitalization. The multivariable analysis showed that GOLD3/4 (odds ratio (OR)=2.04, 95%CI: 1.20-3.44, P = 0.008), systemic glucocorticoids (OR=1.84, 95%CI: 1.41-2.98, P = 0.012), mechanical ventilation (OR=2.66, 95%CI: 1.36-5.18, P = 0.004), and acute exacerbation in the past year before hospitalization (OR=2.03, 95%CI: 1.27-3.23, P = 0.003) were independently associated with acute exacerbation within 1 year after discharge. Eosinophil count was not associated with acute exacerbation within 1 year after discharge.

CONCLUSIONS

Peripheral blood eosinophil counts are not associated with the 1-year AECOPD prognosis.

Asthma-COPD overlap: current understanding and the utility of experimental models

Pathological features of both asthma and COPD coexist in some patients and this is termed asthma-COPD overlap (ACO). ACO is heterogeneous and patients exhibit various combinations of asthma and COPD features, making it difficult to characterise the underlying pathogenic mechanisms. There are no controlled studies that define effective therapies for ACO, which arises from the lack of international consensus on the definition and diagnostic criteria for ACO, as well as scant in vitro and in vivo data. There remain unmet needs for experimental models of ACO that accurately recapitulate the hallmark features of ACO in patients. The development and interrogation of such models will identify underlying disease-causing mechanisms, as well as enabling the identification of novel therapeutic targets and providing a platform for assessing new ACO therapies. Here, we review the current understanding of the clinical features of ACO and highlight the approaches that are best suited for developing representative experimental models of ACO.

Understanding the pathogenesis of asthma-COPD overlap is critical for improving therapeutic approaches. We present current knowledge on asthma-COPD overlap and the requirements for developing an optimal animal model of disease.https://bit.ly/3lsjyvm

Asthma and Chronic Obstructive Pulmonary Disease Overlap According to the Japanese Respiratory Society Diagnostic Criteria: The Prospective, Observational ACO Japan Cohort Study

INTRODUCTION

Patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) present with chronic respiratory symptoms with features of both asthma and COPD. New ACO diagnostic criteria (2018) were suggested by the Japanese Respiratory Society (JRS). This prospective, multicenter, observational cohort study was conducted to investigate the proportion of patients who meet the JRS ACO diagnostic criteria among COPD patients in clinical practice.

METHODS

This 2-year ongoing study enrolled consecutive outpatients aged ≥ 40 years with COPD who visited one of 27 Japanese centers at which the medical examinations/tests required for ACO diagnosis were routinely conducted. At registration, the proportion of ACO or non-ACO patients was determined using the JRS diagnostic criteria, and the characteristics of the two groups were compared using analysis of variance and chi-square test.

RESULTS

Of 708 COPD patients analyzed at registration, 396 (55.9%) had the data necessary for ACO diagnosis to be conducted, and 312 (44.1%) were lacking these data. Of the 396 patients who had the data necessary for ACO diagnosis, 101 (25.5%) met the diagnostic criteria for ACO, and 295 (74.5%) did not (non-ACO patients). ACO patients were younger, had a greater rate of asthma based on a physician's diagnosis, and used more medications, including inhaled corticosteroids (p < 0.05), compared with non-ACO patients.

CONCLUSIONS

We have determined the proportion of patients with the data necessary to diagnose ACO using the JRS criteria, and the proportion of these who met the ACO criteria among the COPD population at the time of registration. Patients, including those lacking necessary examination/test data at registration, will continue to undergo follow-up to explore changes in their testing and ACO diagnostic status over time. Analyses of study data over 2 years will provide relevant information on the ACO symptoms, clinical course, and real-world treatment patterns.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03577795.

Thymus and activation-regulated chemokine (TARC/CCL17) predicts decline of pulmonary function in patients with chronic obstructive pulmonary disease

BACKGROUND

The deterioration of pulmonary function, such as FEV₁-decline, is strongly associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). However, few investigations shed light on useful biomarkers for predicting the decline of pulmonary function. We evaluated whether thymus and activation-regulated chemokine (TARC), a Th2 inflammation marker, could predict rapid FEV₁-decline in COPD patients.

METHODS

We recruited 161 patients with stable COPD and performed pulmonary function test once every six months. At the time of registration, blood tests, including serum levels of TARC were performed. We assessed the correlation between changes in parameters of pulmonary function tests and serum levels of TARC. The rapid-decline in pulmonary function was determined using 25th percentile of change in FEV₁ or FEV₁ percent predicted (%FEV₁) per year.

RESULTS

In the FEV₁-rapid-decline group, the frequency of exacerbations, the degree of emphysema, and serum levels of TARC was higher than in the non-rapid-decline group. When using %FEV₁ as a classifier instead of FEV₁, age, the frequency of exacerbations, the degree of emphysema and serum levels of TARC in the rapid-decline group was significantly greater than those in the non-rapid-decline group. In univariate logistic regression analysis, TARC was the significant predictive factor for rapid-decline group. In multivariate analysis adjusted for emphysema, serum levels of TARC are independently significant predicting factors for the rapid-decline group.

CONCLUSIONS

TARC is an independent predictive biomarker for the rapid-decline in FEV₁. Measuring serum TARC levels may help the management of COPD patients by predicting the risk of FEV₁ decline.

Asthma-chronic obstructive pulmonary disease overlap syndrome

Overlap of asthma and chronic obstructive lung disease (ACO) in patients with obstructive lung disease is growing in recognition, though there is no consistent agreement on the diagnostic criteria for the disease process. Patients with ACO have distinct clinical characteristics and trajectories, which are representative of a heterogenous, multifactorial, and incompletely understood inflammatory pathophysiology. Current treatment strategies are focused on titration of inhaled therapies such as long-acting bronchodilators, with increasing interest in the use of targeted biologic therapies aimed at the underlying inflammatory mechanisms. Future directions for research will focus on elucidating the varied inflammatory signatures leading to ACO, the development of consistent diagnostic criteria and biomarkers of disease, and improving the clinical management with an eye toward targeted therapies.

Clinical Characteristics and Outcomes of Patients with Asthma-COPD Overlap in Japanese Patients with COPD

Purpose

Asthma–COPD overlap (ACO) has been reported as an association with a lower quality of life, frequent exacerbations, and higher mortality than those with COPD alone. However, clinical characteristics and outcomes of ACO remain controversial.

Patients and Methods

We conducted a prospective observational study analyzing data of patients with stable COPD enrolled from the Ishinomaki COPD Network Registry. Patients with features of asthma who had a history of respiratory symptoms that vary over time and intensity, together with documented variable expiratory airflow limitation, were identified, and then defined as having ACO. The characteristics, frequency of exacerbations, and mortality during the 3-year follow-up were compared between patients with ACO and patients with COPD alone.

Results

Among 387 patients with COPD, 41 (10.6%) were identified as having ACO. Patients with ACO tended to be younger, have higher BMI, have a shorter smoking history, and use more respiratory medications, especially inhaled corticosteroids. Inflammatory biomarkers including fractional exhaled nitric oxide, blood eosinophil count, total immunoglobulin E (IgE) level, and presence of antigen-specific IgE were significantly higher in patients with ACO than in those with COPD alone. Lung function, mMRC score, CAT score, and comorbidity index were not different between the groups. The annual rate of all exacerbations and severe exacerbations required hospital admission were not different between ACO and COPD alone (0.20 vs 0.14, 0.12 vs 0.10, events per person, respectively). Mortality was significantly higher in patients with COPD alone compared with those with ACO during the study period (P=0.037).

Conclusion

The results of our study indicate that ACO is not associated with poor clinical features nor outcomes in an outpatient COPD cohort receiving appropriate treatment.

Absolute Blood Eosinophil Counts to Guide Inhaled Corticosteroids Therapy Among Patients with COPD: Systematic Review and Meta-analysis

INTRODUCTION

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2019 recommends the use of absolute blood eosinophil count as a guide for the escalation and de-escalation of inhaled corticosteroids (ICS) in the pharmacological management of patients with chronic obstructive pulmonary disease (COPD). We evaluated the risk of moderate or severe exacerbations among patients escalating and de-escalating ICS therapy by absolute blood eosinophil thresholds in this systematic review.

METHODS

Through a comprehensive literature search of Pubmed/MEDLINE, EMBASE, and clinical trial sites up to April 2019, we identified relevant studies. We used generic inverse variance method with fixed-effects estimates to compare the risk of moderate or severe exacerbations among COPD patients with elevated blood eosinophil counts exposed to inhaled corticosteroids (ICS) versus non-ICS treatments groups expressed as risk ratios.

RESULTS

Ten studies (8 randomised control trials and 2 observational studies) were included, with a total of 85,059 COPD patients. In our pooled analysis, we found an overall reduction in risk of moderate or severe exacerbations in patients with absolute blood eosinophil thresholds ranging from ≥ 100 to ≥ 340 cells/µL among patients escalating ICS (RR, 0.77, 95% CI, 0.73-0.81). For studies evaluating the effects of de-escalation of ICS on moderate to severe exacerbations using blood eosinophil thresholds of ≥ 300 to ≥ 340 cells/µL had an increased risk of moderate or severe exacerbations following the de-escalation of ICS (RR, 1.66, 95% CI, 1.31-2.10).

CONCLUSION

This study confirms the validity of the recommended absolute blood eosinophil count thresholds for the escalation and de-escalation of ICS among COPD patients. However, this recommendation is for COPD patients with prior exacerbations rather than among newly diagnosed COPD patients as observed in this study. COPD patients with current or past history of asthma represent a unique phenotypic group which should be further evaluated.

Unique Mortality Profile in Japanese Patients with COPD: An Analysis from the Hokkaido COPD Cohort Study

Purpose

Causes of death may be unique and different in Japanese patients with COPD because they are generally older, thinner, experience fewer exacerbations, and live longer than those in other countries. We investigated the detailed mortality profile in the Hokkaido COPD cohort study, which completed a 10-year follow-up with a very low dropout rate.

Patients and Methods

We prospectively examined the 10-year natural history in 279 Japanese patients with COPD (GOLD 1, 26%; GOLD 2, 45%; GOLD 3, 24%; and GOLD 4, 5%). The majority of patients were male, and the average age at baseline was 69 years old. About 95% of all patients had accurate mortality data. The risk factors for mortality were also analyzed.

Results

During the 10 years, 112 patients (40%) died. Their median survival time was 6.1 years (interquartile range: 4.7–7.9 years), and age at death was 79 ± 6 years old (mean ± SD). Respiratory diseases, including pneumonia, were the leading causes of death in 45 (40%), followed by lung cancer in 24 (21%), other cancers in 18 (16%), and cardiovascular diseases in 12 (11%). In particular, lung cancer-related death was equally distributed across all COPD stages, with a higher proportion of lung cancer in the relatively younger generation (<64 years old). Older age at baseline, lower BMI, and severer emphysema were significant risk factors for all-cause mortality.

Conclusion

The unique mortality profile observed in this study should be considered when designing strategies for the management of patients with COPD in any geographic region.