Respiratory Oscillometry and Functional Performance in Different COPD Phenotypes

Purpose

Chronic obstructive pulmonary disease (COPD) phenotypes may introduce different characteristics that need to be known to improve treatment. Respiratory oscillometry provides a detailed analysis and may offer insight into the pathophysiology of COPD. In this paper, we used this method to evaluate the differences in respiratory mechanics of COPD phenotypes.

Patients and Methods

This study investigated a sample of 83 volunteers, being divided into control group (CG = 20), emphysema (n = 23), CB (n = 20) and asthma-COPD overlap syndrome (ACOS, n = 20). These analyses were performed before and after bronchodilator (BD) use. Functional capacity was evaluated using the Glittre‑ADL test, handgrip strength and respiratory pressures.

Results

Initially it was observed that oscillometry provided a detailed description of the COPD phenotypes, which was consistent with the involved pathophysiology. A correlation between oscillometry and functional capacity was observed (r=-0.541; p = 0.0001), particularly in the emphysema phenotype (r = -0.496, p = 0.031). BD response was different among the studied phenotypes. This resulted in an accurate discrimination of ACOS from CB [area under the receiver operating curve (AUC) = 0.84] and emphysema (AUC = 0.82).

Conclusion

These results offer evidence that oscillatory indices may enhance the comprehension and identification of COPD phenotypes, thereby potentially improving the support provided to these patients.

Polygenic risk scores identify heterogeneity in asthma and chronic obstructive pulmonary disease

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) have distinct and overlapping genetic and clinical features.

OBJECTIVE

We sought to test the hypothesis that polygenic risk scores (PRSs) for asthma (PRSAsthma) and spirometry (FEV1 and FEV1/forced vital capacity; PRSspiro) would demonstrate differential associations with asthma, COPD, and asthma-COPD overlap (ACO).

METHODS

We developed and tested 2 asthma PRSs and applied the higher performing PRSAsthma and a previously published PRSspiro to research (Genetic Epidemiology of COPD study and Childhood Asthma Management Program, with spirometry) and electronic health record-based (Mass General Brigham Biobank and Genetic Epidemiology Research on Adult Health and Aging [GERA]) studies. We assessed the association of PRSs with COPD and asthma using modified random-effects and binary-effects meta-analyses, and ACO and asthma exacerbations in specific cohorts. Models were adjusted for confounders and genetic ancestry.

RESULTS

In meta-analyses of 102,477 participants, the PRSAsthma (odds ratio [OR] per SD, 1.16 [95% CI, 1.14-1.19]) and PRSspiro (OR per SD, 1.19 [95% CI, 1.17-1.22]) both predicted asthma, whereas the PRSspiro predicted COPD (OR per SD, 1.25 [95% CI, 1.21-1.30]). However, results differed by cohort. The PRSspiro was not associated with COPD in GERA and Mass General Brigham Biobank. In the Genetic Epidemiology of COPD study, the PRSAsthma (OR per SD: Whites, 1.3; African Americans, 1.2) and PRSspiro (OR per SD: Whites, 2.2; African Americans, 1.6) were both associated with ACO. In GERA, the PRSAsthma was associated with asthma exacerbations (OR, 1.18) in Whites; the PRSspiro was associated with asthma exacerbations in White, LatinX, and East Asian participants.

CONCLUSIONS

PRSs for asthma and spirometry are both associated with ACO and asthma exacerbations. Genetic prediction performance differs in research versus electronic health record-based cohorts.

Metabolomics of asthma, COPD, and asthma-COPD overlap: an overview

The two common progressive lung diseases, asthma and chronic obstructive pulmonary disease (COPD), are the leading causes of morbidity and mortality worldwide. Asthma-COPD overlap, referred to as ACO, is another complex pulmonary disease that manifests itself with features of both asthma and COPD. The disease has no clear diagnostic or therapeutic guidelines, thereby making both diagnosis and treatment challenging. Though a number of studies on ACO have been documented, gaps in knowledge regarding the pathophysiologic mechanism of this disorder exist. Addressing this issue is an urgent need for improved diagnostic and therapeutic management of the disease. Metabolomics, an increasingly popular technique, reveals the pathogenesis of complex diseases and holds promise in biomarker discovery. This comprehensive narrative review, comprising 99 original research articles in the last five years (2017-2022), summarizes the scientific advances in terms of metabolic alterations in patients with asthma, COPD, and ACO. The analytical tools, nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), commonly used to study the expression of the metabolome, are discussed. Challenges frequently encountered during metabolite identification and quality assessment are highlighted. Bridging the gap between phenotype and metabotype is envisioned in the future.

Fatigue, Depression, and Anxiety in Patients with COPD, Asthma and Asthma-COPD Overlap

INTRODUCTION

Asthma and COPD are extremely common respiratory diseases that have a serious impact on people's lives around the world. A disease characterized by symptoms characteristic for asthma and COPD is called asthma-COPD overlap (ACO). Fatigue and certain psychological disorders such as anxiety and depression are important comorbidities in these diseases. The purpose of this study was to assess the prevalence of fatigue, anxiety, and depression in patients with asthma, COPD, and ACO and to also consider their mutual correlations.

MATERIAL AND METHODS

A total of 325 patients were enrolled in the study. There were 159 women and 166 men and their mean age was 63. Two standardized questionnaires were used: the Modified Fatigue Impact Scale (MFIS) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

The mean total MFIS score for all patients was 33.03. Patients with asthma generally scored lower than patients with COPD and ACO. There were no statistical differences in the HADS for anxiety between the groups, although around half of the patients registered a score indicating some level of disorder. Patients with COPD and ACO were proven to suffer more from depression than patients with asthma. The HADS and MFIS scores were found to correlate significantly and positively.

CONCLUSIONS

Our study showed that patients with COPD, asthma, and ACO generally suffered from an increased level of fatigue and depression. Anxiety was high in all groups, but it was at a similar level for patients suffering from each of the three diseases under consideration. It is important to treat the physical symptoms as well as the psychological disorders since they greatly impact on the patient outcomes.

Interleukin (IL)-33 immunobiology in asthma and airway inflammatory diseases

OBJECTIVE

Identify key features of IL-33 immunobiology important in allergic and nonallergic airway inflammatory diseases and potential therapeutic strategies to reduce disease burden.

DATA SOURCES

PubMed, clinicaltrials.gov.

STUDY SELECTIONS

A systematic and focused literature search was conducted of PubMed from March 2021 to December 2021 using keywords to either PubMed or BioMed Explorer including IL-33/ST2, genetic polymorphisms, transcription, translation, post-translation modification, nuclear protein, allergy, asthma, and lung disease. Clinical trial information on IL-33 was extracted from clinicaltrials.gov in August 2021.

RESULTS

In total, 72 publications with relevance to IL-33 immunobiology and/or clinical lung disease were identified (allergic airway inflammation/allergic asthma n = 26, non-allergic airway inflammation n = 9, COPD n = 8, lung fibrosis n = 10). IL-33 levels were higher in serum, BALF and/or lungs across inflammatory lung diseases. Eight studies described viral infections and IL-33 and 4 studies related to COVID-19. Mechanistic studies (n = 39) including transcript variants and post-translational modifications related to the immunobiology of IL-33. Single nucleotide polymorphism in IL-33 or ST2 were described in 9 studies (asthma n = 5, inflammatory bowel disease n = 1, mycosis fungoides n = 1, ankylosing spondylitis n = 1, coronary artery disease n = 1). Clinicaltrials.gov search yielded 84 studies of which 17 were related to therapeutic or biomarker relevance in lung disease.

CONCLUSION

An integral role of IL-33 in the pathogenesis of allergic and nonallergic airway inflammatory disease is evident with several emerging clinical trials investigating therapeutic approaches. Current data support a critical role of IL-33 in damage signaling, repair and regeneration of lungs.

Using inflammatory index to distinguish asthma, asthma-COPD overlap and COPD: A retrospective observational study

BACKGROUND

Although asthma and chronic obstructive pulmonary disease (COPD) are two well-defined and distinct diseases, some patients present combined clinical features of both asthma and COPD, particularly in smokers and the elderly, a condition termed as asthma-COPD overlap (ACO). However, the definition of ACO is yet to be established and clinical guidelines to identify and manage ACO remain controversial. Therefore, in this study, inflammatory biomarkers were established to distinguish asthma, ACO, and COPD, and their relationship with the severity of patients' symptoms and pulmonary function were explored.

MATERIALS AND METHODS

A total of 178 patients, diagnosed with asthma (n = 38), ACO (n = 44), and COPD (n = 96) between January 2021 to June 2022, were enrolled in this study. The patients' pulmonary function was examined and routine blood samples were taken for the analysis of inflammatory indexes. Logistic regression analysis was used to establish inflammatory biomarkers for distinguishing asthma, ACO, and COPD; linear regression analysis was used to analyze the relationship between inflammatory indexes and symptom severity and pulmonary function.

RESULT

The results showed that, compared with ACO, the higher the indexes of platelet, neutrophil-lymphocyte ratio (NLR) and eosinophil-basophil ratio (EBR), the more likely the possibility of asthma and COPD in patients, while the higher the eosinophils, the less likely the possibility of asthma and COPD. Hemoglobin and lymphocyte-monocyte ratio (LMR) were negatively correlated with the severity of patients' symptoms, while platelet-lymphocyte ratio (PLR) was negatively correlated with forced expiratory volume in the 1 s/forced vital capacity (FEV1/FVC) and FEV1 percent predicted (% pred), and EBR was positively correlated with FEV1% pred.

CONCLUSION

Inflammatory indexes are biomarkers for distinguishing asthma, ACO, and COPD, which are of clinical significance in therapeutic strategies and prognosis evaluation.

Clinical Indicators for Asthma-COPD Overlap: A Systematic Review and Meta-Analysis

Background

Some clinical indicators have been reported to be useful in differentiating asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) from pure asthma/COPD, but the results were inconsistent. This study aims to evaluate the diagnostic value of these indicators for ACO.

Methods

Databases of PubMed, EMBASE, Ovid and Web of Science were retrieved. Pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated in random-effects models.

Results

48 eligible studies were included. The pooled results indicated, compared with pure asthma, ACO patients had lower levels of forced expiratory volume in the first second (FEV₁)% predicted (pred) (SMD=−1.09, 95% CI −1.3 to −0.87), diffusion lung capacity for carbon monoxide (DLCO)% pred (SMD=−0.83, 95% CI −1.24 to −0.42), fractional exhaled nitric oxide (FeNO) (SMD=−0.23, 95% CI −0.36 to −0.11), and higher levels of induced sputum neutrophil (SMD = 0.51, 95% CI 0.21 to 0.81), circulating YKL-40 (SMD = 0.96, 95% CI 0.27 to 1.64). However, relative to COPD alone, ACO patients had higher levels of FEV₁% pred (SMD = 0.15, 95% CI 0.05 to 0.26), DLCO% pred (SMD = 0.38, 95% CI 0.16 to 0.6), FeNO (SMD = 0.59, 95% CI 0.40 to 0.78), serum total immunoglobulin (Ig)E (SMD = 0.42, 95% CI 0.1 to 0.75), blood eosinophil (SMD = 0.44, 95% CI 0.29 to 0.59), induced sputum eosinophil (SMD = 0.62, 95% CI 0.42 to 0.83), and lower levels of induced sputum neutrophil (SMD=−0.48, 95% CI −0.7 to −0.27), circulating YKL-40 (SMD=−1.09, 95% CI −1.92 to −0.26).

Conclusion

Compared with pure asthma/COPD, ACO patients have different levels of FEV₁% pred, DLCO% pred, FeNO, serum total IgE, blood eosinophil, induced sputum eosinophil/neutrophil, and circulating YKL-40, which could be helpful to establish a clinical diagnosis of ACO.

Clinical Implications of Bronchodilator Testing: Diagnosing and Differentiating COPD and Asthma-COPD Overlap

BACKGROUND

Bronchodilation testing is an important component of spirometry testing, and omitting this procedure has potential clinical implications toward diagnosing respiratory diseases. We aimed to estimate the impact of bronchodilator testing in accurately diagnosing COPD and differentiating COPD from asthma-COPD overlap (ACO).

METHODS

The National Health and Nutrition Examination Survey data were analyzed from 2007-2012. Airflow limitation was defined by FEV₁/FVC < 0.7. Subjects with pre-bronchodilator airflow limitation were classified into pre-but-not-post-bronchodilator airflow limitation and post-bronchodilator airflow limitation groups. Spirometry-confirmed COPD was defined by persistent airflow limitation on post-bronchodilator spirometry. The American Thoracic Society (ATS) and the Spanish Society of Pneumology and Thoracic Surgery (SEPAR) definitions were used to identify possible ACO subjects.

RESULTS

We identified 11,763 subjects ≥ 40 y of age eligible for spirometry; 625 of them had a pre-bronchodilator FEV₁/FVC < 0.7 and completed post-bronchodilator spirometry that met ATS spirometry quality standards. A total of 244 (39%) of these subjects had only pre-not-post-bronchodilator airflow limitation, thereby not meeting the definition of spirometrically confirmed COPD. The prevalence of ACO was 7.6% using the modified ATS definition and 19.8% using the modified SEPAR criteria. When bronchodilator testing-based criteria were excluded from ATS and SEPAR definitions, the number of ACO subjects decreased by 39.3% and 12.3%, respectively.

CONCLUSIONS

Spirometry with bronchodilation is an important element in the accurate diagnosis of ACO and COPD. Spirometry performed without bronchodilator testing may lead to an estimated misclassification of ACO by 7.6% to 19.8% and overdiagnosis of COPD by 39%.

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.

Assessment of Airway Remodeling Using Endobronchial Ultrasound in Asthma-COPD Overlap

Purpose

The aim of this study was to evaluate the structural changes of the airways using the endobronchial ultrasound (EBUS) in ACO patients compared to severe asthma and COPD patients.

Patients and Methods

The study included 17 patients with ACO, 17 patients with COPD and 33 patients with severe asthma. Detailed clinical data were obtained from all participants. Basic laboratory tests were performed, including measurement of eosinophil counts in blood and serum immunoglobulin E (IgE) concentrations. All patients underwent spirometry and bronchoscopy with EBUS (a 20‑MHz ultrasound probe) to measure the total thicknesses of the bronchial walls and their particular layers in segmental bronchi of the right lower lobe. EBUS allows to distinguish five layers of the bronchial wall. Layer 1 (L₁) and layer 2 (L₂) were analyzed separately, while the outer layers (layers 3–5 [L_3–5]) that correspond to cartilage were assessed together.

Results

In patients with ACO the thicknesses of the L₁ and L₂ layers, which are mainly responsible for remodeling, were significantly greater than in patients with COPD and significantly smaller than in patients with severe asthma (median L₁= 0.17 mm vs 0.16 mm vs 0.18 mm, p<0.001; median L₂= 0.18 mm vs 0.17 mm vs 0.20 mm, p<0.001, respectively). The thicknesses of the total bronchial walls (L₁+L₂+L_3–5) and L_3–5 were significantly smaller in ACO and COPD patients compared to asthma patients (median L₁+L₂+L_3–5= 1.2 mm vs 1.14 mm vs 1.31 mm, p<0.001; median L_3–5= 0.85 mm vs, 0.81 mm vs 0.92 mm, p=0.001, respectively).

Conclusion

The process of structural changes in the airways assessed by EBUS is more advanced in individuals with ACO compared to patients with COPD, and less pronounced compared to patients with severe asthma. It seems that EBUS may provide useful information about differences in airway remodeling between ACO, COPD and severe asthma.

Circulating microRNA-15b-5p as a biomarker for asthma-COPD overlap

BACKGROUND

It remains unclear how to characterize different subtypes of asthma and chronic obstructive pulmonary disease (COPD). We previously described serum periostin and chitinase-3-like protein 1 (YKL-40) as useful markers for asthma-COPD overlap (ACO). MicroRNAs (miRNAs) are now recognized as markers for identifying the pathophysiological features in several diseases. This study aimed to identify circulating miRNAs that could discriminate patients with ACO from patients with asthma or COPD.

METHODS

This study included two independent cohorts. First, we screened 84 miRNAs for expression levels in patients with ACO (n = 6) or asthma (n = 6) using a quantitative real-time PCR array. The miRNAs showing at least a 2-fold difference in the discovery phase were analyzed in 30 patients each with asthma, COPD, or ACO in the replication phase. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUROC).

RESULTS

Nine miRNAs were identified in the discovery phase. Five of these miRNAs (miR-148a-3p, miR-15b-5p, miR-223-3p, miR-23a-3p, and miR-26b-5p) had lower levels in ACO patients and could discriminate between ACO patients and patients with either asthma or COPD. miR-15b-5p was the most accurate miRNA for the discrimination of patients with ACO (AUROC, 0.71). Moreover, the combined assessment of miR-15b-5p, serum periostin, and YKL-40 (AUROC, 0.80) improved diagnostic accuracy for ACO compared with the combined model of periostin and YKL-40 (AUROC, 0.69).

CONCLUSIONS

Circulating miR-15b-5p is a potential marker for identifying patients with ACO. By elucidating the molecular pathways controlled by miRNAs, we may better understand the pathophysiology of ACO.

Gender Differences in Inhaled Pharmacotherapy Utilization in Patients with Obstructive Airway Diseases (OADs): A Population-Based Study

Purpose

Gender differences in the incidence, susceptibility and severity of many obstructive airway diseases (OADs) have been well recognized. However, gender differences in the inhaled pharmacotherapy profile are not well characterized.

Methods

We conducted a retrospective cohort study to investigate gender differences in new-users of inhaled corticosteroids (ICS), short-or long-acting beta₂-agonist (SABA or LABA), ICS/LABA, short-or long-acting muscarinic antagonist (SAMA or LAMA) among patients with asthma, COPD or asthma-COPD overlap (ACO). We used Clinical Practice Research Datalink to identify OAD patients, 18 years and older, who were new-users (1-year washout period) from 01-January-1998 to 31-July-2018. Multivariable logistic regression was used to examine gender differences in each of the inhaled pharmacotherapies after controlling for potential confounders.

Results

A total of 242,079 new-users (asthma: 84.93%; COPD: 10.19%; ACO: 4.88%) of inhaled pharmacotherapies were identified. The multivariable analyses showed that males with COPD were more likely to be a new user of a LABA (odds ratio [OR] 1.29; 95% confidence interval [CI], 1.12–1.49), LAMA (OR 1.21; 95% CI 1.10–1.33), SAMA (OR 1.11; 95% CI 1.01–1.21) and less likely to be a new user of a SABA (OR 0.84; 95% CI, 0.80–0.89) compared to females. Similar patterns were also observed for patients with ACO; males were more likely to be prescribed with LABA (OR 1.26; 95% CI 1.03–1.55), LAMA (OR 1.28; 95% CI 1.11–1.48), SAMA (OR 1.28; 95% CI 1.11–1.48), and less likely to be a new user of a SABA (OR 0.89; 95% CI, 0.82–0.96). Also, males with asthma were more likely to be a new-user of ICS/LABA (OR 1.15; 95% CI, 1.08–1.23) and less likely to start an ICS (OR 0.97; 95% CI, 0.95–0.99) in comparison with females.

Conclusion

Our study showed significant gender differences in new-users of inhaled pharmacotherapies among OAD patients. Adjusting for proxies of disease severity, calendar year, smoking and socioeconomic status did not change the association by gender.

Role of pulmonary function and FeNO detection in early screening of patients with ACO

Measurement of fractional exhaled nitric oxide (FeNO) is a quantitative and non-invasive approach to examine airway inflammation, which is a powerful aid in diagnosing chronic disorders of airways like asthma. Diagnostic value of FeNO and relevant indices on pulmonary function in the patients with asthma and chronic obstructive pulmonary disease (COPD) was evaluated. A total of 164 patients [58 asthma, 49 COPD and 57 asthma-COPD overlap (ACO)] were randomly recruited. FeNO, pulmonary ventilation function, and bronchial diastolic function were performed. Eight indicators including FeNO, vital capacity percentage (VC%), forced vital capacity percentage (FVC%), forced expiratory volume in one second percentage (FEV1%), forced expiratory volume in one second to forced vital capacity percentage (FEV1/FVC%), maximum independent ventilation volume percentage (MVV%), the increased percentage of FEV1 after bronchial diastolic test, the increased absolute value of FEV1 after bronchial diastolic test were examined. Significant difference in VC%, FVC%, FEV1%, FEV1/FVC%, MVV%, the increased absolute value of FEV1 after bronchial diastolic test and FeNO were significantly different between patients with asthma and patients with COPD (P<0.05). There were significant differences of VC%, FVC%, FEV1%, FEV1/FVC%, MVV% and the increased percentage of FEV1 after bronchial diastolic test in cases of patients with asthma compared to ACO patients (P<0.05). There was no statistical significance on VC%, FVC%, FEV1%, FEV1/FVC%, MVV% between COPD patients and ACO patients (P>0.05). However, more importantly, the increased percentage of FEV1 after bronchial diastolic test, the increased absolute value of FEV1 after bronchial diastolic test and the alterations on FeNO were found significantly different in ACO group compared with COPD alone (P<0.05). We compared the results from pulmonary ventilation function, bronchial diastolic function examination as well as FeNO detection among 3 groups of asthma, COPD and ACO. The examination of pulmonary ventilation function and bronchial diastolic function combined with FeNO detection is helpful in the early screening of ACO.

Triple Therapy with Budesonide/Glycopyrrolate/Formoterol Fumarate Improves Inspiratory Capacity in Patients with Asthma-Chronic Obstructive Pulmonary Disease Overlap

Purpose

Asthma-chronic obstructive pulmonary disease overlap (ACO), characterized by airway limitation, is an important condition with high incidence and mortality. Although some guidelines recommend triple therapy with inhaled corticosteroids/long-acting muscarinic antagonists/long-acting β2 agonists, this treatment approach is based on the extrapolation of data from studies of asthma or chronic obstructive pulmonary disease (COPD) alone.

Methods

A 12-week, randomized, open-label cross-over pilot study was conducted in 19 patients with ACO to investigate the effect of triple therapy with glycopyrrolate (GLY) 50 µg/day on budesonide/formoterol fumarate (BUD/FORM) 640/18 µg/day. The study period included a 4-week wash-out, 4-week run-in, and 4-week treatment period. Respiratory function tests, fractional exhaled nitric oxide (FeNO), a COPD assessment test (CAT) and an asthma control questionnaire (ACQ) were carried out 0, 4, and 8 weeks after randomization.

Results

A total of 19 patients with stable ACO (19 males and no females) with a mean age of 70.7 ± 7.6 years (± standard deviation, SD; range 55-83 years) participated in this study. All patients were ex-smokers with a smoking history of 63.1 ± 41.1 pack-years (± SD). Mean values for inspiratory capacity (IC), an index of hyperinflation of the lung that causes exertional dyspnea and reduced exercise, were 1.93 L (± 0.47 L) after the run-in, 1.85 L (± 0.51 L) after the BUD/FORM dual therapy period and 2.11 L (± 0.58 L) after the BUD/GLY/FORM triple therapy period. IC values after the BUD/GLY/FORM triple therapy were significantly higher than those after the run-in (p < 0.02). FeNO values, ACQ, and CAT scores were not significantly different among the run-in, wash-out, and triple-therapy periods.

Conclusion

The present pilot study showed that triple therapy with BUD/GLY/FORM results in an improvement in lung function parameters including IC, indicating the potential value of triple therapy as standard treatment for ACO.

Advances in asthma, asthma-COPD overlap, and related biologics in 2018

Over the past year, numerous important advances in our understanding of multiple aspects of asthma, ranging from disease pathogenesis to epidemiology to therapeutics, have been reported. This review is a compilation of highlights from articles published largely in the Journal of Allergy and Clinical Immunology and supplemented by articles published elsewhere that have substantially advanced the fields of asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap and biologic therapies for these disorders. The intention of this article is not to provide a comprehensive review but rather to focus on several areas that have developed quickly and/or received extensive attention from our readers.

Eosinophil Inflammation and Hyperresponsiveness in the Airways as Phenotypes of COPD, and Usefulness of Inhaled Glucocorticosteroids

Background: The differential diagnosis in persistent airway limitation is sometimes not so clear in older adults. Airway eosinophilia and airway hyperresponsiveness may develop in some cases with chronic obstructive lung disease (COPD), independent of asthma. However, little is known about clinical significance of these phenotypes of COPD in detail. Aims and objectives: This clinical study was designed to examine prevalence of airway eosinophilia and airway hyperresponsiveness in COPD who have no symptom and no past history of asthma, and to examine involvement of these pathophysiological features of asthma in the management and therapy for COPD. Methods: Sputum examination via qualitative and quantitative procedures was performed in stable COPD (GOLD 1-3). When sputum eosinophils were qualitatively (≥+) or quantitatively assessed (≥3%), ciclesonide (inhaled glucocorticosteroids) was added on bronchodilators. In cases with FEV₁ ≥ 70% of predicted values, acetylcholine provocation test was examined for assessment of airway hyperresponsiveness. Therapeutic effect was evaluated using spirometry and COPD assessment test (CAT). Results: Sputum eosinophils were observed in 65 (50.4%) of 129 subjects using qualitative analysis; in contrast, lower grade (>0%) and higher grade (≥3%) were observed in 15 (20.3%) and 25 (33.8%) of 74 subjects using quantitative analysis. Airway hyperresponsiveness developed in 46.9% of these subjects with sputum eosinophils. Exacerbations occurred much more frequently in lower-grade airway eosinophilia without ciclesonide than in higher-grade airway eosinophilia with ciclesonide. Airway hyperresponsiveness significantly increased frequency of exacerbations in COPD with both lower and higher grade in airway eosinophilia. Addition of ciclesonide to indacaterol markedly improved lung function (FEV₁, IC), CAT score, and reliever use in these subjects with airway eosinophilia determined by qualitative analysis. However, ciclesonide was less effective in improving these values in subjects with airway hyperresponsiveness than in those without airway hyperresponsiveness. Conclusions: Airway eosinophilia and airway hyperresponsiveness are complicated with 25-50% of COPD that have no symptom and history for asthma. These phenotypes of COPD are closely related to symptom stability and reactivity to glucocorticosteroids. These phenotypes may play key roles for advancement of the management and therapy of this disease.

Prevalence of COPD among workers with work-related asthma

Objective: Concurrent asthma and chronic obstructive pulmonary disease (COPD) diagnoses occur in 15%-20% of patients, and have been associated with worse health outcomes than asthma or COPD alone. Work-related asthma (WRA), asthma that is caused or made worse by exposures in the workplace, is characterized by poorly controlled asthma. The objective of this study was to assess the proportion of ever-employed adults (≥18 years) with current asthma who have been diagnosed with COPD, by WRA status.Methods: Data from 23 137 respondents to the 2012-2014 Behavioral Risk Factor Surveillance System Asthma Call-back Survey from 31 states and the District of Columbia were examined. Logistic regression was used to calculate adjusted prevalence ratios (PRs), examining six disjoint categories of WRA-COPD overlap with non-WRA/no COPD as the referent category.Results: An estimated 51.9% of adults with WRA and 25.6% of adults with non-WRA had ever been diagnosed with COPD. Adults with WRA/COPD were more likely than those with non-WRA/no COPD to have an asthma attack (PR = 1.77), urgent treatment for worsening asthma (PR = 2.85), an asthma-related emergency room visit (PR = 4.21), overnight stay in a hospital because of asthma (PR = 6.57), an activity limitation on 1-13 days (PR = 2.01) or ≥14 days (PR = 5.02), and very poorly controlled asthma (PR = 3.22).Conclusions: COPD was more frequently diagnosed among adults with WRA than those with non-WRA, and adults diagnosed with both WRA and COPD appear to have more severe adverse asthma outcomes than those with non-WRA and no COPD.

Inflammatory endotypes in COPD

Chronic obstructive pulmonary disease (COPD) is a major global health problem that is poorly treated by current therapies as it has proved difficult to treat the underlying inflammation, which is largely corticosteroid-resistant in most patients. Although rare genetic endotypes of COPD have been recognized, despite the clinical heterogeneity of COPD, it has proved difficult to identify distinct inflammatory endotypes. Most patients have increased neutrophils and macrophages in sputum, reflecting the increased secretion of neutrophil and monocyte chemotactic mediators in the lungs. However, some patients also have increased eosinophils in sputum and this may be reflected by increased blood eosinophils. Increased blood and sputum eosinophils are associated with more frequent exacerbations and predict a good response to corticosteroids in reducing and treating acute exacerbations. Eosinophilic COPD may represent an overlap with asthma but the mechanism of eosinophilia is uncertain as, although an increase in sputum IL-5 has been detected, anti-IL-5 therapies are not effective in preventing exacerbations. More research is needed to link inflammatory endotypes to clinical manifestations and outcomes in COPD and in particular to predict response to precision medicines.

Prediction of first acute exacerbation using COPD subtypes identified by cluster analysis

Purpose

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.

Patients and methods

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.

Results

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).

Conclusion

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: identification and optimal treatment

Asthma and chronic obstructive pulmonary disease (COPD) are both highly prevalent conditions that can coexist in the same individual: the so-called ‘asthma -COPD overlap’ (ACO). Its prevalence and prognosis vary widely depending on how ACO is defined in each publication, the severity of bronchial obstruction of patients included and the treatment they are receiving. Although there is a lack of evidence about the biology of ACO, the overlap of both diseases should express a mixture of a Th1 inflammatory pattern (characteristic of COPD) and a Th2 signature (characteristic of asthma). In this review we support a novel algorithm for ACO diagnosis proposed by the Spanish Respiratory Society (SEPAR), based on a sequential evaluation that considers: (a) the presence of chronic airflow limitation in a smoker or ex-smoker patient ⩾35 years old; (b) a current diagnosis of asthma; and (c) the existence of a very positive bronchodilator test (PBT; ⩾15% and ⩾400 ml) or the presence of eosinophilia in blood (⩾300 eosinophils/μl). This algorithm can identify those patients who may benefit from a treatment with inhaled corticosteroids (ICSs) and maybe from biological drugs in a near future. In addition, it is easily applicable in clinical practice. The major disadvantage is that it groups patients with very different characteristics under the ACO’s umbrella. In view of this heterogeneity, we recommend a strategy of defining specific and measurable therapeutic objectives for every single patient and identifying the traits that can be treated to achieve those objectives.

Validated methods to identify patients with asthma-COPD overlap in healthcare databases: a systematic review protocol

INTRODUCTION

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is characterised by patients presenting symptoms of both asthma and COPD. Many efforts have been made to validate different methods of identifying asthma-COPD overlap cases based on symptoms, spirometry and medical history in epidemiological studies using healthcare databases. There are various coding algorithm strategies that can be used and selection depends on targeted validation. The primary objectives of this systematic review are to identify validated methods (or algorithms) that identify patients with ACO from healthcare databases and summarise the reported validity measures of these methods.

METHODS

MEDLINE, EMBASE databases and the Web of Science will be systematically searched by using appropriate search strategies that are able to identify studies containing validated codes and algorithms for the diagnosis of ACO in healthcare databases published, in English, before October 2018. For each selected study, we require the presence of at least one test measure (eg, sensitivity, specificity etc). We will also include studies, in which the validated algorithm is compared with an external reference standard such as questionnaires completed by patients or physicians, medical charts review, manual review or an independent second database. For all selected studies, a uniform table will be created to summarise the following vital information: name of author, publication year, country, data source, population, clinical outcome, algorithms, reference standard method of validation and characteristics of the test measure used to determine validity.

PROSPERO REGISTRATION NUMBER

CRD42018087472.

Longitudinal comparison of outcomes in patients with smoking-related asthma-COPD overlap and in non-smoking asthmatics with incomplete reversibility of airway obstruction

Background

There is a need to characterize the impact of the smoking status on the clinical course of asthmatics with incomplete reversibility of airway obstruction (IRAO).

Objective

To compare longitudinal health care use, symptom control, and medication needs between smoking and non-smoking asthmatics with IRAO.

Materials and methods

This was a 12-month follow-up of a cross-sectional study comparing asthmatics with IRAO according to their tobacco exposure. One group had a tobacco exposure ≥20 pack-years and was considered to have asthma-COPD overlap (ACO) and the second with a past tobacco exposure <5 pack-years was considered as non-smokers with IRAO (NS-IRAO). Study participants were contacted by telephone every 3 months to document exacerbation events and symptom control.

Results

A total of 111 patients completed all follow-up telephone calls: 71 ACO and 40 NS-IRAO. The number of exacerbations per patient over the 12-month follow-up was similar in both groups. However, ACO reported worse symptom control throughout the follow-up as compared to NS-IRAO, although no significant variations within a group were observed over the study period.

Conclusion

Although asthma control scores were poorer in ACO patients over 1 year compared to NS-IRAO, exacerbation rate was similar and low in both groups of asthmatics. These observations suggest that poorer asthma control in ACO was not driven by the number of exacerbations but may reflect the influence of chronic airway changes related to the COPD component.

Practical Guide to the Identification and Diagnosis of Asthma-COPD Overlap (ACO)

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality around the world. COPD is characterised by a heterogeneous clinical presentation and prognosis which may vary according to the clinical phenotype. One of the phenotypes of COPD most frequently studied is the asthma-COPD overlap (ACO), however, there are no universally accepted diagnostic criteria for ACO. It is recognised that the term ACO includes patients with clinical features of both asthma and COPD, such as more intense eosinophilic bronchial inflammation, more severe respiratory symptoms and more frequent exacerbations, but in contrast, it is associated with a better prognosis compared to COPD. More importantly, ACO patients show better response to inhaled corticosteroid treatment than other COPD phenotypes. The diagnosis of ACO can be difficult in clinical practice, and the identification of these patients can be a challenge for non-specialized physicians. We describe how to recognise and diagnose ACO based on a recently proposed Spanish algorithm and by the analysis of three clinical cases of patients with COPD. The diagnosis of ACO is based on the diagnosis of COPD (chronic airflow obstruction in an adult with significant smoking exposure), in addition to a current diagnosis of asthma and/or signficant eosinophilia.

Physiologic Insights from the COPD Genetic Epidemiology Study

COPD Genetic Epidemiology Study (COPDGene^®) manuscripts have provided important insights into chronic obstructive pulmonary disease (COPD) pathophysiology and outcomes, including a better understanding of COPD phenotypes relating computed tomography (CT) anatomic data to spirometric and patient-reported outcomes. Spirometry significantly underdiagnoses smoking-induced lung disease, and there is a marked improvement in sensitivity and specificity with CT scanning. This review also highlights the COPDGene^® exploration of specific spirometry phenotypes (e.g.,PRISm), contributors to spirometric decline, composite physiologic measures, asthma-COPD overlap (ACO) syndrome, consequences of bronchodilator responsiveness, newer methods to assess small airway dysfunction, and spirometric correlates of comorbid diseases such as obesity and diabetes.

Prevalence and features of asthma-COPD overlap in the United States 2007-2012

BACKGROUND

Perceived to be distinct, asthma and chronic obstructive pulmonary disease (COPD) can co-exist and potentially have a worse prognosis than the separate diseases. Yet, little is known about the exact prevalence and the characteristics of the Asthma-COPD overlap (ACO) in the US population.

AIMS

To determine ACO prevalence in the United States, identify ACO predictors, examine ACO association with asthma and COPD severity, and describe distinctive spirometry and laboratory features of ACO.

METHODS

Data on adult participants to the National Health and Nutrition Examination Surveys conducted from 2007 to 2012 was analyzed. ACO was defined as current asthma and post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) <0.7.

RESULTS

Overall, 7,570 participants representing 98.58 million Americans were included in our study. From 2007 to 2012, the crude and age-standardized ACO prevalence were, respectively, 0.96% (95% CI: 0.65%-1.26%) and 1.05% (0.74%-1.37%). In asthma, ACO predictors included older age, male gender, and smoking. In COPD, ACO predictors were non-Hispanic Black race/ethnicity and obesity. ACO was associated with increased ER visits for asthma (OR = 3.46, 95% CI: 1.48-8.06]) and oxygen therapy in COPD (OR = 11.17, 95% CI: 5.17-24.12]). In spirometry, FEV1 and peak expiratory flow were lower in ACO than in asthma or COPD alone.

CONCLUSION

Age-adjusted prevalence of ACO in the United States was 1.05% in 2007-2012, representing 0.94 (95% CI: 0.62-1.26) million Americans. It is much lower than previously reported. The overlap was associated with higher asthma and COPD severity as well as decreased lung function compared with COPD or asthma alone.

Understanding low COPD exacerbation rates in Japan: a review and comparison with other countries

COPD is associated with significant morbidity and is one of the leading causes of death worldwide. Periods of exacerbation, the acute worsening of symptoms, are interspersed throughout the disease's natural history and can result in increased treatment burden and hospitalization for patients with COPD. The frequency of exacerbations varies between countries, with both epidemiological studies and randomized controlled trials (RCTs) showing significant differences in observed prevalence rates. Differences in study design and the healthcare setting are likely to contribute to differences in exacerbation frequency, however the perceived rate of exacerbations in Japan is currently lower then the rest of the world. This review identified nine cohort studies and five RCTs that reported COPD annual exacerbation rates in Japan in the ranges of 0.1-2.1 and 0.33-1.79, respectively. The difference in exacerbation rate between studies appeared greater than the difference between Japan and Western countries, likely because of disparities between settings, design, and inclusion criteria. Of these, only one (Understanding the Long-Term Impacts of Tiotropium) had uniform inclusion criteria across different regions. This study found that the annual rate of exacerbation events per patient in Japan was 0.61, compared with 0.85 worldwide in the placebo groups. This review summarizes the published rates of COPD exacerbations in Japan and the rest of the world and explores the hypotheses as to why rates in Japan might be lower than other countries. These include access to medical care, variance in the associated morbidity profile, environmental factors, diagnostic crossover with related diseases, and differences in study design (including the underreporting of COPD exacerbations in Japan). Understanding the reasons why COPD exacerbation rates appear lower in Japan could help clinicians to recognize and modify treatment behaviors, which may lead to improved patient outcomes in all populations.

Epidemiology and risk factors of asthma-chronic obstructive pulmonary disease overlap in low- and middle-income countries

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents the confluence of bronchial airway hyperreactivity and chronic airflow limitation and has been described as leading to worse lung function and quality of life than found with either singular disease process.

OBJECTIVE

We aimed to describe the prevalence and risk factors for ACO among adults across 6 low- and middle-income countries (LMICs).

METHODS

We compiled cross-sectional data for 11,923 participants aged 35 to 92 years from 4 population-based studies in 12 settings. We defined COPD as postbronchodilator FEV₁/forced vital capacity ratio below the lower limit of normal, asthma as wheeze or medication use in 12 months or self-reported physician diagnosis, and ACO as having both.

RESULTS

The prevalence of ACO was 3.8% (0% in rural Puno, Peru, to 7.8% in Matlab, Bangladesh). The odds of having ACO were higher with household exposure to biomass fuel smoke (odds ratio [OR], 1.48; 95% CI, 0.98-2.23), smoking tobacco (OR, 1.28 per 10 pack-years; 95% CI, 1.22-1.34), and having primary or less education (OR, 1.35; 95% CI, 1.07-1.70) as compared to nonobstructed nonasthma individuals. ACO was associated with severe obstruction (FEV₁ %, <50; 31.6% of ACO vs 10.9% of COPD alone) and severe spirometric deficits compared with participants with asthma (-1.61 z scores FEV₁; 95% CI, -1.48 to -1.75) or COPD alone (-0.94 z scores; 95% CI, -0.78 to -1.10).

CONCLUSIONS

ACO may be as prevalent and more severe in LMICs than has been reported in high-income settings. Exposure to biomass fuel smoke may be an overlooked risk factor, and we favor diagnostic criteria for ACO that include environmental exposures common to LMICs.

Determinants of incident asthma-COPD overlap: a prospective study of 55,110 middle-aged adults

Background and aim

Knowledge of the impact of social determinants driving asthma– chronic obstructive pulmonary disease overlap (ACO) is lacking. Our objective was to identify determinants of incident ACO.

Methods

A total of 55,053 adults (50–64 years) enrolled in the Danish Diet, Cancer, and Health cohort (1993–97) was followed in the National Patient Registry for admissions for asthma (DJ45–46) and chronic obstructive pulmonary disease (COPD; DJ40–44) and vital status. Incident ACO was defined as at least one hospital admission for both asthma and COPD (different time points, one after baseline). Detailed case history was obtained at baseline. Cox proportional hazards model was used to examine associations between possible determinants and incident ACO, in terms of hazard ratio (HR) and 95% confidence interval (CI).

Results

During follow-up, 561 incident cases of ACO were identified. Age (HR 4.4, 95% CI 3.3–5.9, age group 60–65 years), current smoking (HR 3.6, 95% CI 2.8–4.6), unemployment (HR 1.5, 95% CI 1.2–1.8), and being divorced (HR 1.5, 95% CI 1.2–1.9) determined a higher risk of incident ACO, whereas the opposite was found for leisure-time physical activity (HR 0.7, 95% CI 0.6–0.8) and high educational level (HR 0.7, 95% CI 0.5–0.9). In contrast to ACO, preexisting myocardial infarction (MI; HR 1.5, 95% CI 1.2–1.8) and stroke (HR 1.5, 95% CI 1.2–1.9) were associated with a higher risk of COPD.

Conclusion

Incident ACO is to a large extent determined by factors related to lifestyle and socioeconomic status.

Overlap of Asthma and Chronic Obstructive Pulmonary Disease in Patients in the United States: Analysis of Prevalence, Features, and Subtypes

Background

Although asthma and chronic obstructive pulmonary disease (COPD) are clinically distinct diseases, they represent biologically diverse and overlapping clinical entities and it has been observed that they often co-occur. Some research and theorizing suggest there is a common comorbid condition termed asthma-chronic obstructive pulmonary disease overlap (ACO). However, the existence of ACO is controversial.

Objective

The objective of this study is to describe patient characteristics and estimate prevalence, health care utilization, and costs of ACO using claims-based diagnoses confirmed with medical record information.

Methods

Eligible patients were commercial US health plan enrollees; ≥40 years; had asthma, COPD, or ACO; ≥3 prescription fills for asthma/COPD medications; and ≥2 spirometry tests. Records for a random sample of 5000 patients with ACO were reviewed to validate claims-based diagnoses.

Results

The estimated ACO prevalence was 6% (estimated 10,250/183,521) among 183,521 full study patients. In the claims-based cohorts, the comorbidity burden for ACO was greater versus asthma but similar to COPD cohorts. Medication utilization was higher in ACO versus asthma and COPD. Mean total health care costs were significantly higher for ACO versus asthma but similar to COPD. In confirmed diagnoses cohorts, mean total health care costs (medical plus pharmacy) were lower for ACO versus COPD but similar to asthma (US $20,035; P=.56). Among confirmed cases, where there was medical record evidence, smoking history was higher in ACO (300/343, 87.5%) versus asthma cohorts (100/181, 55.2%) but similar to COPD (68/84, 81%).

Conclusions

ACO had more comorbidities, medication utilization, and costs than patients with asthma or COPD but differences were not seen after confirmation with medical records.

Neutrophil gelatinase-associated lipocalin as a complementary biomarker for the asthma-chronic obstructive pulmonary disease overlap

Background

There is no standardized definition of the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Although the blood eosinophil count is regarded as a biomarker for identifying ACO, it has no distinct value. This study aimed to measure plasma levels of neutrophil gelatinase-associated lipocalin (NGAL), a potential biomarker for distinguishing between ACO and non-ACO COPD.

Methods

We used the Korean cohort in the COPD in dusty area (CODA) study which included 137 subjects with COPD confirmed by spirometry. We defined ACO by a positive bronchodilator response (forced expiratory volume in 1 s, FEV₁ >12% and >200 mL from baseline) or based on a previous history of asthma. Plasma levels of NGAL were determined by enzyme immunoassay.

Results

Among the 137 subjects, 77 were ACO and 60 were non-ACO COPD. Overall, the plasma NGAL levels were 15.9±7.9 and 15.6±6.6 ng/mL for non-ACO and ACO subjects respectively, and not significantly different. However, NGAL levels were significantly higher in female subjects with ACO (17.0±6.4 vs. 11.1±4.5, P=0.01). In female subjects, NGAL levels showed a good predictive ability to discriminate between ACO and non-ACO COPD [area under the receiver operating characteristic curve (AUROC), 0.77]; the predictive ability was similar to that of the blood eosinophil count (AUROC, 0.79). There was a higher probability of discriminating ACO from non-ACO among subjects in the highest tertile of NGAL levels (odds ratio, 1.72; 95% confidence interval, 0.69-4.28; P for trend =0.01).

Conclusions

NGAL levels were significantly higher in ACO compared to non-ACO COPD in female subjects. After adjusting for gender as a confounding factor, the ability to distinguish ACO was better at higher levels of NGAL.

Childhood measles contributes to post-bronchodilator airflow obstruction in middle-aged adults: A cohort study

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) has potential origins in childhood but an association between childhood measles and post-bronchodilator (BD) airflow obstruction (AO) has not yet been shown. We investigated whether childhood measles contributed to post-BD AO through interactions with asthma and/or smoking in a non-immunized middle-aged population.

METHODS

The population-based Tasmanian Longitudinal Health Study (TAHS) cohort born in 1961 (n = 8583) underwent spirometry in 1968 before immunization was introduced. A history of childhood measles infection was obtained from school medical records. During the fifth decade follow-up (n = 5729 responses), a subgroup underwent further lung function measurements (n = 1389). Relevant main associations and interactions by asthma and/or smoking on post-BD forced expiratory volume in 1 s/forced vital capacity (FEV₁ /FVC; continuous variable) and AO (FEV₁ /FVC < lower limit of normal) were estimated by multiple regression.

RESULTS

Sixty-nine percent (n = 950) had a history of childhood measles. Childhood measles augmented the combined adverse effect of current clinical asthma and smoking at least 10 pack-years on post-BD FEV₁ /FVC ratio in middle age (z-score: -0.70 (95% CI: -1.1 to -0.3) vs -1.36 (-1.6 to -1.1), three-way interaction: P = 0.009), especially for those with childhood-onset asthma. For never- and ever-smokers of <10 pack-years who had current asthma symptoms, compared with those without childhood measles, paradoxically, the odds for post-BD AO was not significant in the presence of childhood measles (OR: 12.0 (95% CI: 3.4-42) vs 2.17 (0.9-5.3)).

CONCLUSION

Childhood measles infection appears to compound the associations between smoking, current asthma and post-BD AO. Differences between asthma subgroups provide further insight into the complex aetiology of obstructive lung diseases for middle-aged adults.

Considerations for the Correct Diagnosis of COPD and Its Management With Bronchodilators

COPD is often misdiagnosed and inappropriately treated in many patients. COPD is a distinct disease from adult-onset asthma; however, some patients with COPD may present with several forms of airway disease described as asthma-COPD overlap (ACO). Bronchodilators and inhaled corticosteroids (ICS) both have a place in standard maintenance treatment of COPD and asthma; however, recommendations for use differ widely. In patients with COPD, long-acting bronchodilators are effective initial monotherapy treatment, whereas ICS monotherapy is recommended as initial treatment in patients with asthma. Clinicians need to be confident in their diagnosis to ensure that correct treatment is given because misguided treatment decisions can result in significantly increased safety risks for patients. This review highlights the differences in diagnosis and treatment between COPD, asthma, and ACO and discusses the data supporting guideline recommendations for use of bronchodilators in COPD treatment in contrast to asthma or ACO.

Asthma Is a Risk Factor for Respiratory Exacerbations Without Increased Rate of Lung Function Decline: Five-Year Follow-up in Adult Smokers From the COPDGene Study

BACKGROUND

Previous investigations in adult smokers from the COPDGene Study have shown that early-life respiratory disease is associated with reduced lung function, COPD, and airway thickening. Using 5-year follow-up data, we assessed disease progression in subjects who had experienced early-life respiratory disease. We hypothesized that there are alternative pathways to reaching reduced FEV₁ and that subjects who had childhood pneumonia, childhood asthma, or asthma-COPD overlap (ACO) would have less lung function decline than subjects without these conditions.

METHODS

Subjects returning for 5-year follow-up were assessed. Childhood pneumonia was defined by self-reported pneumonia at < 16 years. Childhood asthma was defined as self-reported asthma diagnosed by a health professional at < 16 years. ACO was defined as subjects with COPD who self-reported asthma diagnosed by a health-professional at ≤ 40 years. Smokers with and those without these early-life respiratory diseases were compared on measures of disease progression.

RESULTS

Follow-up data from 4,915 subjects were examined, including 407 subjects who had childhood pneumonia, 323 subjects who had childhood asthma, and 242 subjects with ACO. History of childhood asthma or ACO was associated with an increased exacerbation frequency (childhood asthma, P < .001; ACO, P = .006) and odds of severe exacerbations (childhood asthma, OR, 1.41; ACO, OR, 1.42). History of childhood pneumonia was associated with increased exacerbations in subjects with COPD (absolute difference [β], 0.17; P = .04). None of these early-life respiratory diseases were associated with an increased rate of lung function decline or progression on CT scans.

CONCLUSIONS

Subjects who had early-life asthma are at increased risk of developing COPD and of having more active disease with more frequent and severe respiratory exacerbations without an increased rate of lung function decline over a 5-year period.

TRIAL REGISTRY

ClinicalTrials.gov; No. NCT00608764; https://clinicaltrials.gov.

Therapeutic approaches to asthma-chronic obstructive pulmonary disease overlap

INTRODUCTION

Patients with features of both asthma and chronic obstructive pulmonary disease (COPD) ('asthma-COPD overlap') experience greater symptom burden and higher risk of adverse health outcomes than those with asthma or COPD alone. However, virtually no pharmacotherapy studies have been performed in this overlap population, leading to confusion amongst clinicians regarding therapeutic approaches. Areas covered: A pragmatic approach is suggested to identify patients with typical asthma, typical COPD, and those with overlap features. Interim clinical guidance on the treatment of asthma-COPD overlap is provided, acknowledging that these recommendations are based on expert opinion given the paucity of available evidence. Expert commentary: There is an urgent need for new studies in patients with asthma-COPD overlap to evaluate the efficacy and safety of existing pharmacotherapeutic options. Multiple underlying mechanisms are likely to contribute to the development of asthma-COPD overlap and a greater understanding of these mechanisms may allow a personalised approach to therapy in the future.

Exacerbations and health care resource utilization in patients with airflow limitation diseases attending a primary care setting: the PUMA study

Background

COPD, asthma, and asthma–COPD overlap increase health care resource consumption, predominantly because of hospitalization for exacerbations and also increased visits to general practitioners (GPs) or specialists. Little information is available regarding this in the primary care setting.

Objectives

To describe the prevalence and number of GP and specialist visits for any cause or due to exacerbations in patients with COPD, asthma, and asthma–COPD overlap.

Methods

COPD was defined as post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC) ratio <0.70; asthma was defined as prior medical diagnosis, wheezing in the last 12 months, or wheezing plus reversibility (post-bronchodilator FEV₁ or FVC increase ≥200 mL and ≥12%); asthma–COPD overlap was defined as post-bronchodilator FEV₁/FVC <0.70 plus prior asthma diagnosis. Health care utilization was evaluated as GP and/or specialist visits in the previous year.

Results

Among the 1,743 individuals who completed the questionnaire, 1,540 performed acceptable spirometry. COPD patients had a higher prevalence of any medical visits to any physician versus those without COPD (37.2% vs 21.8%, respectively) and exacerbations doubled the number of visits. The prevalence of any medical visits to any physician was also higher in asthma patients versus those without asthma (wheezing: 47.2% vs 22.7%; medical diagnosis: 54.6% vs 21.6%; wheezing plus reversibility: 46.2% vs 23.8%, respectively). Asthma patients with exacerbations had twice the number of visits versus those without an exacerbation. The number of visits was higher (2.8 times) in asthma–COPD overlap, asthma (1.9 times), or COPD (1.4 times) patients versus those without these respiratory diseases; the number of visits due to exacerbation was also higher (4.9 times) in asthma–COPD overlap, asthma (3.5 times), and COPD (3.8 times) patients.

Conclusion

COPD, asthma, and asthma–COPD overlap increase the prevalence of medical visits and, therefore, health care resource utilization. Attempts to reduce health care resource use in these patients require interventions aimed at preventing exacerbations.

Comorbidome, Pattern, and Impact of Asthma-COPD Overlap Syndrome in Real Life

BACKGROUND

Asthma-COPD overlap syndrome (ACOS) has been described and acknowledged as a distinct clinical entity; however, its characteristics in daily clinical practice are largely unknown. The aim of this study was to identify the prevalence of ACOS in the real-life population, its pattern of comorbidities, and its impact on hospitalization risk.

METHODS

Data for this retrospective cohort study were extracted from the Majorca Real-Life Investigation in COPD and Asthma cohort, including primary care, hospitalization, and pharmacy data from the Balearic Islands, Spain. Patients who had received a physician-confirmed diagnosis of both asthma and COPD were identified as having ACOS and compared with a COPD-only population. In subanalyses, more stringent diagnostic criteria (Global Initiative for Asthma-Global Initiative for Chronic Obstructive Lung Disease) were applied. The pattern and impact of comorbidities on all-cause hospitalization were compared by multivariate logistic regression.

RESULTS

In total, 5,093 patients with ACOS (prevalence, 5.55 per 1,000 inhabitants) were compared with 22,778 patients with COPD (30.40 per 1,000 inhabitants). Patients with ACOS were more frequently female (53.4%) than were patients with COPD (30.8%), younger (ACOS, 64.0 years; COPD, 65.8 years), and differed by nonsmoking status (ACOS, 41.4%; COPD, 22.1%) (all, P < .001). In adjusted analyses, allergic rhinitis (OR, 1.81; 95% CI, 1.63-2.00), anxiety (OR, 1.18; 95% CI, 1.10-1.27), gastroesophageal reflux disease (OR, 1.18; 95% CI, 1.04-1.33), and osteoporosis (OR, 1.14; 95% CI, 1.04-1.26) were more frequent in ACOS than COPD. In contrast, chronic kidney disease (OR, 0.79; 95% CI, 0.66-0.95) and ischemic heart disease (OR, 0.88; 95% CI, 0.79-0.98) were less frequent. In patients with ACOS, cardiovascular diseases showed the strongest association with hospitalization.

CONCLUSIONS

ACOS is prevalent in the general population, and it affects to a large extent females with less smoking exposure compared with patients with COPD only. Cardiovascular comorbidities in particular contribute most to overall hospitalization risk of patients with ACOS.