Prospective Real-World Analysis of Asthma Patients With Preserved and Reduced Physical Activity

BACKGROUND

Asthma is a highly heterogeneous airway disease, and the clinical characteristics of patients with asthma with preserved and reduced physical activity are poorly understood.

OBJECTIVE

We aimed to investigate the risk factors and clinical phenotypes associated with reduced physical activity in a wide range of patients with asthma.

METHODS

We conducted a prospective observational study of 138 patients with asthma, including patients with asthma without chronic obstructive pulmonary disease (COPD) (n = 104) and asthma-COPD overlap (n = 34), and 42 healthy controls. Physical activity levels were measured for 2 weeks using a triaxial accelerometer at baseline and 1 year later.

RESULTS

Higher eosinophils and body mass index (BMI) were associated with reduced physical activity in patients with asthma without COPD. Cluster analysis of asthma without COPD revealed 4 asthma phenotypes. We identified a cluster with preserved physical activity (n = 43) that was characterized by good symptom control and lung function and included a high proportion of biologics users (34.9%). Multivariate regression analysis revealed that patients with late-onset eosinophilic (n = 21), high-BMI noneosinophilic (n = 14), and symptom-predominant asthma phenotypes (n = 26) had lower levels of physical activity than controls. Patients with asthma-COPD overlap also had significantly lower physical activity levels than controls. Similar trends in physical activity levels were observed in each asthma group at 1-year follow-up.

CONCLUSION

This study showed the clinical features of patients with asthma with preserved and reduced physical activity. Reduced physical activity was observed in various asthma phenotypes and in asthma-COPD overlap.

Prevalence and impact of airway diseases on clinical outcomes in idiopathic pulmonary fibrosis

BACKGROUND/AIMS

The prevalence and effects of airway diseases, including asthma, eosinophilic bronchitis (EB), chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) have not been thoroughly studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to evaluate the prevalence of airway diseases in patients with IPF and to identify the differences in symptoms based on the presence of airway diseases.

METHODS

This single-institution prospective cohort study was conducted from June 2017 to September 2018, at the Seoul National University Hospital. Spirometry with bronchodilator, methacholine bronchial provocation test, induced sputum with eosinophil stain, and exhaled nitric oxide were performed to confirm the presence of airway disease. The modified Medical Research Council (mMRC) dyspnea scale, COPD assessment test (CAT), St. George's Respiratory Questionnaire (SGRQ), EuroQol-5 dimension (EQ-5D) index, and cough-specific quality of life questionnaire (CQLQ) data were collected to assess symptom severity.

RESULTS

Total 147 patients with IPF were screened, and 70 patients were analyzed. The prevalence of airway diseases in the participants was as follows: 5.0% had COPD, 1.7% had asthma, 3.3% had ACO, and 1.7% had EB. The mMRC, CAT, SGRQ, EQ-5D, and CQLQ scores did not differ regardless of combined airway disease. After 3 months, the SGRQ (p = 0.028) and CQLQ (p = 0.030) scores were significantly higher in patients with airway disease than in those without.

CONCLUSION

The prevalence of airway diseases in patients with IPF is low, but when airway diseases are accompanied by IPF, symptom severity and quality of life may worsen rapidly.

Visual and Quantitative Assessments of Regional Xenon-Ventilation Using Dual-Energy CT in Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome: A Comparison with Chronic Obstructive Pulmonary Disease

Objective

To assess the regional ventilation in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) using xenon-ventilation dual-energy CT (DECT), and to compare it to that in patients with COPD.

Materials and Methods

Twenty-one patients with ACOS and 46 patients with COPD underwent xenon-ventilation DECT. The ventilation abnormalities were visually determined to be 1) peripheral wedge/diffuse defect, 2) diffuse heterogeneous defect, 3) lobar/segmental/subsegmental defect, and 4) no defect on xenon-ventilation maps. Emphysema index (EI), airway wall thickness (Pi10), and mean ventilation values in the whole lung, peripheral lung, and central lung areas were quantified and compared between the two groups using the Student's t test.

Results

Most patients with ACOS showed the peripheral wedge/diffuse defect (n = 14, 66.7%), whereas patients with COPD commonly showed the diffuse heterogeneous defect and lobar/segmental/subsegmental defect (n = 21, 45.7% and n = 20, 43.5%, respectively). The prevalence of ventilation defect patterns showed significant intergroup differences (p < 0.001). The quantified ventilation values in the peripheral lung areas were significantly lower in patients with ACOS than in patients with COPD (p = 0.045). The quantified Pi10 was significantly higher in patients with ACOS than in patients with COPD (p = 0.041); however, EI was not significantly different between the two groups.

Conclusion

The ventilation abnormalities on the visual and quantitative assessments of xenon-ventilation DECT differed between patients with ACOS and patients with COPD. Xenon-ventilation DECT may demonstrate the different physiologic changes of pulmonary ventilation in patients with ACOS and COPD.

Radiographic Evidence of Sinonasal Inflammation in Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome: An Underrecognized Association

BACKGROUND

Sinonasal inflammation on both clinical examinations and imaging significantly impacts both asthma and chronic obstructive pulmonary disease (COPD).

OBJECTIVE

The objective of this study was to examine the association between sinonasal inflammation and asthma-COPD overlap syndrome (ACOS).

METHODS

A total of 112 patients with a ratio of forced expiratory volume in 1 s to forced vital capacity of less than 70% were enrolled. COPD, asthma, and ACOS were clinically diagnosed according to the 2014 Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease guidelines. Sinonasal inflammatory condition was evaluated using sinus computed tomography, and its severity was assessed according to the Lund-Mackay staging (LMS) system. Ethmoid sinus-dominant shadow was defined as the presence of greater LMS scores for the anterior and posterior ethmoid sinuses than for the maxillary sinus.

RESULTS

COPD, asthma, and ACOS were diagnosed in 55 (49.1%), 39 (34.8%), and 18 patients (16.1%), respectively. The frequency of radiographic evidence of sinonasal inflammation in patients with COPD, asthma, ACOS was 60.0%, 94.9%, and 72.2%, respectively. Patients with ACOS and COPD had only mild radiographic evidence of sinonasal inflammation (LMS score, 1-7), whereas moderate (LMS score, 8-11) and severe (LMS score, ≥12) radiographic evidence of sinonasal inflammation were detected only in patients with asthma. Furthermore, the frequency of ethmoid sinus-dominant shadow was significantly higher in patients with asthma than in those with COPD and ACOS.

CONCLUSIONS

Radiographic evidence of sinonasal inflammation was a common comorbidity in ACOS. Future studies are required to examine the role of sinonasal inflammation in ACOS.

Asthma-chronic obstructive pulmonary disease overlap syndrome: A diagnostic puzzle for the clinicians

Although asthma and chronic obstructive pulmonary disease (COPD) are distinct airway diseases characterized by chronic inflammation, in some cases distinguishing between them is puzzling. For example, chronic smoking leads asthmatic inflammation to a differentiated pattern resembling the COPD inflammation, and in some cases to fixed obstruction as in COPD, and on the other hand, few COPD patients may present with airway reversibility. ACOS is the condition sharing features encountered both in asthma and COPD. Asthma-COPD overlap syndrome (ACOS) represents a diagnostic challenge in the clinical practice, since there is lack of specific indicators to distinguish it from asthma or COPD, and moreover, genetic risk factors, underlying pathology and molecular pathways, clinical characteristics, therapeutic interventions, response to treatment and prognosis are poorly described. The management of ACOS is recommended to be individualized and should target on the maximum effectiveness with the least side effects. Combination therapy with ICS/LABA or LAMA, or newly developed specific anti-eosinophil therapies and treatments specifically targeting neutrophils might be of relevance in the management of ACOS, but studies are needed in order to assess the response and prognosis. Based on the current knowledge about ACOS thus far, it would be recommended that we approached chronic obstructive airway disease rather by describing than by classifying the disease; this would allow us to have a picture that better describes the disease and to implement an individualized therapeutic approach, according to the custom phenotype. Nevertheless, more studies are needed in order to clarify several important issues with regard to ACOS, such as the genetic risk factors for developing ACOS, the links between genotype and phenotype, the molecular pathways and underlying mechanisms of ACOS, the identification of possible specific biomarkers for diagnosis and targeted treatment, the optimal therapeutic interventions, and finally, the prognosis of ACOS.

Understanding asthma-chronic obstructive pulmonary disease overlap syndrome

Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a loosely-defined clinical entity referring to patients who exhibit characteristics of both asthma and chronic obstructive pulmonary disease (COPD). Clinical definitions and classifications for ACOS vary widely, which impacts our understanding of prevalence, diagnosis and treatment of the condition. This literature review was therefore conducted to characterize the prevalence of ACOS and the effect of different disease definitions on these estimates, as this has not previously been explored. From an analysis of English language literature published from 2000 to 2014, the estimated prevalence of ACOS ranges from 12.1% to 55.2% among patients with COPD and 13.3%-61.0% among patients with asthma alone. This variability is linked to differences in COPD and asthma diagnostic criteria, disease ascertainment methods (spirometry-based versus clinical or symptom-based diagnoses and claims data), and population characteristics including age, gender and smoking. Understanding the reasons for differences in prevalence estimates of ACOS across the literature may help guide decision making on the most appropriate criteria for defining ACOS and aid investigators in designing future ACOS clinical studies aimed at effective treatment.