Comparative prevalence of co-morbidities in smoking and non-smoking asthma patients with incomplete reversibility of airway obstruction, non-smoking asthma patients with complete reversibility of airway obstruction and COPD patients

Analysis of comorbidities and multimorbidity in adult patients in the International Severe Asthma Registry

BACKGROUND

Investigation for the presence of asthma comorbidities is recommended by the Global Initiative for Asthma because their presence can complicate asthma management.

OBJECTIVE

To understand the prevalence and pattern of comorbidities and multimorbidity in adults with severe asthma and their association with asthma-related outcomes.

METHODS

This was a cross-sectional study using data from the International Severe Asthma Registry from 22 countries. A total of 30 comorbidities were identified and categorized a priori as any of the following: (1) potentially type 2-related comorbidities, (2) potentially oral corticosteroid (OCS)-related comorbidities, or (3) comorbidities mimicking or aggravating asthma. The association between comorbidities and asthma-related outcomes was investigated using multivariable models adjusted for country, age at enrollment, and sex (ie male or female).

RESULTS

Of the 11,821 patients, 69%, 67%, and 55% had at least 1 potentially type 2-related, potentially OCS-related, or mimicking or aggravating comorbidities, respectively; 57% had 3 or more comorbidities, and 33% had comorbidities in all 3 categories. Patients with allergic rhinitis, nasal polyposis, and chronic rhinosinusitis experienced 1.12 (P = .003), 1.16 (P < .001), and 1.29 times (P < .001) more exacerbations per year, respectively, than those without. Patients with nasal polyposis and chronic rhinosinusitis were 40% and 46% more likely (P < .001), respectively, to have received long-term (LT) OCS. All assessed potential OCS-related comorbidities (except obesity) were associated with a greater likelihood of LTOCS use (odds ratios [ORs]: 1.23-2.77) and, except for dyslipidemia, with a greater likelihood of uncontrolled asthma (ORs: 1.29-1.68). All mimicking or aggravating comorbidities assessed were associated with more exacerbations (1.24-1.68 times more), all (except bronchiectasis) with increased likelihood of uncontrolled asthma (ORs: 1.57-1.81), and all (except chronic obstructive pulmonary disease) with increased likelihood of LTOCS use (ORs: 1.37-1.57). A greater number of comorbidities was associated with worse outcomes.

CONCLUSION

In a global study, comorbidity or multimorbidity is reported in most adults with severe asthma and is associated with poorer asthma-related outcomes.

CLINICAL TRIAL REGISTRATION

The International Severe Asthma Registry database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization Studies (European Network Centres for Pharmacoepidemiology and Pharmacovigilance [ENCEPP]/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EMA 2014; EUPAS44024) and with all applicable local and international laws and regulations, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=48848). Governance was provided by ADEPT (registration number: ADEPT1121).

Asthma and Tobacco Smoking

Asthma is a prevalent chronic pulmonary condition with significant morbidity and mortality. Tobacco smoking is implicated in asthma pathophysiology, diagnosis, prognosis and treatment. Smokers display increased prevalence and incidence of asthma, but a causal association cannot be claimed using existing evidence. Second-hand smoking and passive exposure to tobacco in utero and early life have also been linked with asthma development. Currently, approximately one-fourth of asthma patients are smokers. Regular smokers with asthma might display accelerated lung function decline and non-reversible airflow limitation, making their distinction from chronic obstructive pulmonary disease patients challenging. Asthma patients who smoke typically have uncontrolled disease, as shown by increased symptoms, more exacerbations and impaired quality of life. On the other hand, smoking cessation improves lung function and asthma severity. Thus, asthma patients and their caregivers should be actively questioned about their smoking status at each medical encounter, and smoking cessation ought to be strongly encouraged both for patients with asthma and their close contacts. Smokers with asthma should be provided with comprehensive smoking cessation interventions on top of other anti-asthma medications.

The many faces of asthma-chronic obstructive pulmonary disease overlap

PURPOSE OF REVIEW

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases that often overlap. The term asthma-COPD overlap (ACO) has been used to define this entity but there remain several speculations on its exact definition, impact, pathophysiology, clinical features, and management. We reviewed recent publications on ACO to obtain more insight of current knowledge and outline future needs.

RECENT FINDINGS

Criteria for ACO vary from one publication to another and the many variable features of these patients underline the need to reconsider the evaluation and approach of patients with overlapping features based on clinical traits and underlying biological mechanisms. Epidemiological studies reveal that ACO patients have generally an increased burden of illness and healthcare use in addition to poorer quality of life (QoL) compared with asthma and higher or equal to COPD. However, their long-term outcome seems better than patients with COPD alone. Various methods have been proposed to evaluate these patients but their usefulness compared to 'classical' investigation of obstructive lung diseases remains speculative and needs further evaluation. Furthermore, there are no formal studies that examined and compared the different treatment strategies of well-characterized patients with ACO as such patients are usually excluded from clinical trials.

SUMMARY

ACO is a common condition with variable features and a high burden of disease. There is no consensus on its definition, diagnostic, and clinical features and more research should be done on its optimal management and long-term outcomes.

Airway reversibility in asthma and phenotypes of Th2-biomarkers, lung function and disease control

Background

High bronchodilator reversibility in adult asthma is associated with distinct clinical characteristics. In this study, we aim to make a comparison with T-helper 2 (Th2)-related biomarkers, lung function and asthma control between asthmatic patients with high airway reversibility (HR) and low airway reversibility (LR).

Methods

Patients with asthma diagnosed by pulmonologist according to Global Initiative for Asthma guidelines were recruited from the outpatient department of our hospital from August 2014 to July 2017. Patients were divided into HR and LR subgroups based on their response to bronchodilators of lung function (HR = Δforced expiratory volume in one second (FEV1) postbronchodilator ≥ 20%). Blood eosinophil count and serum IgE level, which are biomarkers of T-helper (Th)-2 phenotypes, were detected for patients. Asthma Control Test (ACT) was used to assess asthma control after the first-month initial treatment.

Results

A total of 265 patients with asthma were followed 1 month after initial treatment. HR group shows a higher level of Th2-high biomarkers (blood eosinophil count (10^9/L): 0.49 ± 0.28 vs 0.36 ± 0.19, P < 0.01; IgE (ng/ml): 1306 ± 842 vs 413 ± 261, P < 0.01), lower baseline lung function (FEV1%pred: 51.91 ± 19.34% vs 60.42 ± 19.22%, P < 0.01; forced expiratory flow (FEF)25–75: 0.76 ± 0.37 vs 1.00 ± 0.67, P < 0.01; FEF25–75%pred: 21.15 ± 10.09% vs 29.06 ± 16.50%, P < 0.01), and better asthma control (ACT score: 22 ± 4 vs 20 ± 4, P = 0.01) than LR group. HR was associated with a decreased risk of uncontrolled asthma after the first-month initial treatment (adjusted OR: 0.12 [95% confidence intervals: 0.03–0.50]).

Conclusions

HR is a physiologic indicator of lower lung function and severer small airway obstruction, and is more related with an increased level of Th2-biomarkers than LR. Moreover, HR may indicate controlled asthma after the first-month initial treatment. This finding may contribute to identification of asthma endotype.