Dynamic hyperinflation impairs daily life activity in asthma

[A simple method to assess dynamic hyperinflation outside a pulmonary function test laboratory: The metronome-paced tachypnea test]

Lung dynamic hyperinflation (DH) is one of the main determinants of dyspnea in chronic respiratory disease patients. Producing evidence of DH is critical during dyspnea assessment, the objectives being to explain the cause, to target treatments, and to monitor their efficacy. The gold standard method consists in repeated measurement of inspiratory capacity (IC) during cardiopulmonary exercise testing (CPET). Unfortunately, access to CPET is limited and assessment of IC during CPET can be challenging in some patients. An alternative method consists in assessment of IC during the testing known as metronome-paced tachypnea (MPT) challenge. This method is feasible, repeatable, valid (i.e. corelated with dyspnea patients' activities of daily living), and responsive to treatments. However, while its diagnostic performance is acceptable, it is lacking in specificity. Methodological standardization is detailed in the present review, as are the differences between IC changes in CPET and in MPT. As a means of assessing DH, MPT challenge is not only applicable to patients outside a pulmonary function test laboratory, but also easily affordable to any chest physician equipped with a simple spirometry device. A diagnosis threshold of 11% for IC decrease during MPT challenge can be used, albeit while bearing in mind the possibility of a false positive result. Moreover, assessment of IC variations during MPT can help to monitor a patient's overall evolution and response to treatments.

Diaphragm function in patients with asthma and healthy controls: A cross-sectional study

BACKGROUND

Asthma is a chronic respiratory disease characterized by airway inflammation and variable respiratory symptoms. While peripheral muscle deconditioning is known to affect lung function and exercise tolerance, the role of respiratory muscle dysfunction, particularly the diaphragm, remains underexplored.

OBJECTIVE

We aim to evaluate potential differences in diaphragm function in patients with asthma.

METHODS

We conducted a prospective, observational study comparing diaphragmatic function of 50 patients with asthma and 50 healthy controls. Two independent operators evaluated diaphragm contraction using tidal breathing thickening fraction (TF). Diaphragm dysfunction was defined as a TF < 20 %. Additional assessments included flow-volume spirometry, impulse oscillometry (IOS), FeNO, blood eosinophil count, and the Sniff Inspiratory Nasal Pressure (SNIP) test.

RESULTS

Patients with asthma demonstrated significantly reduced diaphragm TF compared to healthy controls (p < 0.0001). Diaphragm dysfunction was significantly more prevalent in asthmatic patients (p < 0.0001), affecting 62%-66 % of the right hemidiaphragm and 46%-54 % of the left. Reduced TF was associated with longer disease duration (p = 0.03) and higher exacerbation rates (p = 0.04). No significant correlations were observed between TF and anthropometric data, asthma treatments, lung function, or Th2 biomarkers. SNIP measurements did not correlate with diaphragm TF. The limited sample size and the cross-sectional design were the main limitations of the study.

CONCLUSION

Diaphragm dysfunction is prevalent in asthma and associated with disease severity, including exacerbation frequency and longer disease duration. Impaired diaphragm function may contribute to persistent symptoms and exercise intolerance, representing a novel treatable trait in asthma management.

Long-term effects of mepolizumab in patients with severe eosinophilic asthma: a 6-year real-life experience

Background

Severe eosinophilic asthma (SEA) is often linked to a dysregulation in the Interleukin-(IL)-5 axis. Mepolizumab, a humanized monoclonal antibody, reduces eosinophils by directly binging to IL-5, potentially restoring homeostatic eosinophil biology, with a significant impact on quality of life, acute exacerbations and oral corticosteroids (OCS) elimination in SEA patients. While its short- and middle-term effects are well described, no study has so far investigated its long-lasting effects in SEA patients. The aim of our study was therefore to explore the effects of a long-term, six-year continuous treatment with mepolizumab on clinical control and clinical remission in a cohort of SEA patients.

Methods

We conducted a retrospective review of clinical records of patients who were prescribed mepolizumab between June 2017 and April 2018. We collected demographical, functional, and clinical data from visits performed at baseline and then at the specified timepoints and checked if patients had reached clinical remission after 6 years. We assessed asthma control test (ACT), exacerbation rate, and OCS elimination dose at 6 years. Clinical Remission (CR) was defined on the basis of the elimination of OCS and the contemporary presence of all the following: 1) stable lung function; 2) no exacerbation in the previous 12 months; 3) acceptable symptom control (ACT ≥ 20).

Results

Of 86 patients screened, 62 were included in the final analysis. Our study suggests that mepolizumab is effective and well tolerated after a six-year course of continuous treatment in patients with SEA. We reported a prevalence of 28 (46.8%) patients who reached complete CR at 72 months from the treatment start. 75% of patients eliminated the maintenance OCS already after 1 year of treatment; this proportion reached the 87% within the sixth year of treatment.

Conclusion

Mepolizumab proved to be effective in real-life after 6 years of treatment, inducing a complete clinical remission in the 46.8% of patients, with sustained improvements in quality of life, exacerbation rate, OCS intake and lung function.

Effects of Asthma on the Performance of Activities of Daily Living: A Retrospective Study

The study aim was to identify the most problematic self--reported activities of daily living (ADLs). In a retrospective study, 1935 problematic ADLs were reported by 538 clients with 95% experiencing two or more problematic ADLs. Problematic ADLs were assessed by occupational therapists using the Canadian Occupational Performance Measure with walking (67%), household activities (41%), and climbing the stairs (41%) identified as the most prevalent problematic ADLs. Significant but weak associations were found between clinical determinants (e.g. physical, psychosocial) and problematic ADLs. The wide variety of problematic ADLs and the absence of a strong association with clinical determinants emphasizes the need for using individualized interview-based performance measures in clients with asthma.

Obesity-related asthma: new insights leading to a different approach

PURPOSE OF REVIEW

Obesity is a growing global health threat that significantly contributes to the burden of asthma by increasing the risk of developing asthma and exerting a distinct effect on lung function and inflammation. The treatment of obesity-related asthma is hindered by a poor response to standard asthma treatments, leading to worse asthma control. Weight loss strategies have a significant effect on asthma symptoms but are not feasible for a large proportion of patients, underscoring the need for a better understanding of the pathophysiology and the development of additional treatment options.

RECENT FINDINGS

Recent literature focusing on pathophysiology particularly delved into nontype 2 inflammatory mechanisms, associations with the metabolic syndrome and small airway impairment. Additionally, several new treatment options are currently investigated, including biologics, weight reduction interventions, and novel antiobesity drugs.

SUMMARY

Obesity-related asthma is a highly prevalent asthma phenotype for which weight loss strategies currently stand as the most specific treatment. Furthermore, novel pharmacological interventions aiming at metabolic processes are on the way.

Assessment of hyperinflation: comparison of Global Lung Function Initiative and European Community for Steel and Coal lung volume reference equations

Background

Assessment of static hyperinflation severity is crucial to identify COPD patients eligible for lung volume reduction. The current recommendation of residual volume ≥175% predicted may need to be reconsidered owing to potential differences between the Global Lung Function Initiative (GLI) and the European Community for Steel and Coal (ECSC) reference equations for residual volume and concerns about using percentage of predicted.

Methods

We compared the residual volume reference values derived from the GLI and ECSC equations using mathematically simulated data and used a receiver operating characteristic curve to establish a new GLI-derived z-score cut-off for residual volume using body plethysmography data from patients with severe COPD.

Results

The GLI reference equation for residual volume consistently yields a lower predicted residual volume for individuals with an average or below-average height (females ≤163 cm and males ≤177 cm). Our clinical cohort consisted of 1011 patients with COPD (graded using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria as 38% GOLD 3 and 59% GOLD 4). In this cohort, a GLI-derived residual volume z-score of ≥2.9 could accurately replace the ECSC-derived 175% predicted cut-off and a z-score of ≥3.5 was established for the 200% predicted cut-off.

Conclusion

There are substantial differences in predicted residual volume values between the GLI and ECSC equations, with the GLI generally yielding a lower predicted residual volume in the majority of individuals. A GLI-derived residual volume z-score of ≥2.9 could be used to replace the currently used cut-off of ≥175% predicted to identify potential lung volume reduction candidates.

Impact of biologics on lung hyperinflation in patients with severe asthma

BACKGROUND

In asthma, inflammation affects both the proximal and distal airways and can cause significant hyperinflation, which is thought to be a major cause of dyspnea.

METHODS

This is a retrospective observational study evaluating the effect of three months of treatment with different biologic drugs (benralizumab, dupilumab and omalizumab) on pulmonary hyperinflation in a cohort of patients with severe asthma already receiving regular triple inhaled therapy. Changes in RV, RV/TLC ratio, FRC and FRC/TLC ratio were the primary efficacy measures. Secondary outcomes included FEV1, FVC, FEV1/FVC ratio, IC, IC/TLC ratio, asthma control test, the percentage of eosinophils in the blood and fractional FENO.

RESULTS

Benralizumab led to significant changes (p < 0.001) in RV, RV/TLC, FRC, and FRC/TLC. Dupilumab demonstrated a notable reduction in RV (p = 0.017) and RV/TLC (p = 0.002), but the decreases in FRC and FRC/TLC were merely numerical and not as pronounced as those induced by benralizumab. Omalizumab's positive impact on RV (p = 0.057) and RV/TLC (p = 0.085), as well as FRC (p = 0.202) and FRC/TLC (p = 0.096), was also predominantly numerical, with a tendency towards efficacy, albeit excluding the effect on FRC. Treatment with biologics resulted in improvements in all other lung function parameters assessed and a decrease in FENO levels.

CONCLUSION

This study, although limited by small sample size, lack of a placebo control, and unbalanced group sizes, suggests that biological agents are effective in reducing lung hyperinflation even after a relatively short treatment.

Reliability and validity of the London Chest Activity of Daily Living scale for adults with asthma

INTRODUCTION

Dyspnea during activities of daily living (ADL) is frequently reported by adults with asthma. However, instruments that specifically assess that in people with asthma have not yet been validated.

OBJECTIVES

To investigate the validity and reliability, including standard error of measurement (SEM) and Minimum Detectable Change (MDC), of the London Chest Activity of Daily Living (LCADL) scale for adults with asthma.

METHODS

Adults with asthma answered the LCADL scale which was performed twice by the same rater. Spirometry, 6-min walk test (6MWT), St George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnea scale, Asthma Quality of Life questionnaire (AQLQ), Asthma Control Test (ACT), and Glittre-ADL test were assessed. For statistical analyses, Spearman correlation, Wilcoxon test, Intraclass Correlation Coefficient (ICC), Cronbach's alpha coefficient, SEM, MDC were performed.

RESULTS

Seventy participants were included (30% men, 44 ± 15 years old, BMI 27[23-31]kg/m2, FEV1 80 ± 17%predicted). For convergent validity, the LCADL scale was moderately correlated with SGRQ, AQLQ, and Glittre-ADL (r = 0.57, -0.46, and 0.41 respectively; p < 0.0001). The LCADL scale correlated weakly with the mMRC scale, ACT, and spirometry measures (-0.23

CONCLUSION

The LCADL scale is valid and reliable for assessing dyspnea during ADL in adults with asthma.

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Key Words

• Validity and reliability
• activities of daily living
• asthma
• dyspnea

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MESH Headings

• Male
• Adult
• Humans
• Middle Aged
• Female
• Pulmonary Disease, Chronic Obstructive
• Asthma/diagnosis
• Activities of Daily Living
• Quality of Life
• Reproducibility of Results
• London
• Dyspnea/diagnosis
• Dyspnea/etiology
• Surveys and Questionnaires

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Affiliation(s)

Vitória Cavalheiro Puzzi Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil
Joice Mara de Oliveira Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil
Thainá Bessa Alves Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil
Jessica Priscila da Conceição Silva Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil
Ariele Pedroso Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil
Karina Couto Furlanetto Graduate Program in Rehabilitation Sciences, Pitágoras-Unopar University (UNOPAR), Londrina, Brazil Laboratory of Research in Respiratory Physiotherapy - LFIP, Department of Physiotherapy, Londrina State University, Londrina, Brazil

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Using the 6-min walk test to assess the clinical response to mepolizumab and conventional therapy in severe eosinophilic asthma

Background

Severe asthma limits exercise to avoid respiratory symptoms. The objective of the present study was to investigate the role of the 6-min walk test (6MWT) in severe asthma.

Methods

Consecutive patients with severe eosinophilic asthma were enrolled. A 6MWT was performed before and after 12 months. Inhaled therapy dose, oral corticosteroids dose, pulmonary function tests, eosinophil blood count, fractional exhaled nitric oxide (FeNO), Asthma Control Test (ACT) score and responses to the Asthma Quality of Life Questionnaire (AQLQ) were also recorded.

Results

Of the 22 patients enrolled, 13 were treated with mepolizumab 100 mg every 4 weeks in addition to conventional therapy and nine with conventional therapy only. The majority of the patients were treated with high-dose inhaled corticosteroids/long-acting β-agonists/long-acting muscarinic receptor antagonists, while approximately half were on continuous oral corticosteroids. After 12 months, the mepolizumab group only showed a significant improvement in pulmonary function tests (percentage forced expiratory volume in 1 s and percentage forced expiratory flow at 25-75% forced vital capacity (FEF25-75%), both p<0.001; percentage forced vital capacity, p<0.01) and clinical laboratory parameters (eosinophil count, FeNO measured at a flow rate of 50 mL·s-1, ACT and AQLQ, p<0.001). No significant changes in the proportion of patients using continuous oral corticosteroids and high-dose inhaled corticosteroids/long-acting β-agonists/long-acting muscarinic receptor antagonists were observed in either group (p>0.05). By paired comparisons, statistically significant improvements of the mean 6-min walk distance (6MWD) were observed in the mepolizumab (p<0.001) and conventional therapy (p<0.01) groups, while no improvement was seen in dyspnoea Borg scale, heart rate, percentage oxygen saturation or systolic and diastolic blood pressure. 6MWD showed significant direct correlations with ACT (r=0.5998, p<0.001), AQLQ (r=0.3978, p=0.009) and FEF25-75% (r=0.3589, p=0.017).

Conclusions

The 6MWT could complement severe asthma assessment and be relevant in evaluating the objective response to treatment, including biological therapies like mepolizumab.

The Role of Long-Acting Antimuscarinic Agents in the Treatment of Asthma

The journey of using anticholinergics in the treatment of asthma started with anticholinergic-containing plants such as Datura stramonium and Atropa belladonna, followed by ipratropium bromide and continued with tiotropium, glycopyrronium, and umeclidinium. Although antimuscarinics were used in the maintenance treatment of asthma over a century ago, after a long time (since 2014), it has been recommended to be used as an add-on long-acting antimuscarinic agent (LAMA) therapy in the maintenance treatment of asthma. The airway tone controlled by the vagus nerve is increased in asthma. Allergens, toxins, or viruses cause airway inflammation and inflammation-related epithelial damage, increased sensory nerve stimulation, ganglionic and postganglionic acetylcholine (ACh) release by inflammatory mediators, intensification of ACh signaling at M1 and M3 muscarinic ACh receptors (mAChRs), and dysfunction of M2 mAChR. Optimal anticholinergic drug for asthma should effectively block M3 and M1 receptors, but have minimal effect on M2 receptors. Tiotropium, umeclidinium, and glycopyrronium are anticholinergic agents with this feature. Tiotropium has been used in a separate inhaler as an add-on treatment to inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA), and glycopyrronium and umeclidinium have been used in a single inhaler as a combination of ICS/LABA/LAMA in asthma in recent years. Guidelines recommend this regimen as an optimization step for patients with severe asthma before initiating any biologic or systemic corticosteroid therapy. In this review, the history of antimuscarinic agents, their effectiveness and safety in line with randomized controlled trials, and real-life studies in asthma treatment will be discussed according to the current data.

Muscle Function in Moderate to Severe Asthma: Association With Clinical Outcomes and Inflammatory Markers

BACKGROUND

Patients with severe asthma have been shown to have low muscle mass, but the clinical consequences are unknown.

OBJECTIVE

In a clinical cohort of patients with moderate to severe asthma, we aimed to assess muscle mass and strength and their relation with functional and clinical outcomes, as well as with systemic inflammatory markers.

METHODS

Muscle mass and strength were assessed by the fat-free mass index (FFMI), creatinine excretion in a 24-hour urine sample, and handgrip strength test. Functional outcomes included pulmonary function tests and the 6-minute walking distance, whereas clinical outcomes were assessed with questionnaires on asthma control, quality of life, and health care use. Associations of muscle mass and strength with asthma outcomes were assessed with multivariable regression analyses.

RESULTS

A total of 114 patients participated (36% male; mean age, 51.9 ± 14.4 years; body mass index, 27.7 ± 5.7 kg/m²). According to predefined criteria, 16% had a low FFMI and 8% a low urinary creatinine excretion, which did not differ between categories of asthma severity. Both lower FFMI and urinary creatinine excretion were associated with lower values of FEV₁ and 6-minute walking distance, whereas a lower handgrip strength was related to worse asthma control, poorer quality of life, and a higher probability of emergency visits (all P < .05). Except for higher leukocytes in relation to lower FFMI, we did not find associations between systemic inflammatory markers and muscle function.

CONCLUSIONS

This study demonstrates that low muscle mass is prevalent in patients with moderate to severe asthma and, along with low muscle strength, is associated with poorer clinical and functional outcomes. Our results encourage longitudinal studies into muscle function as a potential target for treatment to improve asthma outcomes.

Differential role of mucus plugs in asthma: Effects of smoking and association with airway inflammation

BACKGROUND

The physiological importance of mucus plugs in computed tomography (CT) imaging is being increasingly recognized. However, whether airway inflammation and smoking affect the association between mucus plugs and clinical-physiological outcomes in asthma remains to be elucidated. The objective of this study is to examine how airway inflammation and/or smoking affect the correlation of CT-based mucus plug scores with exacerbation frequency and airflow limitation indices in asthma.

METHODS

A total of 168 patients with asthma who underwent chest CT and sputum evaluation were enrolled and classified in eosinophilic asthma (EA; n = 103) and non-eosinophilic asthma (NEA; n = 65) groups based on sputum eosinophil percentage (cut-off: 3%). The mucus plug score was defined as the number of lung segments with mucus plugs seen on CT.

RESULTS

More mucus plugs were detected on CT scans in the EA group than in the NEA group, regardless of smoking status. Mucus plug score and exacerbation frequency during one year after enrollment were significantly associated in the EA group but not in the NEA group after adjusting for demographics, blood eosinophil count, and fractional exhaled nitric oxide. Mucus plug score was associated with percentage of predicted forced expiratory volume in 1 s in non-smoking individuals in the EA and NEA group and in smoking individuals in the EA group but not in the NEA group after adjusting for demographics.

CONCLUSIONS

The association of mucus plug score with exacerbation frequency and reduced lung function may vary due to airway inflammatory profile and smoking status in asthma.

Validity and reliability of the Glittre-ADL test in adults with asthma

INTRODUCTION

Adults with asthma may have limitations in their activities of daily living (ADL) and among the most used tests to assess ADL, performance-based instruments such as the Glittre-Activities of Daily Living (Glittre-ADL) test are available. However, metric properties of this instrument have not yet been investigated in this population.

OBJECTIVE

To verify the construct validity and reliability of the Glittre-ADL test in adults with asthma.

METHODS

Fifty-eight adults with asthma had their ADL objectively assessed by Glittre-ADL test, which was performed twice by the same rater. Lung function (spirometry), functional exercise capacity (6-minute walk test, 6MWT), and quality of life (St George's Respiratory Questionnaire, SGRQ) were also assessed.

RESULTS

Participants were 31% men; 43 ± 14 years; FEV1 74 ± 18% predicted. Performance in the Glittre-ADL test correlated with the 6MWT (r = -0.61; P < .0001) and had excellent intraclass correlation coefficient ICC_3,1 = 0.95. Standard error of measurement was 23%, and the minimal detectable change was 29 seconds. Furthermore, the learning effect was 11 seconds (5.03%).

CONCLUSION

The Glittre-ADL test is valid and reliable for assessing ADL in adults with asthma. However, considerable learning effect was observed and therefore the best of two measures can avoid underestimation.

Static lung volumes and diffusion capacity in adults 30 years after being diagnosed with asthma

BACKGROUND

Long-term follow-up studies of adults with well-characterized asthma are sparse. We aimed to explore static lung volumes and diffusion capacity after 30 + years with asthma.

METHODS

A total of 125 adults with an objectively verified diagnosis of asthma between 1974-1990 at a Danish respiratory outpatient clinic completed a follow-up visit 2017-19. All participants (age range 44-88 years) completed a comprehensive workup and were, based on these assessments, classified as having either active asthma or being in complete remission. The examination program included measurements of static lung volumes and diffusion capacity.

RESULTS

Participants with active asthma were hyperinflated (residual volume/total lung capacity ratio 0.43, 95% CI 0.41-0.45) (RV/TLC ratio) compared with those in remission (RV/TLC ratio 0.38, 95% CI 0.36-0.41) (p < 0.03). A tendency towards higher diffusion capacity per liter lung volume was seen in participants with active asthma (KCO 100% predicted, 95% CI 97-104) compared with those in remission (KCO 94% pred., 95% CI 89-99) (P = 0.10). Longer asthma duration was associated with a higher KCO 0.47% pred./year (95% CI 0.14-0.80), adjusted for age and smoking. Patients on GINA step 4 and 5 treatment were more hyperinflated ([Formula: see text] RV 14% pred., 95% CI 3-27) and had higher airway resistance (mean 53% pred., 95% CI 9-97) than participants on lower GINA steps. Patients with uncontrolled disease had substantially higher airway resistance (72% pred. 95% CI 20-124) than well-controlled patients.

CONCLUSION

Thirty years after a confirmed diagnosis of asthma, those continuing to have active asthma and those having severe asthma, have higher diffusion capacity and more hyperinflation than patients in remission.

The 5T approach in asthma: Triple Therapy Targeting Treatable Traits

Using a therapeutic strategy that is free from traditional diagnostic labels and based on the identification of "treatable traits" (TTs), which are influential in clinical presentations in each patient, might overcome the difficulties in identifying and validating asthma phenotypes and endotypes. Growing evidence is documenting the importance of using the triple therapy with ICS, LABA, and LAMAs in a single inhaler (SITT) in cases of asthma not controlled by ICS/LABA and in the prevention of exacerbations. The identification of TTs may overcome the possibility of using SITT without considering the specific needs of the patient. In effect, it allows a treatment strategy that is closer to the precision strategy now widely advocated for the management of patients with asthma. There are different TTs in asthma that may benefit from treatment with SITT, regardless of guideline recommendations. The airflow limitation and small airway dysfunction are key TTs that are present in different phenotypes/endotypes, do not depend on the degree of T2 inflammation, and respond better than other treatments to SITT. We suggest that the 5T (Triple Therapy Targeting Treatable Traits) approach should be applied to the full spectrum of asthma, not just severe asthma, and, consequently, SITT should begin earlier than currently recommended.

Targeting dynamic hyperinflation in moderate-to-severe asthma: a randomised controlled trial

Background

Dynamic hyperinflation is highly prevalent in moderate-to-severe asthma, which may significantly impede activities of daily life. We hypothesised that dynamic hyperinflation in asthma is due to inflammation of large and small airways and can be reduced by systemic anti-inflammatory treatment. Therefore, we investigated the effect of systemic glucocorticoids on dynamic hyperinflation in moderate-to-severe asthma patients and explored the relationships between inflammatory markers and changes in dynamic hyperinflation.

Methods

In this randomised placebo-controlled trial we included 32 asthma patients on inhaled glucocorticoid therapy showing dynamic hyperinflation, defined by a ≥10% reduction in inspiratory capacity measured by standardised metronome-paced tachypnea test. Patients received either triamcinolone (80 mg) or placebo intramuscularly. Before and 2 weeks after treatment, patients completed respiratory health questionnaires, had blood eosinophils and exhaled nitric oxide levels measured, and underwent lung function and dynamic hyperinflation testing.

Results

After adjustment for potential confounders, dynamic hyperinflation was significantly reduced by 28.1% in the triamcinolone group and increased by 9.4% in the placebo group (p=0.027). In the triamcinolone-treated patients, the reduction in dynamic hyperinflation was greater in patients with higher blood eosinophils at baseline (r=−0.592, p=0.020) and tended to be associated with a reduction in blood eosinophils (r=0.412, p=0.127) and exhaled nitric oxide (r=0.442, p=0.099).

Conclusions

This exploratory study suggests that dynamic hyperinflation in asthma can be reduced by systemic anti-inflammatory treatment, particularly in patients with elevated blood eosinophils. This supports the hypothesis that dynamic hyperinflation in asthma is due to airway inflammation and should be considered an important target for treatment.

Dynamic hyperinflation: a target for treatment in asthma, which can be reduced by systemic anti-inflammatory treatmenthttps://bit.ly/3gfyxYv

Long-acting muscarinic antagonists and small airways in asthma: Which link?

Involvement of small airways, those of <2 mm in internal diameter, is present in all stages of asthma and contributes substantially to its pathophysiologic expression. Therefore, small airways are a potential target to achieve optimal asthma control. Airway tone, which is increased in asthma, is mainly controlled by the vagus nerve that releases acetylcholine (ACh) and activates muscarinic ACh receptors (mAChRs) post-synaptically on airway smooth muscle (ASM). In small airways, M₃ mAChRs are expressed, but there is no vagal innervation. Non-neuronal ACh released from the epithelial cells that may express choline acetyltransferase in response to inflammatory stimuli, as well as from other structural cells in the airways, including fibroblasts and mast cells, can activate mAChRs. By antagonizing M₃ mAChR, the contraction of the ASM is prevented and, potentially, local inflammation can be reduced and the progression of remodeling may be averted. In fact, ACh also contributes to inflammation and remodeling of the airways and regulates the growth of ASM. Several experimental studies have demonstrated the potential benefit derived from the use of mAChR antagonists, mainly long-acting mAChR antagonists (LAMAs), on small airways in asthma. However, there are several confounding factors that may cause a wrong estimation of the relationship between LAMAs and small airways in asthma. Further studies are needed to differentiate broncholytic and anti-inflammatory effects of LAMAs and to better understand the interaction between LAMAs and corticosteroids, also in the context of a triple therapy that includes a β₂ -AR agonist, at different levels of the bronchial tree.

Serum periostin reflects dynamic hyperinflation in patients with asthma

Introduction

Dynamic hyperinflation (DH) is sometimes observed and is associated with impaired daily life activities of asthma. We assessed the relationship between DH and asthma biomarkers (blood eosinophil, fractional exhaled nitric oxide (F _eNO) and serum periostin) in patients with asthma.

Methods

Fifty patients with stable asthma were prospectively recruited and underwent blood test, F _eNO measurement, spirometry and metronome-paced tachypnoea (MPT) test to assess DH. In MPT tests, inspiratory capacity (IC) was measured at baseline and after 30 s of MPT with breathing frequencies of 20, 30 and 40 breaths·min^-1. DH was assessed by the decline of IC from baseline, and maximal IC reduction ≥10% was considered as positive DH.

Results

Thirty patients (60%) showed positive DH. Patients with positive DH showed higher serum periostin levels (107.0±30.7 ng·mL^-1) than patients with negative DH (89.7±23.7) (p=0.04). Patients in Global Initiative for Asthma treatment steps 4-5 (n=19) showed higher serum periostin levels (p=0.01) and more severe IC reduction after MPT (p<0.0001) than patients in steps 1-3 (n=31). Maximal IC reduction after MPT was significantly correlated with asthma control test score (r=-0.28, p=0.05), forced expiratory volume in 1 s (r=-0.56, p<0.0001), and serum periostin levels (r=0.41, p=0.003).

Conclusion

Serum periostin may have the possibility to reflect DH in patients with stable asthma.

Asthma and Lung Mechanics

This article will discuss in detail the pathophysiology of asthma from the point of view of lung mechanics. In particular, we will explain how asthma is more than just airflow limitation resulting from airway narrowing but in fact involves multiple consequences of airway narrowing, including ventilation heterogeneity, airway closure, and airway hyperresponsiveness. In addition, the relationship between the airway and surrounding lung parenchyma is thought to be critically important in asthma, especially as related to the response to deep inspiration. Furthermore, dynamic changes in lung mechanics over time may yield important information about asthma stability, as well as potentially provide a window into future disease control. All of these features of mechanical properties of the lung in asthma will be explained by providing evidence from multiple investigative methods, including not only traditional pulmonary function testing but also more sophisticated techniques such as forced oscillation, multiple breath nitrogen washout, and different imaging modalities. Throughout the article, we will link the lung mechanical features of asthma to clinical manifestations of asthma symptoms, severity, and control. © 2020 American Physiological Society. Compr Physiol 10:975-1007, 2020.

New perspectives on the role of muscarinic antagonists in asthma therapy

INTRODUCTION

There is increasing evidence that tiotropium, a long-acting muscarinic agent (LAMA), is useful in the presence of severe-uncontrolled asthma despite the optimization of therapy with inhaled corticosteroids (ICSs) and long-acting β₂ agonists (LABAs) as recommended by the current guidelines. Furthermore, in recent years there have been several  preclinical and clinical studies on the pharmacological and therapeutic impact of other LAMAs in asthma.

AREAS COVERED

We have conducted an extensive search on muscarinic antagonists in asthma therapy throughout several sources and discuss what has emerged in the last 3 years (January 2017-March 2020).

EXPERT OPINION

New evidence indicates that the effectiveness of adding a LAMA, at least tiotropium, is independent of the degree of the type 2 inflammation and age of patient. Therefore, tiotropium can be administered without the need for patient phenotyping. Umeclidinium and glycopyrronium also appear effective in asthma. Initial treatment with LAMA+ICS for those with mild asthma may be an equally effective therapeutic option as LABA+ICS but this hypothesis should be confirmed by statistically powered trials.