Identification of asthma phenotypes based on extrapulmonary treatable traits

Integrating hot topics and implementation of treatable traits in asthma

People with asthma experience many different problems related to their illness. The number and type of problems differ between patients. This results in asthma being a complex and heterogeneous disorder which mandates a personalised approach to management. These features pose very significant challenges for the effective implementation of evidence-based management. "Treatable traits" is a model of care that has been specifically designed to address these issues. Traits are identified in the pulmonary, extrapulmonary (comorbidity) and behavioural/risk factor domains. Traits are clinically relevant, recognisable with validated trait identification markers and treatable using evidence-based therapies. The clinician and patient agree on a personalised management plan that addresses the relevant traits, and trials show superiority of this approach with significant improvements in asthma control and quality of life. A number of tools have now been developed to assist the clinician in the implementation of this approach. The success of the treatable traits model of care is now being realised in other disease areas.

Londrina Activities of Daily Living Protocol: validity, reliability, minimal detectable change, and standard error of measurement in adults with asthma

INTRODUCTION

Asthma symptoms are dyspnea, chronic cough, wheezing, chest tightness, or chest discomfort, which can directly limit the activities of daily living (ADL), which is frequently reported by adults with asthma. Evaluating ADL with a reliable protocol at the usual speed is necessary.

OBJECTIVES

To investigate the validity, reliability, minimal detectable change (MDC), and standard error of measurement (SEM) of the Londrina ADL Protocol (LAP) for adults with asthma.

METHODS

Adults with asthma were evaluated with the LAP test. Spearman's correlation coefficient was used to verify validity with the 6-min walk test (6MWT), Glittre-ADL test, and London Chest Activity of Daily Living (LCADL). To test the reliability, the test was reapplied in at least 30 min; the Wilcoxon test and Intraclass Correlation Coefficient (ICC), SEM, MDC, and learning effect were performed.

RESULTS

Fifty-three individuals were included (26% men, 43 ± 15 years, BMI 28 ± 8 kg/m2, FEV1 70 ± 24%predicted). For convergent validity, the LAP test was correlated with the 6MWT, Glittre-ADL, and LCADL scale (r = -0.49, 0.71, and 0.30, respectively; p < 0.03). There was a difference in test-retest (p < 0.0001) and reliability analysis shows ICC3 of 0.94, SEM of 14.88 s (22%), and MDC of 41.23 s (15%). Furthermore, the individuals performed the second test with -23 ± 19 (7.9%) s.

CONCLUSION

The LAP test is valid and reliable for assessing limitations during ADL in adults with asthma. Considerable learning effect was observed, therefore, the best of two measures may avoid underestimation.

Understanding the impact of breathing pattern disorders in difficult-to-treat asthma

INTRODUCTION

Difficult-to-treat asthma is defined as asthma that is uncontrolled despite high-level treatment or requires such treatment to maintain good control and reduce exacerbations. Breathing pattern disorders (BPD) have been reported as a comorbidity in ~ 24-42% % of patients with difficult-to-treat asthma. This narrative review will assess the association, impact, and management of BPD in difficult-to-treat asthma.

AREAS COVERED

We outline current understandings of the nature of difficult-to-treat asthma and BPD. We then review the impact of BPD on difficult-to-treat asthma and Multidisciplinary Team (MDT) approaches to assessing and managing BPD in this patient group. A comprehensive literature search was performed by an asthma specialist MDT including physiotherapists, psychologists, and physicians to create a holistic perspective on this subject.

EXPERT OPINION

BPD exerts significant negative impacts across multiple domains in patients with difficult-to treat asthma. There is a need for further observational, interventional, qualitative and quantitative research to develop better diagnosis, treatment, and awareness of the impacts of BPD including health economic analysis. Studies should develop multimodal approaches that better treat both BPD and associated comorbidities within the multimorbidity framework of difficult-to-treat asthma. Recognizing and addressing BPD should be key elements in future difficult-to-treat asthma management guidelines and clinical practice.

Weighted Breaths: Exploring Biologic and Non-Biologic Therapies for Co-Existing Asthma and Obesity

PURPOSE OF REVIEW

To discuss the effectiveness of biologics, some of which comprise the newest class of asthma controller medications, and non-biologics in the treatment of asthma co-existing with obesity.

RECENT FINDINGS

Our review of recent preliminary and published data from clinical trials revealed that obese asthmatics respond favorably to dupilumab, mepolizumab, omalizumab, and tezepelumab, which are biologics currently indicated as add-on maintenance therapy for severe asthma. Furthermore, clinical trials are ongoing to assess the efficacy of non-biologics in the treatment of obese asthma, including a glucagon-like peptide-1 receptor agonist, a Janus kinase inhibitor, and probiotics. Although many biologics presently indicated as add-on maintenance therapy for severe asthma exhibit efficacy in obese asthmatics, other phenotypes of asthma co-existing with obesity may be refractory to these medications. Thus, to improve quality of life and asthma control, it is imperative to identify therapeutic options for all existing phenotypes of obese asthma.

Treatable Traits in Pregnant Women with Asthma

BACKGROUND

Asthma is the most common chronic respiratory disease in pregnancy, affecting approximately 8-10% of pregnant women. Uncontrolled asthma is associated with adverse perinatal outcomes, including low birth weight, preterm birth, and maternal complications such as pre-eclampsia.

SUMMARY

A current approach to the management of chronic airway diseases is based on targeting treatable traits. The aim of this review was to define treatable traits in pregnant women with asthma based on recent literature and to determine personalized treatment options according to these traits. Traits addressed in this review that may improve asthma control and pregnancy outcomes are fractional exhaled nitric oxide-based asthma monitoring and treatment, medication adherence and inhalation technique, impaired lung function, smoking cessation and comorbidity including psychological conditions (depression and anxiety), obesity, rhinitis, gastroesophageal reflux disease, chronic rhinosinusitis with or without nasal polyps, and sleep apnea.

KEY MESSAGES

All the treatable traits discussed have the potential to improve asthma control and pregnancy outcomes in pregnant women with asthma. Further research is needed to determine which management approaches are best to improve asthma control during pregnancy, to identify other relevant treatable traits, and to determine whether the treatable trait approach is feasible and beneficial in pregnant women with asthma.

Test-retest reliability, construct validity and determinants of 6-minute walk test performance in adult patients with asthma

INTRODUCTION AND OBJECTIVES

Current knowledge regarding the measurement properties of the 6-minute walk test (6MWT) in patients with asthma is limited. Therefore, the aim of this study was to assess the test-retest reliability, measurement error and construct validity of the 6MWT and identify determinants of 6-minute walk distance (6MWD) in patients with asthma.

PATIENTS AND METHODS

201 asthma patients referred for pre-pulmonary rehabilitation assessment, were retrospectively analyzed (age 61±12 years, 42% male, FEV1 78±27% predicted). Patients performed two 6MWTs on subsequent days using a 30 m straight walking course. Other measurements included resting dyspnea, maximal exercise capacity, body composition, pulmonary function, pulmonary and quadriceps muscle strength and symptoms of anxiety and depression. Measurement error (absolute reliability) was tested using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95%) and Bland and Altman 95% limits of agreement, whereas test-retest reliability (relative reliability) and construct validity were assessed using the intra-class correlation coefficient (ICC2,1) and correlations, respectively.

RESULTS

The 6MWD showed excellent test-retest reliability (ICC2,1: 0.91). The mean change in 6MWD after the second 6MWT was 18m (95%CI 11-24m), with 73% of the patients walking further in the second test. The SEM and MDC95% for the 6MWT were 35 m and 98 m, respectively. The best 6MWD correlated strongly with peak oxygen uptake during CPET and resting dyspnea (r = 0.61-0.64) and had no-to-moderate correlations with body composition, pulmonary function, respiratory and quadriceps muscle strength and symptoms of anxiety and depression (r = 0.02-0.45). Multiple linear regression was able to identify maximal workload, BMI, rollator use, maximal expiratory pressure, FEV1 and DLCO as independent determinants of the best 6MWD (R2 = 0.58).

CONCLUSIONS

The 6MWT was considered to be reliable and valid in patients with asthma, which strengthens its clinical utility. However, the majority of patients demonstrated a considerable learning effect in the second 6MWT, providing a strong rationale for performing two 6MWTs.

Trait profiles in difficult-to-treat asthma: Clinical impact and response to systematic assessment

BACKGROUND

Multidisciplinary systematic assessment improves outcomes in difficult-to-treat asthma, but without clear response predictors. Using a treatable-traits framework, we stratified patients by trait profile, examining clinical impact and treatment responsiveness to systematic assessment.

METHODS

We performed latent class analysis using 12 traits on difficult-to-treat asthma patients undergoing systematic assessment at our institution. We examined Asthma Control Questionnaire (ACQ-6) and Asthma Quality of Life Questionnaire (AQLQ) scores, FEV1 , exacerbation frequency, and maintenance oral corticosteroid (mOCS) dose, at baseline and following systematic assessment.

RESULTS

Among 241 patients, two airway-centric profiles were characterized by early-onset with allergic rhinitis (n = 46) and adult onset with eosinophilia/chronic rhinosinusitis (n = 60), respectively, with minimal comorbid or psychosocial traits; three non-airway-centric profiles exhibited either comorbid (obesity, vocal cord dysfunction, dysfunctional breathing) dominance (n = 51), psychosocial (anxiety, depression, smoking, unemployment) dominance (n = 72), or multi-domain impairment (n = 12). Compared to airway-centric profiles, non-airway-centric profiles had worse baseline ACQ-6 (2.7 vs. 2.2, p < .001) and AQLQ (3.8 vs. 4.5, p < .001) scores. Following systematic assessment, the cohort showed overall improvements across all outcomes. However, airway-centric profiles had more FEV1 improvement (5.6% vs. 2.2% predicted, p < .05) while non-airway-centric profiles trended to greater exacerbation reduction (1.7 vs. 1.0, p = .07); mOCS dose reduction was similar (3.1 mg vs. 3.5 mg, p = .782).

CONCLUSION

Distinct trait profiles in difficult-to-treat asthma are associated with different clinical outcomes and treatment responsiveness to systematic assessment. These findings yield clinical and mechanistic insights into difficult-to-treat asthma, offer a conceptual framework to address disease heterogeneity, and highlight areas responsive to targeted intervention.

Identifying the Characteristics of Responders and Nonresponders in a Behavioral Intervention to Increase Physical Activity Among Patients With Moderate to Severe Asthma: Protocol for a Prospective Pragmatic Study

BACKGROUND

Previous research has suggested that most adults improve their asthma control after a short-term behavioral intervention program to increase physical activity in daily life (PADL). However, the characteristics of individuals who respond and do not respond to this intervention and the medium-term response remain unknown.

OBJECTIVE

This study aims to (1) identify the characteristics of adult responders and nonresponders with asthma to a behavioral intervention to increase physical activity and (2) evaluate the functional and clinical benefits in the medium term.

METHODS

This prospective pragmatic study will include adults with moderate to severe asthma who enroll in a behavioral intervention. All individuals will receive an educational program and an 8-week intervention to increase PADL (1 time/wk; up to 90 min/session). The educational program will be conducted in a class setting through group discussions and video presentations. Behavioral interventions will be based on the transtheoretical model using counseling, incentives, and individual feedback aiming to increase participation in physical activity. Motivational interviewing and guidelines for overcoming barriers will be used to stimulate individuals to reach their goals. Pre- and postintervention assessments will include the following: PADL (triaxial accelerometry), body composition (octopolar bioimpedance), barriers to PADL (questionnaire), clinical asthma control (Asthma Control Questionnaire), quality of life (Asthma Quality of Life Questionnaire), anxiety and depression levels (Hospital Anxiety and Depression Scale), and exacerbations. "Responders" to the intervention will be defined as those who demonstrate an increase in the number of daily steps (≥2500).

RESULTS

In December 2021, the clinical trial registration was approved. Recruitment and data collection for the trial is ongoing, and the results of this study are likely to be published in late 2024.

CONCLUSIONS

The intervention will likely promote different effects according to the clinical characteristics of the individuals, including asthma control, age, anxiety and depression levels, obesity, and several comorbidities. Identifying individuals who respond or do not respond to behavioral interventions to increase PADL will help clinicians prescribe specific interventions to adults with asthma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05159076; https://clinicaltrials.gov/ct2/show/NCT05159076.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/49032.

Physical activity levels in asthma: relationship with disease severity, body mass index and novel accelerometer-derived metrics

OBJECTIVES

Patients with asthma may feel limited in physical activity (PA). Reduced PA has been demonstrated in asthmatics versus healthy controls, and increasing PA associated with improved asthma outcomes. Obesity is commonly found with difficult-to-control asthma and worsens outcomes. We compared PA levels in participants with difficult-to-control asthma and elevated body mass index (BMI) (DOW group) and two mild-moderate asthma groups: one with BMI <25 kg/m² (MHW) and one with BMI ≥25 (MOW).

METHODS

This cross-sectional study used 7-day recordings from wrist-worn accelerometers to compare PA between groups. Inactive time, light (LPA), moderate-vigorous PA (MVPA) were measured, along with two novel metrics: intensity gradient (IG) reflecting PA intensity, and average acceleration (AA) reflecting PA volume. PA parameters were compared using ANOVA or Kruskall-Wallis testing. Correlation and linear regression analyses explored associations between PA parameters and asthma outcomes. As AA was the PA parameter correlated most closely with asthma-related outcomes, an exploratory analysis compared outcomes in highest and lowest AA quartiles.

RESULTS

75 participants were recruited; 57 accelerometer readings were valid and included in analysis. Inactive time was significantly higher (p < 0.001), and LPA (p < 0.007), MVPA (p < 0.001), IG (p < 0.001) and AA (p < 0.001) all significantly lower in DOW versus MHW and MOW groups, even after adjusting for age and BMI. Quartiles based on AA had significantly different asthma profiles.

CONCLUSIONS

Overweight/obese participants with difficult-to-control asthma performed less PA, and activity of reduced intensity and volume. Increased AA is associated with improvement in several asthma-related outcomes. Increased PA should be recommended to relevant patients.

Association between illness perception and clinical control, quality of life, physical activity, and psychosocial status in subjects with moderate to severe asthma: a cluster analysis

Background: Illness perception (IP) is a psychosocial factor involved in several chronic diseases and is associated with relevant clinical outcomes. However, the relationship between IP and health-related quality of life (HRQoL), psychosocial status, and physical activity in daily life (PADL) in subjects with asthma is poorly understood.Objective: To identify groups of subjects with asthma based on their IPs and to assess their association with clinical control, HRQoL, psychosocial disturbances, and PADL.Methods: This cross-sectional study included 149 subjects with moderate to severe asthma. IP, anthropometric data, Asthma Control Questionnaire-7, Asthma Quality of Life Questionnaire, Hospital Anxiety and Depression Scale, PADL (accelerometry), and general self-efficacy (GSE) were assessed. Cluster analysis was performed to identify clusters with similar profiles and investigate their characteristics and differences. Pearson's correlation coefficient was used to test the associations between IP and other variables.Results: Statistical analyses identified two clusters of subjects with asthma based on IP. Cluster 1 presented worse IP in seven out of eight domains than Cluster 2. Cluster 1 had more negative consequences of the disease, worse understanding, and a high emotional representation of the disease than Cluster 2. Cluster 1 also had a greater extent of asthma symptoms, poor clinical control, worse HRQoL, and more symptoms of anxiety and depression. No difference between clusters was found for PADL or self-efficacy.Conclusion: Subjects with asthma who have worse IP have more negative symptoms, worse clinical control, HRQoL, and symptoms of anxiety and depression.

Increasing physical activity in severe asthma: a systematic review and meta-analysis

INTRODUCTION

Physical inactivity is common in asthma and is recognised as an important modifiable risk for poor clinical outcomes such as impaired asthma control and health-related quality of life (HRQoL). Despite evidence supporting the role of physical activity in reducing the risk of these outcomes, little is known about optimal interventions for increasing physical activity in those with severe disease. This systematic review and meta-analysis evaluates the effectiveness of interventions in increasing physical activity in severe asthma.

METHODS

MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, Embase, PubMed, Informit, SPORTDiscus and Cochrane databases were searched up to September 2021 for physical activity-based intervention studies that assessed physical activity outcomes (e.g. steps per day, time spent undertaking physical activity) in adults with severe asthma. Data on asthma-related (e.g. asthma control) and health-related outcomes (e.g. HRQoL) were assessed as secondary outcomes. The revised Cochrane Risk of Bias tool was used to assess risk of bias. Random-effects meta-analyses synthesised data where possible.

RESULTS

Four randomised controlled trials (all 12 weeks in duration) including 176 adults with moderate-to-severe asthma were included. An increase in physical activity was reported with a moderate-vigorous intensity aerobic and resistance training intervention (steps per day and time spent undertaking physical activity), and an unsupervised pedometer-based intervention (steps per day). Meta-analyses showed that physical activity interventions had an overall positive effect on steps per day (mean difference (MD) 1588, 95% CI 399-2778; p=0.009, I2=23), asthma control (MD -0.65, 95% CI -0.95--0.35; p<0.0001, I2=0%) and HRQoL (MD 0.56, 95% CI 0.10-1.01; p=0.02, I2=16%) compared to control.

CONCLUSION

While there is some evidence supporting the effectiveness of interventions in improving physical activity in adults with severe asthma, higher-quality, large-scale studies of longer duration are needed to determine the optimal intervention.

The NLRP3 inflammasome as a new target in respiratory disorders treatment

In recent years a continuous increase in new cases of respiratory disorders, such as rhinitis, asthma, and chronic obstructive pulmonary disease (COPD), has been observed. The exact pathomechanism of these diseases is still blurry, resulting in the lack of targeted and effective therapy. The conventional use of treatment strategies, such as antihistamine drugs and/or glucocorticosteroids act mainly symptomatically and have significant side effects. Specific allergen immunotherapy is only useful in the management of specific allergies and selected patients. Therefore, new therapeutic solutions are constantly being sought. The novelty of recent years has been the association between NLRP3 inflammasome activation and the development of airway inflammatory diseases. This seems to be an interesting therapeutic target that may support or even replace traditional therapies in the future. The review presented, discusses the contribution of NLRP3 inflammasome to the development of allergic rhinitis, allergic asthma, and COPD. Moreover, the modulatory properties of probiotics as potential inhibitors of NLRP3 inflammasome are emphasised.

Multimorbidity in Difficult Asthma: The Need for Personalised and Non-Pharmacological Approaches to Address a Difficult Breathing Syndrome

Three to ten percent of people living with asthma have difficult-to-treat asthma that remains poorly controlled despite maximum levels of guideline-based pharmacotherapy. This may result from a combination of multiple adverse health issues including aggravating comorbidities, inadequate treatment, suboptimal inhaler technique and/or poor adherence that may individually or collectively contribute to poor asthma control. Many of these are potentially "treatable traits" that can be pulmonary, extrapulmonary, behavioural or environmental factors. Whilst evidence-based guidelines lead clinicians in pharmacological treatment of pulmonary and many extrapulmonary traits, multiple comorbidities increase the burden of polypharmacy for the patient with asthma. Many of the treatable traits can be addressed with non-pharmacological approaches. In the current healthcare model, these are delivered by separate and often disjointed specialist services. This leaves the patients feeling lost in a fragmented healthcare system where clinical outcomes remain suboptimal even with the best current practice applied in each discipline. Our review aims to address this challenge calling for a paradigm change to conceptualise difficult-to-treat asthma as a multimorbid condition of a "Difficult Breathing Syndrome" that consequently needs a holistic personalised care attitude by combining pharmacotherapy with the non-pharmacological approaches. Therefore, we propose a roadmap for an evidence-based multi-disciplinary stepped care model to deliver this.

Associations between sarcopenia with asthmatic prevalence, lung function and comorbidity

BACKGROUND

Sarcopenia is listed as a treatment trait in behavioral/risk factors for severe asthma, but studies on asthma and sarcopenia are lacking. This study aimed to determine the associations between sarcopenia with asthmatic prevalence, symptoms, lung function and comorbidities.

METHODS

Fifteen thousand four hundred four individuals from the China Health and Retirement Longitudinal Study(CHARLS) and 10,263 individuals from the Study on global AGEing and adult health(SAGE) in China were included in this study. Four components of this study were used to assess the bidirectional association in the prevalence between sarcopenia with asthma, and estimate the relationships between sarcopenia with asthmatic symptoms, lung function and comorbidities via generalized additive models. The 10-item Center for Epidemiological Studies-Depression Scale ≥ 12 scores was classified as depression.

RESULTS

In the CHARLS and SAGE, the prevalence of sarcopenia in asthmatics was higher than those without asthma. Asthmatics with sarcopenia had a significantly increased prevalence of severe shortness of breath(sarcopenia yes vs. no, adjusted OR = 3.71, 95%CI: 1.43-9.60) and airway obstruction in the SAGE(sarcopenia yes vs. no, adjusted OR = 6.82, 95%CI: 2.54-18.34) and an obvious reduction of PEF in the CHARLS and SAGE(sarcopenia yes vs. no, adjusted RR = 0.86, 95%CI: 0.82-0.91) compared to asthmatics without sarcopenia. The presence of sarcopenia was positively associated with the prevalence of chronic obstructive pulmonary disease(sarcopenia yes vs no, adjusted OR = 5.76, 95%CI:2.01-16.5) and depression(sarcopenia yes vs no, adjusted OR = 1.87, 95%CI:1.11-3.14) in asthmatics.

CONCLUSIONS

Our findings indicated that sarcopenia partakes in the development of asthma by affecting lung function and comorbidities and maybe considered a treatable trait of asthma management.

Pulmonary rehabilitation versus usual care for adults with asthma

BACKGROUND

Asthma is a respiratory disease characterised by variable airflow limitation and the presence of respiratory symptoms including wheeze, chest tightness, cough and/or dyspnoea. Exercise training is beneficial for people with asthma; however, the response to conventional models of pulmonary rehabilitation is less clear.

OBJECTIVES

To evaluate, in adults with asthma, the effectiveness of pulmonary rehabilitation compared to usual care on exercise performance, asthma control, and quality of life (co-primary outcomes), incidence of severe asthma exacerbations/hospitalisations, mental health, muscle strength, physical activity levels, inflammatory biomarkers, and adverse events.

SEARCH METHODS

We identified studies from the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform, from their inception to May 2021, as well as the reference lists of all primary studies and review articles.

SELECTION CRITERIA

We included randomised controlled trials in which pulmonary rehabilitation was compared to usual care in adults with asthma. Pulmonary rehabilitation must have included a minimum of four weeks (or eight sessions) aerobic training and education or self-management. Co-interventions were permitted; however, exercise training alone was not.  DATA COLLECTION AND ANALYSIS: Following the use of Cochrane's Screen4Me workflow, two review authors independently screened and selected trials for inclusion, extracted study characteristics and outcome data, and assessed risk of bias using the Cochrane risk of bias tool. We contacted study authors to retrieve missing data. We calculated between-group effects via mean differences (MD) or standardised mean differences (SMD) using a random-effects model. We evaluated the certainty of evidence using GRADE methodology.

MAIN RESULTS

We included 10 studies involving 894 participants (range 24 to 412 participants (n = 2 studies involving n > 100, one contributing to meta-analysis), mean age range 27 to 54 years). We identified one ongoing study and three studies awaiting classification. One study was synthesised narratively, and another involved participants specifically with asthma-COPD overlap. Most programmes were outpatient-based, lasting from three to four weeks (inpatient) or eight to 12 weeks (outpatient). Education or self-management components included breathing retraining and relaxation, nutritional advice and psychological counselling. One programme was specifically tailored for people with severe asthma.  Pulmonary rehabilitation compared to usual care may increase maximal oxygen uptake (VO2 max) after programme completion, but the evidence is very uncertain for data derived using mL/kg/min (MD between groups of 3.63 mL/kg/min, 95% confidence interval (CI) 1.48 to 5.77; 3 studies; n = 129) and uncertain for data derived from % predicted VO2 max (MD 14.88%, 95% CI 9.66 to 20.1%; 2 studies; n = 60). The evidence is very uncertain about the effects of pulmonary rehabilitation compared to usual care on incremental shuttle walk test distance (MD between groups 74.0 metres, 95% CI 26.4 to 121.4; 1 study; n = 30). Pulmonary rehabilitation may have little to no effect on VO2 max at longer-term follow up (9 to 12 months), but the evidence is very uncertain (MD -0.69 mL/kg/min, 95% CI -4.79 to 3.42; I2 = 49%; 3 studies; n = 66). Pulmonary rehabilitation likely improves functional exercise capacity as measured by 6-minute walk distance, with MD between groups after programme completion of 79.8 metres (95% CI 66.5 to 93.1; 5 studies; n = 529; moderate certainty evidence). This magnitude of mean change exceeds the minimally clinically important difference (MCID) threshold for people with chronic respiratory disease. The evidence is very uncertain about the longer-term effects one year after pulmonary rehabilitation for this outcome (MD 52.29 metres, 95% CI 0.7 to 103.88; 2 studies; n = 42). Pulmonary rehabilitation may result in a small improvement in asthma control compared to usual care as measured by Asthma Control Questionnaire (ACQ), with an MD between groups of -0.46 (95% CI -0.76 to -0.17; 2 studies; n = 93; low certainty evidence); however, data derived from the Asthma Control Test were very uncertain (MD between groups 3.34, 95% CI -2.32 to 9.01; 2 studies; n = 442). The ACQ finding approximates the MCID of 0.5 points. Pulmonary rehabilitation results in little to no difference in asthma control as measured by ACQ at nine to 12 months follow-up (MD 0.09, 95% CI -0.35 to 0.53; 2 studies; n = 48; low certainty evidence). Pulmonary rehabilitation likely results in a large improvement in quality of life as assessed by the St George's Respiratory Questionnaire (SGRQ) total score (MD -18.51, 95% CI -20.77 to -16.25; 2 studies; n = 440; moderate certainty evidence), with this magnitude of change exceeding the MCID. However, pulmonary rehabilitation may have little to no effect on Asthma Quality of Life Questionnaire (AQLQ) total scores, with the evidence being very uncertain (MD 0.87, 95% CI -0.13 to 1.86; 2 studies; n = 442). Longer-term follow-up data suggested improvements in quality of life may occur as measured by SGRQ (MD -13.4, 95% CI -15.93 to -10.88; 2 studies; n = 430) but not AQLQ (MD 0.58, 95% CI -0.23 to 1.38; 2 studies; n = 435); however, the evidence is very uncertain. One study reported no difference between groups in the proportion of participants who experienced an asthma exacerbation during the intervention period. Data from one study suggest adverse events attributable to the intervention are rare.  Overall risk of bias was most commonly impacted by performance bias attributed to a lack of participant blinding to knowledge of the intervention. This is inherently challenging to overcome in rehabilitation studies.  AUTHORS' CONCLUSIONS: Moderate certainty evidence shows that pulmonary rehabilitation is probably associated with clinically meaningful improvements in functional exercise capacity and quality of life upon programme completion in adults with asthma. The certainty of evidence relating to maximal exercise capacity was very low to low. Pulmonary rehabilitation appears to confer minimal effect on asthma control, although the certainty of evidence is very low to low. Unclear reporting of study methods and small sample sizes limits our certainty in the overall body of evidence, whilst heterogenous study designs and interventions likely contribute to inconsistent findings across clinical outcomes and studies. There remains considerable scope for future research.

Body Composition-Specific Asthma Phenotypes: Clinical Implications

Background: Previous studies have indicated the limitations of body mass index for defining disease phenotypes. The description of asthma phenotypes based on body composition (BC) has not been largely reported. Objective: To identify and characterize phenotypes based on BC parameters in patients with asthma. Methods: A study with two prospective observational cohorts analyzing adult patients with stable asthma (n = 541 for training and n = 179 for validation) was conducted. A body composition analysis was performed for the included patients. A cluster analysis was conducted by applying a 2-step process with stepwise discriminant analysis. Logistic regression models were used to evaluate the association between identified phenotypes and asthma exacerbations (AEs). The same algorithm for cluster analysis in the independent validation set was used to perform an external validation. Results: Three clusters had significantly different characteristics associated with asthma outcomes. An external validation identified the similarity of the participants in training and the validation set. In the training set, cluster Training (T) 1 (29.4%) was “patients with undernutrition”, cluster T2 (18.9%) was “intermediate level of nutrition with psychological dysfunction”, and cluster T3 (51.8%) was “patients with good nutrition”. Cluster T3 had a decreased risk of moderate-to-severe and severe AEs in the following year compared with the other two clusters. The most important BC-specific factors contributing to being accurately assigned to one of these three clusters were skeletal muscle mass and visceral fat area. Conclusion: We defined three distinct clusters of asthma patients, which had distinct clinical features and asthma outcomes. Our data reinforced the importance of evaluating BC to determining nutritional status in clinical practice.

The Management of Extrapulmonary Comorbidities and Treatable Traits; Obesity, Physical Inactivity, Anxiety, and Depression, in Adults With Asthma

Asthma is a complex and heterogenous disease characterized by variability in disease expression and severity. Multiple extrapulmonary comorbidities and treatable traits are common in people with asthma, and there is an increasing appreciation of how these may complicate asthma management. This review will discuss the prevalence and impact of extrapulmonary comorbidities/risk factors or "traits," which have been found to co-exist in asthma (obesity, symptoms of depression and/or anxiety and physical inactivity), the impact these traits have on future outcomes (including exacerbation risk and quality of life) and asthma management, and how we should target treatment in asthma when these extrapulmonary traits are present.

The use of treatable traits to address COPD complexity and heterogeneity and to inform the care

COPD is complex and heterogeneous with respect to its aetiology, clinical presentation, phenotypes and biological mechanisms. Despite this, COPD is still diagnosed and treated according to simple clinical measures, including airflow limitation, symptoms and exacerbation frequency, leading to failure to recognise the disease's heterogeneity and/or to provide targeted interventions. COPD continues to have a very large burden of disease with suboptimal outcomes for people with the disease, including frequent hospitalisation with exacerbations, rapid lung function decline, multimorbidity and death from respiratory failure. In light of this, there have been increasing calls for a renewed taxonomy with better characterisation of COPD phenotypes and endotypes. This would allow the unravelling of COPD's complexity and heterogeneity, the implementation of targeted interventions and improved patient outcomes. The treatable traits strategy is a proposed vehicle for the implementation of precision medicine in chronic airway diseases. In this review, in addition to summarising the key knowledge on the heterogeneity of COPD, we refer to the existing evidence pertaining to the treatable traits strategy as applied in COPD and discuss implementation in different settings.

COPD is a heterogeneous clinical syndrome, which requires deconstruction of its individual components to facilitate targeted treatment and improve individual patient outcomes. 
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Treatable Traits in Chronic Respiratory Disease: A Comprehensive Review

Chronic respiratory diseases are major contributors to the global burden of disease. While understanding of these diseases has improved, treatment guidelines have continued to rely on severity and exacerbation-based approaches. A new personalised approach, termed the "treatable traits" approach, has been suggested to address the limitations of the existing treatment strategies. We aim to systematically review the current evidence regarding treatable traits in chronic respiratory diseases and to identify gaps in the current literature. We searched the PubMed and Embase databases and included studies on treatable traits and chronic respiratory diseases. We then extracted information on prevalence, prognostic implications, treatment options and benefits from these studies. A total of 58 papers was included for review. The traits identified were grouped into five broad themes: physiological, biochemical, psychosocial, microbiological, and comorbidity traits. Studies have shown advantages of the treatable traits paradigm in the clinical setting. However, few randomised controlled trials have been conducted. Findings from our review suggest that multidisciplinary management with therapies targeted at treatable traits has the potential to be efficacious when added to the best practices currently implemented. This paradigm has the potential to improve the holistic care of chronic respiratory diseases.

Adult but not childhood onset asthma is associated with the metabolic syndrome, independent from body mass index

INTRODUCTION

Adult-onset asthma (AOA) is usually more severe compared to childhood onset asthma (CoA). Given the increasing evidence that AoA is associated with obesity, we investigated the relationship of other related metabolic comorbid conditions with AoA compared to CoA.

STUDY DESIGN AND METHODS

This cross-sectional study compared the metabolic syndrome and lipid derived inflammatory markers in patients with AoA, CoA and age- and sex-matched control subjects without asthma. Participants were asthma patients visiting the outpatient clinic of two teaching hospitals in Rotterdam, The Netherlands. All participants underwent lung function tests, blood tests and physical activity tracking. AoA was defined as asthma age of onset after the age of 18 years. Metabolic syndrome was defined according to the international joint interim statement criteria.

RESULTS

Eighty-one participants were included (27 AoA, 25 CoA, 29 controls). AoA was associated with the metabolic syndrome (Odds Ratio = 3.64 95% CI (1.16-11.42) p = 0.03, Nagelkerke R² = 0.26), adjusted for age, sex, body mass index and smoking habits. AoA patients had higher median serum IL-6 and leptin-adiponectin (LA) ratio compared to controls (IL-6 (pg/mL): 3.10 [1.11-4.30] vs. 1.13 [0.72-1.58], p = 0.002 and LA ratio (pg/mL): 6.21 [2.45-14.11] vs. 2.24 [0.67-4.71], p = 0.0390). This was not observed in CoA and controls.

CONCLUSION

AoA was associated with the metabolic syndrome and its related pro-inflammatory endocrine and cytokine status. This may suggest adipose tissue derived inflammatory markers play a role in the pathophysiology of AoA.

Recent Insights into the Management of Inflammation in Asthma

The present prevailing inflammatory paradigm in asthma is of T2-high inflammation orchestrated by key inflammatory cells like Type 2 helper lymphocytes, innate lymphoid cells group 2 and associated cytokines. Eosinophils are key components of this T2 inflammatory pathway and have become key therapeutic targets. Real-world evidence on the predominant T2-high nature of severe asthma is emerging. Various inflammatory biomarkers have been adopted in clinical practice to aid asthma characterization including airway measures such as bronchoscopic biopsy and lavage, induced sputum analysis, and fractional exhaled nitric oxide. Blood measures like eosinophil counts have also gained widespread usage and multicomponent algorithms combining different parameters are now appearing. There is also growing interest in potential future biomarkers including exhaled volatile organic compounds, micro RNAs and urinary biomarkers. Additionally, there is a growing realisation that asthma is a heterogeneous state with numerous phenotypes and associated treatable traits. These may show particular inflammatory patterns and merit-specific management approaches that could improve asthma patient outcomes. Inhaled corticosteroids (ICS) remain the mainstay of asthma management but their use earlier in the course of disease is being advocated. Recent evidence suggests potential roles for ICS in combination with long-acting beta-agonists (LABA) for as needed use in mild asthma whilst maintenance and reliever therapy regimes have gained widespread acceptance. Other anti-inflammatory strategies including ultra-fine particle ICS, leukotriene receptor antagonists and macrolide antibiotics may show efficacy in particular phenotypes too. Monoclonal antibody biologic therapies have recently entered clinical practice with significant impacts on asthma outcomes. Understanding of the efficacy and use of those agents is becoming clearer with a growing body of real-world evidence as is their potential applicability to other treatable comorbid traits. In conclusion, the evolving understanding of T2 driven inflammation alongside a treatable traits disease model is enhancing therapeutic approaches to address inflammation in asthma.

Persistent Uncontrolled Asthma: Long-Term Impact on Physical Activity and Body Composition

Rationale

Asthma, obesity and physical activity (PA) are interrelated. However, longitudinal data with objective PA measures and direct assessment of body composition are still lacking.

Objective

To study the impact of symptom control on PA and body composition.

Methods

In a longitudinal cohort study of the German Center for Lung Research, we assessed the body composition of 233 asthma patients and 84 healthy controls using bioelectrical impedance analysis. PA (ie average daily steps and time of at least moderate activity, steps/min) was measured by accelerometry for one week. Asthma control was assessed by ACT score, ACQ-5 score and history of severe exacerbations. After two years of follow-up, we studied changes in physical activity and body composition in relation to asthma control.

Results

Patients with uncontrolled asthma had increased fat mass and decreased muscle mass compared to patients with controlled asthma or healthy controls. Both fat mass and muscle mass correlated better with asthma control than the body mass index (BMI). In multivariate regressions adjusted for age and sex, asthma control and physical activity were independent predictors of body composition (R² = 0.61, p < 0.001). Persistent uncontrolled asthma patients (n=64) had lower physical activity at both baseline (6614 steps/118 min) and follow-up (6195/115). Despite having stable BMI, they also had significant muscle loss (−1.2%, −0.88 kg, p<0.01) and fat accumulation (+1%, +1.1 kg, p<0.01). By contrast, temporarily uncontrolled or controlled asthma patients had higher physical activity at baseline (8670/156) and follow -up (9058/153) with almost unchanged body composition.

Conclusion

Persistent uncontrolled asthma is associated with sustained physical inactivity and adverse changes in body composition that might be overlooked by relying solely on BMI. Physical activity is an independent predictor of body composition and reliable long-term marker of symptom control.

Functional tests for adults with asthma: validity, reliability, minimal detectable change, and feasibility

OBJECTIVE

To verify the validity, reliability, learning effect, Minimal Detectable Change (MDC), and feasibility of four functional tests (4-Meter Gait Speed [4MGS], Timed Up-and-Go [TUG], Sit-To-Stand [STS], and Short Physical Performance Battery [SPPB]) for adults with asthma.

METHODS

In this cross-sectional study, fifty-two subjects with stable asthma underwent three sets of different functional tests protocols (4MGS, TUG, STS, SPPB) in a random order by two raters. For validation analysis, tests were compared with a sex-age matched control group without asthma and correlated with the Six Minute Walking Test (6MWT), and peripheral muscle strength, as well as with quality of life and asthma control questionnaires. Intra-rater and inter-rater reliability, MDC, and feasibility were verified.

RESULTS

Adults with asthma presented worse results than controls in the functional tests, except for SPPB. All functional tests were significantly correlated with 6MWT (0.45 < r < 0.67) and peripheral muscle strength (0.32 < r < 0.63), but not with quality of life and asthma control (0.02 < r < 0.17). The tests presented good to excellent intra-rater Intraclass Correlation Coefficients (ICC ≥ 0.75 for all). In all tests, a considerable learning effect and variability of measurement was observed, therefore, the best of two measurements should be used. MDC ranged from 15 to 31% and all tests were performed in a short time, small space, and without clinical adverse events.

CONCLUSION

Different protocols of 4MGS, TUG, STS, and SPPB are valid, reliable, and feasible to assess the functional capacity of adults with asthma. These tests are quick and practical new alternatives for assessing functional capacity in this population.

A Behavior Change Intervention Aimed at Increasing Physical Activity Improves Clinical Control in Adults With Asthma: A Randomized Controlled Trial

BACKGROUND

Higher levels of physical activity have been associated with better asthma clinical control.

RESEARCH QUESTION

Does a behavior change intervention aimed at increasing physical activity change asthma clinical control, physical activity, sedentary time, health-related quality of life (HRQoL), and anxiety and depression symptoms?

STUDY DESIGN AND METHODS

This single-blind, randomized controlled trial included participants who were allocated to an intervention group (IG) or to a control group (CG). Both groups received usual care and disease-specific education. Participants in the IG also underwent an 8-week behavior change intervention aimed at increasing physical activity. Prior to and following the intervention period, measures were made of asthma clinical control (Asthma Control Questionnaire [ACQ]), physical activity, sedentary time and sleep quality (ActiGraph), HRQoL (Asthma Quality of Life Questionnaire), and anxiety and depression symptoms (Hospital Anxiety and Depression Scale). Data on asthma exacerbations were recorded 12 months prior to and throughout the intervention period.

RESULTS

Fifty-one participants were included (CG, n = 26; IG, n = 25). On completion of the intervention period, compared with the CG, those in the IG exhibited improvements in asthma control (mean difference [95% CI] in ACQ score, -0.8 [-1.1 to -0.4]); in daily step count, 3,605 [1,937 to 8,867] steps/d; in sleep efficiency, 9.2% [-7.1% to 21.9%]; and a reduction in sedentary time, -1.1 [-2.9 to -0.6] h/d). No between-group difference in HRQoL was observed. The percentage of participants who experienced exacerbations during the intervention period was 27% in the IG vs 60% in the CG (P = .04). The change in time spent in moderate-intensity physical activity was inversely associated with change in ACQ (r = -0.60). Compared with the CG, a higher percentage of participants in the IG reported a reduction in anxiety symptoms (43% vs 0%; P < .02).

INTERPRETATION

In adults with moderate to severe asthma, a comprehensive behavior change intervention that increased physical activity also produced improvements in asthma clinical control, sedentary time, sleep quality, and anxiety symptoms.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT03705702; URL: www.clinicaltrials.gov.