Activity limitation and exertional dyspnea in adult asthmatic patients: What do we know?

Systemic inflammation in midlife is associated with late-life functional limitations

Systemic inflammation generally coexists with functional limitations that seriously affect quality of life. This study aimed to investigate the association between systemic inflammation in midlife and the risk of functional limitations in late-life. A total of 10,044 participants with an average age of 53.9 ± 5.7 years at baseline were included in a cohort study. At the last follow-up, the prevalence of impaired activities of daily living (ADLs), instrumental activities of daily living (IADLs), and lower extremity function (LEF) was 14.7%, 21.6%, and 50.3%, respectively. The values of four inflammatory biomarkers were used to calculate the inflammation composite score. Compared with the participants in the lowest quartile of the inflammation composite score (Q1), those in the highest quartile (Q4) exhibited an odds ratio (OR) of 1.589 and a 95% confidence interval (CI) of 1.335-1.892 for impaired ADLs, an OR of 1.426 and a 95% CI of 1.228-1.657 for impaired IADLs, and an OR of 1.728 and a 95% CI of 1.526-1.957 for impaired LEF. The association between systemic inflammation and functional limitations was partly mediated by cardiac and brain function. The present study provides evidence that systemic inflammation in midlife is associated with a higher risk of late-life functional limitations. Protecting vital organ functions in midlife may have a positive impact on reducing the risk of future functional limitations.Trial registration: www.clinicaltrials.gov ; Unique identifier: NCT00005131.

Handgrip strength associates with effort-dependent lung function measures among adolescents with and without asthma

Studies have shown association between handgrip strength (HGS) and FEV1, but the importance of this in relation to asthma pathophysiology and diagnostics remains unclear. We investigated the relationship between HGS and lung function metrics and its role in diagnosing asthma. We included 330 participants (mean age: 17.7 years, males: 48.7%) from the COPSAC2000 cohort and analyzed associations between HGS, asthma status, spirometry measures (FEV1, FVC, MMEF, FEV1/FVC), airway resistance (sRaw), methacholine reactivity (PD20) and airway inflammation (FeNO). Finally, we investigated whether HGS improved FEV1 prediction and classification of asthma status. HGS was only associated with forced flows, i.e., positive association with FEV1 and FVC for both sexes in models adjusted for age, height, and weight (P < 0.023). HGS improved adjusted R2-values for FEV1 prediction models by 2-5% (P < 0.009) but did not improve classification of asthma status (P > 0.703). In conclusion, HGS was associated with the effort-dependent measures FEV1 and FVC, but not with airway resistance, reactivity, inflammation or asthma status in our cohort of particularly healthy adolescents, which suggests that the observed associations are not asthma specific. However, HGS improved the accuracy of FEV1 estimation, which warrants further investigation to reveal the potential of HGS in asthma diagnostics.

The impact of anti-eosinophilic therapy on exercise capacity and inspiratory muscle strength in patients with severe asthma

Introduction

Exercise limitation is frequently described among asthmatic patients and could be related to different mechanisms of the pulmonary, cardiovascular and muscular systems. Despite this, cardiopulmonary exercise testing (CPET) does not have an established role in the management of severe asthma. The aim of our study was to investigate the role of CPET and inspiratory pressure measurement in exercise capacity and muscle strength in severe asthmatic patients treated with anti-IL-5 therapy.

Methods

A monocentric observational study was conducted at Hanover Medical School, Germany, from April 2018 to June 2019. Patients affected by severe asthma treated with either mepolizumab or benralizumab were included. All patients underwent CPET before the initiation of antibody therapy and after 3 months, and follow-up visits were scheduled at 3, 6 and 12 months with plethysmography, inspiratory pressure measurement and blood gas analysis.

Results

14 patients were enrolled: 10 (71.4%) females, median age 52 years (IQR 47-61). Seven patients were treated with benralizumab, seven with mepolizumab. Oxygen uptake (V'_O2 peak) did not change significantly after 3 months of antibody treatment, while the mean value of the breathing reserve exhaustion reduced significantly from 78% to 60% (p=0.004). Whereas at baseline seven patients depleted the breathing reserve and two of them experienced oxygen desaturation during exercise, at 3 months no one presented any desaturation or breathing reserve exhaustion. The inspiratory pressure remained unchanged before and after the antibody therapy.

Conclusion

CPET could show hints of alveolar recruitment and ventilatory efficiency in severe asthma patients treated with antibody therapy.

Validity of the International Physical Activity Questionnaire (short form) in adults with asthma

BACKGROUND

The short form of the International Physical Activity Questionnaire (IPAQ) is widely used to assess PA and has already been used in adults with asthma; however, its validity has not been yet studied in this population. Therefore, the aim of this study was to verify the convergent and discriminative validity of the IPAQ short form in adults with asthma.

METHODS

Fifty-three adults with asthma (36 females; 48±15 years; 29±6 kg/m²) wore the triaxial activity monitor Actigraph for eight days to objectively measure steps/day, time in light physical activity (PA), moderate-to-vigorous PA (MVPA), and sedentary behaviour. Participants filled out the IPAQ matching with the same week they wore the Actigraph, with measures of: time of MVPA and total PA/week; categorization of low, moderate or high PA level; time in seated position.

RESULTS

IPAQ self-reported total time of PA/week was weakly correlated with steps/day. The IPAQ categorization correlated moderately with time in light, MVPA and steps/day. Self-reported time in seated position on weekdays was moderately correlated with objective percentage/day of time in sedentary behaviour in the same period. IPAQ categorization in PA levels was able to differentiate between low to moderate and low to high PA levels.

CONCLUSIONS

These results cannot confidently infer the convergent validity of the IPAQ to quantify number of steps/day and time spent in PA of adults with asthma. However, this instrument may be useful to categorize patients into three levels of PA.

Does the severity of asthma affect exercise capacity and daily physical activity?

OBJECTIVE

Exercise capacity, daily physical activity, and psychological profile are crucial aspects in the management of asthmatic patients. Whether these features are expressed in a different way in mild-moderate (MMA) and severe asthma (SA) is unknown.

METHODS

In this observational cross-sectional study, patients matching the American Thoracic Society/European Respiratory Society (ATS/ERS) definition for SA underwent incremental cardiopulmonary exercise testing (CPET), full lung function testing, and an evaluation of daily step count and physical activity. Questionnaires on quality of life, general fatigue, and presence of anxiety and depression traits (Hospital Anxiety and Depression Scale - HADS) were administered. Patients were compared with a cohort of age- and gender-matched MMA patients.

RESULTS

We enrolled 16 SA, 17 MMA patients, and 16 healthy subjects. Compared to MMA, SA subjects showed a median (interquartile range) reduced peak oxygen consumption during CPET (20.4 (17.2-23.3) vs. 25.6 (18.5-30.3) ml/min/kg; p = 0.019), a reduced resting lung function (FEV1% of predicted 77 (67-84) vs. 96 (84-100); p < 0.001) and a pronounced anxiety trait at HADS (9.5 (3-11.7) vs. 4.0 (2.0-7.5); p = 0.023). In addition, SA patients showed a significantly higher reduction in inspiratory capacity from rest to peak (310 (160-520) vs. 110 (-65-325) ml; p = 0.031). We found no significant differences in mean daily step count or quality of life.

CONCLUSIONS

Compared to MMA, SA patients present a reduced exercise capacity and a more pronounced anxiety trait, but not worse daily physical activity or quality of life. These aspects should be considered in the clinical management and research development of SA.

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.

Characterization of Asthma by Age of Onset: A Multi-Database Cohort Study

BACKGROUND

Asthma can occur at any age but the differences in patient characteristics between childhood-, adult-, and late-onset asthma are not well understood.

OBJECTIVE

To investigate differences in patients' characteristics by age at asthma onset.

METHODS

From 5 European electronic databases, we created a cohort encompassing adult patients with doctor-diagnosed asthma in 2008 to 2013. Patients were categorized based on their age at asthma onset: childhood-onset (age at onset < 18 y), adult-onset (age at onset 18-40 y), and late-onset asthma (age at onset ≥ 40 y). Comorbidities were assessed at study entry. For each characteristic and comorbidity, odds ratios and age- and sex-adjusted odds ratios (OR_adj) comparing asthma-onset categories were estimated per database and combined in a meta-analysis using a random effect model.

RESULTS

In total, 586,436 adult asthma patients were included, 81,691 had childhood-onset, 218,184 adult-onset, and 286,561 late-onset asthma. Overall, 7.3% had severe asthma. Subjects with adult-onset compared with childhood-asthma had higher risks for overweight/obesity (OR_adj 1.4; 95% CI 1.1-1.8) and lower risks for atopic disorders (OR_adj 0.8; 95% CI 0.7-0.95). Patients with late-onset compared with adult-onset asthma had higher risks for nasal polyposis (OR_adj 1.8; 95% CI 1.2-2.6), overweight/obesity (OR_adj 1.3; 95% CI 1.2-1.4), gastroesophageal reflux disease (OR_adj 1.4; 95% CI 1.2-1.7), and diabetes (OR_adj 2.3; 95% CI 1.8-2.9). A significant association between late-onset asthma and uncontrolled asthma was observed (OR_adj 2.8; 95% CI 1.7-4.5).

CONCLUSIONS

This international study demonstrates clear differences in comorbidities between childhood-, adult-, and late-onset asthma phenotypes in adults. Furthermore, patients with late-onset asthma had more frequent uncontrolled asthma.

Electrical activity and fatigue of respiratory and locomotor muscles in obstructive respiratory diseases during field walking test

Introduction

In subjects with obstructive respiratory diseases the increased work of breathing during exercise can trigger greater recruitment and fatigue of respiratory muscles. Associated with these changes, lower limb muscle dysfunctions, further contribute to exercise limitations. We aimed to assess electrical activity and fatigue of two respiratory and one locomotor muscle during Incremental Shuttle Walking Test (ISWT) in individuals with obstructive respiratory diseases and compare with healthy.

Methods

This is a case-control study. Seventeen individuals with asthma (asthma group) and fifteen with chronic obstructive pulmonary disease (COPD group) were matched with healthy individuals (asthma and COPD control groups). Surface electromyographic (sEMG) activity of sternocleidomastoid (SCM), scalene (ESC), and rectus femoris (RF) were recorded during ISWT. sEMG activity was analyzed in time and frequency domains at baseline and during the test (33%, 66%, and 100% of ISWT total time) to obtain, respectively, signal amplitude and power spectrum density (EMG median frequency [MF], high- and low-frequency bands, and high/low [H/L] ratio).

Results

Asthma group walked a shorter distance than controls (p = 0.0007). sEMG amplitudes of SCM, ESC, and RF of asthma and COPD groups were higher at 33% and 66% of ISWT compared with controls groups (all p<0.05). SCM and ESC of COPD group remained higher until 100% of the test. MF of ESC and RF decreased in asthma group (p = 0.016 and p < 0.0001, respectively) versus controls, whereas MF of SCM (p < 0.0001) decreased in COPD group compared with controls. H/L ratio of RF decreased (p = 0.002) in COPD group versus controls.

Conclusion

Reduced performance is accompanied by increased electromyographic activity of SCM and ESC and activation of RF in individuals with obstructive respiratory diseases during ISWT. These are susceptible to be more pronounced respiratory and peripheral muscle fatigue than healthy subjects during exercise.

Occupational Competence and Activities of Daily Living Performance in Bronchial Asthma : Compétence professionnelle et performance des activités de la vie quotidienne pour la bronchite asthmatique

Background. Activity restriction is one of the most common symptoms reported by people living with bronchial asthma. Purpose. The study aimed to determine occupational competence and values in people living with bronchial asthma and compare with the occupational competence and activities of daily living (ADL) of healthy controls. Methods. Twenty individuals with asthma and 20 healthy controls were enrolled. Occupational competence and values were assessed using the Occupational Self-Assessment (OSA) questionnaire. Restriction of ADL was determined using the London Chest ADL Scale. Findings. Occupational competence was lower, and all London Chest ADL scores were significantly higher in asthma individuals compared to controls (p < .05). The most affected parameters reported by asthma individuals on the OSA were the ability to concentrate, perform physical tasks, work toward goals, and use abilities effectively. Implications. Evaluating occupational competence in people living with bronchial asthma is important to identify their occupational problem areas and provide appropriate interventions.

Incidence and predictors of asthma exacerbations in middle-aged and older adults: the Rotterdam Study

Aim

The aim of this study was to investigate occurrence and determinants of asthma exacerbations in an ageing general population.

Methods

Subjects aged 45 years or above with physician-diagnosed asthma in the Rotterdam Study, a population-based prospective cohort from January 1991 to May 2018, were assessed for asthma exacerbations. Exacerbations were defined as acute episodes of worsening asthma treated with oral corticosteroids. Cox proportional hazards analysis was used to investigate risk factors for a future exacerbation.

Results

Out of 763 participants with asthma (mean age 61.3 years, 69.2% female), 427 (56.0%) experienced at least one exacerbation, in a mean follow-up time of 13.9 years. The mean annual exacerbation rate was 0.22. Most exacerbations occurred during winter months. Risk factors for exacerbations were a history of previous exacerbations (HR 4.25; 95% CI 3.07–5.90, p<0.001)), respiratory complaints (HR 2.18; 95% CI 1.48–3.21, p<0.001), airflow obstruction (HR 1.52; 95% CI 1.07–2.15, p=0.019), obesity (HR 1.38; 95% CI 1.01–1.87, p=0.040) and depressive symptoms (HR 1.55; 95% CI 1.05–2.29, p=0.027). Compared to those not using respiratory medication, we observed higher hazard ratios for those on short-acting β₂-agonists (SABA, i.e. rescue medication) only (HR 3.08, 95% CI 1.61–5.90, p=0.001) than those on controller medication (HR 2.50, 95% CI 1.59–3.92, p<0.001).

Conclusion

Many older adults with asthma suffer from at least one severe exacerbation. Previous exacerbations, use of SABA without concomitant controller medication, respiratory complaints, obesity, airway obstruction and depression are independent risk factors for exacerbations.

Most middle-aged and older adults with asthma suffer from at least one severe exacerbation. Risk factors are previous exacerbations, use of SABA without concomitant controller medication, respiratory complaints, obesity, airway obstruction and depression.https://bit.ly/3gcTO6t

Validity and reliability of 6-minute pegboard and ring test in patients with asthma

OBJECTIVE

The 6-minute pegboard and ring test (6PBRT) is a test of upper-extremity functional capacity designed for and validated in chronic obstructive pulmonary disease. The aim of this study was to evaluate the validity and reliability of the 6PBRT in asthma patients.

METHODS

Thirty-four adults (30 women, 4 men) with well-controlled asthma were included. Unsupported upper-extremity exercise capacity was assessed using 6PBRT, maximal arm exercise capacity using an arm ergometer, handgrip strength using a hand dynamometer, activities of daily living with the London Chest Activities of Daily Living Scale (LCADL), Milliken ADL scale (MAS) and health-related quality of life using the Asthma Quality of Life Questionnaire (AQLQ) and Health Assessment Questionnaire Disability Index (HAQ-DI).

RESULTS

The 6PBRT showed moderate to excellent test-retest reliability with an intraclass correlation coefficient (ICC) value of 0.872 [95% confidence interval (CI) 0.702-0.941]. The 6PBRT was reproducible according to Bland-Altman analysis, with upper and lower limits of agreement of 53.51 and -25.08 rings moved, respectively. The 6PBRT score was significantly correlated with maximum workload (r = 0.514, p = 0.002) achieved in the arm ergometer test, change in dyspnea during 6PBRT (r = -0.402, p = 0.020), LCADL-self-care (r = -0.364, p = 0.037), MAS total (r = 0.483, p = 0.005), AQLQ-symptom domain (r = 0.420, p = 0.026) and HAQ-DI total scores (r = -0.390, p = 0.025).

CONCLUSIONS

The 6PBRT can be used as a valid and reliable test to evaluate functional arm exercise capacity in patients with well-controlled asthma.

[Physical activity and pulmonary rehabilitation in adults with asthma]

Physical activity is reduced in people with asthma compared to the general population, especially in situations where patients have uncontrolled asthma symptoms, persistent airflow obstruction and other long-term medical problems, in particular obesity and anxiety. Exertional dyspnea, which is of multifactorial origin, is the main cause of reduced physical activity reduction and draws patients into a vicious circle further impairing quality of life and asthma control. Both the resumption of a regular physical activity, integrated into daily life, adapted to patients' needs and wishes as well as physical and environmental possibilities for mild to moderate asthmatics, and pulmonary rehabilitation (PR) for severe and/or uncontrolled asthmatics, improve control of asthma, dyspnea, exercise tolerance, quality of life, anxiety, depression and reduce exacerbations. A motivational interview to promote a regular programme of physical activity in mild to moderate asthma (steps 1 to 3) should be offered by all health professionals in the patient care pathway, within the more general framework of therapeutic education. The medical prescription of physical activities, listed in the Public Health Code for patients with long-term diseases, and pulmonary rehabilitation should be performed more often by specialists or the attending physician. Pulmonary rehabilitation addresses the needs of severe asthma patients (steps 4 and 5), and of any asthmatic patient with poorly controlled disease and/or requiring hospitalized for acute exacerbations, regardless of the level of airflow obstruction, and/or with associated comorbidities, and before prescribing biological therapies.

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.

"Can Do" Versus "Do Do" in Patients with Asthma at First Referral to a Pulmonologist

BACKGROUND

Pharmacotherapy is key in asthma control, including preventing lung function decline, in primary care. However, patients' physical functioning (eg, physical capacity [PC] [=can do] and physical activity [PA] [=do do]) correlates poorly with lung function. Therefore, a better insight into the physical function of patients with asthma is needed, using the "can do, do do" concept.

OBJECTIVE

To explore the "can do, do do" concept in adult patients with asthma at referral for the first time to an outpatient consultation of a pulmonologist.

METHODS

PC was measured using the six-minute walk test and PA by using an accelerometer. Patients were classified into quadrants: low PC (6-minute walking distance <70% predicted), low PA (<7000 steps/d, "'can't do, don't do"); preserved PC, low PA ("can do, don't do"); low PC, preserved PA ("'can't do, do do"); or preserved PC, preserved PA ("can do, do do").

RESULTS

A total of 479 patients with asthma had a median (interquartile range) 6-minute walking distance of 74% (66%-82%) predicted, and walked 6829 (4593-9075) steps/d. Only 29% were classified as "can do, do do," whereas 30% were classified as "can't do, don't do." The Asthma Control Questionnaire and the Asthma Quality of Life Questionnaire scores were worst in the "can't do" groups.

CONCLUSIONS

Low PC and/or PA was found in most patients with asthma at the index referral to a pulmonologist. An impaired PC is accompanied by a significantly reduced asthma control and disease-specific quality of life. This justifies further studies on safety and efficacy of nonpharmacological interventions, such as physiotherapy.

A Dyadic Growth Modeling Approach for Examining Associations Between Weight Gain and Lung Function Decline

The relationship between body weight and lung function is complex. Using a dyadic multilevel linear modeling approach, treating body mass index (BMI; weight (kg)/height (m)2) and lung function as paired, within-person outcomes, we tested the hypothesis that persons with more rapid increase in BMI exhibit more rapid decline in lung function, as measured by forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and their ratio (FEV1:FVC). Models included random intercepts and slopes and adjusted for sociodemographic and smoking-related factors. A sample of 9,115 adults with paired measurements of BMI and lung function taken at ≥3 visits were selected from a pooled set of 5 US population-based cohort studies (1983-2018; mean age at baseline = 46 years; median follow-up, 19 years). At age 46 years, average annual rates of change in BMI, FEV1, FVC, and FEV1:FVC ratio were 0.22 kg/m2/year, -25.50 mL/year, -21.99 mL/year, and -0.24%/year, respectively. Persons with steeper BMI increases had faster declines in FEV1 (r = -0.16) and FVC (r = -0.26) and slower declines in FEV1:FVC ratio (r = 0.11) (all P values < 0.0001). Results were similar in subgroup analyses. Residual correlations were negative (P < 0.0001), suggesting additional interdependence between BMI and lung function. Results show that greater rates of weight gain are associated with greater rates of lung function loss.

Cardiopulmonary exercise testing in patients with asthma: What is its clinical value?

Asthma is one of the most common respiratory disorders, characterized by fully or largely reversible airflow limitation. Asthma symptoms can be triggered or magnified during exertion, while physical activity limitation is often present among asthmatic patients. Cardiopulmonary exercise testing (CPET) is a dynamic, non-invasive technique which provides a thorough assessment of exercise physiology, involving the integrative assessment of cardiopulmonary, neuromuscular and metabolic responses during exercise. This review summarizes current evidence regarding the utility of CPET in the diagnostic work-up, functional evaluation and therapeutic intervention among patients with asthma, highlighting its potential role for thorough patient assessment and physician clinical desicion-making.

Extrapulmonary associations of health status in severe asthma and bronchiectasis: Comorbidities and functional outcomes

BACKGROUND

Severe asthma and bronchiectasis are heterogeneous diseases that contribute to disability beyond the pulmonary system. The magnitude of the impact that these extrapulmonary features has on health-related quality of life (HRQoL) is unknown.

METHODS

We analysed the cross-sectional relationships between HRQoL (St. George's Respiratory Questionnaire; SGRQ) and extrapulmonary characteristics, including physical activity (steps/day), anxiety and depression, isometric leg strength, systemic inflammation, and several comorbidities in adults with severe asthma (n = 70) and bronchiectasis (n = 61).

RESULTS

Participants with severe asthma and bronchiectasis had similar SGRQ total scores (mean scores 43.7 and 37.8 for severe asthma and bronchiectasis; p > 0.05), and similar pulmonary and extrapulmonary characteristics. The associations between extrapulmonary variables and HRQoL did not differ according to diagnosis (all interactions p > 0.05). Greater anxiety and depressive symptoms, fewer steps/day and greater systemic inflammation were statistically associated with poorer HRQoL in both diseases (p < 0.05). Lower isometric leg strength in severe asthma, and greater Charlson Comorbidity Index in bronchiectasis were also associated with poorer HRQoL (p < 0.05). In the multivariable regression model performed in the combined disease groups, anxiety and depression, steps/day, systemic inflammation and isometric leg strength remained independently associated with HRQoL. Associations between extrapulmonary characteristics and SGRQ domains were stronger for the activity and impact domains, than symptoms.

CONCLUSION

In severe asthma and bronchiectasis, extrapulmonary features including physical activity and leg strength have a significant impact on HRQoL, especially within the activity and impact domains. These features should be considered as part of the assessment of these conditions, and they may represent additional treatment targets to improve HRQoL.

Dynamic hyperinflation impairs daily life activity in asthma

INTRODUCTION

Dynamic hyperinflation has been documented in asthma, yet its impact on overall health and daily life activities is unclear. We assessed the prevalence of dynamic hyperinflation in moderate to severe asthma and its relationship with the scores of a set of specific and general respiratory health questionnaires.

METHODS

77 nonsmoking asthma patients (Global Initiative for Asthma steps 4-5) were recruited consecutively and completed five questionnaires: Asthma Control Questionnaire, Clinical COPD (chronic obstructive pulmonary disease) Questionnaire, St George's Respiratory Questionnaire, London Chest Activity of Daily Living scale (LCADL) and Shortness of Breath with Daily Activities (SOBDA). Dynamic hyperinflation was defined as ≥10% reduction in inspiratory capacity induced by standardised metronome-paced tachypnoea. Associations between level of dynamic hyperinflation and questionnaire scores were assessed and adjusted for asthma severity.

RESULTS

81% (95% CI 71.7-89.4%) of patients showed dynamic hyperinflation. Higher levels of dynamic hyperinflation were related to poorer scores on all questionnaires (r=0.228-0.385, p<0.05). After adjustment for asthma severity, dynamic hyperinflation remained associated with poorer scores on LCADL (p=0.027) and SOBDA (p=0.031).

CONCLUSION

Dynamic hyperinflation is associated with poorer overall health and impaired daily life activities, independent of asthma severity. Because of its major impact on everyday life activities, dynamic hyperinflation is an important target for treatment in asthma.

Understanding the measurement properties of the incremental shuttle walk test in patients with severe asthma

BACKGROUND AND OBJECTIVE

We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO_2pk ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma.

METHODS

Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis.

RESULTS

A total of 50 patients (32 females, mean (SD), age: 54 (13) years, forced expiratory volume in 1 s (FEV₁ ): 1.9 (0.8) L and body mass index (BMI): 32 (6) kg/m² ) completed all five tests. The mean (SD) ISWT distance for each test was 400 (156), 418 (142) and 438 (157) m (P = 0.001), respectively. There was a strong correlation between the ISWT distance with VO_2pk derived from ITM (r = 0.74, P < 0.001) and ICE (r = 0.75, P < 0.001).

CONCLUSION

There was a small increase in the mean ISWT distance on sequential testing. In clinical practice, the coefficient of repeatability and heteroscedasticity need to be considered when assessing whether a true change has occurred within an individual patient. The ISWT has validity compared to VO_2pk on both ICE and ITM, but they are not interchangeable.

[Dyspnoea in asthma: diagnostic approach]

Dyspnoea is a cardinal symptom of asthma and an essential part of assessing control of the disease. Its intensity is variable for the same level of bronchial obstruction, which suggests the involvement of other mechanisms. Therefore, it is extremely important to characterize and measure dyspnoea in asthmatic patients because its profile can be quantitatively and qualitatively modified by disease control, comorbidities and anxiety. Hence the value of using additional tools to ACT and ACQ because the latter do not characterize nor measure specifically dyspnoea in asthma. Different tools can be used in this regard, at rest as the subjective assessment of dyspnoea by scales such as the modified Medical Research Council (mMRC), the New York Heart Association (NYHA) and the Visual Analogue Scale (VAS) or more recently using the Dyspnea-12 and the Multidimensional Dyspnea Profile (MDP) questionnaire, which assesses the sensory and affective dimensions of dyspnoea; and during exercise testing such as the "modified" Borg scale, graduated from 0 to 10, or the VAS. Among the factors contributing to dyspnoea in asthmatic patients, probably bronchial obstruction, increased airway resistance and dynamic hyperinflation play an important role. Despite this, the asthmatic patient's description of dyspnoea may be masked by hyperventilation syndrome or other comorbidities that can easily be detected and treated through educational programs and targeted therapies.

Outpatient pulmonary rehabilitation for severe asthma with fixed airway obstruction: Comparison with COPD

Background: The benefit of exercise has been demonstrated in asthma, but the role of pulmonary rehabilitation (PR) in people with severe asthma, especially with airway obstruction, has been less investigated. The activity limitation mechanisms differ in asthma and COPD, so the effect of a PR program not specific to asthma is unclear. Methods: We retrospectively compared the effect of an ambulatory PR program in nonsmoking patients with severe asthma and airway obstruction (FEV1/FVC ratio <70% and FEV1 < 80% measured twice, not under an exacerbation) and sex-, age-, FEV1-, and BMI-matched COPD controls. Results: We included 29 patients, each with asthma and COPD. Airway obstruction was moderate (median FEV1 57% [44-64]). VO₂ at peak was higher for asthma than COPD patients (19.0 [15.7-22.2] vs 16.1 [15.3-19.6] ml.min^-1.kg^-1, p = 0.05). After PR, asthma and COPD groups showed a significant and similar increase in constant work cycling test of 378 [114-831] s and 377 [246-702] s. Changes in Hospital Anxiety and Depression Scale (HAD) total score were similar (-2.5 [-7.0 to 0.0] vs -2.0 [-5.0 to 2.0], p > 0.05). Quality of life on the St. George's Respiratory Questionnaire (SGRQ) was significantly improved in both groups (-14.0 [-17.7 to -2.0], p < 0.005 and -8.3 [-13.0 to -3.6], p < 0.0001). Conclusion: Outpatient PR is feasible and well tolerated in patients with severe asthma with fixed airway obstruction. A nondedicated program strongly improves HAD and SGRQ scores and constant work-rate sub-maximal cycling, with similar amplitude as with COPD.

Thoracoabdominal Asynchrony Contributes to Exercise Limitation in Mild Asthmatic Subjects

This study aimed to better understand how subjects with stable asthma and without exercise-induced bronchoconstriction respond to mild exercise. Breathing pattern, chest wall compartmental and operational volumes, and thoracoabdominal asynchrony were assessed in 11 stable asthmatic subjects and 10 healthy subjects at rest and during exercise in a cycle-ergometer through optoelectronic plethysmography. Dyspnea and sensation of leg effort were assessed through Borg scale. During exercise, with similar minute ventilation, a significant lower chest wall tidal volume (p = 0.003) as well as a higher respiratory rate (p < 0.05) and rapid shallow breathing (p < 0.05) were observed in asthmatic when compared to healthy subjects. Asthmatic subjects exhibited a significantly lower inspiratory (p < 0.05) and expiratory times (p < 0.05). Intergroup analysis found a significant higher end-expiratory chest wall volume in asthmatic subjects, mainly due to a significant increase in volume of the pulmonary ribcage (RCp; 170 ml, p = 0.002), indicating dynamic hyperinflation (DH). Dyspnea and sensation of leg effort were both significantly greater (p < 0.0001) in asthmatic when compared to healthy subjects. In addition to a higher thoracoabdominal asynchrony found between RCp and abdominal (AB) (p < 0.005) compartments in asthmatic subjects, post-inspiratory action of the inspiratory ribcage and diaphragm muscles were observed through the higher expiratory paradox time of both RCp (p < 0.0001) and AB (p = 0.0002), respectively. Our data suggest that a different breathing pattern is adopted by asthmatic subjects without exercise-induced bronchoconstriction during mild exercise and that this feature, associated with DH and thoracoabdominal asynchrony, contributes significantly to exercise limitation.

Dynamic hyperinflation during the 6-min walk test in severely asthmatic subjects

We tested the hypothesis that dynamic hyperinflation develops in severe asthmatic subjects during exercise. Changes in inspiratory capacity (IC) were measured during the 6-min walk test (6MWT) in severe asthmatic subjects compared with chronic obstructive pulmonary disease (COPD) subjects with a similar degree of bronchial obstruction. We assessed whether changes in IC were associated with changes in dyspnoea perception.

27 severe asthmatic subjects (10 males and 17 females) and 43 COPD subjects (35 males and eight females) were recruited. The two groups performed similarly in the 6MWT (p=0.90). At the end of the test, the Borg score increased significantly in both groups (mean difference: for asthmatic subjects 1.7±1.6; p<0.0001; for COPD subjects 3.1±1.9; p<0.0001). IC measured at the beginning of 6MWT was not different between groups (2.25±0.47 L in asthmatic subjects versus 2.38±0.60 L in COPD subjects; p=0.32) and decreased in both groups (mean difference: for asthmatic subjects 0.160 L; p=0.02; for COPD subjects 0.164 L; p<0.0001). However, changes in IC were significantly associated with changes in the Borg score in the COPD group (r²=0.17; p=0.006), but not in the asthma group (r²=0.06; p=0.20).

In severe asthmatic subjects, IC significantly drops during the 6MWT to the same extent as COPD subjects with a similar degree of lung impairment, indicating the development of dynamic hyperinflation. Contrary to COPD, in asthmatic subjects the occurrence of dynamic hyperinflation was not associated with changes in dyspnoea perception.

Severe asthma is characterised by occurrence of dynamic hyperinflation during exercise; inspiratory capacity drops in severe asthmatic subjects during the 6MWT to the same extent as in COPD subjects with similar lung impairmenthttp://ow.ly/InfQ30jjivW

Mechanisms, measurement and management of exertional dyspnoea in asthma: Number 5 in the Series "Exertional dyspnoea" Edited by Pierantonio Laveneziana and Piergiuseppe Agostoni

Asthma is a heterogeneous condition, with dyspnoea during exercise affecting individuals to a variable degree. This narrative review explores the mechanisms and measurement of exertional dyspnoea in asthma and summarises the available evidence for the efficacy of various interventions on exertional dyspnoea. Studies on the mechanisms of dyspnoea in asthma have largely utilised direct bronchoprovocation challenges, rather than exercise, which may invoke different physiological mechanisms. Thus, the description of dyspnoea during methacholine challenge can differ from what is experienced during daily activities, including exercise. Dyspnoea perception during exercise is influenced by many interacting variables, such as asthma severity and phenotype, bronchoconstriction, dynamic hyperinflation, respiratory drive and psychological factors. In addition to the intensity of dyspnoea, the qualitative description of dyspnoea may give important clues as to the underlying mechanism and may be an important endpoint for future interventional studies. There is currently little evidence demonstrating whether pharmacological or non-pharmacological interventions specifically improve exertional dyspnoea, which is an important area for future research.

Advances in the Evaluation of Respiratory Pathophysiology during Exercise in Chronic Lung Diseases

Dyspnea and exercise limitation are among the most common symptoms experienced by patients with various chronic lung diseases and are linked to poor quality of life. Our understanding of the source and nature of perceived respiratory discomfort and exercise intolerance in chronic lung diseases has increased substantially in recent years. These new mechanistic insights are the primary focus of the current review. Cardiopulmonary exercise testing (CPET) provides a unique opportunity to objectively evaluate the ability of the respiratory system to respond to imposed incremental physiological stress. In addition to measuring aerobic capacity and quantifying an individual's cardiac and ventilatory reserves, we have expanded the role of CPET to include evaluation of symptom intensity, together with a simple "non-invasive" assessment of relevant ventilatory control parameters and dynamic respiratory mechanics during standardized incremental tests to tolerance. This review explores the application of the new advances in the clinical evaluation of the pathophysiology of exercise intolerance in chronic obstructive pulmonary disease (COPD), chronic asthma, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). We hope to demonstrate how this novel approach to CPET interpretation, which includes a quantification of activity-related dyspnea and evaluation of its underlying mechanisms, enhances our ability to meaningfully intervene to improve quality of life in these pathologically-distinct conditions.