The Global Lung Function Initiative (GLI) Network: bringing the world's respiratory reference values together

SYmbicort given as needed in mild asthma (SYGMA study): a retrospective subanalysis of the Russian population

INTRODUCTION

While mild asthma is generally better controlled than more severe disease, patients with mild asthma may experience severe exacerbations. Definite differences between countries in terms of asthma severity and control were described previously. Since SYGMA was a global study, this sub-analysis was conducted in geographic region to investigate potential regional specificities.

METHODS

The SYGMA2 trial is double-blind multicenter study involving patients ≥12 years of age with mild asthma (n = 4176), eligible for regular treatment with inhaled corticosteroid (ICS). We conducted an open-label descriptive subanalysis of the baseline characteristics of the Russian population (n = 579) comparing to rest of participants of SYGMA2 trial from other 24 countries. The subanalysis is solely descriptive and will be used for hypothesis generation.

RESULTS

The Russian population of patients with mild asthma hardly differs from the population in other countries in terms of baseline demographic and anthropometric characteristics, smoking status, and duration of asthma. At the study entry few patients from Russia received maintenance therapy with ICS and had symptom control, but the majority was uncontrolled on short-acting bronchodilators, thus the uncontrolled/controlled ratio was 52%/48% vs 45%/55% in other countries. More patients with mild asthma in the Russian group had faced at least one severe exacerbation in the previous year (30.1% vs 20.7%).

CONCLUSIONS

The subanalysis revealed a delayed prescription of controller (ICS) therapy and overuse of short-acting bronchodilators in the Russian population with mild asthma. These factors can lead to insufficient symptom control and higher risk of severe exacerbation in the Russian population with mild asthma.

Telomere length and risk of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease: a mendelian randomisation study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease accounting for 1% of UK deaths. In the familial form of pulmonary fibrosis, causal genes have been identified in about 30% of cases, and a majority of these causal genes are associated with telomere maintenance. Prematurely shortened leukocyte telomere length is associated with IPF and chronic obstructive pulmonary disease (COPD), a disease with similar demographics and shared risk factors. Using mendelian randomisation, we investigated evidence supporting a causal role for short telomeres in IPF and COPD.

METHODS

Mendelian randomisation inference of telomere length causality was done for IPF (up to 1369 cases) and COPD (13 538 cases) against 435 866 controls of European ancestry in UK Biobank. Polygenic risk scores were calculated and two-sample mendelian randomisation analyses were done using seven genetic variants previously associated with telomere length, with replication analysis in an IPF cohort (2668 cases vs 8591 controls) and COPD cohort (15 256 cases vs 47 936 controls).

FINDINGS

In the UK Biobank, a genetically instrumented one-SD shorter telomere length was associated with higher odds of IPF (odds ratio [OR] 4·19, 95% CI 2·33-7·55; p=0·0031) but not COPD (1·07, 0·88-1·30; p=0·51). Similarly, an association was found in the IPF replication cohort (12·3, 5·05-30·1; p=0·0015) and not in the COPD replication cohort (1·04, 0·71-1·53; p=0·83). Meta-analysis of the two-sample mendelian randomisation results provided evidence inferring that shorter telomeres cause IPF (5·81 higher odds of IPF, 95% CI 3·56-9·50; p=2·19 × 10-12). There was no evidence to infer that telomere length caused COPD (OR 1·07, 95% CI 0·90-1·27; p=0·46).

INTERPRETATION

Cellular senescence is hypothesised as a major driving force in IPF and COPD; telomere shortening might be a contributory factor in IPF, suggesting divergent mechanisms in COPD. Defining a key role for telomere shortening enables greater focus in telomere-related diagnostics, treatments, and the search for a cure in IPF. Investigation of therapies that improve telomere length is warranted.

FUNDING

Medical Research Council.

Residual symptoms and lower lung function in patients recovering from SARS-CoV-2 infection

Initial reports of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection indicate only mild disease in 81% of symptomatic cases [1]. Nearly half of the infected individuals do not seem to develop clinical symptoms at all, depending on the cohort investigated [2]. Comorbidities and older age were identified early during the pandemic as predictors for severe or critical disease [3], which is found in about 19% [1]. Independently from disease severity, little is known about longer-term outcomes as well as resolution of symptoms. We therefore set out to systematically evaluate residual symptoms and lung function impairment in patients after SARS-CoV-2 infection.

About half of the patients recovering from SARS-CoV-2 have persistent symptoms and lower lung function as long as 2 months after infection. This is common even in younger SARS-CoV-2 convalescents with few comorbidities.https://bit.ly/38dyCYB

Response of individual airways in vivo to bronchial thermoplasty

Bronchial thermoplasty (BT) is a treatment for moderate-to-severe asthma, which generally improves quality-of-life scores but not conventional measures of lung function. Newer methodologies have begun to demonstrate the underlying physiological changes and elucidate the mechanism of action. We postulated that systematic, computed tomography (CT)-based assessment of the response of individual airways to BT is feasible, and our aim was to determine the distribution of these responses and the relationship with airway size. Twenty patients meeting the European Respiratory Society/American Thoracic Society (ERS/ATS) definition of severe asthma underwent BT and assessment including CT, Asthma Control Questionnaire (ACQ), and spirometry. Treatment was structured so that the left and right lungs are treated sequentially with a midtreatment assessment providing an internal control. Pairs of CT scans were analyzed using a new semiautomatic processing algorithm that matched individual segmented airways for quantitative comparison. Cross-sectional airway lumen area from matched airway pairs in treated lungs increased on average by 6.4% after BT (P < 0.02) but showed no change in the untreated lung. Matched airway length was also unchanged. Breakdown by airway size showed amplified response in more distal airways, with the smallest quintile of measured airways dilating by 13.2% (P < 0.001). ACQ improved from 3.5 ± 0.9 to 1.9 ± 1.2 (P < 0.001). These data show that the response to BT in individual airways can be assessed by CT and that dilation is heterogeneous and predominant in distal compared with proximal airways. A CT-based approach may further our understanding of the physiological changes in BT and aid in the development of refined and personalized versions of the therapy.NEW & NOTEWORTHY CT scanning was used to evaluate the response of individual airways in patients undergoing bronchial thermoplasty. Airways dilated after treatment by 6.4% on average with substantial heterogeneity and a greater response in the most distal airways measured.

The applicability of the global lung initiative equations and other regional equations on a sample of healthy Middle Eastern adolescents

BACKGROUND

The Global Lung Initiative 2012 (GLI-2012) spirometry equations are multi-ethnic equations that cover all ages between 3 and 95. However, there is a need to evaluate the suitability of these equations to a sample of Middle Eastern adolescents prior to being applied in clinical practice. The aim of this study is to evaluate the suitability of GLI-2012 equations and two regional equations to a sample of Jordanian adolescents.

METHODS

Spirometric measures were collected from 1036 healthy 14 to 17-year-old Jordanian children. z-scores, predicted values, percent predicted values, and frequency of measures below lower limit of normal (LLN) were calculated for each adolescent using the studied equations.

RESULTS

The means of z-scores produced by GLI-2012 equations for Caucasians in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC% and mid forced expiratory flow (FEF25-75) for boys were 0.12, -0.06, 0.34 and 0.09, respectively, while for girls they were -0.09, -0.16, 0.19 and -0.05, respectively. The mean of z-scores produced by GLI-2012 Other or Mixed equations in FEV1, FVC, FEV1/FVC% and FEF25-75 for boys were 0.74, 072, 021 and 0.33, respectively, and for girls were 0.53, 0.56,0.02 and 0.2, respectively. The frequency of measures below LLN as produced by GLI 2012 for Caucasians were significantly different from the expected 5% in FEV1 and FEF25-75 in boys only, whereas Other or Mixed produced frequencies significantly different from the expected 5% in most of the parameters.

CONCLUSION

Spirometry reference equations formulated for Jordanian adolescents may improve the diagnosis and treatment of asthma in Jordan.

Patients with cystic fibrosis and advanced lung disease benefit from lumacaftor/ivacaftor treatment

BACKGROUND

Several studies have assessed safety and efficacy outcomes for lumacaftor/ivacaftor therapy. We report on lumacaftor/ivacaftor's impact on lung function, physical performance, and health-related quality of life (HRQOL) in a subpopulation of Danish people with Cystic Fibrosis (CF; PWCF) with advanced pulmonary disease who would not fulfill inclusion criteria for these studies.

METHODS

This follow-up study examined lumacaftor/ivacaftor's effect in a highly selected CF population. Inclusion criteria included low percent predicted forced expiratory volume in one second (ppFEV₁ ), fast deteriorating ppFEV₁ , low body mass index (BMI), and difficult-to-treat infections. Primary endpoints included change in ppFEV₁ slope, cardiopulmonary exercise testing (CPET), and all domains of the Cystic Fibrosis Questionnaire-Revised (CFQ-R). Secondary outcomes included change in ppFEV₁ , BMI Z-score, and sweat chloride concentration.

RESULTS

A total of 21 patients homozygous for the F508del mutation and a median ppFEV₁ of 38.7 were included. We found significant improvements in ppFEV₁ (+4.2 p < .01, +5.8 p < .01, +4.8 p < .01 and +3.8 p = .03 ppFEV₁ after 3, 6, 9, and 12 months of treatment compared to baseline), ppFEV₁ slope (+6.84 ppFEV₁ /year between the year before and the year after treatment initiation; p = .02), and saturation at CPET initiation (+1.4%, p < .02) and termination (+2.6%, p < .01) after 6 months of treatment. Finally, HRQOL improved significantly in all CFQ-R domains except Emotion and Treat.

CONCLUSIONS

Our findings suggest that lumacaftor/ivacaftor reduces lung function decline, improves lung function, physical performance, and HRQOL to a greater extent in PWCF with severe lung disease than previously recognized.

Bronchial thermoplasty reduces ventilation heterogeneity measured by multiple breath nitrogen washout

BACKGROUND

Despite demonstrated symptomatic benefit from bronchial thermoplasty (BT), the underlying pathophysiological benefits have been uncertain. The purpose of the present study was to relate clinical benefit after BT to changes in lung physiology, focusing on ventilation homogeneity assessed using multiple breath nitrogen washout (MBNW), and how this may be affected by changes in airway volume and resistance.

METHODS

Consecutive patients (n = 21) with severe asthma scheduled for BT, were evaluated at baseline, 6 weeks and 6 months after completion of treatment. Assessments included the Asthma Control Questionnaire (ACQ), medication usage, exacerbation frequency, spirometry, plethysmography and MBNW. Eighteen of these patients underwent detailed CT evaluation for the estimation of airway volume at baseline and then after the left lung had received BT treatment but prior to right lung treatment. Data are mean ± STDEV.

RESULTS

Patients responded to BT with an improvement in ACQ from 3.4 ± 0.8 at baseline to 2.0 ± 1.1 at 6 months (p < 0.001). Steroid requiring exacerbations fell from 3.1 ± 2.9 in the 6 months prior to BT to 1.4 ± 1.7 following BT (p < 0.001). Significant reductions in maintenance oral steroid dosing and short acting beta agonist use were observed. Airway volume measured by CT scanning significantly increased after treatment. The FEV1 improved from 1.34 ± 0.65 l to 1.52 ± 0.76 l (p = 0.024). The Residual Volume fell from 2.87 ± 0.89 l to 2.71 ± 0.93 l (p = 0.008) and Total Airway Resistance (Raw) from 10.58 ± 6.56 to 7.64 ± 3.74 cmH2O.s.l-1 (p = 0.020). The Lung Clearance Index (LCI) was 187 ± 63% predicted at baseline and improved after treatment from 12.7 ± 3.3 to 11.8 ± 2.4 (p = 0.049). The improvement in LCI correlated with the improvement in Raw (r = 0.463, p = 0.035).

CONCLUSION

Clinical benefit after BT is accompanied by improvements in lung physiology, including normalisation of lung homogeneity that seems to be driven by airway dilation and reduced resistance.

The effect of bronchial thermoplasty on airway volume measured 12 months post-procedure

Bronchial thermoplasty induces atrophy of the airway smooth muscle layer, but the mechanism whereby this improves patient health is unclear. In this study, we use computed tomography (CT) to evaluate the effects of bronchial thermoplasty on airway volume 12 months post-procedure. 10 consecutive patients with severe asthma were evaluated at baseline by the Asthma Control Questionnaire (ACQ), and high-resolution CT at total lung capacity (TLC) and functional residual capacity (FRC). The CT protocol was repeated 4 weeks after the left lung had been treated by bronchial thermoplasty, but prior to right lung treatment, and then again 12 months after both lungs were treated. The CT data were also used to model the implications of including the right middle lobe (RML) in the treatment field. The mean patient age was 62.7±7.7 years and forced expiratory volume in 1 s (FEV₁) 42.9±11.5% predicted. 12 months post-bronchial-thermoplasty, the ACQ improved, from 3.4±1.0 to 1.5±0.9 (p=0.001), as did the frequency of oral steroid-requiring exacerbations (p=0.008). The total airway volume increased 12 months after bronchial thermoplasty in both the TLC (p=0.03) and the FRC scans (p=0.02). No change in airway volume was observed in the untreated central airways. In the bronchial thermoplasty-treated distal airways, increases in airway volume of 38.4±31.8% at TLC (p=0.03) and 30.0±24.8% at FRC (p=0.01) were observed. The change in distal airway volume was correlated with the improvement in ACQ (r=-0.71, p=0.02). Modelling outputs demonstrated that treating the RML conferred no additional benefit. Bronchial thermoplasty induces long-term increases in airway volume, which correlate with symptomatic improvement.

Influence of methodology on the estimation of the particle surface area dose received by a population in all-day activities

In everyday life, people are exposed to different concentrations of airborne particles depending on the microenvironment where they perform their different activities. Such exposure can lead to high sub-micron particle doses. The received dose depends on particle concentration to which people are exposed (typically expressed in terms of number or surface area), time spent in each activity or microenvironment (time activity pattern) and amount of air inhaled (inhalation rate). To estimate an actual value of the received dose, all these parameters should be measured under real-life conditions; in fact, the concentrations should be measured on a personal scale (i.e. through a direct exposure assessment), whereas time activity patterns and inhalation rates specific to the activity performed should be considered. The difficulties in obtaining direct measurements of these parameters usually lead to adopt time activity patterns and inhalation rates already available in scientific literature for typical populations, and local outdoor particle concentrations measured with fixed monitoring stations and extrapolated for all the other microenvironments. To overcome these limitations, we propose a full-field method for estimating the received dose of a population sample, in which all the parameters (concentration levels, time activity patterns and inhalation rates) are measured under real-life conditions (also including the inhalation rates, that were evaluated on the basis of the measured heart rates). Specifically, 34 volunteers were continuously monitored for seven days and the data of sub-micron particle concentrations, activities performed, and inhalation rates were recorded. The received dose was calculated with the proposed method and compared with those obtained from different simplified methodologies that consider typical data of particle concentrations, time activity patterns and inhalation rates obtained from literature. The results show that, depending on the methodology used, the differences in the received daily dose can be significant, with a general underestimation of the most simplified method.

Breathomics in Asthmatic Children Treated with Inhaled Corticosteroids

BACKGROUND

"breathomics" enables indirect analysis of metabolic patterns underlying a respiratory disease. In this study, we analyze exhaled breath condensate (EBC) in asthmatic children before (T0) and after (T1) a three-week course of inhaled beclomethasone dipropionate (BDP).

METHODS

we recruited steroid-naive asthmatic children for whom inhaled steroids were indicated and healthy children, evaluating asthma control, spirometry and EBC (in asthmatics at T0 and T1). A liquid-chromatography-mass-spectrometry untargeted analysis was applied to EBC and a mass spectrometry-based target analysis to urine samples.

RESULTS

metabolomic analysis discriminated asthmatic (n = 26) from healthy children (n = 16) at T0 and T1, discovering 108 and 65 features relevant for the discrimination, respectively. Searching metabolomics databases, seven putative biomarkers with a plausible role in asthma biochemical-metabolic processes were found. After BDP treatment, asthmatic children, in the face of an improved asthma control (p < 0.001) and lung function (p = 0.01), showed neither changes in EBC metabolomic profile nor in urinary endogenous steroid profile.

CONCLUSIONS

"breathomics" can discriminate asthmatic from healthy children, with prostaglandin, fatty acid and glycerophospholipid as putative markers. The three-week course of BDP-in spite of a significant clinical improvement-was not associated with changes in EBC metabolic arrangement and urinary steroid profile.

The clinical and inflammatory relationships between periodontitis and chronic obstructive pulmonary disease

AIM

To investigate associations between periodontitis and chronic obstructive pulmonary disease (COPD) with and without alpha-1 antitrypsin deficiency (AATD), including neutrophil functions implicated in tissue damage.

METHODS

The presence and severity of periodontitis (using two international criteria) and lung disease were assessed in 156 COPD patients with and without AATD accounting for common confounding factors. Saliva and systemic inflammatory markers were measured by ELISA together with neutrophil migration.

RESULTS

COPD and AATD patients exhibited higher prevalence of periodontitis (COPD 95%; AATD 88%) than reported in unselected community-dwelling populations even when risk factors (age, smoking history, socio-economic status and dental habits) were considered. Periodontitis severity associated with lung disease severity (AATD, periodontitis versus no periodontitis; FEV1 = 56% versus 99% predicted; TLCO = 59% versus 81% predicted, p < .0001 for both). Neutrophil migratory accuracy declined in stage II-IV periodontitis patients with COPD or AATD compared to COPD or AATD with no or stage I periodontitis. Improved dental habits appeared to be associated with a reduction in exacerbation frequency in COPD.

CONCLUSION

The results support shared pathophysiology between periodontitis and COPD, especially when associated with AATD. This may reflect an amplification of neutrophilic inflammation and altered neutrophil functions, already described in periodontitis, COPD and AATD.

Unrecognized Respiratory Morbidity among Adolescents and Young Adults in Nigeria: Implications for Future Health Outcomes

Background:

Lung function impairment is a major determinant of morbidity and mortality. Unrecognized respiratory morbidity may be a missed opportunity to improve future health outcomes.

Aim:

The aim of this study was to investigate the prevalence of respiratory symptoms and the relationship to spirometry abnormalities and respiratory diagnosis among medical students in Lagos, Nigeria.

Methods:

This was a cross-sectional study among students aged 16–35 years. We assessed frequency of respiratory symptoms, previous respiratory diagnosis, and spirometry abnormalities. The relationship between respiratory symptoms, spirometry pattern, and previous respiratory diagnosis was determined using the Chi-square test and stepwise forward logistic regression analysis.

Results:

Of 640 participants, 464 (72.5%) performed good quality spirometry tests. Two hundred and forty-four (52.6%) had at least one respiratory symptom. Preexisting conditions were only identified in 60 (12.9%): 49 (7.7%) asthma, 29 (4.5%) allergic rhinitis, 16 (2.5%) treated tuberculosis, and 8 (1.3%) bronchitis/chronic obstructive pulmonary disease. Using the Global Lung Function Initiative (GLI) lung function predicted values, obstructive (8.4%) and restrictive abnormalities (25.4%) were common. An obstructive pattern was associated with previous diagnosis of asthma, but there was no significant association for the restrictive spirometry pattern.

Conclusions:

Among otherwise healthy students, respiratory symptoms and lung function abnormalities are common. The vast majority are without a formal diagnosis. Asthma accounted for the majority of obstructive spirometry pattern seen, but the restrictive abnormalities based on GLI equations remain unexplained. Further research is required to determine the cause of these abnormalities and long-term implications in apparently healthy young individuals.

Epidemiology and persistence of rhinovirus in pediatric lung transplantation

BACKGROUND

Infection with rhinovirus (HRV) occurs following pediatric lung transplantation. Prospective studies documenting frequencies, persistence, and progression of HRV in this at-risk population are lacking.

METHODS

In the Clinical Trials in Organ Transplant in Children prospective observational study, we followed 61 lung transplant recipients for 2 years. We quantified molecular subtypes of HRV in serially collected nasopharyngeal (NP) and bronchoalveolar lavage (BAL) samples and correlated them with clinical characteristics.

RESULTS

We identified 135 community-acquired respiratory infections (CARV) from 397 BAL and 480 NP samples. We detected 93 HRV events in 42 (68.8%) patients, 22 of which (23.4%) were symptomatic. HRV events were contiguous with different genotypes identified in 23 cases, but symptoms were not preferentially associated with any particular species. Nine (9.7%) HRV events persisted over multiple successive samples for a median of 36 days (range 18-408 days). Three persistent HRV were symptomatic. When we serially measured forced expiratory volume in one second (FEV1) in 23 subjects with events, we did not observe significant decreases in lung function over 12 months post-HRV.

CONCLUSION

In conjunction with our previous reports, our prospectively collected data indicate that molecularly heterogeneous HRV infections occur commonly following pediatric lung transplantation, but these infections do not negatively impact clinical outcomes.

Lung Function Testing and Prediction Equations in Adult Population from Maputo, Mozambique

Background: Local spirometric prediction equations are of great importance for interpreting lung function results and deciding on the management strategies for respiratory patients, yet available data from African countries are scarce. The aim of this study was to collect lung function data using spirometry in healthy adults living in Maputo, Mozambique and to derive first spirometric prediction equations for this population. Methods: We applied a cross-sectional study design. Participants, who met the inclusion criteria, underwent a short interview, anthropometric measurements, and lung function testing. Different modelling approaches were followed for generating new, Mozambican, prediction equations and for comparison with the Global Lung Initiative (GLI) and South African equations. The pulmonary function performance of participants was assessed against the different reference standards. Results: A total of 212 males and females were recruited, from whom 155 usable spirometry results were obtained. The mean age of participants was 35.20 years (SD 10.99) and 93 of 155 (59.35%) were females. The predicted values for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and the FEV1/FVC ratio based on the Mozambican equations were lower than the South African—and the GLI-based predictions. Conclusions: This study provides first data on pulmonary function in healthy Mozambican adults and describes how they compare to GLI and South African reference values for spirometry.

The Lung Function Laboratory to Assist Clinical Decision-making in Pulmonology: Evolving Challenges to an Old Issue

The lung function laboratory frequently provides relevant information to the practice of pulmonology. Clinical interpretation of pulmonary function and exercise tests, however, has been complicated more recently by temporal changes in demographic characteristics (higher life expectancy), anthropometric attributes (increased obesity prevalence), and the surge of polypharmacy in a sedentary population with multiple chronic degenerative diseases. In this narrative review, we concisely discuss some key challenges to test interpretation that have been affected by these epidemiologic shifts: (a) the confounding effects of advanced age and severe obesity, (b) the contemporary controversies in the diagnosis of obstruction (including asthma and/or COPD), (c) the importance of considering the diffusing capacity of the lung for carbon monoxide (Dlco)/"accessible" alveolar volume (carbon monoxide transfer coefficient) in association with Dlco to uncover the causes of impaired gas exchange, and (d) the modern role of the pulmonary function laboratory (including cardiopulmonary exercise testing) in the investigation of undetermined dyspnea. Following a Bayesian perspective, we suggest interpretative algorithms that consider the pretest probability of abnormalities as indicated by additional clinical information. We, therefore, adopt a pragmatic approach to help the practicing pulmonologist to apply the information provided by the lung function laboratory to the care of individual patients.

The influence of an electrical impedance tomography belt on lung function determined by spirometry in sitting position

OBJECTIVE

The aim of the study was to examine whether an electrical impedance tomography (EIT) electrode belt changed the lung function in healthy volunteers and patients with respiratory muscle weakness (RMW) and chronic obstructive pulmonary disease (COPD).

APPROACH

In total, thirty subjects were included (10 healthy volunteers, 10 subjects with RMW, maximum inspiratory pressure < 40 cmH₂O, and 10 COPD, grade I-IV). Spirometry measurements were conducted in a sitting position once a day at similar times on two consecutive days. Slow expiratory vital capacity (VC), forced vital capacity (FVC) and maximum voluntary ventilation (MVV) manoeuvres were performed. On day 1, spirometry was performed without the EIT electrode belt, and on day 2, the belt was attached to the thorax.

MAIN RESULTS

Lung function was not influenced by the electrode belt in healthy subjects. The test-retest reliability in the healthy group was 0.89, 0.89 and 0.85 for VC, FVC and MVV, respectively. On the other hand, all investigated parameters were significantly decreased in the RMW group (VC, 51.3 ± 18.0 versus 46.5 ± 18.0% predicted, without versus with EIT belt, p< 0.01; FVC, 51.7 ± 19.0 versus 45.8 ± 18.1% predicted, p< 0.01; MVV, 41.0 ± 20.0 versus 38.8 ± 19.6% predicted, p< 0.01). VC and MVV also decreased significantly in the COPD group (VC, 77.4 ± 20.5 versus 74.6 ± 18.8% predicted, p< 0.05; MVV, 57.4 ± 15.7 versus 54.4 ± 12.5% predicted, p< 0.05).

SIGNIFICANCE

An EIT electrode belt could reduce lung volumes in subjects with pre-existing lung diseases. Comparing lung function acquired with an electrode belt to corresponding values obtained without the belt should be avoided.

Bronchial thermoplasty versus mepolizumab: Comparison of outcomes in a severe asthma clinic

BACKGROUND AND OBJECTIVE

BT and interleukin-blocking monoclonal antibodies are both effective therapies for severe asthma, but there have been no direct comparisons between the two treatments. The aim of this study was to compare the efficacy and safety of BT and mepolizumab, in a real-world setting.

METHODS

Patients with severe asthma despite optimized inhaler therapy were drawn from a severe asthma clinic in a tertiary hospital. Every patient commencing therapy with BT or mepolizumab was prospectively included in a national registry. At predetermined assessment points over a 12-month period, assessments were made of ACQ, spirometry, oral corticosteroid requiring exacerbations, reliever medication and maintenance oral corticosteroid use.

RESULTS

A total of 91 patients with severe asthma participated: mean ACQ score 3.5 ± 1.0, FEV₁ 51.4 ± 17.7%, maintenance oral steroids 48.3% and 11.5 ± 10.0 inhalations/day reliever therapy. Forty-seven patients received mepolizumab and 44 received BT. Baseline characteristics were similar except significantly higher blood eosinophil count in the mepolizumab group. At 12 months, there were no differences between treatment outcomes for ACQ (1.9 ± 1.3 mepolizumab vs 1.7 ± 1.3 BT), exacerbation rate (0.9 ± 1.1 vs 0.9 ± 1.5), reduction in reliever use (-6.3 ± 10.5 vs -5.0 ± 8.8 puffs/day) or reduction in oral corticosteroids (-3.3 ± 7.5 vs - 5.8 ± 6.7 mg/day). The FEV₁ improved equally (160 ± 290 vs 150 ± 460 mL). Readmission or prolonged admission was observed in 18.2% of BT patients, whilst 25.5% of mepolizumab patients had discontinued treatment at 12 months, 14.9% due to an adverse event or non-compliance.

CONCLUSION

The results suggest that BT is as efficacious as mepolizumab for the treatment of severe asthma.

Re-evaluation of the Uplift Clinical Trial Using Age-Appropriate Spirometric Criteria

BACKGROUND

The clinical trial of tiotropium in COPD, UPLIFT, enrolled adults with a mean age of 65 years and moderate-to-severe airflow obstruction, based on criteria from the Global Initiative for Chronic Obstructive Lung Disease (GOLD). For the UPLIFT cohort, however, GOLD-based criteria are not age-appropriate.

RESEARCH QUESTION

Will the use of more age-appropriate criteria for airflow obstruction from the Global Lung Function Initiative (GLI) modify the spirometric classification of the UPLIFT cohort and, in turn, the mortality effect of tiotropium in COPD?

STUDY DESIGN AND METHODS

Baseline spirometric classifications were first cross-tabulated by GLI- and GOLD-based criteria. Next, in GLI- and GOLD-based airflow obstruction, modified intention-to-treat analyses evaluated differences in time to death over 4 years, comparing tiotropium vs placebo. Because treatment response may differ by COPD severity, the mortality effect also was evaluated within stratum defined by GLI- and GOLD-based moderate and severe airflow obstruction.

RESULTS

Of 5,898 participants with GOLD-based airflow-obstruction, staged as moderate in 2,739 (46.4%) and severe in 3,156 (53.5%), GLI-based criteria established airflow obstruction in 5,750 (97.5%), staged as moderate in 795 (13.5%) and severe in 4,947 (83.9%). Relative to placebo, tiotropium yielded statistically nonsignificant adjusted hazard ratios (adjHRs) (95% CI) for death of 0.91 (0.80-1.04) and 0.91 (0.79-1.03) in GLI- and GOLD-based airflow obstruction, respectively. However, statistically significant effect modification was observed, but only in GLI-based moderate and severe airflow-obstruction, with tiotropium yielding adjHRs for death of 0.53 (0.34-0.81) and 0.99 (0.86-1.13), respectively. The P value for interaction was .007.

INTERPRETATION

Mortality reduction by tiotropium was only statistically significant in GLI-based moderate airflow-obstruction, a group that was underrepresented in UPLIFT because of severity misclassification by the original GOLD-based enrollment criteria.

Bronchial thermoplasty reduces airway resistance

BACKGROUND

The mechanism for symptomatic improvement after bronchial thermoplasty (BT) is unclear, since spirometry reveals little or no change. In this study, the effects of BT on airway resistance were examined using two independent techniques.

METHODS

Eighteen consecutive patients, with severe asthma (57.6 ± 14.2 years) were evaluated by spirometry and plethysmography at three time points: (i) baseline, (ii) left lung treated but right lung untreated and (iii) 6 weeks after both lungs were treated with BT. At each assessment, total and specific airway resistance (Raw, sRaw) were measured. High resolution CT scans were undertaken at the first two assessments, and measurements of lobar volume, airway volume and airway resistance were made. The Asthma Control Questionnaire (ACQ) was administered at each assessment.

RESULTS

The baseline ACQ score was 3.5 ± 0.9, and improved progressively to 1.8 ± 1.2 (p < 0.01). At baseline, severe airflow obstruction was observed, FEV1 44.8 ± 13.7% predicted, together with gas trapping, and elevated Raw at 342 ± 173%predicted. Following BT, significant improvements in Raw and sRaw were observed, as well as a reduction in Residual Volume, increase in Vital Capacity and no change in FEV1. The change in Raw correlated with the change in ACQ (r = 0.56, p < 0.05). CT scans demonstrated reduced airway volume at baseline, which correlated with the increased Raw determined by plethysmography (p = - 0.536, p = < 0.05). Following BT, the airway volume increased in the treated lung, and this was accompanied by a significant reduction in CT-determined local airway resistance.

CONCLUSION

Symptomatic improvement after BT is mediated by increased airway volume and reduced airway resistance.

Clinical utility of fractional exhaled nitric oxide in severe asthma management

Asthma is a chronic inflammatory disease of the airways, affecting over 350 million people worldwide and placing a significant burden on healthcare providers and wider society. Approximately 5-10% of asthma patients are diagnosed with severe asthma and typically are associated with increased risk of hospitalisation from exacerbations, increased morbidity, mortality and higher asthma-associated healthcare costs. Nitric oxide (NO) is an important regulator of immune responses and is a product of inflammation in the airways that is over-produced in asthma. Fractional exhaled NO (F _eNO) is predominantly used as a predictor of response to inhaled corticosteroids (ICSs), to monitor adherence and as a diagnostic tool in ICS-naïve patients. In the UK, the National Institute for Health and Care Excellence (NICE) guidelines recommend the use of F _eNO for the initial diagnosis of patients with suspected asthma. In the USA, American Thoracic Society (ATS) guidelines recommend F _eNO as part of the initial diagnosis of asthma and for monitoring of airway inflammation. F _eNO has also been shown to be a predictive factor for asthma exacerbations, with higher levels being associated with a greater number of exacerbations. In addition, higher levels of F _eNO have been shown to be associated with a decline in lung function. F _eNO testing is a cost-effective procedure and has been shown to improve patient management when combined with standard assessment methods. Recent evidence suggests that F _eNO may also be useful as a surrogate biomarker for the assessment and management of severe asthma and to predict responsiveness to some biological therapies.

Clinical and Physiologic Implications of Negative Cardiopulmonary Interactions in Coexisting Chronic Obstructive Pulmonary Disease-Heart Failure

Chronic obstructive pulmonary disease (COPD) and heart failure with reduced ejection fraction (HF) frequently coexist in the elderly. Expiratory flow limitation and lung hyperinflation due to COPD may adversely affect central hemodynamics in HF. Low lung compliance, increased alveolar-capillary membrane thickness, and abnormalities in pulmonary perfusion because of HF further deteriorates lung function in COPD. We discuss how those negative cardiopulmonary interactions create challenges in clinical interpretation of pulmonary function and cardiopulmonary exercise tests in coexisting COPD-HF. In the light of physiologic concepts, we also discuss the influence of COPD or HF on the current medical treatment of each disease.

Sildenafil improves exercise capacity in patients with cystic fibrosis: a proof-of-concept clinical trial

Background:

Exercise intolerance is a common phenotype observed in patients with cystic fibrosis (CF). Treatment with sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, has previously been shown to improve exercise capacity (VO₂ peak) in other patient populations. Thus, the present study sought to determine the acute and subacute effects of sildenafil on exercise capacity in patients with CF.

Methods:

The present investigation utilized a randomized, double-blind, placebo-controlled, crossover study with an acute dose of either sildenafil (50 mg) or placebo (n = 13, age 25 ± 10), followed by a 4 week open-label extension with sildenafil (20 mg, TID; n = 15, age 23 ± 11). A comprehensive evaluation of pulmonary function and a maximal exercise test were each performed at every visit.

Results:

A significant increase in VO₂ peak was observed after the acute sildenafil dose with no changes following placebo (77 ± 13 versus 72 ± 13% predicted; p = 0.033). In addition, after 4 weeks of treatment, patients showed a significant increase in exercise capacity (72 ± 12 versus 75 ± 12% predicted; p = 0.028) and exercise duration (409 ± 98 versus 427 ± 101 s; p = 0.014). A robust correlation (r = 0.656; p = 0.008) between baseline FEV₁ (% predicted) and the change in exercise capacity following 4 weeks of treatment was identified.

Conclusions:

This proof-of-concept clinical trial demonstrates that sildenafil treatment can improve exercise capacity in patients with CF and that pulmonary function may play an important role in the effectiveness of treatment. Future investigations of sildenafil treatment in patients with CF are certainly warranted.

Measuring quality of life in COPD patients: comparing disease-specific supplements to the EQ-5D-5L

Objectives: Patients with chronic obstructive pulmonary disease (COPD) show impairments in health-related quality of life (HRQL). We aimed to find a disease-specific questionnaire for routine application in large cohorts and to assess its additional explanatory power to generic HRQL tool (EQ-5D-5L). Methods: 1,350 participants of the disease management program COPD received the EQ-5D-5L combined with one of the three disease-specific tools: COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ) or St. George's Respiratory Disease Questionnaire (SGRQ) (450 participants each). We compared metric properties and evaluated the Germany-specific experience-based values (EBVS) and utilities in comparison to the Visual Analogue Scale (VAS). We calculated the additional explanatory power of the identified disease-specific tool on VAS through regression analysis. Results: 344 patients returned the questionnaire. CAT, CCQ, and SGRQ group did not differ regarding baseline characteristics. The questionnaire specific response rates were 33.7% for CAT, 30.5% for CCQ, and 34.6% SGRQ, thereof 94.0%, 94.3%, and 65.6% valid answers, respectively. EBVS was better suited to reflect VAS than utilities. CAT increased the explanatory power by 10%. Conclusion: CAT outperformed CCQ and SGRQ, and it increased the explanatory power of VAS. EBV combined with CAT seems superior to only generic or disease-specific approaches.

Re-evaluation of combination therapy in chronic obstructive pulmonary disease (COPD)

BACKGROUND

Clinical trials of COPD pharmacotherapy typically involve aging populations with moderate-to-severe COPD, but the latter is often diagnosed by spirometric criteria that are not age-appropriate across the continuum of lung function. We have therefore re-evaluated the clinical effect of combination therapy (salmeterol plus fluticasone) in moderate-to-severe COPD, using more age-appropriate spirometric criteria from the Global Lung Function Initiative (GLI) and trial data from Towards a Revolution in COPD Health (TORCH).

METHODS

Of the 6112 TORCH participants, 5688 (93.1%) had GLI-based moderate-to-severe COPD (mean age 64.8 years). The primary outcome was all-cause mortality and the primary comparison was combination therapy vs. placebo. Secondary outcomes included COPD and cardiovascular (CV) mortality and pneumonia. A modified intention-to-treat analysis evaluated differences in time-to-event over a three-year period, using Cox proportional hazards models with statistical significance at p < 0.010 (acknowledging repeated significance testing).

RESULTS

Relative to placebo, combination therapy yielded a statistically non-significant reduction in all-cause mortality-adjusted hazard ratio [adjHR] 0.78 (95% confidence interval [CI]: 0.64, 0.95), p = 0.012. Relative to placebo, combination therapy also yielded statistically non-significant reductions in COPD and CV mortality-adjHR 0.75 (95% CI: 0.55, 1.02), p = 0.068 and adjHR 0.76 (95% CI: 0.53, 1.09), p = 0.135, respectively. In contrast, combination therapy yielded a statistically significant increased risk of pneumonia, relative to placebo-adjHR 1.80 (95% CI: 1.46, 2.21), p < 0.001.

CONCLUSION

In GLI-based moderate-to-severe COPD, combination therapy yields a statistically significant increased risk of pneumonia but the reductions in mortality are not statistically significant, although could potentially be clinically meaningful.

Advances in spirometry testing for lung function analysis

Introduction: Spirometry, the most common lung function test, is used to evaluate individuals with respiratory complaints or known respiratory disease. However, its underutilization and the misinterpretation of its parameters are causes for concern. Areas covered: This review describes new spirometry-derived metrics, new reference equations, recent recommendations for presentation of results, recent spirometry-based prevalence studies, and technological advances in spirometry equipment. Expert opinion: The underutilization of spirometry can be overcome by increasing access to portable, hand-held, and user-friendly spirometers, together with strategies that increase awareness of the importance of spirometry. New metrics derived from spirometry, together with traditional spirometric criteria, can identify individuals with structural lung disease and respiratory morbidity. Some problems with the reference equations were solved by the Global Lung Function Initiative (GLI), which covers a wider age range and more ethnic groups and provides limits of normality using the z-score. Despite these advantages, the GLI equations lack data from large populations (especially those from Africa, South Asia, and Latin America) and greater representation of older people. Another disadvantage attributed to the GLI is the lack of predicted values for peak expiratory flow and other airflows, limiting the interpretation of the maximal expiratory flow-volume curve.

Transfer coefficient of the lung for carbon monoxide and the accessible alveolar volume: clinically useful if used wisely

A 67-year-old morbidly obese female (body mass index: 46.3 kg·m⁻²) with a history of long-term cigarette smoking (>30 pack-years) was referred from Cardiology to Respirology due to progressive dyspnoea and recent findings of extensive mosaic attenuation of the lungs on a high-resolution computed tomography (HRCT) scan (figure 1). She had been followed by Cardiology on the grounds of multivalvular disease (severe aortic stenosis and moderate mitral regurgitation), ischaemic heart disease, hypertension and hypercholesterolaemia.

Transfer coefficient of the lung for carbon monoxide (K_CO) and alveolar volume (V_A) increase the yield of clinical information obtained from transfer factor of the lung for carbon monoxide (T_LCO) measurements in clinical practicehttp://ow.ly/AVgu30na1vu

Current challenges in managing comorbid heart failure and COPD

INTRODUCTION

Heart failure (HF) with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.