Consensus on mild asthma management: results of a modified Delphi study.

OBJECTIVE: In order to understand the role of regular controller inhaled corticosteroids (ICS) versus as-needed ICS-formoterol in managing mild asthma, we performed a modified Delphi procedure. METHODS: Opinions from 16 respiratory experts to three surveys and during a virtual scientific workshop helped to develop final consensus statements (pre-defined as 70% agreement). RESULTS: Thirteen participants completed all rounds (response rate 81%). At the end of the procedure, there was final consensus on: regular daily ICS being the recommended treatment approach in mild persistent asthma, with better symptom control and robust long-term clinical data compared with as-needed ICS-formoterol (85%); to avoid noncompliance, frequently seen in mild asthma patients, regular ICS dosing should be accompanied by ongoing education on treatment adherence (100%); treatment aims should be targeting asthma control (92%) and reduction of exacerbation risk (85%). No consensus was reached on whether GINA or national guidelines most influence prescribing decisions. CONCLUSIONS: It is important to encourage patients to be adherent and to target both asthma control and exacerbation risk reduction. There is robust clinical evidence to support proactive regular dosing with ICS controller therapy plus as-needed short-acting beta-agonists for the management of patients with mild asthma.

The effect of low-dose corticosteroids and theophylline on the risk of acute exacerbations of COPD: the TASCS randomised controlled trial.

BACKGROUND: The highest burden of chronic obstructive pulmonary disease (COPD) occurs in low- and middle-income countries. Low-cost oral medications, if effective, could enable affordable, accessible COPD treatment. METHODS: In this randomised, three-arm, double-blind, double-dummy, placebo-controlled study conducted in 37 centres in China, symptomatic patients with moderate to very severe COPD were randomised 1:1:1 to placebo twice daily plus placebo once daily, low-dose theophylline 100 mg twice daily plus placebo once daily or low-dose theophylline 100 mg twice daily plus low-dose oral prednisone 5 mg once daily for 48 weeks. The primary end-point was annualised exacerbation rate. RESULTS: 1670 subjects were randomised and 1242 completed the study (1142 with acceptable data at week 48). Subjects (75.7% male) had a mean age of 64.4 years, with mean±sd baseline post-bronchodilator forced expiratory volume in 1 s (FEV1) 1.1±0.4 L (42.2% predicted) and St George's Respiratory Questionnaire (SGRQ) score 45.8±20.1. There were negligible differences between annualised exacerbation rates across the three treatments: 0.89 (95% CI 0.78-1.02) on theophylline plus prednisone, 0.86 (95% CI 0.75-0.99) on theophylline plus placebo and 1.00 (95% CI 0.87-1.14) on placebo. The rate ratio for theophylline plus prednisone versus pooled theophylline plus placebo and placebo was 0.96 (95% CI 0.83-1.12), for theophylline plus placebo versus placebo was 0.87 (95% CI 0.73-1.03; p=0.101) and for theophylline plus prednisone versus placebo was 0.90 (95% CI 0.76-1.06; p=0.201). Secondary outcomes of hospitalisations, FEV1, SGRQ and COPD Assessment Test score showed no statistically significant difference between treatment arms. Serious adverse events other than exacerbations were <2% and did not differ between treatment arms. CONCLUSIONS: Low-dose theophylline alone or in combination with prednisone did not reduce exacerbation rates or clinically important secondary end-points compared with placebo.

Reduced lung elastic recoil and fixed airflow obstruction in asthma.

BACKGROUND AND OBJECTIVE: Fixed airflow obstruction (FAO) in asthma occurs despite optimal inhaled treatment and no smoking history, and remains a significant problem, particularly with increasing age and duration of asthma. Increased lung compliance and loss of lung elastic recoil has been observed in older people with asthma, but their link to FAO has not been established. We determined the relationship between abnormal lung elasticity and airflow obstruction in asthma. METHODS: Non-smoking asthmatic subjects aged >40 years, treated with 2 months of high-dose inhaled corticosteroid/long-acting beta-agonist (ICS/LABA), had FAO measured by spirometry, and respiratory system resistance at 5 Hz (Rrs5 ) and respiratory system reactance at 5 Hz (Xrs5 ) measured by forced oscillation technique. Lung compliance (K) and elastic recoil (B/A) were calculated from pressure-volume curves measured by an oesophageal balloon. Linear correlations between K and B/A, and forced expiratory volume in 1 s/forced vital capacity (FEV1 /FVC), Rrs5 and Xrs5 were assessed. RESULTS: Eighteen subjects (11 males; mean ± SD age: 64 ± 8 years, asthma duration: 39 ± 22 years) had moderate FAO measured by spirometry ((mean ± SD z-score) post-bronchodilator FEV1 : -2.2 ± 0.5, FVC: -0.7 ± 1.0, FEV1 /FVC: -2.6 ± 0.7) and by increased Rrs5 (median (IQR) z-score) 2.7 (1.9 to 3.2) and decreased Xrs5 : -4.1(-2.4 to -7.3). Lung compliance (K) was increased in 9 of 18 subjects and lung elastic recoil (B/A) reduced in 5 of 18 subjects. FEV1 /FVC correlated negatively with K (rs = -0.60, P = 0.008) and Rrs5 correlated negatively with B/A (rs = -0.52, P = 0.026), independent of age. Xrs5 did not correlate with lung elasticity indices. CONCLUSION: Increased lung compliance and loss of elastic recoil relate to airflow obstruction in older non-smoking asthmatic subjects, independent of ageing. Thus, structural lung tissue changes may contribute to persistent, steroid-resistant airflow obstruction. CLINICAL TRIAL REGISTRATION: ACTRN126150000985583 at anzctr.org.au (UTN: U1111-1156-2795).

Peripheral airway dysfunction and relationship with symptoms in smokers with preserved spirometry.

BACKGROUND AND OBJECTIVE: Smokers develop respiratory symptoms and peripheral airway dysfunction even when spirometry is preserved. Multiple breath nitrogen washout (MBNW) and impulse oscillometry system (IOS) are potentially useful measures of peripheral airway function but they have not been compared in such subjects. We hypothesized that MBNW and IOS are jointly abnormal in smokers with normal spirometry and that these abnormalities relate to respiratory symptoms. METHODS: Eighty smokers with normal spirometry completed a symptom questionnaire, had ventilation heterogeneity in diffusion (Sacin) and convection-dependent (Scond) airways and trapped gas volume at functional residual capacity as a percentage of vital capacity (%VtrFRC/VC) measured by MBNW. Respiratory resistance and reactance at 5 and 20 Hz were measured using IOS. RESULTS: Respiratory symptoms were reported in 55 (68%) subjects. Forty (50%) subjects had at least one abnormal MBNW parameter, predominantly in Sacin. Forty-one (51%) subjects had at least one abnormal IOS parameter, predominantly in resistance. Sixty-one (76%) subjects had an abnormality in either MBNW or IOS. Chronic bronchitis symptoms were associated with an increased Scond, while wheeze was associated with lower spirometry and an increased resistance. Abnormalities in MBNW and IOS parameters were unrelated to each other. CONCLUSIONS: Respiratory symptoms and peripheral airway dysfunction are common in smokers with normal spirometry. Symptoms of chronic bronchitis related to conductive airway abnormalities, while wheeze was related to spirometry and IOS. The clinical significance of abnormalities in peripheral airway function in smokers remains undetermined.

Contribution of air pollution to COPD and small airway dysfunction.

Although in many Western countries levels of ambient air pollution have been improving with the setting of upper limits and better urban planning, air pollution in developing countries and particularly those with rapid industrialization has become a major global problem. Together with increased motor vehicle ownership and traffic congestion, there is a growing issue with airborne particles of respirable size. These particles are thought responsible for respiratory and cardiovascular effects and have also been implicated in cancer pathogenesis. The pathologic effects in the lung are mediated via inflammatory pathways and involve oxidative stress similar to cigarette smoking. These effects are seen in the peripheral airways where the smaller particle fractions are deposited and lead to airway remodelling. However, emphysema and loss of bronchioles seen with cigarette smoking have not been described with ambient air pollution, and there are few studies specifically looking at peripheral airway function. Definitive evidence of air pollution causing COPD is lacking and a different study design is required to link air pollution and COPD.

Bronchodilator responsiveness of peripheral airways in smokers with normal spirometry.

BACKGROUND AND OBJECTIVE: Cigarette smoke exposure increases airway smooth muscle (ASM) contractility. Abnormalities in peripheral airway function in smokers with normal spirometry could be due to the effects of ASM tone. We aimed to determine the contribution of ASM tone to peripheral airway function in smokers with normal spirometry from the response to bronchodilator (BD). METHODS: Ventilation heterogeneity in peripheral conductive (Scond) and acinar (Sacin) airways were measured in 50 asymptomatic smokers and 20 never-smokers using multiple breath nitrogen washout, before and 20 min after inhalation of 200 µg salbutamol and 80 µg ipratropium bromide. Z-scores were calculated to define abnormality in Sacin and Scond. RESULTS: Nineteen smokers had abnormal Sacin, and 12 had abnormal Scond; 7 had abnormalities in both. After BD, Sacin improved in smokers with normal Sacin (6.5 ± 15.9%, P = 0.02), smokers with abnormal Sacin (9.2 ± 16.9%, P = 0.03) and in control subjects (11.7 ± 18.2%, P = 0.01), with no differences in improvements between groups. Sacin remained abnormal in 15/19 smokers and their post-BD values correlated with smoking exposure (r = 0.53, P = 0.02). After BD, Scond improved in smokers with abnormal Scond (28.3 ± 15.9%, P = 0.002) and normalized in 9/12 subjects, but not in those with normal Scond (0.25 ± 32.7%, P = 0.44) or control subjects (-1.7 ± 21.2%, P = 0.64). CONCLUSION: In smokers with normal spirometry, abnormal conductive airway function could be attributed to increased bronchomotor tone. In contrast, bronchomotor tone in acinar airways is unaffected by smoking and functional abnormality. There may be different causal mechanisms underlying acinar and conductive airway abnormalities in smokers with normal spirometry.

Association between peripheral airway function and neutrophilic inflammation in asthma.

BACKGROUND AND OBJECTIVE: Small airway dysfunction is associated with asthma severity and control, but its association with airway inflammation is unknown. The aim was to determine the association between sputum inflammatory cells and the site of small airway dysfunction, measured by multiple breath nitrogen washout in convection-dependent (Scond) and more peripheral diffusion-dependent (Sacin) airways. METHODS: Fifty-three (20-67 years) subjects with asthma on inhaled corticosteroid (ICS) treatment were characterized by spirometry, Scond, Sacin and induced sputum differential counts. %Predicted values for Scond and Sacin were calculated from published reference equations to adjust for the effects of age. Univariate correlations were assessed using the Spearman test. Multivariate linear regressions were performed to account for potential confounders, including age, gender, disease duration, body mass index and ICS dose. RESULTS: Sacin (%predicted) correlated significantly with neutrophil% (rs = 0.33, P = 0.02), ICS dose (rs = -0.28, P = 0.04) and age (rs = 0.27, P = 0.05). In multivariate analysis, Sacin related only to neutrophil% (adjusted R(2) = 0.18, P = 0.001). Scond (%predicted) correlated significantly only with eosinophil% (rs = 0.39, P = 0.004). There was a trend for a negative relationship with ICS dose (rs = -0.26, P = 0.06). In multivariate analysis, Scond related to eosinophil% and ICS dose independently (adjusted R(2) = 0.12, P = 0.02). CONCLUSIONS: Acinar and conductive airway dysfunction is associated with different inflammatory profiles in asthmatic airways, independently of the effects of age and disease duration. The association between acinar airway dysfunction and neutrophilic airway inflammation may have implications for asthma treatment.

Respiratory disease and respiratory physiology: putting lung function into perspective interstitial lung disease.

The interstitial lung diseases pathologically involve the pulmonary interstitium but may also involve the airways, pleura and pulmonary circulation. They may be idiopathic, be part of other conditions, or be related to drug or environmental exposures. This review will focus on diagnostic and prognostic information provided by lung function tests in the idiopathic interstitial pneumonias, particularly idiopathic pulmonary fibrosis and non-specific interstitial pneumonia. These disorders are characterized by small stiff lungs with impaired gas exchange. Lung function tests, particularly lung volumes and gas transfer, used initially on patient presentation and then repeatedly on follow up, together with high-resolution computed tomography scans, can generate predictive formulae which are superior to single tests and can be used to provide useful information to assess the natural history of the disease or guide therapy. The concomitant presence of emphysema may mask the degree of restriction and may have adverse prognostic implications when accompanied by pulmonary hypertension.

Relationship between airway pathophysiology and airway inflammation in older asthmatics.

BACKGROUND AND OBJECTIVE: Asthma-related morbidity is greater in older compared with younger asthmatics. Airway closure is also greater in older asthmatics, an observation that may be explained by differences in airway inflammation. We hypothesized that in older adult patients with asthma, neutrophil airway inflammation increases airway closure during bronchoconstriction, while eosinophil airway inflammation increases airway hyperresponsiveness (AHR). METHODS: Asthmatic subjects (n = 26), aged ≥55 years (68% female), were studied, and AHR to 4.5% saline challenge was measured by the response-dose ratio (%fall in forced expiratory volume in 1 s (FEV1 )/mg saline). Airway closure was assessed during bronchoconstriction percent change in forced vital capacity (FVC)/percent change in FEV1 (i.e. Closing Index). Airway inflammation was assessed by induced sputum and exhaled nitric oxide (eNO). RESULTS: Mean patient age was 67 years (confidence interval: 63-71) with a mean FEV1 of 78 % predicted (confidence interval: 70-85%). AHR correlated with sputum eosinophils (r = 0.68, P = 0.005) and eNO (r = 0.71, P < 0.001), but not with neutrophils or neutrophil mediators. The Closing Index correlated with total sputum neutrophils (r = 0.66, P = 0.005), neutrophil elastase, matrix metalloproteinase-9 and interleukin-8 (all P < 0.05). Further, FEV1 /FVC and residual volume/total lung capacity at rest correlated with neutrophil elastase (r = -0.46 and 0.66 respectively, P < 0.05) but not with eosinophils or eNO. CONCLUSIONS: In older patients with asthma, airway inflammatory cells are linked to abnormal airway physiology. Eosinophilic airway inflammation is associated with AHR while neutrophilic inflammation may be an important determinant of airflow limitation at rest and airway closure during bronchoconstriction. The clinical implications of these findings remain to be determined.

Ventilation heterogeneity predicts asthma control in adults following inhaled corticosteroid dose titration.

BACKGROUND: Asthma guidelines recommend inhaled corticosteroid (ICS) dose titration for patients on the basis of an assessment of current asthma control. However, the physiological determinants of asthma symptom control are poorly understood and spirometry is a poor predictor of symptomatic response. OBJECTIVE: To determine the role of small airway measurements in predicting the symptom response following ICS dose titration. METHODS: Adult asthmatic patients had the Asthma Control Questionnaire (ACQ) scores and lung function measured at baseline and after 8 weeks. Tests included spirometry, plethysmography, sputum cell count, exhaled nitric oxide, airway hyperresponsiveness to mannitol, respiratory system mechanics using the forced oscillation technique, and ventilation heterogeneity using the multiple breath nitrogen washout. The parameters ventilation heterogeneity in convection-dependent airways and ventilation heterogeneity in diffusion-dependent airways were derived as measures of ventilation heterogeneity in the small airways. The dose of ICS was doubled if the ACQ score was greater than or equal to 1.5 (uptitration) and quartered if the ACQ score was less than 1.5 (downtitration). The relationships between baseline physiological parameters and the change in the symptom-only 5-item ACQ (deltaACQ-5) were examined by using Spearman correlations, forward stepwise linear regressions, and receiver operator curve analyses. RESULTS: ICS dose uptitration (n= 20) improved ACQ-5 scores (1.76 to 1.16; P= .04). Baseline fraction of exhaled nitric oxide (r= -0.55; P= .01) and ventilation heterogeneity in convection-dependent airways (r= -0.64; P= .002) correlated with deltaACQ-5, but ventilation heterogeneity in convection-dependent airways was the only independent predictor (r(2) = 0.34; P = 0.007). ICS dose downtitration (n= 41) worsened ACQ-5 scores (0.46 to 0.80; P< .001), with 29% of the patients having a deltaACQ-5 of greater than 0.5. Only baseline ventilation heterogeneity in diffusion-dependent airways correlated with deltaACQ-5 (r= 0.40; P= .009) and identified subjects with deltaACQ-5 of greater than 0.5 (receiver operator curve area under the curve= 0.78; P= .0003). CONCLUSIONS: Ventilation heterogeneity predicts symptomatic responses to ICS dose titration. Worse small airways function predicts symptomatic improvement to ICS dose uptitration and loss of symptom control during downtitration.

The role of the small airways in the clinical expression of asthma in adults.

BACKGROUND: The clinical relevance of increased ventilation heterogeneity, a marker of small-airways disease, in asthmatic patients is unclear. Ventilation heterogeneity is an independent determinant of airway hyperresponsiveness (AHR), improves with bronchodilators and inhaled corticosteroids (ICSs), and worsens during exacerbations, but its relationship to asthma control is unknown. OBJECTIVE: We sought to determine the association between ventilation heterogeneity and current asthma control before and after ICS treatment. METHODS: Adult subjects with asthma had lung function and asthma control (5-item Asthma Control Questionnaire [ACQ-5 score] ≥1.5 = poorly controlled, ACQ-5 score ≤0.75 = well controlled) measured at baseline. A subgroup with AHR had repeat measurements after 3 months of high-dose ICS treatment. The indices of ventilation heterogeneity in the regions of the lung where gas transport occurs predominantly through convection (ventilation heterogeneity in convection-dependent airways [Scond]) and through diffusion (ventilation heterogeneity in diffusion-dependent airways [Sacin]) were derived by using the multiple-breath nitrogen washout technique. RESULTS: At baseline (n = 105), subjects with poorly controlled asthma had worse FEV(1), fraction of exhaled nitric oxide measured at 200 mL/s (Feno), Scond, and Sacin values. In the treatment group (n = 50) spirometric, Feno, residual volume (RV)/total lung capacity (TLC), AHR, and Scond values significantly improved. Asthma control also improved (mean ACQ-5 score, 1.3-0.7; P < .0001). The change in ACQ-5 score correlated with changes in Feno (r(s) = 0.31, P = .03), Sacin (r(s) = 0.32, P = .02), and Scond (r(s) = 0.41, P = .003) values. The independent predictors of a change in asthma control were changes in Scond and Sacin values (model r(2) = 0.20, P = .005). CONCLUSIONS: Current asthma control is associated with markers of small-airways disease. Improvements in ventilation heterogeneity with anti-inflammatory therapy are associated with improvements in symptoms. Sensitive measures of small-airway function might be useful in monitoring the response to therapy in asthmatic subjects.

Assessing the Effects of Changing Patterns of Inhaled Corticosteroid Dosing and Adherence with Fluticasone Furoate and Budesonide on Asthma Management.

INTRODUCTION: Pharmacological asthma management focuses on the use of inhaled corticosteroid (ICS)-containing therapies, which reduce airway inflammation and provide bronchoprotection, improving symptom control and reducing exacerbation risk. ICS underuse due to poor adherence is common, leading to poor clinical outcomes including increased risk of mortality. This article reviews efficacy versus systemic activity profiles for various adherence patterns and dosing regimens of fluticasone furoate (FF)-containing and budesonide (BUD)-containing asthma therapies in clinical trials and real-world studies. METHODS: We performed a structured literature review (1 January 2000-3 March 2022) and mathematical modelling analysis of FF-containing and BUD-containing regular daily dosing in patients with mild-to-severe asthma, as-needed BUD/formoterol (FOR) in mild asthma, and BUD/FOR maintenance and reliever therapy (MART) dosing in moderate-to-severe asthma, to assess efficacy (bronchoprotection) and systemic activity (cortisol suppression) profiles of dosing patterns of ICS use in multiple adherence scenarios. RESULTS: A total of 22 manuscripts were included in full-text review and 18 in the model simulations. Focusing on FF-containing or BUD-containing treatments at comparable adherence rates, regular daily FF or FF/vilanterol (VI) dosing provided more prolonged bronchoprotection and fewer systemic effects than daily BUD, daily BUD/FOR, or BUD/FOR MART dosing, especially in low adherence scenarios. In model simulations and the real-world setting, FF/VI generally provided longer bronchoprotection, lower systemic activity, and greater clinical benefits over BUD/FOR as well as consistently higher adherence. CONCLUSION: In this literature review and modelling analysis, FF/VI was found to show clinical advantages on asthma control over BUD/FOR. These findings have implications for helping clinicians select the most suitable inhaled therapy for their patients with asthma.

Assessment and diagnosis of chronic dyspnoea: a literature review.

Dyspnoea or breathlessness is a common presenting symptom among patients attending primary care services. This review aimed to determine whether there are clinical tools that can be incorporated into a clinical decision support system for primary care for efficient and accurate diagnosis of causes of chronic dyspnoea. We searched MEDLINE, EMBASE and Google Scholar for all literature published between 1946 and 2020. Studies that evaluated a clinical algorithm for assessment of chronic dyspnoea in patients of any age group presenting to physicians with chronic dyspnoea were included. We identified 326 abstracts, 55 papers were reviewed, and eight included. A total 2026 patients aged between 20-80 years were included, 60% were women. The duration of dyspnoea was three weeks to 25 years. All studies undertook a stepwise or algorithmic approach to the assessment of dyspnoea. The results indicate that following history taking and physical examination, the first stage should include simply performed tests such as pulse oximetry, spirometry, and electrocardiography. If the patient remains undiagnosed, the second stage includes investigations such as chest x-ray, thyroid function tests, full blood count and NT-proBNP. In the third stage patients are referred for more advanced tests such as echocardiogram and thoracic CT. If dyspnoea remains unexplained, the fourth stage of assessment will require secondary care referral for more advanced diagnostic testing such as exercise tests. Utilising this proposed stepwise approach is expected to ascertain a cause for dyspnoea for 35% of the patients in stage 1, 83% by stage 3 and >90% of patients by stage 4.

New Versus Old: The Impact of Changing Patterns of Inhaled Corticosteroid Prescribing and Dosing Regimens in Asthma Management.

Inhaled corticosteroid (ICS)-containing therapies are the mainstay of pharmacological management of asthma. They can be administered alone or in combination with a long-acting bronchodilator, depending on asthma severity, and may also be supplemented with short-acting bronchodilators for as-needed rescue medication. Adherence to asthma therapies is generally poor and characterized by underuse of ICS therapies and over-reliance on short-acting bronchodilators, which leads to poor clinical outcomes. This article reviews efficacy versus systemic activity profiles for various dosing regimens of budesonide (BUD) and fluticasone propionate (FP). We performed a structured literature review of BUD and FP regular daily dosing, and BUD/formoterol (FOR) as-needed dosing, to explore the relationship between various dosing patterns of ICS regimens and the risk-benefit profile in terms of the extent of bronchoprotection and cortisol suppression. In addition, we explored how adherence could potentially affect the risk-benefit profile, in patients with mild, moderate, and moderate-to-severe asthma. With a specific focus on BUD or FP-containing treatments, we found that regular daily ICS and ICS/long-acting ß2-agonist (LABA) dosing had a greater degree of bronchoprotection than as-needed BUD/FOR dosing or BUD/FOR maintenance and reliever therapy (MART) dosing, and still maintained low systemic activity. We also found that the benefits of regular daily ICS dosing regimens were diminished when adherence was low (50%); the shorter duration of bronchoprotection observed was similar to that seen with typical as-needed BUD/FOR usage. These findings have implications for aiding clinicians with selecting the most suitable treatment option for asthma management, and subsequent implications for the advice clinicians give their patients.

Inhaled corticosteroid (ICS)-containing therapies can be administered in a variety of ways depending on a patient's asthma severity. Patients with mild asthma tend to experience symptom relief with as-needed or regular daily use of an ICS alone, whereas patients with more severe asthma may require regular daily use of an ICS plus a long-acting ß₂-agonist (LABA) to experience sufficient asthma control. However, failure to correctly adhere to ICS-containing therapies or an over-reliance on short-acting bronchodilators for symptom relief hinders optimal asthma management, thus negatively affecting overall patient health and wellbeing. Understanding how different dosing regimens affect the degree of bronchoprotection (efficacy) and cortisol suppression (systemic activity) of ICS treatments would benefit physicians by helping them to prescribe the most appropriate treatment for their patient's asthma. We performed a structured literature review of two ICS molecules­budesonide (BUD) (alone and combined with formoterol [FOR]) and fluticasone propionate (FP)­to explore the relationship between various ICS dosing regimens, and then used these findings to construct models for ICS risk­benefit profiles. Our models factored in different ICS dosing regimens­as-needed, regular daily dosing, and maintenance and reliever therapy (MART)­and various degrees of treatment adherence. We found that regular daily ICS and ICS/LABA dosing provided better bronchoprotection than as-needed BUD/FOR dosing or BUD/FOR MART dosing, but this benefit was diminished with low adherence. Regular daily dosing maintained low cortisol suppression, which indicated a fairly low risk of negative side effects. Our findings have subsequent implications for optimizing treatment in patients with asthma.

Blood Eosinophils in Chinese COPD Participants and Response to Treatment with Combination Low-Dose Theophylline and Prednisone: A Post-Hoc Analysis of the TASCS Trial.

BACKGROUND AND OBJECTIVES: The burden of chronic obstructive pulmonary disease (COPD) disproportionately affects patients in low to middle-income countries. Although the Theophylline and Steroids in COPD Study (TASCS) showed no clinical benefit from administering low-dose theophylline and prednisone in COPD patients compared to placebo, it was hypothesized that those with elevated blood eosinophil counts would receive clinical benefit from the intervention. METHODS: This was a post-hoc analysis of the TASCS dataset - a double-blinded, placebo-controlled trial conducted in patients with moderate-severe COPD in China. Participants were allocated 1:1:1 to low-dose oral theophylline (100mg bd) and prednisone (5mg qd; PrT), theophylline (100mg bd) and prednisone-matched placebo (TP), or double-matched placebo (DP) groups and followed-up for 48 weeks. A baseline count of ≥300 eosinophils/µL blood was categorized as elevated/eosinophilic, and the primary outcome was the annualized moderate-severe exacerbation rate. RESULTS: Of 1487 participants eligible for analysis, 325 (22%) were eosinophilic. These participants were predominantly male (82%), had a mean (SD) age of 64 (±8) years and a predicted forced expiratory volume in 1s (FEV1) of 43% (±16). The annualized moderate-severe exacerbation rate was significantly higher in the PrT group compared to the pooled results of the TP and DP groups (incidence rate ratio = 1.6; ([95% CI 1.06-1.76]) p = 0.016). Changes in spirometry values and reported disease impact scores (St. George's Respiratory Questionnaire and COPD Assessment Test) at week 48 were not significantly different between groups. CONCLUSION: Combination low-dose theophylline and prednisone was associated with a significant increase in the annual moderate-severe exacerbation rate in participants with a blood eosinophil count ≥300 cells/µL compared to placebo.

Normal limits for oscillometric bronchodilator responses and relationships with clinical factors.

INTRODUCTION: We aimed to determine normal thresholds for positive bronchodilator responses for oscillometry in an Australian general population sample aged ≥40 years, to guide clinical interpretation. We also examined relationships between bronchodilator responses and respiratory symptoms, asthma diagnosis, smoking and baseline lung function. METHODS: Subjects recruited from Sydney, Melbourne and Busselton, Australia, underwent measurements of spirometry, resistance (R rs6 ) and reactance (X rs6 ) at 6 Hz, before and after inhalation of salbutamol 200 µg. Respiratory symptoms and/or medication use, asthma diagnosis, and smoking were recorded. Threshold bronchodilator responses were defined as the fifth percentile of decrease in R rs6 and 95th percentile increase in X rs6 in a healthy subgroup. RESULTS: Of 1318 participants, 1145 (570 female) were analysed. The lower threshold for ΔR rs6 was -1.38 cmH2O·s·L-1 (-30.0% or -1.42 Z-scores) and upper threshold for ΔX rs6 was 0.57 cmH2O·s·L-1 (1.36 Z-scores). Respiratory symptoms and/or medication use, asthma diagnosis, and smoking all predicted bronchodilator response, as did baseline oscillometry and spirometry. When categorised into clinically relevant groups according to those predictors, ΔX rs6 was more sensitive than spirometry in smokers without current asthma or chronic obstructive pulmonary disease (COPD), ∼20% having a positive response. Using absolute or Z-score change provided similar prevalences of responsiveness, except in COPD, in which responsiveness measured by absolute change was twice that for Z-score. DISCUSSION: This study describes normative thresholds for bronchodilator responses in oscillometry parameters, including intra-breath parameters, as determined by absolute, relative and Z-score changes. Positive bronchodilator response by oscillometry correlated with clinical factors and baseline function, which may inform the clinical interpretation of oscillometry.

Deep inspirations protect against airway closure in nonasthmatic subjects.

The mechanism by which deep inspirations protect against increased airway responsiveness in nonasthmatic subjects is not known. The aim was to investigate the role of airway closure and airway narrowing in deep inspiration bronchoprotection. Twelve nonasthmatic and nine asthmatic subjects avoided deep inspirations (DI) for 20 min, then took five DI expired to functional residual capaciy (DI-FRC) or, on a separate day, no DI (no DI) before inhaling a single dose of methacholine. On another day, eight nonasthmatic subjects took five DI expired to residual volume (DI-RV). Peripheral airway function was measured by respiratory system reactance (Xrs), using the forced oscillation technique, and by forced vital capacity (FVC) as an index of airway closure. Respiratory system resistance (Rrs) and forced expiratory volume in 1 s (FEV1)/FVC were measured as indexes of airway narrowing. In nonasthmatic subjects, DI-FRC reduced the response measured by FEV1 (P=0.019), Xrs (P=0.02), and FVC (P=0.0005) but not by Rrs (P=0.15) or FEV1/FVC (P=0.52) compared with no DI. DI-RV had a less protective effect than DI-FRC on response measured by FEV1 (P=0.04) and FVC (P=0.016). There was no difference between all protocols when the response was measured by Xrs (P=0.20), Rrs (P=0.88), or FEV1/FVC (P=0.88). DI had no effect on methacholine response in asthmatic subjects. DI protect against airway responsiveness through an effect on peripheral airways involving reduced airway closure. The protective effect of DI on FEV1 and FVC was abolished by expiration to residual volume. We speculate that the reduced airway closure is due to reduced baseline ventilation heterogeneity and/or reduced airway surface tension.