The clinical features of the overlap between COPD and asthma

Background

The coexistence of COPD and asthma is widely recognized but has not been well described. This study characterizes clinical features, spirometry, and chest CT scans of smoking subjects with both COPD and asthma.

Methods

We performed a cross-sectional study comparing subjects with COPD and asthma to subjects with COPD alone in the COPDGene Study.

Results

119 (13%) of 915 subjects with COPD reported a history of physician-diagnosed asthma. These subjects were younger (61.3 vs 64.7 years old, p = 0.0001) with lower lifetime smoking intensity (43.7 vs 55.1 pack years, p = 0.0001). More African-Americans reported a history of asthma (33.6% vs 15.6%, p < 0.0001). Subjects with COPD and asthma demonstrated worse disease-related quality of life, were more likely to have had a severe COPD exacerbation in the past year, and were more likely to experience frequent exacerbations (OR 3.55 [2.19, 5.75], p < 0.0001). Subjects with COPD and asthma demonstrated greater gas-trapping on chest CT. There were no differences in spirometry or CT measurements of emphysema or airway wall thickness.

Conclusion

Subjects with COPD and asthma represent a relevant clinical population, with worse health-related quality of life. They experience more frequent and severe respiratory exacerbations despite younger age and reduced lifetime smoking history.

Trial registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT00608764","term_id":"NCT00608764"}}NCT00608764     

Systemic Inflammation in Young Adults Is Associated with Abnormal Lung Function in Middle Age

Background

Systemic inflammation is associated with reduced lung function in both healthy individuals and those with chronic obstructive pulmonary disease (COPD). Whether systemic inflammation in healthy young adults is associated with future impairment in lung health is uncertain.

Methodology/Principal Findings

We evaluated the association between plasma fibrinogen and C-reactive protein (CRP) in young adults and lung function in the Coronary Artery Risk Development in Young Adults cohort study. Higher year 7 fibrinogen was associated with greater loss of forced vital capacity (FVC) between years 5 and 20 (439 mL in quartile 4 vs. 398 mL in quartile 1, P<0.001) and forced expiratory volume in 1 second (FEV₁) (487 mL in quartile 4 vs. 446 mL in quartile 1, P<0.001) independent of cigarette smoking, body habitus, baseline lung function and demographic factors. Higher year 7 CRP was also associated with both greater loss of FVC (455 mL in quartile 4 vs. 390 mL in quartile 1, P<0.001) and FEV₁ (491 mL in quartile 4 vs. 442 mL in quartile 1, P = 0.001). Higher year 7 fibrinogen and CRP were associated with abnormal FVC at year 20 (odds ratio (OR) per standard deviation 1.51 (95% confidence interval (CI): 1.30–1.75) for fibrinogen and 1.35 (95% CI: 1.14–1.59) for CRP). Higher year 5 fibrinogen was additionally associated with abnormal FEV₁. A positive interaction was observed between pack-years cigarette smoking and year 7 CRP for the COPD endpoint, and among participants with greater than 10 pack-years of cigarette exposure, year 7 CRP was associated with greater odds of COPD at year 20 (OR per standard deviation 1.53 (95% CI: 1.08–2.16).

Conclusion/Significance

Systemic inflammation in young adults is associated with abnormal lung function in middle age. In particular, elevated CRP may identify vulnerability to COPD among individuals who smoke.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00005130","term_id":"NCT00005130"}}NCT00005130     

Epidemiology,radiology, and genetics of nicotine dependence in COPD

Background

Cigarette smoking is the principal environmental risk factor for developing COPD, and nicotine dependence strongly influences smoking behavior. This study was performed to elucidate the relationship between nicotine dependence, genetic susceptibility to nicotine dependence, and volumetric CT findings in smokers.

Methods

Current smokers with COPD (GOLD stage ≥ 2) or normal spirometry were analyzed from the COPDGene Study, a prospective observational study. Nicotine dependence was determined by the Fagerstrom test for nicotine dependence (FTND). Volumetric CT acquisitions measuring the percent of emphysema on inspiratory CT (% of lung <-950 HU) and gas trapping on expiratory CT (% of lung <-856 HU) were obtained. Genotypes for two SNPs in the CHRNA3/5 region (rs8034191, rs1051730) previously associated with nicotine dependence and COPD were analyzed for association to COPD and nicotine dependence phenotypes.

Results

Among 842 currently smoking subjects (335 COPD cases and 507 controls), 329 subjects (39.1%) showed high nicotine dependence. Subjects with high nicotine dependence had greater cumulative and current amounts of smoking. However, emphysema severity was negatively correlated with the FTND score in controls (ρ = -0.19, p < .0001) as well as in COPD cases (ρ = -0.18, p = 0.0008). Lower FTND score, male gender, lower body mass index, and lower FEV1 were independent risk factors for emphysema severity in COPD cases. Both CHRNA3/5 SNPs were associated with FTND in current smokers. An association of genetic variants in CHRNA3/5 with severity of emphysema was only found in former smokers, but not in current smokers.

Conclusions

Nicotine dependence was a negative predictor for emphysema on CT in COPD and control smokers. Increased inflammation in more highly addicted current smokers could influence the CT lung density distribution, which may influence genetic association studies of emphysema phenotypes.

Trial registration

ClinicalTrials (NCT): {"type":"clinical-trial","attrs":{"text":"NCT00608764","term_id":"NCT00608764"}}NCT00608764     

The Salford Lung Study protocol: a pragmatic,randomised phase III real-world effectiveness trial in chronic obstructive pulmonary disease

Background

New treatments need to be evaluated in real-world clinical practice to account for co-morbidities, adherence and polypharmacy.

Methods

Patients with chronic obstructive pulmonary disease (COPD), ≥40 years old, with exacerbation in the previous 3 years are randomised 1:1 to once-daily fluticasone furoate 100 μg/vilanterol 25 μg in a novel dry-powder inhaler versus continuing their existing therapy. The primary endpoint is the mean annual rate of COPD exacerbations; an electronic medical record allows real-time collection and monitoring of endpoint and safety data.

Conclusions

The Salford Lung Study is the world’s first pragmatic randomised controlled trial of a pre-licensed medication in COPD.

Trial registration

Clinicaltrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT01551758","term_id":"NCT01551758"}}NCT01551758.     

Genetic susceptibility for chronic bronchitis in chronic obstructive pulmonary disease

Background

Chronic bronchitis (CB) is one of the classic phenotypes of COPD. The aims of our study were to investigate genetic variants associated with COPD subjects with CB relative to smokers with normal spirometry, and to assess for genetic differences between subjects with CB and without CB within the COPD population.

Methods

We analyzed data from current and former smokers from three cohorts: the COPDGene Study; GenKOLS (Bergen, Norway); and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). CB was defined as having a cough productive of phlegm on most days for at least 3 consecutive months per year for at least 2 consecutive years. CB COPD cases were defined as having both CB and at least moderate COPD based on spirometry. Our primary analysis used smokers with normal spirometry as controls; secondary analysis was performed using COPD subjects without CB as controls. Genotyping was performed on Illumina platforms; results were summarized using fixed-effect meta-analysis.

Results

For CB COPD relative to smoking controls, we identified a new genome-wide significant locus on chromosome 11p15.5 (rs34391416, OR = 1.93, P = 4.99 × 10^-8) as well as significant associations of known COPD SNPs within FAM13A. In addition, a GWAS of CB relative to those without CB within COPD subjects showed suggestive evidence for association on 1q23.3 (rs114931935, OR = 1.88, P = 4.99 × 10^-7).

Conclusions

We found genome-wide significant associations with CB COPD on 4q22.1 (FAM13A) and 11p15.5 (EFCAB4A, CHID1 and AP2A2), and a locus associated with CB within COPD subjects on 1q23.3 (RPL31P11 and ATF6). This study provides further evidence that genetic variants may contribute to phenotypic heterogeneity of COPD.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00608764","term_id":"NCT00608764"}}NCT00608764, {"type":"clinical-trial","attrs":{"text":"NCT00292552","term_id":"NCT00292552"}}NCT00292552

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0113-2) contains supplementary material, which is available to authorized users.     

COPD association and repeatability of blood biomarkers in the ECLIPSE cohort

Background

There is a need for biomarkers to better characterise individuals with COPD and to aid with the development of therapeutic interventions. A panel of putative blood biomarkers was assessed in a subgroup of the Evaluation of COPD Longitudinally to Identify Surrogate Endpoints (ECLIPSE) cohort.

Methods

Thirty-four blood biomarkers were assessed in 201 subjects with COPD, 37 ex-smoker controls with normal lung function and 37 healthy non-smokers selected from the ECLIPSE cohort. Biomarker repeatability was assessed using baseline and 3-month samples. Intergroup comparisons were made using analysis of variance, repeatability was assessed through Bland-Altman plots, and correlations between biomarkers and clinical characteristics were assessed using Spearman correlation coefficients.

Results

Fifteen biomarkers were significantly different in individuals with COPD when compared to former or non-smoker controls. Some biomarkers, including tumor necrosis factor-α and interferon-γ, were measurable in only a minority of subjects whilst others such as C-reactive protein showed wide variability over the 3-month replication period. Fibrinogen was the most repeatable biomarker and exhibited a weak correlation with 6-minute walk distance, exacerbation rate, BODE index and MRC dyspnoea score in COPD subjects. 33% (66/201) of the COPD subjects reported at least 1 exacerbation over the 3 month study with 18% (36/201) reporting the exacerbation within 30 days of the 3-month visit. CRP, fibrinogen interleukin-6 and surfactant protein-D were significantly elevated in those COPD subjects with exacerbations within 30 days of the 3-month visit compared with those individuals that did not exacerbate or whose exacerbations had resolved.

Conclusions

Only a few of the biomarkers assessed may be useful in diagnosis or management of COPD where the diagnosis is based on airflow obstruction (GOLD). Further analysis of more promising biomarkers may reveal utility in subsets of patients. Fibrinogen in particular has emerged as a potentially useful biomarker from this cohort and requires further investigation.

Trial Registration

SCO104960, clinicaltrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT00292552","term_id":"NCT00292552"}}NCT00292552     

Efficacy and safety of once-daily aclidinium in chronic obstructive pulmonary disease

Background

The long-term efficacy and safety of aclidinium bromide, a novel, long-acting muscarinic antagonist, were investigated in patients with moderate to severe chronic obstructive pulmonary disease (COPD).

Methods

In two double-blind, 52-week studies, ACCLAIM/COPD I (n = 843) and II (n = 804), patients were randomised to inhaled aclidinium 200 μg or placebo once-daily. Patients were required to have a post-bronchodilator forced expiratory volume in 1 second (FEV₁)/forced vital capacity ratio of ≤70% and FEV₁ <80% of the predicted value. The primary endpoint was trough FEV₁ at 12 and 28 weeks. Secondary endpoints were health status measured by St George''s Respiratory Questionnaire (SGRQ) and time to first moderate or severe COPD exacerbation.

Results

At 12 and 28 weeks, aclidinium improved trough FEV₁ versus placebo in ACCLAIM/COPD I (by 61 and 67 mL; both p < 0.001) and ACCLAIM/COPD II (by 63 and 59 mL; both p < 0.001). More patients had a SGRQ improvement ≥4 units at 52 weeks with aclidinium versus placebo in ACCLAIM/COPD I (48.1% versus 39.5%; p = 0.025) and ACCLAIM/COPD II (39.0% versus 32.8%; p = 0.074). The time to first exacerbation was significantly delayed by aclidinium in ACCLAIM/COPD II (hazard ratio [HR] 0.7; 95% confidence interval [CI] 0.55 to 0.92; p = 0.01), but not ACCLAIM/COPD I (HR 1.0; 95% CI 0.72 to 1.33; p = 0.9). Adverse events were minor in both studies.

Conclusion

Aclidinium is effective and well tolerated in patients with moderate to severe COPD.

Trial registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT00363896","term_id":"NCT00363896"}}NCT00363896 (ACCLAIM/COPD I) and {"type":"clinical-trial","attrs":{"text":"NCT00358436","term_id":"NCT00358436"}}NCT00358436 (ACCLAIM/COPD II).     

Characterisation of exacerbation risk and exacerbator phenotypes in the POET-COPD trial

Background

Data examining the characteristics of patients with frequent exacerbations of chronic obstructive pulmonary disease (COPD) and associated hospitalisations and mortality are scarce.

Methods

Post-hoc analysis of the Prevention Of Exacerbations with Tiotropium in COPD (POET-COPD) trial, targeting exacerbations as the primary endpoint. Patients were classified as non-, infrequent, and frequent exacerbators (0, 1, or ≥ 2 exacerbations during study treatment), irrespective of study treatment. A multivariate Cox regression model assessed the effect of covariates on time to first exacerbation.

Results

In total, 7376 patients were included in the analysis: 63.5% non-exacerbators, 22.9% infrequent, 13.6% frequent exacerbators. Factors significantly associated with exacerbation risk were age, sex, body mass index, COPD duration and severity, smoking history, baseline inhaled corticosteroid use, and preceding antibiotic or systemic corticosteroid courses. Frequent exacerbators had greater severity and duration of COPD, received more pulmonary medication, and ≥ 2 systemic corticosteroid or antibiotic courses in the preceding year, and were more likely to be female and ex-smokers. The small proportion of frequent exacerbators (13.6%) accounted for 56.6% of exacerbation-related hospitalisations, which, overall, were associated with a three-fold increase in mortality.

Conclusion

The frequent exacerbator phenotype was closely associated with exacerbation-related hospitalisations, and exacerbation-related hospitalisations were associated with poorer survival.

Trial registration

{"type":"clinical-trial","attrs":{"text":"NCT00563381","term_id":"NCT00563381"}}NCT00563381; Study identifier: BI 205.389.     

The Continuum of Physiological Impairment during Treadmill Walking in Patients with Mild-to-Moderate COPD: Patient Characterization Phase of a Randomized Clinical Trial

Background

To have a better understanding of the mechanisms of exercise limitation in mild-to-moderate chronic obstructive pulmonary disease (COPD), we compared detailed respiratory physiology in patients with COPD and healthy age- and sex-matched controls.

Methods

Data were collected during the pre-treatment, patient characterization phase of a multicenter, randomized, double-blind, crossover study. Patients with COPD met Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 or 2 spirometric criteria, were symptomatic, and had evidence of gas trapping during exercise. All participants completed pulmonary function and symptom-limited incremental treadmill exercise tests.

Results

Chronic activity-related dyspnea measured by Baseline Dyspnea Index was similarly increased in patients with GOLD 1 (n = 41) and 2 (n = 63) COPD compared with controls (n = 104). Plethysmographic lung volumes were increased and lung diffusing capacity was decreased in both GOLD groups. Peak oxygen uptake and work rate were reduced in both GOLD groups compared with controls (p<0.001). Submaximal ventilation, dyspnea, and leg discomfort ratings were higher for a given work rate in both GOLD groups compared with controls. Resting inspiratory capacity, peak ventilation, and tidal volume were reduced in patients with GOLD 2 COPD compared with patients with GOLD 1 COPD and controls (p<0.001).

Conclusions

Lower exercise tolerance in patients with GOLD 1 and 2 COPD compared with controls was explained by greater mechanical abnormalities, greater ventilatory requirements, and increased subjective discomfort. Lower resting inspiratory capacity in patients with GOLD 2 COPD was associated with greater mechanical constraints and lower peak ventilation compared with patients with GOLD 1 COPD and controls.

Trial Registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT01072396","term_id":"NCT01072396"}}NCT01072396     

EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as Tobacco Cigarettes Substitute: A Prospective 12-Month Randomized Control Design Study

Background

Electronic cigarettes (e-cigarettes) are becoming increasingly popular with smokers worldwide. Users report buying them to help quit smoking, to reduce cigarette consumption, to relieve tobacco withdrawal symptoms, and to continue having a ‘smoking’ experience, but with reduced health risks. Research on e-cigarettes is urgently needed in order to ensure that the decisions of regulators, healthcare providers and consumers are based on science. Methods ECLAT is a prospective 12-month randomized, controlled trial that evaluates smoking reduction/abstinence in 300 smokers not intending to quit experimenting two different nicotine strengths of a popular e-cigarette model (‘Categoria’; Arbi Group Srl, Italy) compared to its non-nicotine choice. GroupA (n = 100) received 7.2 mg nicotine cartridges for 12 weeks; GroupB (n = 100), a 6-week 7.2 mg nicotine cartridges followed by a further 6-week 5.4 mg nicotine cartridges; GroupC (n = 100) received no-nicotine cartridges for 12 weeks. The study consisted of nine visits during which cig/day use and exhaled carbon monoxide (eCO) levels were measured. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed.

Results

Declines in cig/day use and eCO levels were observed at each study visits in all three study groups (p<0.001 vs baseline), with no consistent differences among study groups. Smoking reduction was documented in 22.3% and 10.3% at week-12 and week-52 respectively. Complete abstinence from tobacco smoking was documented in 10.7% and 8.7% at week-12 and week-52 respectively. A substantial decrease in adverse events from baseline was observed and withdrawal symptoms were infrequently reported during the study. Participants’ perception and acceptance of the product under investigation was satisfactory.

Conclusion

In smokers not intending to quit, the use of e-cigarettes, with or without nicotine, decreased cigarette consumption and elicited enduring tobacco abstinence without causing significant side effects.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01164072","term_id":"NCT01164072"}}NCT01164072 {"type":"clinical-trial","attrs":{"text":"NCT01164072","term_id":"NCT01164072"}}NCT01164072     

Childhood pneumonia increases risk for chronic obstructive pulmonary disease: the COPDGene study

Background

Development of adult respiratory disease is influenced by events in childhood. The impact of childhood pneumonia on chronic obstructive pulmonary disease (COPD) is not well defined. We hypothesize that childhood pneumonia is a risk factor for reduced lung function and COPD in adult smokers.

Methods

COPD cases and control smokers between 45–80 years old from the United States COPDGene Study were included. Childhood pneumonia was defined by self-report of pneumonia at <16 years. Subjects with lung disease other than COPD or asthma were excluded. Smokers with and without childhood pneumonia were compared on measures of respiratory disease, lung function, and quantitative analysis of chest CT scans.

Results

Of 10,192 adult smokers, 854 (8.4 %) reported pneumonia in childhood. Childhood pneumonia was associated with COPD (OR 1.40; 95 % CI 1.17-1.66), chronic bronchitis, increased COPD exacerbations, and lower lung function: post-bronchodilator FEV₁ (69.1 vs. 77.1 % predicted), FVC (82.7 vs. 87.4 % predicted), FEV₁/FVC ratio (0.63 vs. 0.67; p < 0.001 for all comparisons). Childhood pneumonia was associated with increased airway wall thickness on CT, without significant difference in emphysema. Having both pneumonia and asthma in childhood further increased the risk of developing COPD (OR 1.85; 95 % CI 1.10-3.18).

Conclusions

Children with pneumonia are at increased risk for future smoking-related lung disease including COPD and decreased lung function. This association is supported by airway changes on chest CT scans. Childhood pneumonia may be an important factor in the early origins of COPD, and the combination of pneumonia and asthma in childhood may pose the greatest risk.

Clinical trials registration

ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00608764","term_id":"NCT00608764"}}NCT00608764 (Active since January 28, 2008).

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0273-8) contains supplementary material, which is available to authorized users.     

Nocturnal CPAP improves walking capacity in COPD patients with obstructive sleep apnoea

Background

Exercise limitation is an important issue in patients with chronic obstructive pulmonary disease (COPD), and it often co-exists with obstructive sleep apnoea (overlap syndrome). This study examined the effects of nocturnal continuous positive airway pressure (CPAP) treatment on walking capacity in COPD patients with or without obstructive sleep apnoea.

Methods

Forty-four stable moderate-to-severe COPD patients were recruited and completed this study. They all underwent polysomnography, CPAP titration, accommodation, and treatment with adequate pressure. The incremental shuttle walking test was used to measure walking capacity at baseline and after two nights of CPAP treatment. Urinary catecholamine and heart rate variability were measured before and after CPAP treatment.

Results

After two nights of CPAP treatment, the apnoea-hypopnoea index and oxygen desaturation index significantly improved in both overlap syndrome and COPD patients, however these changes were significantly greater in the overlap syndrome than in the COPD group. Sleep architecture and autonomic dysfunction significantly improved in the overlap syndrome group but not in the COPD group. CPAP treatment was associated with an increased walking capacity from baseline from 226.4 ± 95.3 m to 288.6 ± 94.6 m (P < 0.05), and decreased urinary catecholamine levels, pre-exercise heart rate, oxygenation, and Borg scale in the overlap syndrome group. An improvement in the apnoea-hypopnoea index was an independent factor associated with the increase in walking distance (r = 0.564).

Conclusion

Nocturnal CPAP may improve walking capacity in COPD patients with overlap syndrome.

Trial registration

{"type":"clinical-trial","attrs":{"text":"NCT00914264","term_id":"NCT00914264"}}NCT00914264     

Correlating changes in lung function with patient outcomes in chronic obstructive pulmonary disease: a pooled analysis

Background

Relationships between improvements in lung function and other clinical outcomes in chronic obstructive pulmonary disease (COPD) are not documented extensively. We examined whether changes in trough forced expiratory volume in 1 second (FEV₁) are correlated with changes in patient-reported outcomes.

Methods

Pooled data from three indacaterol studies (n = 3313) were analysed. Means and responder rates for outcomes including change from baseline in Transition Dyspnoea Index (TDI), St. George''s Respiratory Questionnaire (SGRQ) scores (at 12, 26 and 52 weeks), and COPD exacerbation frequency (rate/year) were tabulated across categories of ΔFEV₁. Also, generalised linear modelling was performed adjusting for covariates such as baseline severity and inhaled corticosteroid use.

Results

With increasing positive ΔFEV₁, TDI and ΔSGRQ improved at all timepoints, exacerbation rate over the study duration declined (P < 0.001). Individual-level correlations were 0.03-0.18, but cohort-level correlations were 0.79-0.95. At 26 weeks, a 100 ml increase in FEV₁ was associated with improved TDI (0.46 units), ΔSGRQ (1.3-1.9 points) and exacerbation rate (12% decrease). Overall, adjustments for baseline covariates had little impact on the relationship between ΔFEV₁ and outcomes.

Conclusions

These results suggest that larger improvements in FEV₁ are likely to be associated with larger patient-reported benefits across a range of clinical outcomes.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00393458","term_id":"NCT00393458"}}NCT00393458, {"type":"clinical-trial","attrs":{"text":"NCT00463567","term_id":"NCT00463567"}}NCT00463567, and {"type":"clinical-trial","attrs":{"text":"NCT00624286","term_id":"NCT00624286"}}NCT00624286     

Changes in the endurance shuttle walk test in COPD patients with chronic respiratory failure after pulmonary rehabilitation: the minimal important difference obtained with anchor- and distribution-based method

Background

Although the endurance shuttle walk test (ESWT) has proven to be responsive to change in exercise capacity after pulmonary rehabilitation (PR) for COPD, the minimally important difference (MID) has not yet been established. We aimed to establish the MID of the ESWT in patients with severe COPD and chronic hypercapnic respiratory failure following PR.

Methods

Data were derived from a randomized controlled trial, investigating the value of noninvasive positive pressure ventilation added to PR. Fifty-five patients with stable COPD, GOLD stage IV, with chronic respiratory failure were included (mean (SD) FEV₁ 31.1 (12.0) % pred, age 62 (9) y). MID estimates of the ESWT in seconds, percentage and meters change were calculated with anchor based and distribution based methods. Six minute walking distance (6MWD), peak work rate on bicycle ergometry (Wpeak) and Chronic Respiratory Questionnaire (CRQ) were used as anchors and Cohen’s effect size was used as distribution based method.

Results

The estimated MID of the ESWT with the different anchors ranged from 186–199 s, 76–82% and 154–164 m. Using the distribution based method the MID was 144 s, 61% and 137 m.

Conclusions

Estimates of the MID for the ESWT after PR showed only small differences using different anchors in patients with COPD and chronic respiratory failure. Therefore we recommend using a range of 186–199 s, 76–82% or 154–164 m as MID of the ESWT in COPD patients with chronic respiratory failure. Further research in larger populations should elucidate whether this cut-off value is also valid in other COPD populations and with other interventions.

Trial registration

ClinicalTrials.Gov (ID {"type":"clinical-trial","attrs":{"text":"NCT00135538","term_id":"NCT00135538"}}NCT00135538).

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0182-x) contains supplementary material, which is available to authorized users.     

Three-year follow-up of Interleukin 6 and C-reactive protein in chronic obstructive pulmonary disease

Background

Past studies have shown that mean values of Interleukin-6 (IL-6) and C-reactive protein (CRP) do not change significantly in COPD patients over a one-year period. However, longer period follow-up studies are still lacking. Thus, the aim of this study is to evaluate plasma CRP and IL-6 concentration over three years in COPD patients and to test the association between these inflammatory mediators and disease outcome markers.

Methods

A cohort of 77 outpatients with stable COPD was evaluated at baseline, and 53 (mean FEV₁, 56% predicted) were included in the prospective study. We evaluated Interleukin-6 (IL-6), C-reactive protein (CRP), six-minute walking distance (6MWD), and body mass index (BMI) at baseline and after three years. Plasma concentration of IL-6 was measured by high sensitivity ELISA, and CRP was obtained by high sensitivity particle-enhanced immunonephelometry.

Results

IL-6 increased significantly after 3 years compared to baseline measurements [0.8 (0.5-1.3) vs 2.4 (1.3-4.4) pg/ml; p < 0.001] and was associated with worse 6MWD performance. In the Cox regression, increased IL-6 at baseline was associated with mortality [Hazard Ratio (95% CI) = 2.68 (0.13, 1.84); p = 0.02]. CRP mean values did not change [5 (1.6-7.9) vs 4.7 (1.7-10) pg/L; p = 0.84], although eleven patients (21%) presented with changes >3 mg/L in CRP after 3 years.

Conclusions

The systemic inflammatory process, evaluated by IL-6, seems to be persistent, progressive and associated with mortality and worse physical performance in COPD patients.

Trial registration

No.:{"type":"clinical-trial","attrs":{"text":"NCT00605540","term_id":"NCT00605540"}}NCT00605540     

Efficacy and safety of AZD3199 vs formoterol in COPD: a randomized,double-blind study

Background

We investigated the efficacy and safety of AZD3199, a novel inhaled ultra-LABA, with the main aim of establishing a dose that would maintain 24-hour bronchodilation in patients with COPD.

Methods

Patients (n = 329) were randomized to AZD3199 (200, 400 or 800 μg o.d.), formoterol (9 μg b.i.d.) or placebo via Turbuhaler® in a parallel group study. The primary objective of the study was to compare the clinical efficacy of three doses of AZD3199 inhaled once daily with 9 μg formoterol twice daily and placebo, over a 4-week treatment period in adults with moderate-to-severe COPD. After 4 weeks, peak (0–4 h) and trough (24–26 h) forced expiratory volume in 1 second (FEV₁) were assessed as the primary efficacy outcome variables.

Results

All AZD3199 doses significantly increased mean peak and trough FEV₁ versus placebo (106–171 ml and 97–110 ml increases, respectively), but with no clear dose–response; the level of bronchodilation was comparable to or greater than that achieved with formoterol. Forced vital capacity (FVC) at peak bronchodilation also significantly increased with AZD3199 versus placebo (153–204 ml). COPD symptom scores and reliever use were reduced with AZD3199, while FEV₁ reversibility was unaltered. Adverse events were mild-to-moderate, with no safety concerns identified. Drug exposure was dose-proportional, but lower than predicted from healthy volunteers.

Conclusions

All three doses of AZD3199 produced 24-hour bronchodilation, but with no clear dose–response, suggesting that doses of 200 μg or less may be sufficient to maintain bronchodilation over 24 hours in patients with COPD. No safety concerns were identified. Further studies are required to determine the once-daily AZD3199 dose for COPD.

Trial registration

Clinicaltrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00929708","term_id":"NCT00929708"}}NCT00929708     

Low intensity,long-term outpatient rehabilitation in COPD: a randomised controlled trial

Background

Most pulmonary rehabilitation programmes currently involve 2–3 sessions per week as recommended by international guidelines. We aimed to investigate whether relevant improvements in physical capabilities and quality of life in patients with chronic obstructive pulmonary disease (COPD) could be achieved by a long-term, low intensity, once weekly rehabilitation programme using limited resources.

Methods

100 patients with moderate to severe COPD were randomised to a continuous outpatient interdisciplinary rehabilitation programme or standard care. Physiotherapy-led supervised outpatient training sessions were performed once weekly in addition to educational elements. Outcome measures at baseline and after 26 weeks were 6-minute-walk-test, cycle ergometry, and health-related quality of life.

Results

37 patients in the training group and 44 patients in the control group completed the study. After 26 weeks there were clinically significant differences between the groups for 6 minute-walk-distance (+59 m, 95% CI 28–89 m), maximum work load (+7.4 Watt, 95% CI 0.5-13.4 Watt) and St. George’s Respiratory Questionnaire score (−5 points, 95% CI −10 to −1 points). Total staff costs of the programme per participant were ≤ €625.

Conclusion

Clinically meaningful improvements in physical capabilities and health-related quality of life may be achieved using long-term pulmonary rehabilitation programmes of lower intensity than currently recommended. Trial registration: clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01195402","term_id":"NCT01195402"}}NCT01195402.     

Reduction of exacerbations by the PDE4 inhibitor roflumilast - the importance of defining different subsets of patients with COPD

Background

As chronic obstructive pulmonary disease (COPD) is a heterogeneous disease it is unlikely that all patients will benefit equally from a given therapy. Roflumilast, an oral, once-daily phosphodiesterase 4 inhibitor, has been shown to improve lung function in moderate and severe COPD but its effect on exacerbations in unselected populations was inconclusive. This led to the question of whether a responsive subset existed that could be investigated further.

Methods

The datasets of two previous replicate, randomized, double-blind, placebo-controlled, parallel-group studies (oral roflumilast 500 μg or placebo once daily for 52 weeks) that were inconclusive regarding exacerbations were combined in a post-hoc, pooled analysis to determine whether roflumilast reduced exacerbations in a more precisely defined patient subset.

Results

The pooled analysis included 2686 randomized patients. Roflumilast significantly decreased exacerbations by 14.3% compared with placebo (p = 0.026). Features associated with this reduction were: presence of chronic bronchitis with or without emphysema (26.2% decrease, p = 0.001), presence of cough (20.9% decrease, p = 0.006), presence of sputum (17.8% decrease, p = 0.03), and concurrent use of inhaled corticosteroids (ICS; 18.8% decrease, p = 0.014). The incidence of adverse events was similar with roflumilast and placebo (81.5% vs 80.1%), but more patients in the roflumilast group had events assessed as likely or definitely related to the study drug (21.5% vs 8.3%).

Conclusions

This post-hoc, pooled analysis showed that roflumilast reduced exacerbation frequency in a subset of COPD patients whose characteristics included chronic bronchitis with/without concurrent ICS. These observations aided the design of subsequent phase 3 studies that prospectively confirmed the reduction in exacerbations with roflumilast treatment.

Trials registration

ClinicalTrials.gov identifiers: {"type":"clinical-trial","attrs":{"text":"NCT00076089","term_id":"NCT00076089"}}NCT00076089 and {"type":"clinical-trial","attrs":{"text":"NCT00430729","term_id":"NCT00430729"}}NCT00430729.