Salbutamol use in relation to maintenance bronchodilator efficacy in COPD: a prospective subgroup analysis of the EMAX trial

Background

Short-acting β₂-agonist (SABA) bronchodilators help alleviate symptoms in chronic obstructive pulmonary disease (COPD) and may be a useful marker of symptom severity. This analysis investigated whether SABA use impacts treatment differences between maintenance dual- and mono-bronchodilators in patients with COPD.

Methods

The Early MAXimisation of bronchodilation for improving COPD stability (EMAX) trial randomised symptomatic patients with low exacerbation risk not receiving inhaled corticosteroids 1:1:1 to once-daily umeclidinium/vilanterol 62.5/25 μg, once-daily umeclidinium 62.5 μg or twice-daily salmeterol 50 μg for 24 weeks. Pre-specified subgroup analyses stratified patients by median baseline SABA use (low, < 1.5 puffs/day; high, ≥1.5 puffs/day) to examine change from baseline in trough forced expiratory volume in 1 s (FEV₁), change in symptoms (Transition Dyspnoea Index [TDI], Evaluating Respiratory Symptoms-COPD [E-RS]), daily SABA use and exacerbation risk. A post hoc analysis used fractional polynomial modelling with continuous transformations of baseline SABA use covariates.

Results

At baseline, patients in the high SABA use subgroup (mean: 3.91 puffs/day, n = 1212) had more severe airflow limitation, were more symptomatic and had worse health status versus patients in the low SABA use subgroup (0.39 puffs/day, n = 1206). Patients treated with umeclidinium/vilanterol versus umeclidinium demonstrated statistically significant improvements in trough FEV₁ at Week 24 in both SABA subgroups (59–74 mL; p < 0.001); however, only low SABA users demonstrated significant improvements in TDI (high: 0.27 [p = 0.241]; low: 0.49 [p = 0.025]) and E-RS (high: 0.48 [p = 0.138]; low: 0.60 [p = 0.034]) scores. By contrast, significant reductions in mean SABA puffs/day with umeclidinium/vilanterol versus umeclidinium were observed only in high SABA users (high: − 0.56 [p < 0.001]; low: − 0.10 [p = 0.132]). Similar findings were observed when comparing umeclidinium/vilanterol and salmeterol. Fractional polynomial modelling showed baseline SABA use ≥4 puffs/day resulted in smaller incremental symptom improvements with umeclidinium/vilanterol versus umeclidinium compared with baseline SABA use < 4 puffs/day.

Conclusions

In high SABA users, there may be a smaller difference in treatment response between dual- and mono-bronchodilator therapy; the reasons for this require further investigation. SABA use may be a confounding factor in bronchodilator trials and in high SABA users; changes in SABA use may be considered a robust symptom outcome.

Funding

GlaxoSmithKline (study number 201749 [NCT03034915]).

Self-administered prescriptions of oral steroids and antibiotics in chronic obstructive pulmonary disease: are we doing more harm than good?

Patients with chronic obstructive pulmonary disease (COPD) are often given a prescription for a short course of oral steroids and antibiotics for self-administration during an acute exacerbation. The main objective of this study was to determine the impact of such prescriptions on medical care utilization, and steroids and antibiotics intake. This retrospective cohort study included patients with moderate to severe COPD participating in a self-management programme. We compared the number of unplanned medical visits (including hospitalizations) and the utilization of systemic steroids (number of short courses, number of days on treatment) and antibiotics (number of treatments) over a period of six months following registration to the programme in patients who received such a prescription and those who did not. Data were collected from hospital and community pharmacy files. A total of 89 patients were included; 46 received a self-administered prescription. During the study period, we found no difference between the two groups in the number of unplanned medical visits. However, we observed small but significant differences in the number of short courses of Prednisone ( P = 0.018) and antibiotics ( P = 0.006). This translated in an important difference in the number of days on steroids over the same period (`Prescription' group: 26; controls: 8; P = 0.005). Self-administered prescriptions may increase steroids and antibiotics utilization in patients with moderate to severe COPD, without reducing the number of unplanned medical visits. Chronic Respiratory Disease 2007; 4: 143—147

Characteristics of COPD in never-smokers and ever-smokers in the general population: results from the CanCOLD study

BACKGROUND

There is limited data on the risk factors and phenotypical characteristics associated with spirometrically confirmed COPD in never-smokers in the general population.

AIMS

To compare the characteristics associated with COPD by gender and by severity of airway obstruction in never-smokers and in ever-smokers.

METHOD

We analysed the data from 5176 adults aged 40 years and older who participated in the initial cross-sectional phase of the population-based, prospective, multisite Canadian Cohort of Obstructive Lung Disease study. Never-smokers were defined as those with a lifetime exposure of <1/20 pack year. Logistic regressions were constructed to evaluate associations for 'mild' and 'moderate-severe' COPD defined by FEV1/FVC <5th centile (lower limits of normal). Analyses were performed using SAS V.9.1 (SAS Institute, Cary, North Carolina, USA).

RESULTS

The prevalence of COPD (FEV1/FVC<lower limits of normal) in never-smokers was 6.4%, constituting 27% of all COPD subjects. The common independent predictors of COPD in never-smokers and ever-smokers were older age, self reported asthma and lower education. In never-smokers a history of hospitalisation in childhood for respiratory illness was discriminative, while exposure to passive smoke and biomass fuel for heating were discriminative for women. COPD in never-smokers and ever-smokers was characterised by increased respiratory symptoms, 'respiratory exacerbation' events and increased residual volume/total lung capacity, but only smokers had reduced DLCO/Va and emphysema on chest CT scans.

CONCLUSIONS

The study confirmed the substantial burden of COPD among never-smokers, defined the common and gender-specific risk factors for COPD in never-smokers and provided early insight into potential phenotypical differences in COPD between lifelong never-smokers and ever-smokers.

TRIAL REGISTRATION NUMBER

NCT00920348 (ClinicalTrials.gov); study ID number: IRO-93326.

Exacerbation-like respiratory symptoms in individuals without chronic obstructive pulmonary disease: results from a population-based study

RATIONALE

Exacerbations of COPD are defined clinically by worsening of chronic respiratory symptoms. Chronic respiratory symptoms are common in the general population. There are no data on the frequency of exacerbation-like events in individuals without spirometric evidence of COPD.

AIMS

To determine the occurrence of 'exacerbation-like' events in individuals without airflow limitation, their associated risk factors, healthcare utilisation and social impacts.

METHOD

We analysed the cross-sectional data from 5176 people aged 40 years and older who participated in a multisite, population-based study on lung health. The study cohort was stratified into spirometrically defined COPD (post-bronchodilator FEV1/FVC < 0.7) and non-COPD (post bronchodilator FEV1/FVC ≥ 0.7 and without self-reported doctor diagnosis of airway diseases) subgroups and then into those with and without respiratory 'exacerbation-like' events in the past year.

RESULTS

Individuals without COPD had half the frequency of 'exacerbation-like' events compared with those with COPD. In the non-COPD group, the independent associations with 'exacerbations' included female gender, presence of wheezing, the use of respiratory medications and self-perceived poor health. In the non-COPD group, those with exacerbations were more likely than those without exacerbations to have poorer health-related quality of life (12-item Short-Form Health Survey), miss social activities (58.5% vs 18.8%), miss work for income (41.5% vs 17.3%) and miss housework (55.6% vs 16.5%), p<0.01 to <0.0001.

CONCLUSIONS

Events similar to exacerbations of COPD can occur in individuals without COPD or asthma and are associated with significant health and socioeconomic outcomes. They increase the respiratory burden in the community and may contribute to the false-positive diagnosis of asthma or COPD.

Prescribing exercise training in pulmonary rehabilitation: a clinical experience

Built around exercise training, pulmonary rehabilitation (PR) is a multidisciplinary, evidence-based, comprehensive approach to working with the patient as a whole and not just the pulmonary component of the disease. Integrated into the individualized treatment, this intervention aims to reduce symptoms, optimize functional status, increase participation in daily life, and reduce health care costs through stabilizing or reversing systemic manifestations of the disease. Although there are many other components that should be considered to manage the impairment and symptom burden, supervised exercise training is considered the cornerstone of effective pulmonary rehabilitation. This paper addresses our clinical experience at Institut universitaire de cardiologie et de pneumologie de Québec to assess and manage exercise training in line with the current recommendations and guidelines surrounding PR.

[Diaphragm and skeletal muscle dysfunction in COPD]

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is often accompanied by skeletal muscle alterations, resulting in enhanced morbidity and mortality.

STATE OF THE ART

Many studies have highlighted important structural and biochemical modifications in limb and respiratory muscles in COPD. Reviewing the similarities and differences between the two most studied muscles in COPD, the quadriceps and the diaphragm, may provide important clues about the mechanisms dictating muscle changes that occur in this disease.

PERSPECTIVES

Though these two muscle groups share a common systemic environment, discrepancies are observed in their respective alterations. These phenotypic differences suggest that, in addition to systemic factors, the local microenvironment must participate in the reorganization seen in these two muscles in COPD.

CONCLUSIONS

The current review introduces the alterations observed in the quadriceps and diaphragm in the context of COPD and suggests possible signaling pathways involved in the development of muscle dysfunction.

Pulmonary rehabilitation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and an important worldwide cause of disability and handicap. Centered around exercise training, pulmonary rehabilitation is a global, multidisciplinary, individualized and comprehensive approach acting on the patient as a whole and not only on the pulmonary component of the disease. Pulmonary rehabilitation is now well recognized as an effective and key intervention in the management of several respiratory diseases particularly in COPD. Modern and effective pulmonary rehabilitation programs are global, multidisciplinary, individualized and use comprehensive approach acting on the patient as a whole and not only on the pulmonary component of the disease. In the last two decades interest for pulmonary rehabilitation is on the rise and a growing literature including several guidelines is now available. This review addresses the recent developments in the broad area of pulmonary rehabilitation as well as new methods to consider in the development of future and better programs. Modern literature for rationale, physiopathological basis, structure, exercise training as well challenges for pulmonary rehabilitation programs are addressed. Among the main challenges of pulmonary rehabilitation, efforts have to be devoted to improve accessibility to early rehabilitation strategies, not only to patients with COPD but to those with other chronic respiratory diseases.

[Cardiovascular manifestations in patients with COPD]

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is characterized mainly by airway obstruction due to chronic bronchitis and/or emphysema. In addition, COPD is frequently associated with other health problems with serious systemic manifestations. In particular, COPD patients are at increased risk of cardiovascular disease.

BACKGROUND

Current knowledge about cardiovascular disease in patients with COPD mainly concerns the high prevalence of cardiac arrhythmias in this population. Systemic hypertension, cardiovascular disease, heart failure and cerebro-vascular disease are also frequently encountered. This review discusses the cardiovascular manifestations associated with COPD, excluding right heart failure due to pulmonary hypertension.

VIEWPOINTS AND CONCLUSION

Non pulmonary health problems in patients with COPD, such as cardiovascular disease, are arousing increasing interest in the medical community. More studies are needed to increase our knowledge of cardiovascular disease in COPD and allow better medical management of patients.

Metabolic and inflammatory profile in obese patients with chronic obstructive pulmonary disease

BACKGROUND

Overweight and obesity have been associated with better survival in patients with chronic obstructive pulmonary disease (COPD). On the other hand, excess body weight is associated with abnormal metabolic and inflammatory profiles that define the metabolic syndrome and predispose to cardiovascular diseases. This study was undertaken to evaluate the impact of overweight and obesity on the prevalence of the metabolic syndrome and on the metabolic and inflammatory profiles in patients with COPD.

METHODS

Twenty-eight male patients with COPD were divided into an overweight/obese group [ n = 16, body mass index (BMI) = 33.5 +/- 4.2 kg/m(2)] and normal weight group (n = 12, BMI = 21.1 +/- 2.6 kg/m(2)). Anthropometry, pulmonary function and body composition were assessed. The metabolic syndrome was diagnosed according to waist circumference, circulating levels of triglyceride and high-density lipoprotein cholesterol levels, fasting glycemia and blood pressure. C-reactive protein, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), leptin and adiponectin plasma levels were measured.

RESULTS

Airflow obstruction was less severe in overweight/obese compared with normal weight patients (forced expiratory volume(1): 51 +/- 19% versus 31 +/- 12% predicted, respectively, P < 0.01). The metabolic syndrome was diagnosed in 50% of overweight/obese patients and in none of the normal weight patients. TNF-alpha, IL-6 and leptin were significantly higher in overweight/obese patients whereas the adiponectin levels were reduced in the presence of excess weight.

CONCLUSIONS

The metabolic syndrome was frequent in overweight/obese patients with COPD. Obesity in COPD was associated with a spectrum of metabolic and inflammatory abnormalities.

Assessing the impact of pulmonary rehabilitation on functional status in COPD

BACKGROUND

The optimal way of assessing the impact of pulmonary rehabilitation on functional status in chronic obstructive pulmonary disease (COPD) is currently unknown. The minimal clinically important difference for the constant work rate cycling exercise test also needs to be investigated to facilitate its interpretation. A study was undertaken to evaluate the changes in the 6-min walking test and in the constant work rate cycle endurance test immediately following and 1 year after pulmonary rehabilitation, together with the importance of these changes in terms of health status in patients with COPD.

METHODS

Patients with COPD of mean (SD) age 65 (8) years and mean (SD) forced expiratory volume in 1 s (FEV1) 45 (15)% predicted were recruited from a multicentre prospective cohort study and evaluated at baseline, immediately after a pulmonary rehabilitation programme (n = 157) and at 1 year (n = 106). The 6-min walking test and the cycle endurance test were performed at each evaluation. Health status was evaluated with the St George Respiratory Questionnaire.

RESULTS

Following pulmonary rehabilitation, cycle endurance time increased (198 (352) s, p<0.001) and stayed over baseline values at 1 year (p<0.001). The 6-min walking distance also showed improvements following rehabilitation (25 (52) m, p<0.001) but returned to baseline values at the 1-year follow-up. Changes in cycle endurance time were more closely associated with changes in health status than with the 6-min walking test. An improvement of 100-200 s in the cycle endurance time was associated with clinically meaningful changes in the St George Respiratory Questionnaire scores.

CONCLUSIONS

The cycle endurance test was more responsive than the 6-min walking test in detecting improvement in exercise tolerance following pulmonary rehabilitation, and was also better correlated with improvements in health status. An improvement in the cycle endurance time of 100-200 s appeared to be clinically meaningful.

Counting, analysing and reporting exacerbations of COPD in randomised controlled trials

BACKGROUND

Clinical trials measure exacerbations of chronic obstructive pulmonary disease (COPD) inconsistently. A study was undertaken to determine if different methods for ascertaining and analysing COPD exacerbations lead to biased estimates of treatment effects.

METHODS

Information on the methods used to count, analyse and report COPD exacerbation rates was abstracted from clinical trials of long-acting bronchodilators or long-acting bronchodilator/inhaled steroid combination products published between 2000 and 2006. Data from the Canadian Optimal Therapy of COPD Trial was used to illustrate how different analytical approaches can affect the estimate of exacerbation rates and their confidence intervals.

RESULTS

22 trials (17,156 patients) met the inclusion criteria and were reviewed. None of the trials adjudicated exacerbations or determined independence of events. 14/22 studies (64%) introduced selection bias by not analysing outcome data for subjects who prematurely stopped study medications. Only 31% of trials used time-weighted analyses to calculate the mean number of exacerbations/patient-year and only 15% accounted for between-subject variation. In the Canadian Optimal Therapy of COPD Trial the rate ratio for exacerbations/patient-year was 0.85 when all data were included in a time-weighted analysis, but was overestimated as 0.79 when data for those who prematurely stopped study medications were excluded and was further overestimated as 0.46 when a time-weighted analysis was not conducted; p values ranged from 0.03 to 0.24 depending on how exacerbations were determined and analysed.

CONCLUSIONS

Clinical trials have used widely different methods to define and analyse COPD exacerbations and this can lead to biased estimates of treatment effects. Future trials should strive to include blinded adjudication and assessment of the independence of exacerbation events, and trials should report time-weighted intention-to-treat analyses with adjustments for between-subject variation in COPD exacerbations.

Test-retest Reproducibility of Constant Rate Step and Shuttle Walk Test for the Assessment of Exertional Dyspnea in patients with COPD

Background: Alternatives for laboratory exercise testing are needed to better reflect symptoms of physical activities of daily living in chronic disease. Such a tool should accurately set the exercise intensity and show good reproducibility. This study examined the reproducibility of constant rate walking (CRWT) and stepping tests (CRST) to assess exertional dyspnea in patients with COPD. Methods: Stable COPD patients (n=43; 65 ± 6.5 yr; FEV1= 49 ± 16% pred.) equipped with a portable Jaeger Oxycon Mobile® metabolic system completed both the CRWT and the CRST. Each test included four 3-min constsant rate stages separated by a 10-min rest period on two occasions separated by 7 to 14 days. For both exercise modalities the selected rates targeted intensities between 25 and 80% VO2 peak for moderately-severe COPD patients. Ventilation (VE) and gas exchange were obtained during the third minute and the Borg dyspnea score at the end of each exercise bout. Results: An equal proportion of patients (35%) completed stage 4 of the CRWT and of the CRST. The test-retest correlation coefficients for dyspnea scores ranged from 0.79 to 0.95 for stages 1 through 4 for theCRWTand from 0.88 to 0.85 for the CRST while those for VE (L·min-1) ranged from 0.95 to 0.98 and 0.91 to 0.95 respectively. Conclusion: These results show both the CRWT and the CRST to be highly reproducible for the assessment of exertional dyspnea in patients with moderate-severe COPD. However, a better linearity in VE and VO2 with exercise stages was seen for the CRST than for the CRWT since patients complied more easily to the imposed external load with stepping than with walking.

Chronic Obstructive Pulmonary Disease (COPD) as a Risk Factor for Glucose Metabolism Perturbation and Insulin Resistance

Background: High body mass index (BMI) is associated with better survival in COPD. However, increased BMI and especially waist circumference is associated with elevated pro-inflammatory systemic markers that might contribute to glucose intolerance. On the other hand, COPD is a chronic inflammatory disease that could be a risk factor for impaired glucose metabolism. The objective of this study was to compare the prevalence of glucose intolerance in COPD patients and control subjects with high waist circumference. Methods: Eleven patients with COPD (age:68±8 yr mean±SD; FEV1:49±17% pred) and 10 control subjects (C) (age:63±6 yr) underwent a 75g oral glucose tolerance test (OGTT). All subjects had a waist circumference >102cm and no previous history of diabetes. Height and weight were measured and each subject underwent dual-energy X-ray absorptiometry (DEXA) to evaluate fat-free mass (FFM) and fat mass (FM) and abdominal tomography to evaluate visceral fat (VF). Blood samples were taken to measure inflammatory markers (C-reactive protein (CRP), tumor necrosis factor (TNF), interleukin (IL)-6). Venous blood samples of glucose and insulin were taken while fasting and during OGTT. Insulin resistance was estimated with the fasting homeostasis model assessment (HOMA) index. Results: FM, FFM and VF were not different between groups. Diabetes was diagnosed in two subjects in both groups (2hr post OGTT glucose ≥11.1 mmol/l). Four COPD and 1 C had impaired fasting glucose (fasting glucose 5.6–6.9 mmol/l) while 1 COPD and 2 C had impaired glucose tolerance (2hr post OGTT glucose 7.8–11.1 mmol/l). In COPD patients a negative correlation was found between the HOMA index and FEV1 (r2:0.52, P < 0.05). Conclusions: COPD subjects with high waist circumference are similar to control subjects in term of FFM and FM, level of systemic inflammation and response to OGTT. In COPD, the severity of the disease is associated with an insulin resistance that may potentiate the risk for the development of type 2 diabetes in these patients.

Stable COPD: predicting benefit from high-dose inhaled corticosteroid treatment

The role of inhaled corticosteroids in the management of chronic obstructive pulmonary disease (COPD) remains controversial. The purpose of this study was to evaluate whether sputum eosinophilia (defined as eosinophils > or = 3%) predicts clinical benefit from inhaled corticosteroid treatment in patients with smoking-related clinically stable moderate-to-severe COPD. Forty consecutive patients with effort dyspnoea (mean age 67 yrs; 52 pack-yr smoking history; post-bronchodilator forced expiratory volume in one second (FEV1) <60% predicted, consistent with moderate-to-severe smoking-related chronic airflow limitation) were enrolled. Subjects were treated with inhaled placebo followed by inhaled budesonide (Pulmicort Turbuhaler 1,600 microg.day(-1)), each given for 4 weeks. While the treatment was single-blind (subject level), sputum cell counts before and after treatment interventions were double-blind, thus removing bias. Outcome variables included spirometry, quality-of-life assessment and 6-min walk test. Sputum eosinophilia was present in 38% of subjects. In these, budesonide treatment normalised the eosinophil counts and, in comparison to placebo treatment, resulted in clinically significant improvement in the dyspnoea domain of the disease-specific chronic respiratory questionnaire (0.8 versus 0.3) and a small but statistically significant improvement in post-bronchodilator spirometry (FEV1 100 mL versus 0 mL; p<0.05). In conclusion, sputum eosinophilia predicts short-term clinical benefit from high-dose inhaled corticosteroid treatment in patients with stable moderate-to-severe chronic obstructive pulmonary disease.