Tiotropium as essential maintenance therapy in COPD

Physical Activity, Muscle Oxidative Capacity, and Coronary Artery Calcium in Smokers with and without COPD

Introduction

Severe chronic obstructive pulmonary disease (COPD) is partly characterized by diminished skeletal muscle oxidative capacity and concurrent dyslipidemia. It is unknown whether such metabolic derangements increase the risk of cardiovascular disease. This study explored associations among physical activity (PA), muscle oxidative capacity, and coronary artery calcium (CAC) in COPDGene participants.

Methods

Data from current and former smokers with COPD (n = 75) and normal spirometry (n = 70) were retrospectively analyzed. Physical activity was measured for seven days using triaxial accelerometry (steps/day and vector magnitude units [VMU]) along with the aggregate of self-reported PA amount and PA difficulty using the PROactive D-PPAC instrument. Muscle oxidative capacity (k) was assessed via near-infrared spectroscopy, and CAC was assessed via chest computerized tomography.

Results

Relative to controls, COPD patients exhibited higher CAC (median [IQR], 31 [0–431] vs 264 [40–799] HU; p = 0.003), lower k (mean ± SD = 1.66 ± 0.48 vs 1.25 ± 0.37 min⁻¹; p < 0.001), and lower D-PPAC total score (65.2 ± 9.9 vs 58.8 ± 13.2; p = 0.003). Multivariate analysis—adjusting for age, sex, race, diabetes, disease severity, hyperlipidemia, smoking status, and hypertension—revealed a significant negative association between CAC and D-PPAC total score (β, −0.05; p = 0.013), driven primarily by D-PPAC difficulty score (β, −0.03; p = 0.026). A 1 unit increase in D-PPAC total score was associated with a 5% lower CAC (p = 0.013). There was no association between CAC and either k, steps/day, VMU, or D-PPAC amount.

Conclusion

Patients with COPD and concomitantly elevated CAC exhibit greater perceptions of difficulty when performing daily activities. This may have implications for exercise adherence and risk of overall physical decline.

The dyspnoea-inactivity vicious circle in COPD: development and external validation of a conceptual model

The vicious circle of dyspnoea-inactivity has been proposed, but never validated empirically, to explain the clinical course of chronic obstructive pulmonary disease (COPD). We aimed to develop and validate externally a comprehensive vicious circle model.We utilised two methods. 1) Identification and validation of all published vicious circle models by a systematic literature search and fitting structural equation models to longitudinal data from the Spanish PAC-COPD (Phenotype and Course of COPD) cohort (n=210, mean age 68 years, mean forced expiratory volume in 1 s (FEV1) 54% predicted), testing both the hypothesised relationships between variables in the model ("paths") and model fit. 2) Development of a new model and external validation using longitudinal data from the Swiss and Dutch ICE COLD ERIC (International Collaborative Effort on Chronic Obstructive Lung Disease: Exacerbation Risk Index Cohorts) cohort (n=226, mean age 66 years, mean FEV1 57% predicted).We identified nine vicious circle models for which structural equation models confirmed most hypothesised paths but showed inappropriate fit. In the new model, airflow limitation, hyperinflation, dyspnoea, physical activity, exercise capacity and COPD exacerbations remained related to other variables and model fit was appropriate. Fitting it to ICE COLD ERIC, all paths were replicated and model fit was appropriate.Previously published vicious circle models do not fully explain the vicious circle concept. We developed and externally validated a new comprehensive model that gives a more relevant role to exercise capacity and COPD exacerbations.

Combining tiotropium and salmeterol in COPD: Effects on airflow obstruction and symptoms

BACKGROUND

Clinical information on 24-h spirometric efficacy of combining tiotropium and salmeterol compared to single-agent therapy is lacking in patients with COPD.

METHODS

A randomized, double-blind, four-way crossover study of 6-week treatment periods comparing combination therapy of tiotropium 18 microg plus qd or bid salmeterol 50 microg versus single-agent therapy. Serial 24-h spirometry (FEV(1), FVC), effects on dyspnea (TDI focal score) and rescue salbutamol use were evaluated in 95 patients.

RESULTS

Tiotropium plus qd salmeterol was superior to tiotropium or salmeterol alone in average FEV(1) (0-24h) by 72 mL and 97 mL (p<0.0001), respectively. Compared to this qd regimen, combination therapy including bid salmeterol provided comparable daytime (0-12h: 12 mL, p=0.38) bronchodilator effects, but significantly more bronchodilation during the night-time (12-24h: 73 mL, p<0.0001). Clinically relevant improvements in TDI focal score were achieved with bronchodilator combinations including salmeterol qd or bid (2.56 and 2.71; p<0.005 versus components). Symptom benefit of combination therapies was also reflected in less need for reliever medication. All treatments were well tolerated.

CONCLUSION

Compared to single-agent therapy, combination therapy of tiotropium plus salmeterol in COPD provided clinically meaningful improvements in airflow obstruction and dyspnea as well as a reduction in reliever medication.

Long-Acting Bronchodilator Therapy for the Treatment of Chronic Obstructive Pulmonary Disease

Objective:

To review clinical data on the use of long-acting bronchodilator agents as monotherapy and in combination for the treatment of moderate-to-severe chronic obstructive pulmonary disease (COPD).

Data Sources:

A literature search was performed via MEDLINE (1966–April 2008). In addition, references from publications identified were reviewed. These searches were limited to human data published in the English language. Searches used the following terms: COPD, long-acting β2-agonisls, long-acting anticholinergics, combination therapy, pharmacoeconomics, safety, tiotropium, salmeterol, and formoterol.

Study Selection and Data Extraction:

Relevant information on the pharmacology, safety, efficacy, pharmacoeconomics, adherence, and available agents used in the treatment of COPD was selected. Randomized clinical trials and retrospective reviews were included.

Data Synthesis:

The Global Initiative for Chronic Obstructive Lung Disease guidelines provide general management recommendations to guide providers regarding treatment choices for COPD; however, they lack clarity regarding which long-acting bronchodilator to use and when combining agents becomes appropriate. Prospective trials evaluating short-acting anticholinergics and long-acting β2-agonists have utilized spirometric endpoints that relate most to short-term symptomatic relief. Tiotropium trials have focused more on patient-oriented outcomes, with data being reported for one year. Tiotropium significantly lowers exacerbation rates and improves health resource usage as well as health-related quality of life. Tiotropium also provides superior bronchodilation and improvement in dyspnea at all timo points, although onset of bronchodilation is slower than with long-acting β2-agonists. Combining these agents has been shown to decrease daytime rescue inhaler use, improve morning and evening peak expiratory flow rates, and improve bronchodilator efficacy compared with monotherapy. Pharmacoeconomic data lend support to the recommendation of tiotropium as a first-line long-acting agent.

Conclusions:

Tiotropium appears to be the best option as a first-line drug for patients with moderate-to-severe COPD because of its ability to sustain bronchodilator effect, improve quality of life, reduce COPD exacerbations, and reduce health resource usage. Patients who remain symptomatic may benefit from the addition of a long-acting β2-agonist to tiotropium monotherapy.