In view of such results, we believe that the decrease of respiratory chain complex III activity found in some cases of IDC is a secondary phenomenon, and not due to a primary mitochondrial disease.

Aclidinium significantly increased exercise tolerance, improved airflow obstruction and lung hyperinflation, and was safe and well tolerated. REGISTRATION OF TRIAL: This trial was registered with ClinicalTrials.gov (NCT00500318) under the name "A Study of Exercise Endurance and Lung Hyperinflation in Patients with Moderate to Severe COPD".

The Phase IV, 8-week, randomized, double-blind, placebo-controlled ACTIVATE study (NCT02424344) evaluated the effect of aclidinium/formoterol (AB/FF) 400/12 μg twice daily on lung hyperinflation, exercise capacity, and physical activity in patients with moderate-to-severe COPD. Patients received AB/FF (n=134) or placebo (n=133) (1:1) via the Genuair™/Pressair® dry powder inhaler for 8 weeks. From Weeks 5 to 8, all patients participated in behavioral intervention (BI; daily messages providing step goals). The primary end point was trough functional residual capacity (FRC) at Week 4. Exercise endurance time and physical activity were assessed at Week 4 (pharmacotherapy only) and at Week 8 (8 weeks of pharmacotherapy plus 4 weeks of BI). Other end points included post-dose FRC, residual volume, and inspiratory capacity (IC) at rest and during exercise. After 4 weeks, trough FRC improved with AB/FF versus placebo but did not reach significance (125 mL; P=0.0690). However, post-dose FRC, residual volume, and IC at rest improved significantly with AB/FF at Week 4 versus placebo (all P<0.0001). AB/FF significantly improved exercise endurance time and IC at isotime versus placebo at Week 4 (P<0.01 and P<0.0001, respectively) and Week 8 (P<0.05 and P<0.0001, respectively). AB/FF achieved higher step counts (P<0.01) with fewer inactive patients (P<0.0001) at Week 4 versus placebo. Following BI, AB/FF maintained improvements in physical activity at Week 8 and nonsignificant improvements were observed with placebo. AB/FF 400/12 μg demonstrated improvements in lung hyperinflation, exercise capacity, and physical activity versus placebo that were maintained following the addition of BI. A 4-week period of BI might be too short to augment the improvements of physical activity observed with AB/FF.

BackgroundThis study evaluated the effects of aclidinium bromide, a long-acting muscarinic antagonist indicated for maintenance treatment of chronic obstructive pulmonary disease (COPD), on exercise endurance, dyspnea, lung hyperinflation, and physical activity.MethodsIn this randomized, double-blind, crossover study, patients with stable COPD and moderate-to-severe airflow limitation received aclidinium 400 μg twice daily or placebo via Genuair®/Pressair®a for 3 weeks (2-week washout between treatment periods). The primary endpoint was change from baseline to Week 3 in endurance time, measured by constant work rate cycle ergometry testing at 75% peak incremental work rate. Changes from baseline in intensity of exertional dyspnea (Borg CR10 Scale®) and trough inspiratory capacity were secondary endpoints. Additional endpoints included changes from baseline in other spirometric, plethysmographic, and physical activity (assessed by objective accelerometer measurement) parameters. Efficacy endpoints were analyzed using an analysis of covariance model.ResultsIn total, 112 patients were randomized and treated (mean age 60.3 years; mean post-bronchodilator forced expiratory volume in 1 s 1.7 L [56.7% predicted]; mean endurance time 485.7 s). After 3 weeks, endurance time was significantly increased with aclidinium versus placebo (treatment difference 58.5 s; p < 0.05). At Week 3, aclidinium significantly reduced dyspnea intensity at isotime during exercise (treatment difference -0.63; p < 0.05) and improved trough inspiratory capacity (treatment difference 78 mL; p < 0.05) versus placebo. Significant improvements in spirometric, plethysmographic, and some physical activity parameters were observed with aclidinium versus placebo.ConclusionsThese results suggest that aclidinium significantly improves exercise endurance, exertional dyspnea, hyperinflation, and physical activity in patients with COPD.Trial registrationClinicalTrials.gov identifier: NCT01471171; URL: http://www.clinicaltrials.gov.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2466-14-209) contains supplementary material, which is available to authorized users.