Influence of indacaterol on daily physical activity in patients with untreated chronic obstructive pulmonary disease

BACKGROUND: Indacaterol, a once-daily, long-acting β(2)-agonist, may improve not only respiratory function, dyspnea symptoms, and quality of life, but also physical activity for patients with chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the effect of 12-week indacaterol therapy on daytime physical activity in patients with untreated COPD. METHODS: The subjects were stable and untreated COPD outpatients with a percent predicted forced expiratory volume in 1 second (%FEV(1)) below 80%. Baseline assessments included clinical assessment, respiratory function testing, arterial blood gas analysis, the COPD assessment test (CAT™), and the Medical Outcomes Study 36-Item Short-Form Health Survey, Japanese version 2 (SF-36v2(®)). Patients underwent monitoring by uniaxial accelerometer before and after 12 weeks once-daily inhalation of indacaterol 150 μg/day. RESULTS: Eighteen patients were evaluable. Patient characteristics included a mean age of 74.2 years, and three patients were current smokers. Indacaterol improved mean (± standard deviation [SD]) %FEV(1) from 55.2% (±17.9%) to 61.0% (±17.3%) (P=0.003), CAT scores from 16.4 (±10.2) points to 12.4 (±8.2) points (P=0.04), some scales of the SF-36v2 (physical component summary, 41.6±9.7 points to 45.1±7.9 points, P=0.03), and number of daily steps (3,311.5±2,103.3 steps/day to 3,841.8±2,096.8 steps/day, P=0.02), but did not affect daily energy expenditure (85.0±77.2 kcal change to 90.9±56.8 kcal, P=0.29) or exercise duration of an intensity of level 1 or more (36.4±23.9 minutes increase to 40.8±21.6 minutes, P=0.12). CONCLUSION: Twelve weeks of indacaterol improved respiratory function and quality of life, but did not significantly affect physical activity in patients with moderate-to-severe COPD.