Combination of assist use of short-acting beta-2 agonists inhalation and guidance based on patient-specific restrictions in daily behavior: Impact on physical activity of Japanese patients with chronic obstructive pulmonary disease.

BACKGROUND: Assist use of inhaled short-acting beta 2 agonists (SABAs) is reportedly effective for preventing shortness of breath on exertion in chronic obstructive pulmonary disease (COPD) patients. However, it is unclear what strategy would be useful for improving physical activity in such patients. The aim is to investigate the effects of assisted use of SABA (procaterol) on physical activity in Japanese COPD patients targeting patient-specific restrictions in daily behavior.

METHODS: Fourteen patients with stable COPD (age: 72.1±1.5, %FEV1 : 55.6±4.5%) were asked to inhale 20 μg of procaterol 15 minutes before patient-specific daily physical activity that had been identified as limited by a questionnaire and document their usage in a diary. Physical activity was measured using a triaxial accelerometer and the results were collected every month for 2 months. In the first month, a clinician assessed whether inhalation of SABA was appropriate based on a usage diary and coached patients to conduct adequate assist use of SABA for limited physical activity.

RESULTS: The strategy significantly improved the physical activity level, assessed using the values of the metabolic equivalents (METs) multiplied by physical activity endurance, at ≥3.0 METs (p<0.05), and physical activity endurance at ≥2.5 and ≥3.0 METs, (p<0.05, p<0.05, respectively). The degree of improvement of physical activity level was significantly positively correlated with the baseline %FVC and %FEV1 (p<0.05, p<0.05, respectively).

CONCLUSIONS: Assist use of SABA targeting patient-specific restrictions, particularly when better lung function is still preserved, could be a useful approach for improving physical activity in patients with COPD.