Age-related changes in airway resistance using an impulse oscillation system in patients with asthma

[Abstract] OBJECTIVE : Spirometry is used to investigate airflow limitation in patients with asthma ; however, this method is burdensome for elderly subjects. An impulse oscillation system (IOS) allows examinations to be performed quickly and with little burden and can be used to evaluate the resistance of total airway (R5), large airway (R20), small airway (R5-R20), reactance (X5), and resonant frequency of reactance (Fres). The airway resistance of elderly and non-elderly patients with asthma was compared using IOS. METHODS : IOS was performed for 51 elderly (65 years old or older) and 58 non-elderly (below 65 years old) patients with asthma. RESULTS : R5, R5-R20, and Fres were significantly higher in the elderly group. X5 was significantly lower in the elderly group. CONCLUSION : These results suggest that IOS can be used to reveal small airway lesions in elderly patients with asthma and is useful as a method of evaluating airway lesions in patients with asthma.