Abstract
Background: The decline of peak inspiratory flow (PIF) reduces the effectiveness of inhaled corticosteroid (ICS). The purposes of this study were to survey the PIF and its predictive factor among patients with asthma using ICS. Methods: One hundred thirty patients (males 47, females 83) with asthma were recruited. PIF was measured with In-Check Dial for which the discus type adaptor was used. Results: The average level of PIF was 86.9±26.9 L/min, and PIF of males was significantly higher than that of females. Even after adjustment of PIF for age and height, PIF of males was still significantly higher than that of females. Six (4.6%) patients (5 females) showed PIF of lower than 50 L/min. Age, height, %FVC, %FEV1, and ACT (Asthma Control Test) showed significant correlations, however, BMI and FEV1% had no correlation with PIF. Multivariate analyses adjusted for each parameter showed a significant correlation with PIF; significant correlations between PIF and age, %FVC, and %FEV1, were revealed suggesting that these parameters were independent factors which can be considered to predict the levels of PIF. Conclusion: Our results show that when providing ICS for elderly adults, especially women, whose pulmonary function is declined, ICS should be chosen considering that their PIF might be declined.
