Effect of an inhaled glucocorticosteroid on airway mucosal blood flow in mild asthma

We determined airway mucosal blood flow (Qaw) and FEV1 before and after inhaled albuterol in 19 glucocorticosteroid (GS)-naive patients with mild intermittent asthma, and assessed the effects of a 2-wk course of fluticasone propionate (FP; 440 mu g daily) on these parameters. Twelve healthy nonsmokers served as controls. Baseline Qaw was 55.5 +/- 0.7 mu l/min/ml (mean +/- SE) in the asthmatic subjects and 44.2 +/- 0.7 mu l/min/ml in the controls; the respective FEV1 values were 2.8 +/- 0.2 L and 3.4 +/- 0.2 L (p < 0.01 for both parameters). Albuterol increased Qaw by 27 +/- 3% in the control subjects (p < 0.01) but had no effect on Qaw in the asthmatic subjects; it increased FEV1 by 7 +/- 1% and 6 +/- 1% in the two groups, respectively. Qaw decreased to 49.2 +/- 0.8 mu l/min/ml (p < 0.05 versus baseline), and the Qaw responsiveness to albuterol was restored (+21 +/- 2%; p < 0.05) in the asthmatic subjects after FP. Eleven asthmatic subjects stopped using FP at this time; 2 wk later, their Qaw returned to baseline (55.2 +/- 0.9 mu l/min/ml) and they lost the Qaw responsiveness to albuterol, Mean (+/- SE) FEV1 and FEV1 responsiveness to albuterol were not affected by FP, The GS-sensitive increase in Qaw and its hyporesponsiveness to albuterol in asthmatic subjects may be consequences of airway inflammation.