A randomized controlled trial on the effect of inhaled corticosteroids on airways inflammation in adult cigarette smokers

Study objective: To determine whether inhaled corticosteroid treatment can reduce airways inflammation in adult cigarette smokers. Design: This was a randomized, placebo-controlled, double-blinded clinical trial, Setting: The subjects were recruited from the community by advertising, Participants: Seventy-one adults with a greater than or equal to 5 pack-yea r history who were current smokers, had a normal FEV1, and produced sputum daily. Intervention: Sixty subjects were randomized to receive four puffs of place bo or beclomethasone dipropionate ([BDP]; total dosage, 1,000 mu g/d) using a metered-dose aerosol inhaler with a valved holding chamber (AeroChamber; Trudell Medical; London, Ontario, Canada) for 28 days. Measurements and results: Eleven subjects were not randomized because of po or compliance. The primary outcome was fractional airway neutrophilia, as a ssessed by a differential cell count of sputum, Additional outcome measures were spirometry, measurement of airway responsiveness by methacholine chal lenge, and lung epithelial permeability measured by the clearance of radiol abeled diethylenetriamine pentaacetic acid. There were no significant diffe rences between the two groups in any outcome measurement after 4 weeks of t reatment, Conclusions: With normal spirometry, nle found no benefit of treatment with inhaled BDP, 1,000 mu g/d, on noninvasive measures of airways inflammation in adult smokers. This indicates that cigarette smoke-induced inflammation in its early stages (before a demonstrable airflow obstruction) is not ste roid sensitive. This may occur because the site of involvement is not acces sible to inhaled medications or because the inflammatory process is resista nt to moderate doses of inhaled corticosteroids.