Smoking and Lung Function Response to Inhaled Glucocorticoids in Adult-Onset Asthma.

Introduction: Tobacco smoking has been associated with reduced response to inhaled corticosteroids (ICS). However, little is known about how smoking affects lung function response to ICS treatment in new-onset asthma. Aims and Objectives: To evaluate the sub-acute ICS response on lung function in new adult-onset asthma in steroid-naïve patients classified according to smoking status in a real-life longitudinal cohort. Methods: In the Seinäjoki Adult Asthma Study, 203 patients with new adult-onset asthma were followed for 12 years. Patients who were dispensed ICS during the first two years of the follow-up were included (n=174). Lung function was evaluated at baseline, and the maximum lung function point was determined during the first 2.5 years (Max Results: At asthma diagnosis 50% (n=90) were ex- or current smokers. The increase of forced vital capacity % predicted from baseline to Max Conclusion: Although the harmful effects of smoking on asthma control and long-term lung function decline have been well established, sub-acute lung function response to ICS in adult-onset asthma seems not to differ according to smoking status. The result suggests that patients should have similar ICS therapy initiation regardless of their smoking history. Clinical Trial Registration: This study is registered at www.ClinicalTrials.gov with identifier number NCT02733016.