Inhaled corticosteroids reduce the progression of airflow limitation in chronic obstructive pulmonary disease: a meta-analysis

Background: Chronic obstructive pulmonary disease ( COPD) is a syndrome of chronic progressive airflow limitation which occurs as a result of chronic inflammation of the airways and lung parenchyma. However, the role of inhaled corticosteroids in the treatment of COPD is controversial. We hypothesised that inhaled corticosteroids reduce the progression of airflow limitation in COPD. Methods: A comprehensive literature search was conducted and data were analysed using random effects methodology. The effect of inhaled steroids on annual change in forced expiratory volume in 1 second (FEV1) was determined for all trials, for trials with high dose treatment regimens, and for trials in subjects with moderate to severe airflow limitation. Results: Data from eight controlled clinical trials of greater than or equal to 2 years were included ( n = 3715 subjects). Meta-analysis of all study data revealed that inhaled corticosteroids reduce the rate of FEV1 decline by 7.7 ml/ year (95% confidence interval (CI) 1.3 to 14.2, p = 0.02). Meta-analysis of studies with high dose regimens revealed a greater effect of 9.9 ml/year (95% CI 2.3 to 17.5, p = 0.01) compared with the meta-analysis of all studies. Conclusions: Inhaled corticosteroid treatment for greater than or equal to 2 years slows the rate of lung function decline in COPD. The effect observed with high dose regimens is greater than that with all regimens combined. These data suggest a potential role for inhaled corticosteroids in modifying the long term natural history of COPD.