Statins improve asthma symptoms by suppressing inflammation: a meta-analysis based on RCTs.

Asthma is a chronic airway inflammatory disease caused by high infiltration of multiple inflammatory cells and factors in airway tissues. Statins may inhibit inflammation, hence improve asthma symptoms. This meta-analysis aimed to assess the efficacy of statins in the treatment of asthma patients.We searched in PubMed, OVID, Cochrane Library, and Web of Science databases using the following key words: "statin", "atorvastatin", "simvastatin", "pravastatin", "rosuvastatin", "pitavastatin", "fluvastatin", and "asthma". The effects of statins on function, serum biomarkers, sputum mediators, and serum biochemical markers were analyzed from the identified studies.Twelve articles (613 participants) were included in the meta-analysis. Results showed that statins significantly improved asthma symptoms (ACQ score: MD: -0.43, 95% CI: -0.47 - -0.38, p<0.01; ACT score: MD: 1.96, 95% CI: 1.26-2.67, p<0.01). Furthermore, statins significantly reduced serum hsCRP (MD: -0.50, p=0.02) and cholesterol (MD: -32.76, p<0.01) levels and the proportion of sputum eosinophils (MD: -1.25, p<0.01) and IL6 levels (MD: -64.56, p=0.04) in sputum. However, lung function was not significantly different between the statin and placebo treatment groups.Although statins did not change the lung function in patients with asthma, they improved asthma symptoms and reduced the serum hsCRP, sputum eosinophil ratio, and IL6 levels.