title: A systematic review of statin efficacy in asthma.
abstract: BACKGROUND
  Statins are known for their lipid-lowering effects and role in the treatment of atherosclerotic disease. They also have anti-inflammatory and immunomodulatory properties which could benefit asthma patients. We aimed to review the evidence on the efficacy and safety of statins in asthma-related outcomes.
  
  
  METHODS
  A systematic review of the literature on the effects of statins on asthma-related outcomes was performed following a search of the National Guideline Clearinghouse, Cochrane, Scopus, and Pubmed Medline databases in January 2012. Randomized controlled trials (RCTs) and observational studies (cohort/case-control design) assessing the effect of statins were included. The Grading of Recommendations Assessment Development and Evaluation (GRADE) system was used to rate the levels of evidence and grade of recommendation.
  
  
  RESULTS
  Twenty-four of the 379 articles retrieved electronically and one article identified by hand search were selected for full-text scrutiny by two independent reviewers. Eight studies were included: six RCTs and two observational studies. Statin use was not associated with consistent, statistical significant improvements in patient outcomes (asthma control, quality of life, steroid-sparing effects) or disease outcomes (lung function, airway responsiveness), and all the studies analyzed had low or very low quality of evidence. Inflammatory outcome improvements were observed in mild allergic asthma.
  
  
  CONCLUSIONS
  Statins do not seem to have any additional benefit in asthma control or steroid-sparing effect in asthma treatment. Considering the prevalence of both statin use and asthma, more, better designed studies are needed to determine whether a specific phenotype of asthma exists that could benefit from statin treatment.
authors.affiliation: Immuno-Allergology Department, Centro Hospitalar São João, Porto, Portugal. disolha@gmail.com
authors.forename: Diana
authors.initials: D
authors.lastname: Silva
authors.forename: Mariana
authors.initials: M
authors.lastname: Couto
authors.forename: Luís
authors.initials: L
authors.lastname: Delgado
authors.forename: André
authors.initials: A
authors.lastname: Moreira
mesh_terms: D018927:Anti-Asthmatic Agents / Q000008:administration & dosage; D001249:Asthma / Q000188:drug therapy*; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012129:Respiratory Function Tests; D012720:Severity of Illness Index
chemical_list: D018927:Anti-Asthmatic Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors