title: Selenium supplementation for asthma.
abstract: BACKGROUND
  Selenium deficiency may be important in chronic asthma. Observational studies have demonstrated that patients with chronic asthma may have lower levels of selenium than their control. Nevertheless, selenium supplementation has not been recommended with drug therapy for asthma. This review systematically examines RCTs that evaluated the role of selenium supplementation in chronic asthma.
  
  
  OBJECTIVE
  Recognition that chronic asthma can be associated with selenium deficiency has led to the investigation of the role of selenium supplementation in reducing the symptoms and impact of chronic asthma. The objective of this review was to assess the efficacy of selenium supplementation as an adjunct to medication for the treatment of chronic asthma.
  
  
  METHODS
  We searched the Cochrane Airways Group trials register, MEDLINE/PUB MED, and EMBASE. Searches were current as of August 2003.
  
  
  METHODS
  Randomised trials comparing patients with chronic asthma receiving selenium supplementation in conjunction with asthma medication, with patients taking asthma medication only.
  
  
  METHODS
  Two reviewers applied the study inclusion criteria
  
  
  RESULTS
  One trial with a total of 24 patients suffering from chronic asthma was included. The study reported significant clinical improvement in the selenium-supplemented group, as compared with the placebo group, in terms of a 'clinical evaluation'. However, this improvement could not be validated by significant changes in separate objective parameters of lung function and airway hyper-responsiveness.
  
  
  CONCLUSIONS
  There is some indication that selenium supplementation may be a useful adjunct to medication for patients with chronic asthma. This conclusion is limited because of insufficient studies and lack of improvement in the clinical parameters of lung function.
authors.affiliation: Preventive Medicine and Public Health Department, Faculty of Medicine, University of Cordoba, Avda. Menéndez Pidal, s/n, Cordoba, Spain, 14004.
authors.forename: M F
authors.initials: MF
authors.lastname: Allam
authors.forename: R A
authors.initials: RA
authors.lastname: Lucane
mesh_terms: D001249:Asthma / Q000628:therapy*; D002908:Chronic Disease; D019587:Dietary Supplements; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012643:Selenium / Q000008:administration & dosage* / Q000172:deficiency
chemical_list: D012643:Selenium