Effect of inhaled corticosteroids on bronchial responsiveness in patients with "corticosteroid naive" mild asthma: a meta-analysis.
BACKGROUND
Inhaled corticosteroids are the most efficacious anti-inflammatory drugs in asthma. International guidelines also advocate the early introduction of inhaled corticosteroids in corticosteroid naive patients. A study was undertaken to assess the effects of inhaled corticosteroids on bronchial hyperresponsiveness in patients with corticosteroid naive asthma by conventional meta-analysis.


METHODS
A Medline search of papers published between January 1966 and June 1998 was performed and 11 papers were selected in which the patients had no history of treatment with inhaled or oral corticosteroids. Bronchial responsiveness to bronchoconstricting agents was considered as the main outcome parameter. Doubling doses (DD) of histamine or methacholine were calculated.


RESULTS
The total effect size of inhaled corticosteroids (average daily dose 1000 microg) versus placebo in the 11 studies was +1.16 DD (95% confidence interval (CI) +0.76 to +1.57). When only the eight short term studies (2-8 weeks) were analysed the effect size of the bronchoconstricting agent was +0.91 DD (95% CI +0.65 to +1.16). No relationship was found between the dose of inhaled corticosteroid used and the effect on bronchial responsiveness.


CONCLUSIONS
This meta-analysis in patients with corticosteroid naive asthma indicates that, on average, high doses of inhaled corticosteroids decrease bronchial hyperresponsiveness in 2-8 weeks. It remains unclear whether there is a dose-response relationship between inhaled corticosteroids and effect on bronchial hyperresponsiveness.
van Grunsven
P M
PM
Department of General Practice and Social Medicine, P O Box 9101, 6500 HB Nijmegen, The Netherlands.
van Schayck
C P
CP
Molema
J
J
Akkermans
R P
RP
van Weel
C
C
D000280:Administration, Inhalation; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000188:drug therapy*; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D004334:Drug Administration Schedule; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000627:therapeutic use; D006632:Histamine; D006801:Humans; D016210:Methacholine Chloride
D000893:Anti-Inflammatory Agents; D016085:Bronchoconstrictor Agents; D005938:Glucocorticoids; D016210:Methacholine Chloride; D006632:Histamine