Randomised aspirin assignment and risk of adult-onset asthma in the Women's Health Study.
BACKGROUND
Randomised data in men show a small but significant reduction in the risk of adult-onset asthma among those given aspirin. The results from an observational study in women suggest that frequent use of aspirin decreases the risk of adult-onset asthma, but randomised data in women are lacking. A study was undertaken to test the effect of 100 mg aspirin or placebo on alternate days on the risk of adult-onset asthma in the Women's Health Study.


METHODS
A randomised, double-blind, placebo-controlled clinical trial of aspirin and vitamin E was performed in apparently healthy women with no indication or contraindication to aspirin therapy and no history of asthma at study entry. Female health professionals self-reported an asthma diagnosis on yearly questionnaires.


RESULTS
Among 37 270 women with no reported history of asthma prior to randomisation and during 10 years of follow-up, there were 872 new cases diagnosed with asthma in the aspirin group and 963 in the placebo group (hazard ratio 0.90; 95% CI 0.82 to 0.99; p = 0.027). This apparent 10% lower relative risk of incident adult-onset asthma among those assigned to aspirin was significantly modified by body mass index, with no effect in women with a body mass index of >/=30 kg/m2. The effect of aspirin on adult-onset asthma was not significantly modified by age, smoking status, exercise levels, postmenopausal hormone use or randomised vitamin E assignment.


CONCLUSIONS
In this large randomised clinical trial of apparently healthy adult women, administration of 100 mg aspirin on alternate days reduced the relative risk of a newly reported diagnosis of asthma.
Kurth
T
T
Division of Preventive Medicine, Brigham and Women's Hospital, 900 Commonwealth Ave East, 3rd Floor, Boston, MA 02215, USA. tkurth@rics.bwh.harvard.edu
Barr
R G
RG
Gaziano
J M
JM
Buring
J E
JE
D000368:Aged; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D000975:Antioxidants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D012307:Risk Factors; D014810:Vitamin E / Q000627:therapeutic use
D018927:Anti-Asthmatic Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D014810:Vitamin E; D001241:Aspirin