Gender differences in allergic and non-allergic asthma over 20 years of follow-up

Abstract

Background: Gender differences in asthma incidence and asthma evolution have been little studied in adults. Aims: To prospectively investigate gender differences in incidence and evolution of allergic and non-allergic asthma in 20 to 48 year-olds followed-up as part of the European Community Respiratory Health Survey. Methods: We defined allergic asthma as asthma with positive skin prick tests, and applied Cox and logistic models to 5,418 participants without asthma at baseline and 642 asthmatics, respectively. Results: Compared to men, women were at increased risk of developing non-allergic asthma, independently of the age at asthma onset (figure). The adjusted hazard-ratio for non-allergic asthma (aHR: 4.6 [95%CI 2.6-8.0]) was not modified by BMI and was significant in subgroup analyses. A slightly increased risk of new-onset allergic asthma was also observed in women (aHR: 1.8[1.0-3.2]), but the female predominance remained significant only in obese individuals. Non-allergic asthma was less likely to remit in women as compared to men (aOR: 0.27[0.08-0.95]). There was no other gender difference in asthma evolution (table). Conclusion: Non-allergic asthma is more likely to develop, and less likely to remit in adult women.