Sensitization to individual allergens as risk factors for lower FEV1 in young adults

Background Atopy may impair ventilatory function, but results are controver sial. We assess the association between individual reactivity to allergens and the level of baseline maximal one-second forced expiratory volume (FEV1 ), by smoking and respiratory symptoms. Methods The 1472 participants (response 44.5%) of the five Spanish areas of the European Community Respiratory Health Survey (ECRHS) who performed res piratory function tests, skin prick tests and/or specific IgE against commo n aeroallergens (e.g. mites, pets, mould, pollens) are included. Bronchial hyperreactivity (BHR) was measured with a methacholine challenge. Results After adjusting for BRR and smoking, in addition to the other aller gens, skin reactivity to Alternaria 1-208 mi, 95% CI:-451, 35) and IgE anti bodies against cat (-124 mi; 95% CI:-269, 21) and Timothy grass (-115 mi, 9 5% CI:-190, -40) were associated with a decrease in FEV1 in females. Among males, skin reactivity to olive showed the strongest association (-111 mi; 95% CI:-261, 38). The associations were stronger in females. Smoking modifi es the association for Alternaria and cat (P for interaction < 0.05). While cat is associated with a decrease in FEV1 in current smokers (-190 mi), Al ternaria (-336 mi) was associated among never smokers. The exclusion of sub jects with asthma symptoms, or adjustment for respiratory symptoms, led to similar results. Conclusions We conclude that immunoresponse to individual allergens (partic ularly outdoor) is associated with the level of FEV1, and this association occurred independently of asthma, and in smokers and non-smokers, which may be of interest in natural history of chronic obstructive pulmonary disease (COPD).