Bronchial responsiveness in bakery workers: relation to airway symptoms, IgE sensitization, nasal indices of inflammation, flour dust exposure and smoking.
BACKGROUND: Bronchial hyperresponsiveness (BHR) is common in bakery workers. The relation between bronchial responsiveness measured with a tidal breathing method and smoking, airway symptoms, IgE-sensitization, nasal indices of inflammation and flour dust exposure have been studied with bronchial responsiveness expressed as a continuous outcome. MATERIAL AND METHODS: Bakery workers (n = 197) were subjected to interviews, questionnaires, allergy tests, workplace dust measurements and bronchial metacholine provocation. Eosinophil cationic protein (ECP) and alpha(2)-macroglobulin were measured in nasal lavage. Bronchial responsiveness was expressed as slope(conc), a measurement based on regressing the per cent reduction in FEV(1) at each provocation step. RESULTS: BHR expressed as slope(conc) was associated with smoking (P = 0.009), asthma symptoms at work (P = 0.001), and occupational IgE sensitization (P = 0.048). After adjusting for baseline lung function the association between BHR and IgE sensitization was no longer present. We demonstrated an association between nasal ECP and BHR (slope(conc)