Increased variability in bronchial responsiveness in aluminum potroom workers with work-related asthma-like symptoms

In a longitudinal study, we studied the variability in bronchial responsiveness (BR) to methacholine in aluminum potroom workers suffering from work-related asthma-like symptoms (WASTH) and in symptom-free workers. In the index group, 26 men suffering from WASTH were selected from a cross-sectional survey. The reference group comprised 45 symptom-free men recruited from the enrollment of new employees. Bronchial responsiveness was expressed as the dose-response slope (DRS) of the line through origin and the last data point. The standard deviation of the log-transformed DRS was positively associated with symptom score (P = .012) and the mean BR (P < .001). Our results indicate that the severity of respiratory symptoms in aluminum potroom workers with WASTH reflects the variability in BR.