Trajectory of the response to bronchodilator and respiratory outcomes in adults with asthma-like symptoms

In the real world, health professionals need to care for individuals with asthma-like symptoms who have a persistently negative bronchodilator response (BDR). Little is known about the evolution of symptoms and lung function of these individuals because they are usually excluded from studies on asthma. The aim of this study was to evaluate whether individuals with asthma-like symptoms but with a persistently negative BDR have a different evolution of symptoms and lung function compared to individuals with asthma proven by positive BDR. This prospective cohort study included adults with asthma-like symptoms. Individuals participated in two visits 12 months apart. They responded to questionnaires and underwent a spirometry test. In individuals without airway obstruction in the first visit, those with asthma-like symptoms and persistently negative BDR were less likely to lose forced expiratory volume in the first second during follow-up or progress to airway obstruction at the final visit compared to individuals with asthma proven by positive BDR. Among individuals with airway obstruction at baseline, those with asthma-like symptoms and persistently negative BDR were less likely to resolve the airway obstruction during follow-up compared to individuals with asthma proven by positive BDR. In individuals with proven asthma, the emergence or persistence of positive BDR during follow-up was accompanied by a worsening of asthma outcomes compared to the remission of positive BDR. Thus, BRD is an accessible marker of disease progression in individuals with asthma-like symptoms. In individuals with asthma proven by positive BDR, the trend in BDR was associated with the evolution of symptoms and lung function.