RESPONSE OF THE NOSE TO EXERCISE IN HEALTHY-SUBJECTS AND IN PATIENTS WITH RHINITIS AND ASTHMA

Background - Although the nose and the bronchi are both involved in th e process of regulating respiratory heat exchange, thermal changes may precipitate airway obstruction during exercise but rarely cause nasal obstruction in patients with rhinitis. The cause of the different res ponse of the nose and bronchial tree has hardly been investigated. Thi s study was performed to assess the response of the nose during exerci se in the presence of rhinitis, asthma, and in normal controls. Method s - Ten healthy subjects (group 1), 15 patients with asthma and rhinit is (group 2), 10 with rhinitis only (group 3), and 11 with asthma only (group 4) were included in the study. Exercise was performed on a bic ycle ergometer for six minutes, reaching a heart rate of 80% of predic ted. Bronchial and nasal responses were measured by forced expiratory volume in one second (FEV(1)) and posterior rhinomanometry, respective ly. A drop in the FEV(1) of 20% or more was considered a positive exer cise induced asthma challenge test. Results - Heart rate and ventilati on increased by a similar proportion in the four groups. The FEV(1) si gnificantly decreased in asthmatic patients (groups 2 and 4) but it di d not change in healthy subjects (group 1) or in those with rhinitis ( group 3). Thirteen asthmatic patients developed exercise induced asthm a. Nasal patency increased with exercise by a similar proportion in al l groups, and no differences were detected between those with rhinitis (groups 2 and 3) and those without (groups 1 and 4). Nasal patency ha d returned to basal values at 25 minutes after completion of exercise in the four groups. The nose of patients with exercise induced asthma, however, remained significantly more patent than in patients without exercise induced asthma between 10 and 30 minutes after exercise. Conc lusions - These results suggest that the nose responds differently fro m the bronchi during exercise induced airway obstruction: whereas the bronchial tree responds by becoming narrowed, the nose becomes more pa tent. These findings suggest that the mechanisms regulating the respon se of the nose to exercise are different from those involved in the re sponse of the bronchial tree.