24-HOUR RHYTHM IN BRONCHIAL HYPERREACTIVITY TO HOUSE DUST IN ASTHMATICS

[摘要] Four subjects, 2 males (17 and 35 yr of age) and 2 females (24 and 47 yr of age) suffering from allergic asthma, were studied for 10 days in allergen-shielded rooms without receiving medication. Synchronization of subjects to activity was by light on at 7 a.m. and sleep by light off at midnight. A single bronchial challenge to the threshold concentration of house dust, predetermined for each subject, was presented every other day at designated clock hours such that during a 10 day study span tests were presented at the following times: 8 a.m., 3 p.m., 7 p.m., and 11 p.m. The effect upon bronchial patency determined by FEV1.0 [1 s forced expiratory volume] 15 min after house dust inhalation resulted in greatest effect at 11 p.m., while that at 8 a.m. resulted in the least effect. The differences were statistically significant (P < 0.025). Peak expiratory flow (PEF), self-measured at 3 h intervals throughout the 10 day span, revealed practically no persistence of effect for inhalation of the house dust preparation at 8 a.m.; considerable persistence of effect on airway patency occurred from tests carried out at 11 p.m. The differences between the 24 h rhythm-adjusted means (mesors) in the PEF for the (24 h) spans following house dust inhalation at 8 a.m. and 11 p.m. were statistically significant (P < 0.025) as well.