The effect of inhaled budesonide on the diurnal variation in airway mechanics, airway responsiveness and serum neutrophil chemotactic activity in Asian patients with predominant nocturnal asthma.

The effectiveness of inhaled corticosteroids in the control of daytime symptoms in asthma is well established, but the specific use against nocturnal asthma has not been systematically studied in Asian patients. This study examined the effect of treatment with inhaled budesonide on the nocturnal variation in measurements of airway calibre, bronchial hyperresponsiveness to inhaled histamine and circulating neutrophil chemotactic activity in Asian patients with nocturnal asthma. Thirty patients, with nocturnal asthma, were randomized into a 2-month, double-blind, parallel group study. Twice as many subjects were allocated to the group who received two consecutive months of inhaled budesonide 1600 microg daily as to the group who received placebo followed by budesonide. Spirometry, lung mechanics, bronchial hyperresponsiveness and serum neutrophil chemotactic factor (NCA) were measured at 16.00 h, 22.00 h and at 04.00 h on 3 days and nights, 4 weeks apart before and after either placebo or budesonide. The combined measurements for the two groups at 04.00 h before and after treatment with budesonide were: forced expiratory volume in 1 s (FEV1) mean (SEM) litres 1.34 (0.17) before, 2.00 (0.19) after; thoracic gas volume (TGV) litres 3.05 (0.32) before, 2.25 (0.14) after; specific airway conductance (sGaw) (cmH20.0 sec)(-1) 0.39 (0.07) before, 1.16 (0.17) after; PD20 microg geometric mean 1.16 before, 44.74 after; neutrophil chemotactic activity (NCA) in units of graduations of migration 98.8 (4.2) before, 101 (14.2) after. The data showed that short and intermediate term high dose inhaled budesonide is an effective specific treatment for nocturnal asthma in Asian patients, resulting in marked improvements in symptoms and in lung mechanics, and reductions in the diurnal variations in bronchial hyperresponsiveness, before any change could be demonstrated in a circulating marker of airway inflammation.