[Circadian rhythm in the treatment of asthma]

The circadian rhythm of respiratory function was examined in normal males and asthmatic subjects. In both groups, maximal flow decreased in the early morning. The major factor contributing to the circadian change in V50 was lung elastic recoil pressure in normal males and upstream resistance in asthmatic subjects. In some asthmatic patients, beclomethasone inhaled in the afternoon and at night was more effective than in the morning in increasing both the circadian maximal and minimal peak expiratory flow rates. This indicates the importance of chronotherapy in asthma.