[Different responses of morning dipping and nocturnal dipping to inhaled and/or oral steroids in chronic asthmatics].

Clinical experiences have suggested distinct differences in responses to anti-asthmatic drugs between patients suffering early morning asthmatic attacks and those experiencing nocturnal ones. However, there has been no report on any difference in the improvement of asthmatic flow dipping after inhaled and/or oral steroid treatment. In this retrospective study, the peak expiratory flow rates (PEF), which had been monitored four times a day, were reviewed in 40 chronic asthmatics. The group consisted of 19 patients with very low PEF (geometrical mean PEF/week [mPEF] < 60% of the personal best PEF), 15 patients with moderately low PEF (mPEF 60% to 70% of personal best PEF), 2 patients with mildly low PEF (mPEF 70% to 80% of personal best PEF) and 4 patients with occasionally low PEF (mPEF > 80% of personal best PEF). Of 40 chronic asthmatics, 22 patients had morning dipping alone and 10 patients had both morning dipping and nocturnal dipping. After inhaled and/or oral steroid treatment at sufficient level, mPEF was improved in all patients. All the dipping disappeared except for morning dipping in five cases. We concluded that there was a difference in responses to inhaled and/or oral steroids during early morning dipping and during nocturnal dipping in chronic asthmatics. There should be further investigation to discriminate between pathophysiological events that may be related to morning dipping and to nocturnal dipping.