[Diagnosis and therapy of nocturnal asthma]

The bronchial tonus depends on circadian oscillations like all other organ functions. The tendency to increased nocturnal bronchoconstriction in some asthmatic subjects is well known. The reasons of such individual variations are different concentrations of cortisol, adrenaline, histamine, cAMP in serum as well as imbalance between vagal and sympathetic interactions. In practice, the early diagnosis of severe nocturnal bronchial constriction is important for prevention of asthma attacks and status asthmaticus. We report on our circadian measurements of airway resistance (Ros) or peak-flow. By adequate therapy an improvement of the individual bronchial tolerance could be achieved, however the biorhythm remained unchanged. Measurements of airway resistance at 2 a.m. were significantly improved by therapy, as was the mean level measurements during 4-hourly readings. High dose bedtime or slow release theophylline decreased the number of nocturnal asthma attacks.