[The occurrence of circadian rhythm in respiration in healthy persons and in patients with bronchial asthma].

The authors examined in 69 healthy young men at times 0, 3, 6, 9, 12, 15, 18 and 21 hours values of FVC, FEV1, FEF50 a PEF. In 149 patients with bronchial asthma after the same time intervals FEV1 was assessed, whereby the interval at 3 a.m. was used as the mean of values at times 0 and 6 a.m. By analysis of variance the minima of the majority of investigated indicators were assessed in healthy subjects at 3 a.m. and 9 a.m. By cosinor analysis a statistically insignificant circadian rhythm for values FEC and FEV1 was proved in the entire group of healthy subjects and in subgroups of smokers and non-smokers. No rhythm was found in values of FEF50 and PEF. Rhythms in the ventilation values were detected in 40-60% of the subjects, in the remainder no rhythms were detected. In patients with bronchial asthma a significant circadian rhythm of FEV1 changes was found in groups with a morning or variable type of respiration. In groups with a stabilized ventilation a rhythm was detected but was not significant. In the group with an apparently irreversible obstruction no circadian rhythm was found.