The authors examined a group of patients with the sleep apnoea syndrome, healthy subjects and patients with essential hypertension. They assessed the circadian variability during monitoring of the blood pressure and heart rate. They evaluated the therapeutic effect of overpressure in the airways for a period of 12 months on these parameters. In the sleep laboratory there were examined 16 patients with the sleep apnoea syndrome, 16 patients with essential hypertension and 11 healthy subjects. Complete polysomnography, 24-hour monitoring of the blood pressure and electrocardiogram were perfomed. For evaluation cosinor analysis and non-parametric tests were used – Mann-Whitney U – Wilcoxon Rank Sum W test and Wilcoxon Matched – Pairs Signed Ranks Test. Monitoring of the blood pressure revealed a smaller circadian variability of the systolic and in particular diastolic blood pressure in the group of patients with the sleep apnoea syndrome as compared with the group of healthy and hypertonic subjects. Synchronization between the circadian variability of the blood pressure and heart rate in patients with the sleep apnoea syndrome is smaller than in the other groups. The parameters practically did not changes after 12 months of treatment with permanent overpressure. As typical changes were found in the routine monitoring of the blood pressure, this monitoring can be used for prediction of the sleep apnoea syndrome.

        Key words: sleep apnoea syndrome, blood pressure, permanent overpressure, CPAP, hypertension,