[Obstructive sleep apnea syndrome and cardiovascular risk factors in the antihypertensive therapy "escape" phenomenon].

Aim: To assess the role of obstructive sleep apnea and other cardiovascular (CV) risk factors in the development of the antihypertensive therapy (AHT) efficacy "escape" phenomenon in patients with arterial hypertension (AH).
Materials and Methods: The data of 75 patients with AH stage I-II, grades 1-3 were proceeded. All patients included in the study underwent night respiratory monitoring. After AHT prescription, blood pressure (BP) was monitored by three measurement methods (office, daily monitoring and self-control of blood pressure) - initially, in 1, 3 and 6 months after the inclusion - in order to confirm the initial therapy efficacy and to identify or exclude the "escape" phenomenon.
Results: In 36.0% of patients, the "escape" phenomenon was diagnosed in 1 or 3 months of observation. When comparing the group with the "escape" phenomenon, an initially higher level of systolic BP was revealed according to office measurements, 24-hour monitoring and self-control BP monitoring (134.0±4.7 mmHg vs 126.0±8.5 mmHg; 129.0±2.3 mmHg vs 121.0±7.7 mmHg; 131.0±8.2 mmHg vs 121.5±6.2 mmHg resp.; р <0,05). There were no differences in sleep apnea and CV risk factors between the groups. However in patients with a minimal SpO ₂ ≤85% during sleep, there were a higher levels of office systolic BP both before the AHT prescription, and during its use (157.6±10.4 mmHg vs 152.4±8.1 mmHg resp., р <0,05; 132.0±6.8 vs 127.1±8.9 mmHg resp.; р <0,05), and mean 24-hour systolic BP (125.7±5.9 vs 121.6±8.2 mmHg resp.; р <0,05) - compared with patients with a minimum SpO ₂ >85%.
Conclusion: The higher BP level in patients with lover nocturnal hypoxemia does not allow us to exclude the delayed negative impact of obstructive sleep apnea, especially severe, on the BP profile in case of initially successful AH control.