This study aimed to determine association obstructive sleep apnea (OSA) with increased coagulability and reveal possible effects of constant positive airway pressure (CPAP).Design and method:
We included 77 patients with arterial hypertension (duration of AH = 13.8 ± 3.7 years), middle-aged (45.9 ± 10.5 years). 41 (53.2%) of them had severe OSA (AHI = 59.6 ± 26). OSA was diagnosed by means of cardiorespiratory monitoring. In patients with severe OSA blood samples (D-dimer, viscosity of blood, erythrocyte aggregation) were taken at baseline and after 3–4 nights of effective CPAP therapy (AHI < 5).Results:
Patients with severe OSA have higher activity of coagulation system in levels of D-dimer (302.1 ± 186.5 g/l. vs 242.7 ± 177.6 g/l. p = 0.01), fibrinogen (3.3 ± 0.6 ng/ml. vs 3.0 ± 0.4 ng/ml. p = 0.01), plasmin-alpha2-antiplasmin complex (212.9 ± 242 ng/ml. vs. 123.3 ± 83.5 ng/ml. p = 0.03) and erythrocyte aggregation (5.6 ± 0.4 cP. vs 5.2 ± 0,9 cP. p = 0.04). No significant changes of blood rheological properties were found in patients on short-term CPAP therapy (3–4 nights).Conclusions:
The coagulation and fibrinolytic system is disturbed in severe OSA patients, with higher levels of D-dimer, fibrinogen, plasmin-alpha2-antiplasmin complex and erythrocyte aggregation. We found no effect of short-term CPAP therapy on these parameters, what may be associated with the short duration of CPAP therapy. The study will continue with analyzing the parameters mentioned above after 3 months of effective CPAP therapy.