Prothrombotic Markers in Patients with Arterial Hypertension and Obstructive Sleep Apnea Syndrome

Introduction: Obstructive sleep apnea syndrome (OSA) may cause more than 500 pauses in breathing, what leads to reduction in oxygen saturation of blood. In some individuals OSA is also associated with higher risk of thrombotic events. Material and methods: In our study we included forty-five patients with arterial hypertension (duration of AH=9.8±5.7 years), middle-aged (47.6±9.1 years). 25(55.5%) of patients had severe OSA (AHI= 59.2±27). In 12 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). OSA was diagnosed by means of cardio respiratory monitoring. Results: Patients with severe OSA have higher activity of coagulation system in levels of D-dimer (319.7± 162.6 ng/ml vs 200.1±95.8 ng/ml p = 0.04), elevated blood viscosity in areas with slow blood flow (32.9± 6.6 cP. vs 29.0±6,5cP. p = 0.04) and erythrocyte aggregation (5.6 ± 0.5 cP. vs 5.0 ± 1,0 cP. p = 0.01). No significant changes of blood rheological properties were found in patients on short-term CPAP therapy (3-4 nights). Conclusions: Patients with severe OSA are demonstrating increased activity of the coagulation system: higher levels of D-dimer, blood viscosity in veins, microcirculation and erythrocyte aggregation. We found no effect of CPAP therapy on these parameters, what may be associated with a small number of subjects and the short duration of CPAP therapy. The study will continue recruiting patients and analyzing the parameters mentioned above after 3 months of effective CPAP therapy.