CPAP improves altered plasma fibrin clot properties in hypertensive patients with OSA
Treatment with continuous positive airway pressure (CPAP) significantly improves unfavourable prothrombotic fibrin clot characteristics, including hypofibrinolysis, which are common in hypertensive patients with obstructive sleep apnoea (OSA), according to a recent study.
A total of 50 hypertensive patients with clinically significant OSA (age 50.0 ±8.8 years; 39 males) were analysed, and 38 hypertensive patients with OSA balanced for age, sex, blood pressure, cardiovascular risk factors and metabolic status served as controls. Researchers determined plasma fibrin clot properties, including clot permeability coefficient, clot lysis time (CLT) and turbidimetric parameters of clot formation.
OSA patients had more compact fibrin structure (lower median clot permeability coefficient, 6.00 vs 7.25 10−9 cm2; p<0.001), impaired fibrinolysis (longer median CLT, 108.00 vs 92.50 min; p<0.001) and faster clot formation (shorter median lag phase, 40.50 vs 42.50 s; p=0.041), and higher median maximum clot absorbency indicating denser fibrin networks (0.87 vs 0.81; p=0.028) than controls.
Clot permeability coefficient and CLT were associated with apnoea‒hypopnoea index (r=‒0.46; p<0.001 and r=0.44; p<0.001, respectively) as well as with mean (r=0.31; p=0.003; r=‒0.36; p=0.001, respectively) and minimal oxygen saturation (r=0.46; p<0.001; r=‒0.49; p<0.001, respectively).
Treatment with CPAP for 3 months resulted in an increase in clot permeability coefficient (5.95 vs 7.60 10−9 cm2; p=0.001), shortened CLT (107.00 vs 87.00; p=0.006), a longer lag phase of fibrin formation (40.00 vs 43.50 s; p=0.013) and a trend toward lower maximum clot absorbency (0.86 vs 0.81; p=0.058).
A 2011 study found that CPAP treatment for OSA improves postprandial triglyceride concentration curve and cholesterol levels, which may reduce the risk of cardiovascular events. [Am J Respir Crit Care Med 2011;184:355-61]