Some circulating risk factors and obstructive sleep apnea in ischemic strokes

ABSTRACT

obstructive sleep apnea [OSA] has a high prevalence in patients with ischemic stroke and may also be an independent risk factor. The purpose of our study was to investigate the relationship between plasma fibrinogen levels, activated coagulation factor VII [FVIIa], activated factor XII [FXIIa] and cholesterol and the degree of coexisting OSA as determined by full polysomnography in patients with ischemic stroke. Thirty patients [20 men, 10 women, a mean age of 56.1 +/- 6.28 yr], with excessive daytime sleepiness [Epworth Sleepiness Score >9] and proven OSA on overnight polysomnography with all forms of ischemic infarctions were considered for inclusion in the study. The diagnosis of stroke was confirmed by a complete neurological examination and brain imaging including computed tomography and/or magnetic resonance imaging. Plasma levels of fibrinogen, FVIIa, FXIIa, and total cholesterol were measured 40 days after stroke onset in these patients and in twenty similar patients[13 males and 7 females] with a mean age of [55.5 +/- 6.74 yr] without OSA. We excluded patients with inflammatory or cardioembolic etiology, smokers and those receiving anticoagulants. We found that there is a significant higher plasma fibrinogen level in patients with OSA [3.9 +/- 0.83 gm/l] than in patients without OSA [2.9 +/- 0.29 gm/l], and there is no significant difference between both groups of patients as regarding plasma levels of FVIIa, FXIIa and cholesterol .The levels of these risk factors were higher in ischemic patients with OSA than that of other patients group. There was a significant difference between different degrees of OSA severity as measured by respiratory disturbance index as regarding plasma levels of fibrinogen and cholesterol. Patients with severe OSA had a higher plasma fibrinogen level and higher plasma cholesterol levels than patients with less OSA severity. There was a significant higher plasma fibrinogen level [4.0 +/- 0.67 gm/l] in patients with more oxygen desaturation[?10%] than that [3.1 +/- 0.76 gm/l] of patients with less oxygen desaturation [>10%]. We concluded that patients with ischemic stroke and OSA have elevated fibrinogen and cholesterol levels than ischemic patients without OSA, which were significantly associated with indices of sleep apnea severity. The demonstration of several raised circulating cerebrovascular risk markers in ischemic patients with OSA compared with patients without OSA adds to the evidence that OSA is associated with higher levels of cerebrovascular risk