Fibrinogen levels and obstructive sleep apnea in ischemic stroke

The plasma level of fibrinogen is felt to be an independent risk factor for vascular events. Obstructive sleep apnea (OSA) has a high prevalence in pa tients with stroke and may also be an independent risk factor. The aim of o ur study was to determine the association between OSA and plasma revels of fibrinogen in patients with stroke. Polysomnography was performed during ne urological rehabilitation in 113 patients (82 men, 31 women, age 58 +/- 11. 1 yr, mean +/- SD) with ischemic stroke. OSA was absent (RDI < 5) in 44 pat ients, 42 had mild OSA (5 <less than or equal to> RDI < 20), and 27 had mod erate to severe OSA (RDI <greater than or equal to> 20). Parameters of OSA (respiratory disturbance index [RDI], oxygen indices) were correlated to pl asma levels of fibrinogen, measured in the morning after admission to rehab ilitation. Fibrinogen was positively correlated with RDI (r = 0.24 p = 0.00 7), duration of the longest apnea (r = 0.18 p = 0.049), and negatively corr elated with several oxygen indices including average minimal oxygen saturat ion (r = -0.41, p < 0.001). Correlation coefficients were slightly higher w hen excluding patients with stroke of presumed cardiac origin. Multiple lin ear regression identified minimal mean oxygen saturation and sex as indepen dent predictors of fibrinogen level. The correlation between severity of co existing OSA and fibrinogen level in patients with stroke suggests a possib le pathophysiological mechanism for an increased risk of stroke in patients with OSA.