Circulating antiangiogenic proteins in obstructive sleep apnea and hypertension.

Introduction: Obstructive sleep apnea (OSA) causes endothelial dysfunction and is an independent risk factor for hypertension and cardiovascular diseases. Although vasoactive agents and sympathoexcitation have been implicated and operational in the pathogenesis of hypertension associated with OSA the exact mechanisms underlying hypertension have not been established. Soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) are released under hypoxic stress and cause endothelial dysfunction and hypertension in humans and animals.

Impaired cerebral autoregulation in obstructive sleep apnea.

Obstructive sleep apnea (OSA) increases the risk of stroke independent of known vascular and metabolic risk factors. Although patients with OSA have higher prevalence of hypertension and evidence of hypercoagulability, the mechanism of this increased risk is unknown. Obstructive apnea events are associated with surges in blood pressure, hypercapnia, and fluctuations in cerebral blood flow.