Endothelial Dysfunction and Circulating Microparticles from Patients with Obstructive Sleep Apnea

Abstract

Endothelial dysfunction is involved in vascular complications of obstructive sleep apnea (OSA). In this study, circulating microparticles (MPs) from patients with OSA-induced nocturnal desaturations were characterized and their effects on endothelial function were evaluated. Two age-matched groups of patients undergoing polysomnography for OSA were compared: 35 desaturators with a 3% oxyhemoglobin desaturation index (ODI) > or = 10 events per hour of sleep and 27 nondesaturators with ODI <10 events per hour. MPs were characterized by flow cytometry and then either used to treat in vitro human endothelial cells or to study endothelial function in mice. Circulating MPs did not differ between groups, but MPs from granulocytes and activated leukocytes (CD62L(+)) were found at higher levels in desaturators. In vitro, MPs from desaturators reduced endothelial nitric oxide (NO) production by enhancing phosphorylation of endothelial NO synthase at the site of inhibition and expression of caveolin-1. CD62L(+) MPs positively correlated with ODI. Endothelial NO production negatively correlated with both CD62L(+) MPs and ODI. MPs from desaturators increased expression of endothelial adhesion molecules including E-selectin, ICAM-1 and ITGA5, and cyclooxygenase 2. Moreover, injection of MPs from desaturators into mice impaired endothelium-dependent relaxation in aorta and flow-induced dilation in small mesenteric arteries. This study demonstrates an association between endothelial dysfunction and increased circulating levels of CD62L(+) MPs. This may initiate atherogenic processes in patients with OSA and severe nighttime hypoxia.

Serum Inflammatory Markers in Obstructive Sleep Apnea: A Meta-Analysis

“…In the current meta-analysis, ICAM was found to be higher in OSA patients than the control group. In many studies, ICAM-1 (intercellular adhesion molecule 1) was found to be higher in patients with OSAS 60,82,83 and its level correlated with OSAS severity, particularly with nocturnal hypoxemia.…”

Retinal and choroidal thickness evaluation by SD-OCT in adults with obstructive sleep apnea-hypopnea syndrome (OSAS)

“…1 Meanwhile, hypoxia can lead to increased blood pressure and a weakened response of the vascular system to vasodilatation factors, resulting in dysfunction of blood vessel and tissue selfregulation 2 and vascular endothelial disorders. 3 Previous studies have suggested that OSAS acts as an independent risk factor and leads to hypertension, heart disease, and stroke through the mechanisms described above. [4][5][6] OSAS can have a similar effect on the eye.…”

Study of Insulin Resistance, Inflammatory Cytokines and Adhesive Molecules in Obese Subjects with Obstructive Sleep Apnea

“…In addition, Korzh et al [42] stated that the levels of VCAM-1, E-selectin, P-selectin, CRP, WBC count were higher in OSA patients than in control subjects [42]. Similarly, several studies found direct significant relationship between adhesive molecules and severity of OSA measured by ODI and AHI [43][44][45][46].…”