The Induction of IL-6 by NF-kB in PBMC in OSA

Obstructive sleep apnea syndrome (OSAS) has emerged in recent years as an important risk factor for cardiovascular morbidity. The mechanisms responsible for developments of cardiovascular sequelae in patients with OSA include hypoxia, hypercapnia, exaggerated negative intrathoracic pressure and bursts of sympathetic activity provoking surges in blood pressure and heart rate. Meanwhile, increase of inflammatory mediators, which included C-reactive protein (CRP), oxidative stress, adhesion molecules, vascular endothelial growth factor (VEGF) and proinflammatory cytokines (interleukin (IL) -1, IL-2, IL-6, IL-8, IL-10 and tumor necrotic factor- (TNF-)), also involve in the development of cardiovascular disease in patients with OSAS.

According to our preliminary study, serum levels of IL-6 and CRP were higher in patients with OSAS than control subjects and levels of both IL-6 and CRP were highly correlated with the lowest pulse oxygen saturation. Hypoxia triggered the production of IL-6 through the induction of NFB, which was demonstrated in ischemic heart disease and pancreatitis. However, this mechanism has not been prooved in OSAS.

Therefore, we conduct this study to prove our hypothesis (1) The mRNA expression of IL-6 in peripheral blood monocytes was significantly higher in patients with OSAS than control subjects (2) The activation of NF-k B in peripheral blood monocytes was more significant in patients with OSAS than control subjects, and the level of NF- kB activation is associated with the level of IL-6 mRNA expression (3) CPAP therapy could lower both the activation of NF-kB and IL-6 mRNA expression in patients with moderate-severe OSAS.