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.