• CPAP effect [ Time Frame: 4-week after CPAP treatment ]
  

Obstructive sleep apnea syndrome (OSAS) is characterized with recurrent collapse of upper airway during sleep and resulted in hypoxia and sleep fragmentation. Several systemic and cardiovascular complications have been attributed to OSAS, which is caused by hypoxia and bursts of sympathetic activity. Increase of inflammatory mediators, which included C-reactive protein, oxidative stress, adhesion molecules, vascular endothelial growth factor and proinflammatory cytokines, were thought to involve in the developments of cardiovascular diseases in patients with OSAS. In our preliminary study, both serum levels of IL-6 and CRP were higher in patients with OSAS than control subjects, and the levels were inversely correlated with the lowest pulse oxygen saturation. Factors triggering inflammatory cascades in OSAS included hypoxia and sympathetic hyperactivity.

Hypoxia was thought to be the trigger factor for the elevated production of inflammatory mediators. Through the induction of transcriptional factors and critical signaling pathways, hypoxia induces several physiologic responses, like increased anaerobic metabolism, angiogenesis, vasodilation, erythropoiesis and increased breathing.

Microarray is the more mature gene analysis techniques so far, which can allow high throughput analysis of the function of many genes. Microarray can be used to understand the disease mechanisms and is also very useful to improve disease diagnosis, disease classification, prognosis evaluation and to improve treatment outcome. In this project, we use oligo microarray to genome-wide profile the altered gene expressions in peripheral blood mononuclear cells of OSAS patients; and to correlate the dysregulations of gene expression with the clinical outcome. We will also examine the gene expression patterns change before and after treatment with CPAP. The information obtained by this approach will be very useful to understand the pathogenic mechanism of OSAS that leads to the systemic and cardiovascular complications. Further therapeutic intervention may therefore be possible.