The goal of this research is to improve our understanding of the effectiveness of surgical OSA treatment by evaluating its impact on these health-related and functional outcomes and comparing these effects to the changes in respiratory physiology achieved after surgery. To achieve this goal, we will examine key health-related (C-reactive protein, homocysteine, leptin, the homeostasis model of insulin resistance, and heart rate variability) and functional (sleep-related quality of life and vigilance) measures among a surgical group of OSA patients who do not tolerate non-surgical treatment (positive airway pressure, PAP) and a comparison group of matched OSA patients who tolerate PAP.