The purpose of this study is to evaluate the associations of circadian variations, sleep architecture, hypertension and prostanoids in the patients with sleep apnea. In addition, the patients introduced to continuous positive airway pressure(CPAP) treatment, the effects of CPAP are also evaluated.

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of upper airway obstruction during sleep that provoke frequents arousals, sleep fragmentation, oxygen desaturation, and excessive daytime sleepiness. OSA may contribute to the development of systemic hypertension, cardiovascular disease. Many studies has reported a crucial role for the prostaglandin D system in sleep regulation. In addition, it has been described urinary or blood levels of prostaglandins was higher in the patients with hypertension, diabetes mellitus, and these values were associated with the severity of coronary artery disease. However, the relation between alterations of prostaglandin D system and sleep architecture, sleepiness, and clinical outcomes such as hypertension, arteriosclerosis in the patients with OSA are not known. Additionally, after CPAP treatment, we will investigate the association between change of prostaglandin system and sleep architecture, sleepiness, clinical outcomes.

Inclusion Criteria:

• Subjects on admission for sleep study under the Respiratory Care and Sleep Control Medicine, Kyoto University Hospital.
• Subjects diagnosed with OSA (apnea hypopnea index >=5/hour) by overnight polysomnography.

Exclusion Criteria:

• Subjects treating for acute infections or malignancy.
• Subjects with severe cardiovascular disease, diabetes,and renal failure.
• Subjects taking nonsteroidal anti-inflammatory drugs, steroids or immunosuppressants.