This prospective observational study will enroll 60 moderate-to-severe OSA patients (AHI≧15/hour, 30 obese [BMI>=27] & 30 non-obese [BMI<27]) and 40 age-, gender-, BMI-matched controls without OSA. Venous blood 10 ml will be collected to isolate neutrophils, which are later tested for their ability to produce neutrophil extracellular traps (NETs) under the effect of PMA (phorbol 12-myristate 13-acetate). The test will be repeated if OSA patients receive CPAP therapy (continous positive airway pressure therapy).

Obstructive sleep apnea (OSA) is a common disease, affecting around one billion people worldwide. This disorder is characterized by repetitive upper airway collapse during sleep, thereby leading to intermittent hypoxia (IH). The severity of OSA is gauged by AHI(apnea-hypopnea index), which can be determined by a sleep test, polysomnography. Literature revealed OSA confers a higher risk for incident pneumonia and sepsis-related adverse outcomes, suggestive of defective immunity in those patients. CPAP therapy (continous positive airway pressure therapy) is the mainstay treatment for OSA. This research is aimed to investigate the impact of IH on the ability of neutrophils to produce neutrophil extracellular traps (NETs). We will enroll 60 moderate-to-severe OSA patients (AHI≧15/hour, 30 obese [BMI>=27] & 30 non-obese [BMI<27]) and 40 age-, gender-, BMI-matched controls without OSA. Venous blood 10 ml will be collected to isolate neutrophils, which are later tested for their ability to produce NETs under the effect of PMA (phorbol 12-myristate 13-acetate).

Inclusion Criteria

• Adults with clinical diagnosis of moderate or severe OSA (AHI >=15/hour)
• Must be willing to participate in this study and sign permit

Exclusion Criteria

• Not willing to participate in this study
• Ever treated with continous positive airway pressure (CPAP) or other therapy for OSA
• Age < 20 years
• Have comorbid disease or condition, which could impact immunity (such as malignancy, chemotherapy, immune disease, diabetes etc)

This prospective observational study will enroll 60 moderate-to-severe OSA patients (AHI≧15/hour, 30 obese [BMI>=27] & 30 non-obese [BMI<27]) and 40 age-, gender-, BMI-matched controls without OSA. Venous blood 10 ml will be collected to isolate neutrophils, which are later tested for their ability to produce neutrophil extracellular traps (NETs) under the effect of PMA (phorbol 12-myristate 13-acetate).