Mechanism of Endothelial Dysfunction in Obstructive Sleep Apnea (OSA)

Participants: will be 36 patients with newly diagnosed OSA and 36 age and BMI matched controls.

Patients with OSA will be enrolled from the sleep disorders center at OSU among patients who underwent a recent (past 4 weeks) polysomnography that is positive for OSA, and never were treated with CPAP.

Inclusion criteria will be AHI > 15 events per hours.

Inclusion criteria:

1. AHI > 15 events per hours.

Exclusion criteria:

1. Hypertension defined by existing treatment with antihypertensives or any measurement of systolic pressure above 130 mmHg, or diastolic pressure above 85 mmHg;
2. Dyslipidemia defined by fasting cholesterol above 200; or fasting LDL over 150 mg/dl;
3. Diabetes defined as existing diagnosis, hemoglobin A1C >7 or fasting glucose >110 on two separate measurements (standard fasting glucose or HbA1C criteria);
4. CAD defined by history of angina, coronary event or abnormal stress test;
5. PVD defined by history of stroke, claudication or abnormal Ankle brachial index;
6. Concurrent smoking;
7. Pregnancy;
8. Use of erectile dysfunction drugs, or any medications for chronic conditions; 9)Chronic liver or renal disease. Fasting blood test for glucose, cholesterol, on all participants who have not had these tests in the 6 month prior to enrollment, will be obtained at the time of screening. The remaining criteria will be evaluated by reviewing the medical records and history taking on the day of first visit.