The investigators seek to advance the understanding of obstructive sleep apnea as it relates to different ethnic origins as well as sex differences. The investigators will compare Somali patients with known obstructive sleep apnea (OSA) to individuals without OSA, and to individuals of other ethnic/racial origins to determine the risk factors (genetic and/or physiologic) associated with developing cardiovascular diseases. This will help the investigators to understand the unique sleep pathology of individuals of African descent.

Participants can be healthy volunteers or volunteers diagnosed with obstructive sleep apnea. All patients may undergo a sleep study (i.e. hospital or home-based), physical examination, questionnaires, blood and urine samples, ultrasound scan of the heart and brachial artery in the arm, CT scan, DEXA scan, paced breathing test, cardiopulmonary test and chemo-sensitivity test.

Inclusion Criteria:

• Self-identify as Somali, African, Asian, and European descent.
• Adult males and females who are older than 18 years of age.

Exclusion Criteria:

• Minors under 18 years or adults over 100 years
• Positive pregnancy

The study population are individuals who are of Somali descent compared to those of different racial/ethnic origins.