Regulation of Vascular Thrombosis in Sleep Apnea

Obstructive Sleep Apnea (OSA) is a prevalent condition that has been increasingly diagnosed in the adult population and is now considered an independent risk factor for the development of cardiovascular disease. More specifically, OSA has been linked with thrombosis, or the formation of clots in the blood vessels which can lead to heart attack or stroke. A better understanding of the mechanisms associated with thrombosis and the development of cardiovascular disease in patients with obstructive sleep apnea is needed.

This research will investigate the function of the enzyme adenosine deaminase (ADA) in subjects with sleep disorders. ADA is responsible for metabolizing adenosine, a neuromodulator that is released during periods of sleep apnea and that has been found to promote vascular thrombosis. There are multiple types of ADA that are genetically determined and have different levels of function. Those different forms of this enzyme may determine groups that are more susceptible to the development of thrombosis. Given the known association between sleep apnea and thrombosis, this study will determine if polymorphisms of this enzyme are differentially found in subjects with sleep apnea as compared to other sleep disturbances.

A total of 60 subjects presenting for the evaluation of sleep disorders to the Weill Cornell Pulmonary Associates and the Cornell Center for Sleep Medicine practices will be offered participation in this study. The subjects with sleep apnea will be ethnically matched to the subjects with sleep disorders other than sleep apnea (controls). Once written informed consent is obtained by the Principal Investigator, venipuncture will be performed in the office by a trained phlebotomist. A total of 15 ml (approximately 1 tablespoon) of blood will be collected. The patient will be monitored for ten minutes following the blood draw to ensure adequate hemostasis. The blood samples will be utilized for DNA sequencing and determination of adenosine deaminase genotype and phenotype.

Information from clinically indicated overnight sleep studies performed within 6 months of (prior or after) the visit will be used to categorize subjects into groups (sleep apnea vs. sleep disorder other than sleep apnea).

Inclusion criteria

• 21 years or older
• Patient of the Weill Cornell Pulmonary Associates and Cornell Center for Sleep Medicine practices
• Clinically indicated for an overnight sleep study within six months prior to or after the outpatient office visit

Exclusion criteria

• Pregnancy