RecruitingPhase 2Drug trialDo Endotypes Predict Response and Sequelae in OSA PatientsThis study will investigate why some people have Obstructive Sleep Apnea (OSA) and how the underlying cause may relate to OSA manifestations (including sleepiness and high blood pressure) and response to different therapeutic approaches (ie CPAP, eszopiclone, and supplemental oxygen). Understanding why someone has OSA could affect how best to treat that individual, but may also have an impact on what problems the disease might cause.