Spironolactone to Improve Apnea and Cardiovascular Markers in Obstructive Sleep Apnea Patients

Inclusion Criteria: * Body Mass Index (BMI) greater than or equal to 30 * Diagnosis of moderate to severe OSA via diagnostic polysomnography (AHI≥15) or home sleep apnea test (respiratory event index (REI)≥15). * Diagnosis of cardiovascular disease * Meet criteria for hypertension (minimum systolic blood pressure ≥ 140 but \<180) * Prescribed PAP therapy but non-adherent (failure to use PAP for at least 4 hours per night on minimum 5/7 nights per week on average over a one-month period) Exclusion Criteria: * Diagnosis of congestive heart failure; resistant hypertension; hepatic disease; Addison's disease; cancer; or recent (past 3 months) myocardial infarction, or stroke * Diagnosis of central sleep apnea * Patients who are not using PAP at all (untreated) or using another form of treatment for OSA * Currently taking, recent trial (past month), or allergy for spironolactone * Severe respiratory disease (e.g., diagnosis of chronic obstructive pulmonary disease, uncontrolled asthma) * History of leukopenia and/or thrombocytopenia * Current use of another potassium sparing diuretic (e.g., amiloride or eplerenone) * Current use of lithium, barbiturates, narcotics, muscle relaxants, pressor amines, or cholestyramine * Patients who plan to have surgery during the time period of the study