Pilot 2: Glucagon-like Peptide-1 in Sleep Disordered Breathing

This is a pilot study aimed at measuring the change in obstructive apnea/hypopnea index in non-diabetic patients being treated for the first time with the glucagon-like peptide-1 (GLP-1) agonist, Liraglutide. Sleep disordered breathing (SDB) consists of nocturnal alveolar hypoventilation and / or obstructive sleep apnea which result from abnormalities in upper airway tone and ventilation during sleep. The development of a new pharmacological treatment for sleep disordered breathing (SDB) could bring a breakthrough discovery that will impact a rapidly growing population of children and adults with this disorder. The investigators hypothesize that GLP-1 plays a central role in the improvement of SDB and that the administration of GLP-1 receptor agonist to patients with OSA will correct or improve SDB. Hypothesis 1: Administration of Liraglutide to patients with severe OSA defined as apnea hypopnea index ≥ 8 /hr. will result in a mean reduction in the index by a minimum of 50% after 4 weeks. Hypothesis 2: Administration of Liraglutide will result in significant increase in Orexin level, decrease in leptin, decrease in Epworth Sleepiness Scale (ESS) score and increase in carbon dioxide (CO2) chemosensitivity. This is an open label, non-randomized, controlled pilot study. Subjects are heavy to obese non-diabetic adults that are diagnosed with sleep apnea. 20 subjects will be treated with liraglutide for 4 weeks and compared to 10 untreated controls. Study time points are baseline and 4 weeks post treatment. Study procedures include pre and post treatment: fasting blood for glucose, hemoglobin A1C (HbA1C), Orexin and leptin; ESS questionnaire; pulmonary function test and hypercapnic challenge. The procedures also include a post treatment overnight research sleep study to measure change in apnea index from diagnostic sleep study done previous to study enrollment or if needed, the baseline research sleep study.