Mid-and Long-term Efficacy of Ventilation Non-invasive and Continuos Positive Airway Pressure in Obesity Hypoventilation Syndrome

Primary objectives: evaluate the efficacy of noninvasive ventilation (NIV) treatment versus continuous positive airway pressure (CPAP) and life style modification treatment in Obesity Hypoventilation Syndrome (OHS), with PCO2 (first phase) and days of hospitalization (second phase) analyzed as a primary variables and percentage of dropouts for medical reasons and mortality as operative variables. As secondary variables: Measure functional and clinical improvement during sleep and wakefulness, quality of life, echocardiography and the incidence and blood pressure and evolution of cardiovascular events. Objectives secondaries:role of apneogenic sleep events on molecular inflammation, endothelial damage and the genesis of diurnal hypercapnia. Methods:prospective, randomized controlled trial. Patients with OHS will be divided initially into two groups based on their apnea-hypopnea index (AHI) score, >=30 and < 30, using conventional polysomnography. The AHI >=30 group will be randomized to CPAP, NIV or life style modification treatments. The AHI <=30 groups will be randomized to NIV or life style modification treatments. Treatment efficacy at the medium- and long-term will be analyzed by comparing groups. The role of apneic events and leptin in the genesis of daytime alveolar hypoventilation will be analyzed by comparing the daytime PCO2/AHI coefficient between responders and non-responders to CPAP treatment, and the evolution of leptin levels in the four branches of the study. The role of apneic events in metabolic and biochemical alterations and endothelial dysfunction will be analyzed by comparing basal and post-treatment levels of related substances between groups, with and without significant AHI.