Alternative of Treatment in Obesity Hypoventilation Syndrome

Primary objectives: evaluate the efficacy of noninvasive ventilation (NIV) treatment versus continuous positive airway pressure (CPAP) and the "historic" treatment (weight loss and oxygen) in Obesity Hipoventilation Syndrome (OHS), with PCO2 and days of hospitalization 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, and the incidence 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 historic treatment. The AHI <=30 groups will be randomized to NIV or historic 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.