1. Respiratory Department, Hospital Universitari Vall d’Hebron, Barcelona, Spain
2. Multidisciplinary Sleep Unit, Hospital Universitari Vall d’Hebron, Barcelona, Spain
3. Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
4. CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain