1. Department of Cardiology and Angiology, Interdisciplinary Center of Sleep Medicine; Charité Universitätsmedizin Berlin; Berlin Germany
2. Department of Internal Medicine B, Cardiology, Pneumology, Weaning, Infectious Diseases, Intensive Care Medicine; University Hospital Greifswald; Greifswald Germany
3. Department of Internal Medicine, Pneumology; Vivantes Hospital Berlin Spandau; Berlin Germany
4. Institute for Community Medicine, SHIP/Clinical Epidemiology Research; University Hospital Greifswald; Greifswald Germany