1. Department of Clinical Neurophysiology, Turku University Hospital and University of Turku, Turku, Finland
2. Sleep Research Centre, Department of Pulmonary Diseases and Clinical Allergology, University of Turku, Turku, Finland
3. Department of Obstetrics and Gynecology, Turku University Hospital and University of Turku, Turku, Finland
4. HUSLAB Laboratory Services, Helsinki University Central Hospital, Helsinki, Finland
5. Department of Clinical Chemistry, Helsinki University, Helsinki and University of Eastern Finland, Kuopio, Finland
6. Heart Center, Turku University Hospital and University of Turku, Turku, Finland