1. South Karelian Central Hospital, Department of Clinical Physiology and Nuclear Medicine, Lappeenranta, Finland
2. Oulu University Hospital, Department of Cardiology, Oulu, Finland
3. Tampere University Hospital, Department of Clinical Physiology, Tampere, Finland
4. UKK Institute for Health Promotion Research, Tampere, Finland
5. Centre for Laboratory Medicine, Department of Clinical Chemistry, Tampere University Hospital, Tampere, Finland