1. Research Department, Innlandet Hospital Trust, P.O. Box 104, N-2381 Brumunddal, Norway
2. Faculty of Health and Social Sciences, Inland Norway University of Applied Sciences, P.O. Box 400, N-2418 Elverum, Norway
3. Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
4. Oslo Centre for Clinical Heart Research Laboratory, Department of Cardiology, Oslo University Hospital Ullevål, P.O. Box 4950, Nydalen, N-0424 Oslo, Norway
5. Faculty of Medicine, University of Oslo, N-0370 Oslo, Norway
6. Norwegian Institute of Public Health, P.O. Box 222, N-0213 Oslo, Norway