1. Department of Public Health (B.O.A., L.J.V.), Faculty of Medicine, Norwegian University of Science and Technology, N-7489 Trondheim, Norway
2. Department of Medicine (B.O.A.), St. Olavs Hospital, Trondheim University Hospital, N-7006 Trondheim, Norway
3. Department of Medical Biochemistry (T.B.), Rikshospitalet, Oslo University Hospital and University of Oslo, N-0027 Oslo, Norway