1. General Practice Research Unit, Department of Community Medicine The Arctic University of Norway Tromsø Norway
2. Department of Community Medicine The Arctic University of Norway Tromsø Norway
3. Department of Laboratory Medicine University Hospital of North Norway Tromsø Norway
4. Campus Ahus, Institute of Clinical Medicine University of Oslo Oslo Norway
5. Department of Cardiology Akershus University Hospital Nordbyhagen 1478 Norway
6. Institute of Clinical Medicine The Arctic University of Norway Tromsø Norway