1. Tromsø Endocrine Research Group, Department of Clinical Medicine, University of Tromsø, 9037 Tromsø, Norway
2. Division of Internal Medicine, University Hospital of North Norway, 9038 Tromsø, Norway
3. Department of Community Medicine, University of Tromsø, 9037 Tromsø, Norway
4. Department of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
5. Division of Laboratory Medicine, University Hospital of North Norway, 9038 Tromsø, Norway