1. Department of Internal MedicineAcademic Medical Center Amsterdam The Netherlands
2. Department of DiabetesRoyal Infirmary of Edinburgh Edinburgh UK
3. Department of Clinical Chemistry, Laboratory of Endocrinology and RadiochemistryAcademic Medical Center Amsterdam The Netherlands
4. Department of Internal MedicineTergooi Hilversum The Netherlands
5. Department of Internal MedicineUniversity Medical Center Utrecht The Netherlands
6. Department of Internal MedicineWestfriesgasthuis Hoorn The Netherlands
7. Department of Biomedical SciencesNNF Centre for Basic Metabolic Research, Panum Institute, University of Copenhagen Copenhagen Denmark
8. Department of Internal MedicineGentofte Hospital, University of Copenhagen Copenhagen Denmark