1. Diabetes Centre, Isala, PO Box 10400, Zwolle 8000 GK, The Netherlands
2. Langerhans Medical Research Group, The Netherlands
3. Gelre Ziekenhuizen – Internal Medicine, Apeldoorn, The Netherlands
4. Department of General Practice – University Medical Center Groningen, Groningen, The Netherlands
5. Langerhans Medical Research Group, Universitair Medisch Centrum Groningen – Internal medicine, Groningen, The Netherlands
6. Department of Internal Medicine – University Medical Center Groningen, Groningen, The Netherlands
7. Isala – Internal Medicine, Zwolle, The Netherlands
8. Langerhans Medical Research Group, Zwolle, The Netherlands