1. Department of Endocrinology & Metabolism Amsterdam University Medical Centers Amsterdam the Netherlands
2. Division of Endocrinology, Diabetes, and Metabolism Department of Medicine Beth Israel Deaconess Medical Center Harvard Medical School Boston MA USA
3. Department of Surgery Northwest Clinics Alkmaar the Netherlands
4. Clinical Chemistry Laboratory of Endocrinology Amsterdam University Medical Centers Amsterdam the Netherlands
5. Department of Surgery Rijnstate Hospital Arnhem the Netherlands
6. Department of Surgery Spaarne Hospital Hoofddorp the Netherlands