1. Department of Diabetology and Angiology, Marienkrankenhaus gGmbH, Soest, Germany
2. Department of Endocrinology, Diabetology and Geriatrics, Klinikum Stuttgart, Bad Cannstatt, Germany
3. University Diabetes Center and Interdisciplinary Diabetic Foot Center of Central Hesse, University Hospital Giessen and Marburg GmbH, Giessen site and GZW Diabetes Clinic Bad Nauheim, Germany
4. Practice for Diabetology and Nephrology, KfH kidney center, Bernkastel-Kues, Germany
5. Department of Internal Medicine, Mariannen-Hospital, Werl, Germany
6. Diabetes Center, Department of Internal Medicine North, Dortmund, Germany
7. Upper Rhine Vascular Center, Department of Vascular Surgery, Diakonissen Stiftungs Hospital, Speyer, Germany
8. Diabetes Center Rheine, Department of Internal Medicine III (Mathias Hospital and Jacobi Hospital), Rheine, Germany