1. Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
2. Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine, University Hospital Tübingen, Tübingen, Germany
3. Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
4. German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
5. Department of General, Visceral and Transplant Surgery, University Hospital Tübingen, Tübingen, Germany