1. Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
2. Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
3. German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
4. III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany