1 German Diabetes Foundation, Düsseldorf, Germany.
2 Division of Endocrinology and Diabetology, University Obesity Centre Hamburg, University Hospital Hamburg-Eppendorf, Germany.
3 German Centre for Diabetes Research (DZD e. V.), Neuherberg, Germany.
4 Department of Internal Medicine IV, Diabetology, Endocrinology, Nephrology, University Hospital Tübingen, Germany.
5 Department of Internal Medicine I, Marienhospital, Stuttgart, Germany.
6 MVZ for Diagnostics and Therapy Bochum, Bergstraße 26, 44791 Bochum, Germany.
7 Department of Internal Medicine I, Aachen University Hospital RWTH, Aachen, Germany.
8 Diabetology, Endocrinology and Metabolism Section, Department of Internal Medicine I, St. Josef Hospital, Ruhr University, Bochum, Germany.
9 MVZ Metabolic Medicine Leipzig, Leipzig, Germany.
10 Department of Internal Medicine - Gastroenterology, Diabetology/Endocrinology and Nutritional Medicine, St. Josefkrankenhaus Heidelberg GmbH, Heidelberg, Germany.