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 Department of Internal Medicine I, University Hospital Bergmannsheil, Bochum, Germany.
7 Department of Internal Medicine I, University Hospital RWTH, Aachen, Germany.
8 Diabetes Centre Bochum-Hattingen, 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.