1. Department for Endocrinology and Diabetology; University Medical Centre Hamburg-Eppendorf; Hamburg Germany
2. Department for Diagnostic and Interventional Radiology; University Medical Centre Hamburg-Eppendorf; Hamburg Germany
3. Institute for Clinical Chemistry and Laboratory Medicine; University Medical Centre Hamburg-Eppendorf; Hamburg Germany
4. General, Visceral and Thoracic Surgery Department; University Medical Centre Hamburg-Eppendorf; Hamburg Germany
5. Centre for Diabetes Research, Gentofte Hospital; University of Copenhagen; Hellerup Denmark
6. NNF Centre for Basic Metabolic Research and Department of Biomedical Sciences; The Panum Institute, University of Copenhagen; Copenhagen Denmark
7. Diabetes Division, Department of Medicine I, St Josef Hospital; Ruhr University Bochum; Bochum Germany