1. Department of Internal Medicine, Catholic University, Rome, Italy
2. CNR-Institute of Systems Analysis and Computer Science, BioMatLab, Rome, Italy
3. Department of General Surgery, Catholic University, Rome, Italy
4. Department of Medicine III, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Dresden, Germany
5. Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
6. Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital Dresden, a member of the German Center for Diabetes Research, Dresden, Germany