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