1. Unit of Endocrinology and Diabetes; University Campus Bio Medico of Rome; Rome Italy
2. Clinical Pathology and Microbiology Laboratory; University Campus Bio Medico of Rome; Rome Italy
3. The Biostatistics Center; George Washington University; Rockville Maryland USA
4. Centre of Diabetes, Blizard Institute, Queen Mary University of London; Barts and The London School of Medicine; London UK