1. Unit of Internal Medicine; Casa Sollievo della Sofferenza Hospital, IRCCS; San Giovanni Rotondo Italy
2. Department of Internal Medicine and Medical Specialties; Sapienza University; Rome Italy
3. Unit of Biostatistics; Casa Sollievo della Sofferenza Hospital, IRCCS; San Giovanni Rotondo Italy
4. Unit of Biostatistics; DCPE, Consorzio Mario Negri Sud; Santa Maria Imbaro Italy
5. Unit of Endocrinology and Diabetology, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico; University of Milan; Milan Italy