1. Endocrinology Laboratory Unit , “Luigi Sacco” University Hospital , Milan , Italy
2. Medical Statistics Unit, Department of Biomedical and Clinical Sciences L. Sacco , “Luigi Sacco” University Hospital , Università degli Studi di Milano , Milan , Italy
3. Fondazione Ca’ Granda Ospedale Maggiore Policlinico Research Institute of Milano , Milan , Italy
4. Department of Biomedical Sciences for Health , Università degli Studi di Milano , Milan , Italy
5. Department of Medicine-DIMED , University of Padova , Padua , Italy