1. Department of Endocrinology; Oxford Centre for Diabetes, Endocrinology and Metabolism; Churchill Hospital; University of Oxford; Oxford UK
2. Department of Experimental Medicine; Sapienza University of Rome; Rome Italy
3. Department of Endocrinology; S.S. Annunziata Hospital; Taranto Italy
4. Department of Clinical Biochemistry; John Radcliffe Hospital; University of Oxford; Oxford UK