Declaration of interest
A Gastaldelli has worked as a consultant for Eli-Lilly, Roche, Genentech; received grant support from Amylin-BMS-AZ; attended invited seminars for Sanofi Aventis and Menarini Italy. M Gaggini has received a fellowship from Gilead. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.