INS and diabetes mellitus: A residual beta cell function carries great patient benefit as even a small preserved insulin secretion is associated with fewer episodes of ketoacidosis7 and serious hypoglycemia and less risk of late diabetes complications.8 We have recently confirmed the association between low age, ketoacidosis, higher HbA1c, high titers of glutamic acid decarboxylase antibody (GADA) and islet antigen-2 antibody (IA-2A), and a more rapid loss of endogenous insulin secretion.9 Moreover, we found that a rapid decline in C-peptide is associated with an increased incidence of severe hypoglycemia.