INS and type 1 diabetes mellitus: Consistent with these findings, we have separately shown that islet-autoantibody-negative clinician-diagnosed type 1 diabetes, when measured within 1 year of diagnosis, had substantially slower loss of endogenous insulin secretion (C-peptide), with many participants who were initially diagnosed and treated as type 1 diabetes being able to successfully stop insulin after being informed of the negative islet-autoantibody results [31].