Aims To compare outcomes of glucagon‐stimulated C‐peptide tests (GSCTs) in people with latent autoimmune diabetes in adults (LADA) after a 21‐month intervention with either insulin or the dipeptidyl peptidase‐4 inhibitor sitagliptin. Research design and methods We included 64 glutamic acid decarboxylase (GAD) antibody‐positive individuals, who were diagnosed with diabetes