GCG and type 1 diabetes mellitus: Patients with FT1DM had lower C-P0 and C-P2hr levels and higher Glu2hr, Glu0/C-P0, and Glu2hr/C-P2hr levels than those with T1DM (p < 0.05), suggesting that the regulation of glucagon secretion from α cells is impaired in FT1DM.