A and B: Plasma levels of IR-GIP and xenin-25 during GGIs A and B: Plasma levels of IR-GIP and xenin-25 during GGIs. Subjects with NGT were administered GGIs with a primed-continuous intravenous infusion of GIP alone, xenin-25 (Xen) alone, or the combination of GIP plus xenin-25. A and B: Plasma levels of IR-GIP and xenin-25 during GGIs. Subjects with NGT were administered GGIs with a primed-continuous intravenous infusion of GIP alone, xenin-25 (Xen) alone, or the combination of GIP plus xenin-25. IR peptide levels (group average ± SEM) in subjects with IGT and T2DM were similar to those shown for subjects with NGT. Burton M. Wice et al. Diabetes 2012;61:1793-1800 ©2012 by American Diabetes Association