Figure 2

Baseline intravenous glucose challenge 4 weeks after training. Young-Control (n = 8), Old-Control (n = 9), and Old + GLP-1 (n = 7) dogs underwent to an intravenous glucose challenge prior to randomization to GLP-1 infusion. (A) Higher peak of plasma glucose response and (B) greater increase in plasma insulin in the older dogs, both suggesting whole body insulin resistance in the older groups compared to Young-Control animals. IV GTT, intravenous glucose tolerance test; *p < 0.01.