GCG and Hypoglycemia: In T1D, deficiency of the secretory response of glucagon to hypoglycemia is an early acquired (<2 years of onset) abnormality of counter-regulation and leads to severe hypoglycemia (Cryer, 2002; Siafarikas et al., 2012), which may in part be explained by the major structural and functional changes that occur to islets in T1D.