GCG and type 1 diabetes mellitus: DKA occurs primarily at the onset of type 1 diabetes mellitus (T1DM) as a result of absolute or relative insulin deficiency due to autoimmune destruction of the β-cells of the islet of Langerhans and concomitant elevation of counter-regulatory hormones induced by stress, such as glucagon, growth hormone, catecholamines, and cortisol.