GCG and diabetes mellitus: It has been suggested that these drugs may alter the normal counter-regulatory hormonal response to insulin deficiency, particularly during periods of metabolic stress, leading to reduced glucose utilization and ketone production.[7] Additionally, DPP-4 inhibitors may impair insulin secretion and promote glucagon release under stressful conditions such as head trauma, exacerbating the development of ketoacidosis despite normal or low blood glucose levels.