INS and endothelial dysfunction: Diminished production of insulin in type 1 diabetes (T1DM) or resistance to insulin action in type II diabetes mellitus (T2DM) not only leads to hyperglycemia, a major triggering factor of endothelial dysfunction, but also to a reduction in the vasculoprotective effects of insulin [2] which further enhance the deleterious effects of hyperglycemia on vascular function.