Abstract

Obesity and type 2 diabetes mellitus (T2DM) are diseases associated with hypertension and metabolic alterations. A significant group of patients present both obesity and T2DM, a condition defined as diabesity. One of the metabolic features in these conditions is the clinical presentation of insulin resistance. Several tissues, including the liver, skeletal muscle, and vasculature, and patients with T2DM, gestational diabetes, and obesity show insulin resistance. The vascular effect of insulin, including vasodilation, is mainly mediated by the generation of nitric oxide. Several mechanisms are proposed to elucidate the origin of insulin resistance; nevertheless, a common finding is the endothelial dysfunction in these diseases. Endothelial cells from subjects with obesity show reduced nitric oxide synthesis, an effect that is unaltered by insulin. Individuals with T2DM show a misbalance between the synthesis, release, and biological actions of vasodilators and vasoconstrictors such as nitric oxide and endothelin-1. However, whether these mechanisms are involved in the vascular alterations seen in patients with diabesity is unclear. In this review, we discussed the modifications on insulin signalling, insulin resistance in obesity and T2DM, and the reported changes in signalling pathways in diabesity.