Insulin resistance and skeletal muscle vasculature: significance, assessment and therapeutic modulators.

Overnutrition and sedentarism are closely related to the alarming incidence of obesity and type 2 diabetes mellitus (DM2) in the Western world. Resistance to the actions of insulin is a common occurrence in conditions such as obesity, hypertension and DM2. In the skeletal muscle vasculature, insulin promotes vasodilation and its own transport across the vascular wall to reach its target tissue. Furthermore, insulin resistance (IR) in the skeletal muscle vasculature results in impaired skeletal muscle glucose uptake and altered whole-body glucose homeostasis. The development of different invasive and noninvasive techniques has allowed the characterization of the actions of insulin and other vasoactive hormones in the skeletal muscle vasculature in both health and disease. Current treatment strategies for DM2 do not necessarily address the impaired effect of insulin in the vasculature. Understanding the effects of insulin and other metabolically active hormones in the vasculature should facilitate the development of new therapeutic strategies targeted at the modulation of IR and improvement of whole-body glucose tolerance.