ABSTRACT
This chapter highlights the problem of insulin resistance in elderly subjects. The insulin-resistance syndrome is a cluster of cardiovascular risk factors that are frequently, but not always, associated with obesity. The association of essential hypertension with insulin resistance is very well established. Multiple potential mechanisms are proposed by which insulin resistance may cause hypertension. These include resistance to insulin-mediated vasodilatation, impaired endothelial function, sympathetic nervous system overactivity, sodium retention, increased vascular sensitivity to the vasoconstrictor effect of pressor amines, and enhanced growth factor activity leading to proliferation of smooth muscle walls. Cytokines arising from the adipose tissue may be partly responsible for the metabolic, hemodynamic, and hemostatic abnormalities associated with insulin resistance. Insulin and amino acids have also been shown to enhance muscle mitochondrial biogenesis and mitochondrial protein synthesis. The insulin-induced increase in muscle mitochondrial adenosine triphosphate productive is defective in type 2 diabetic patients with insulin resistance.
