Selective aspects of the insulin resistance syndrome

There is increasing recognition of new features in the insulin resistance s yndrome and its association with new disease states or treatment modalities . Recent additions to the list of features in the insulin resistance syndro me include elevated non-esterified fatty acids, abnormalities in visceral f at metabolism, elevated uric acid, elevated hematocrit, endothelial dysfunc tion, abnormalities in glucocorticoids, and differences in the phenotypic e xpression of the syndrome between men and women. A critical factor that may be inherent in the syndrome is the distribution and metabolism of visceral fat. This finding is also accompanied by the recognition of the role of no n-esterified fatty acids as a cause of many of the risk factors in the insu lin resistance syndrome, Elevated non-esterified fatty acids contribute to hypertension, glucose intolerance and increased arteriosclerosis, Elevated cortisol levels and disrupted metabolism, as well as abnormalities in the h ypothalamic-pituitary-adrenal axis are seen in the insulin resistance syndr ome, In women, adipose cells express fewer glucocorticoid receptors and les s of the enzyme that metabolizes cortisol, 11 beta -hydroxysteroid dehydrog enase. Several inflammatory factors such as tumor necrosis factor-alpha may be an etiologic link in the risk found in the insulin resistance syndrome. Certain cases of the syndrome appear to be related to specific drug therap ies (steroids, immunosuppressive agents and antiretroviral agents), as seen in transplant patients and HIV-infected individuals. Curr Opin Nephrol Hyp ertens 10:507-514. (C) 2001 Lippincott Williams & Wilkins.