The operative risk factors in the metabolic syndrome: is it lipids and high BP or are there direct vascular effects of insulin resistance and obesity.

Increase in patients with central obesity and insulin resistance is an important cause for the worldwide increased incidence of type 2 diabetes. Several risk factors such as glucose intolerance, hyperinsulinemia, obesity, dyslipidemia, and hypertension, but also endothelial dysfunction and inflammation, have been found to cluster and often precede type 2 diabetes mellitus. Seeing the importance of early identification, the US National Cholesterol Education Program created a readily applicable definition of the metabolic syndrome for daily clinical practice. It is assumed that the cardiovascular risk for patients belonging to the metabolic syndrome can just be calculated out of the sum of the separate cardiovascular risk factors dyslipidemia and hypertension. However, there are also data pointing toward a higher risk than expected from these separate cardiovascular risk factors because of possible direct vascular effects of insulin resistance and obesity. Awareness of the underlying disorders of insulin resistance and its associated (non-) traditional risk factors such as endothelial dysfunction and inflammation is important for understanding the pathophysiology and thus coherent treatment.