[Metabolic syndrome: a true syndrome or only a cluster of risk factors?]

Abstract

Although the classical cardiovascular risk factors (such as smoking, hypertension and hypercholesterolemia) are becoming gradually more effectively controlled, a continuous increase of the so-called "cardiometabolic risk" linked to obesity and impaired glycemic control is observed. Starting from the beginning of this century, the definition of the "metabolic syndrome" has become very popular to identify a combination of different factors concurring to increase cardiovascular risk. In the medical literature a controversy does exist concerning this question: is the metabolic syndrome a real syndrome or should it be considered a simple cluster of risk factors? In this synthetic review the analysis of the most recent studies suggests that a) the metabolic syndrome causes an increased cardiovascular risk; b) this risk varies in accordance with the number and characteristics of the diagnostic criteria used; and c) the adjustment for the traditional risk factors lowers but does not eliminate entirely the incremental relative risk attributable to the metabolic syndrome. Whether the risk of metabolic syndrome is greater than the risk attributable to the sum of each component remains to be elucidated. However, the most reliable evidence supports the opinion that the risk prediction associated with this syndrome is not greater than the sum of its parts.