The metabolic syndrome--new and old data.

Initially called the "X Syndrome" by Reaven, then the "Killer Quartet" by Kaplan, the MS prevalence has dramatically increased in the past decades. The first criteria elaborated by WHO in 1998, and afterwards reformulated in 1999, were conceived by diabetologists as a working instrument for clinical practice and they shall consequently be updated in accordance with the new acquisitions in this field. MS expresses the complex disorder of the organism energetic metabolism, having as central element insulin resistance and compensatory hyperinsulinism, associated with the presence of some risk factors involved in the etiology and/or physiology of atherosclerosis.