Metabolic syndrome X is a multifaceted syndrome, which occurs frequently in
the general population. It is more common in men than in women. A large se
gment of the adult population of industrialized countries develops the meta
bolic syndrome, produced by genetic, hormonal and lifestyle factors such as
obesity, physical inactivity and certain nutrient excesses. This disease i
s characterized by the clustering of insulin resistance and hyperinsulinemi
a, and is often associated with dyslipidemia (atherogenic plasma lipid prof
ile), essential hypertension, abdominal (visceral) obesity, glucose intoler
ance or noninsulin-dependent diabetes mellitus and an increased risk of car
diovascular events. Abnormalities of blood coagulation (higher plasminogen
activator inhibitor type 1 and fibrinogen levels), hyperuricemia and microa
lbuminuria have also been found in metabolic syndrome X. This review summar
izes the present knowledge of abnormalities in this syndrome. Each risk fac
tor is reviewed, and potential criteria for diagnosis and therapeutic targe
ts are discussed. Because patients with metabolic syndrome X accumulate car
diac risk factors, they should be given special attention in terms of diagn
osis and treatment.