Metabolic Syndrome: epidemiology and more extensive phenotypic description. Cross-sectional data from the Bruneck Study

OBJECTIVES: The present study aimed at evaluating the prevalence of the Metabolic Syndrome and at identifying its additional clinical features. RESEARCH DESIGN AND METHODS: Within a prospective population-based survey examining 888 subjects aged 40 - 79 y, subjects were identified fulfilling the WHO and the National Cholesterol Education Program-Adult Treatment Panel III ( NCEP-ATPIII) criteria for diagnosing the Metabolic Syndrome. In these subjects and in the rest of the sample ( controls), several metabolic and nonmetabolic biochemical parameters were compared. RESULTS: The prevalence of the Metabolic Syndrome by WHO criteria was 34.1% ( 95% CI 31.0 - 37.2) and by NCEP-ATPIII criteria 17.8% (15.5 - 20.3). The prevalence was significantly higher in older subjects and in those less physically active. Subjects with the Metabolic Syndrome either by WHO or by NCEP-ATPIII criteria showed higher levels of oxidized low-density lipoprotein, apolipoprotein B, urate, leptin, fibrinogen, leukocytes, erythrocyte sedimentation rate, GOT, gamma-GT and soluble endothelial adhesion molecules (E-selectin, vascular adhesion molecule-1 and intercellular adhesion molecule-1) and lower apolipoprotein A concentrations. Insulin resistance, as assessed by the Homeostasis Model Assessment, increased with the increase in the number of traits composing the syndrome found within the single individual. Subjects with insulin resistance had more pronounced abnormalities in several parameters, including the additional features of the syndrome (eg fibrinogen and soluble adhesion molecules). CONCLUSIONS: The Metabolic Syndrome occurs very frequently in the general population aged 40 - 79 y, and is associated with several additional metabolic and nonmetabolic abnormalities that likely contribute to an increased cardiovascular risk. Insulin resistance seems to play a major role in classic and additional abnormalities featuring the Metabolic Syndrome.