Impact of different definitions of the metabolic syndrome on the prevalence of organ damage, cardiometabolic risk and cardiovascular events.

Objectives: We compared definitions of metabolic syndrome performed by ATPIII [the National Cholesterol Education Program Adult Treatment Panel III; three criteria of the following: systolic blood pressure >or=130 mmHg and/or diastolic blood pressure >or=85 mmHg, fasting serum glucose >or=110 mg/dl, high-density lipoprotein plasma cholesterol or=150 mg/dl, waist circumference >or=102 cm (men) or 88 cm (women)], AHA (the American Heart Association; same cut-off of ATPIII except serum glucose >or= 100 mg/dl) and IDF [the International Diabetes Federation; mandatory criteria of visceral obesity with reduced cut-off of 94 cm (men) or 80 cm (women), and at least two criteria with the same cut-off as in AHA] for their impact on metabolic syndrome prevalence, cardiac organ damage, long-term risk of cardiovascular events and death for any cause and risk of developing diabetes mellitus, in-office and out-of-office hypertension and left ventricular hypertrophy (LVH).

Methods: In 2051 participants, we measured office, home and ambulatory blood pressure as well as metabolic, anthropometric and echocardiographic variables. Measurements were performed between 1990 and 1992 and repeated 10 years later. Information on long-term incidence of cardiovascular events and all-cause deaths was also collected.

Results: Prevalence of metabolic syndrome was significantly greater when using the AHA and IDF as compared to the ATPIII definition. Prevalence of LVH was higher in participants with than without metabolic syndrome and similar for the three definitions. Over 12-year follow-up, there were 179 cardiovascular events and 233 deaths for any cause. The risk of cardiovascular events and death was markedly greater for participants with as compared with those without metabolic syndrome, regardless of the definition of metabolic syndrome. This was the case also for the risk of new-onset diabetes mellitus, office, home and ambulatory hypertension and new-onset LVH.

Conclusion: Risks of fatal and nonfatal cardiovascular events, diabetes mellitus, hypertension and LVH were similar for the three definitions of metabolic syndrome. However, the AHA and IDF definitions are more sensitive than that of ATPIII in identifying metabolic syndrome condition.