Metabolic syndrome predicts death, cardio disease

Metabolic syndrome is a significant predictor of cardiovascular outcomes and all-cause mortality, according to a new systematic review and meta-analysis.

The analysis included 87 studies (with more than 900,000 patients) that assessed the relationship between metabolic syndrome and cardiovascular outcomes. Most of the studies used the 2001 National Cholesterol Education Program (NCEP) definition of metabolic syndrome, which requires three or more of five cardiovascular risk factors: central obesity, elevated triglycerides, diminished HDL cholesterol, systemic hypertension and elevated fasting glucose. The other studies used the 2004 revised (rNCEP) definition, which differs mainly in that the threshold for fasting glucose was lowered from 110 to 100 mg/dL.

After the definitions and the studies were pooled, the analysis found that metabolic syndrome was associated with a more than doubled risk of cardiovascular disease and stroke, and a 1.5-fold increase in the risk of all-cause mortality. The researchers also looked at whether this increased risk could be explained by patients with metabolic syndrome having a high rate of type 2 diabetes. They found this not to be true; even in patients without type 2 diabetes, metabolic syndrome was associated with a 62% increased risk of myocardial infarction and 86% increased risk for stroke.

There is still a need for prospective research to determine whether metabolic syndrome identifies a risk independent of that of its individual components, the study authors said. Despite that uncertainty, they recommended that health care workers use metabolic syndrome as a diagnostic tool for identifying at-risk patients.

The use of the NCEP versus the rNCEP definition of metabolic syndrome makes little difference in identifying risk, the authors noted, and they suggested that the definition of metabolic syndrome should not require type 2 diabetes as a component, because nondiabetic patients also face significantly increased risks. The analysis was published in the Sept. 20 Journal of the American College of Cardiology.