Why metabolic syndrome criteria have not made prime time: a view from the clinic

Objective: Much has been written on the metabolic syndrome and related recent criteria. However, it remains unclear whether such criteria help clinical practice. This review will evaluate the usefulness of metabolic syndrome criteria to enhance risk prediction for either cardiovascular disease or diabetes. Design: This is a narrative review that is based on the author's experience from relevant publications from his group and from other related research. Results: Although the presence of metabolic syndrome, however defined, is clearly associated with higher risk for vascular disease, the criteria do not enhance coronary heart disease (CHD) prediction from simpler Framingham-based risk scores. The dichotomous nature of metabolic syndrome criteria - either you have it or you do not - combined with the lack of age, low-density lipoprotein cholesterol and smoking account for their inferior predictive value. Metabolic syndrome criteria are, in fact, more strongly associated with incident diabetes, an observation demonstrated in the West of Scotland Coronary Prevention Study (WOSCOPS). This is because three of the five parameters within metabolic syndrome criteria (waist, glucose and triglyceride) are more closely linked to risk for diabetes than risk for CHD. However, screening for prevalent or high risk of incident diabetes is a complex and debated issue and is by no means guaranteed to be widely adopted. Conclusions: Metabolic syndrome criteria do not offer benefits beyond established methods of vascular risk assessment. Thus, the focus in clinical practice should remain on established risk factors (for example, smoking, lipids, blood pressure) both to determine CHD risk, through established charts, and to reduce it.