Drs. Vinicor and Bowman (1) point to a number of challenges associated with formalizing medical syndromes for clinical and public health purposes in this issue of Diabetes Care. I agree with the issues they raise; it is not yet clear whether the metabolic syndrome is a separate syndrome or simply a collection of commonly recognized cardiovascular risk factors. The current working definitions provide a useful means for clinicians to identify high-risk patients and manage them accordingly. Researchers can use the criteria to readily identify patients with the syndrome and enhance our understanding of the basic pathophysiology and management. Although the vigorous and systematic evaluation of proposed criteria for the metabolic syndrome is necessary and valuable, we need to keep the criteria simple and clinically relevant. An example of the use of an original set of criteria that was later elucidated by further research is the case of rheumatic fever. The original definition of rheumatic fever, the Jones criteria, was based on the occurrence of specific manifestations (2). We now know that evidence of recent group A streptococcal infection (positive throat culture or elevated antistreptolysin O or other streptococcal antibody titers) is much more important than whether any of the specific manifestations is present. There may also be a limit to what can be gained by perfecting the current working definition of metabolic syndrome. Rather, progress with regard to the metabolic syndrome will more likely come from an improved understanding of its pathophysiology. With regard to the metabolic syndrome and insulin resistance, important research (314) has recently appeared in the medical literature that may provide important clues to help substantially improve our understanding. While there is no doubt that this research will generate as many new questions as answers, available criteria to identify individuals with metabolic syndrome serve to appropriately focus our attention and facilitate future progress to benefit our patients.

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