Critical Questions About the Metabolic Syndrome

In this issue of Circulation , Hanley et al1 show that the metabolic syndrome, whether defined according to criteria of the National Cholesterol Education Program,2 the International Diabetes Federation,3 or the World Health Organization,4 predicts the development of diabetes. The new finding of Hanley et al is that the International Diabetes Federation criteria, including central obesity as a critical feature of the metabolic syndrome, predicts diabetes as well as the other definitions, at least in the cohort studied. Thus, clinicians could define metabolic syndrome in any of the above 3 ways and thereby identify many patients at heightened risk of diabetes. Although diabetes and its prediction are of interest to clinicians in a variety of medical specialties and this article provides useful and valid information on this topic, the report by Hanley et al1 leaves aside issues of cardiovascular disease (CVD) origin, pathogenesis, and risk that arguably have constituted the major impetus for heightened attention to the metabolic syndrome over the past 5 years.Article p 3713 Despite recognition of the presence of clustering of metabolic and cardiovascular risk factors for many years,5 the term “metabolic syndrome” appeared relatively uncommonly in the medical literature until the 2001 report of the National Cholesterol Education Program (NCEP), which described the syndrome as a means of identifying more patients as candidates for lipid-altering therapies and other CVD risk factor treatments.2 I conducted a PubMed search spanning from 1991 through August 2005 for articles containing the title phrase “metabolic syndrome” and found a total of 776 references cited. Before 2001, fewer than …