Evaluating CMR

IDF Clinical Criteria for Diagnosing the Metabolic Syndrome

International Diabetes Federation (IDF) clinical criteria for diagnosing the metabolic syndrome were proposed in 2005 (Table 1) (1) (2). These criteria provide a new screening strategy for diagnosing the metabolic syndrome in clinical practice and are not a new “definition” of the syndrome. These screening tools are similar to those proposed by the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III or ATP III). However, since the clinical criteria of many organizations did not consider ethnic differences in body fat distribution and susceptibility to intra-abdominal (visceral) adiposity, the IDF committee proposed ethnic-specific waist cut-off values (Table 2). For instance, some ethnic groups, such as Asians, are more likely to develop complications of the metabolic syndrome at much lower waist circumference than Caucasians (3). 

Screening tools that do not consider ethnicity may therefore over or underestimate the prevalence of the metabolic syndrome depending on the population studied. The early waist cut-off values initially proposed by NCEP-ATP III did not encompass all Asian individuals with the metabolic syndrome, who on average have lower waist circumference values than Caucasians. Accordingly, waist circumference thresholds have been lowered in the IDF statement. The other major advance ushered in by the IDF criteria is that waist circumference is now a mandatory feature in identifying the metabolic syndrome. Individuals diagnosed with the metabolic syndrome must have an elevated waist girth plus at least two other features, which are comparable to those proposed by NCEP-ATP III. By taking this stance, the IDF recognizes that abdominal obesity is by far the most prevalent form of the metabolic syndrome seen in clinical practice.