Metabolic syndrome: a fata morgana?

The criteria used to define the metabolic syndrome are increased waist circumference, increased triglycerides, decreased HDL-cholesterol, increased blood pressure and increased plasma glucose. According to the most widely used definition, the metabolic syndrome is diagnosed in persons who have three or more of these five abnormalities [1]. The history of the designation of the syndrome dates back to 1993, when it was stressed in the second report of the Adult Treatment Panel (ATP-II) of the National Cholesterol Education Program (NCEP), that the rising prevalence of obesity should be controlled from the perspective of prevention of cardiovascular (CV) disease [2]. Later, it was acknowledged that, despite recommendations, the problem of obesity had taken immense proportions, and that it would be a daunting task to treat every obese subject. In the third report of the Adult Treatment Panel (ATP-III) of the NCEP, in 2001, the metabolic syndrome was put forward with an intention of easing this task through putting emphasis on overweight and obese persons with evidence of medical complications [3]. Such persons would then deserve priority in clinical efforts to prevent the development of comorbidities of obesity through lifestyle changes, particularly weight reduction and increased physical activity. Meanwhile, the metabolic syndrome has been exposed to vigorous critique [4,5]. The criteria have been found to be ambiguous and incomplete. It is uncertain whether insulin resistance is a unifying aetiology. The medical value of diagnosing the syndrome is unclear. Importantly, the most compelling point of the critique was that CV disease risk associated with the syndrome is not greater than the sum of its parts. Critics are even questioning whether the metabolic syndrome exists [5]. Others are vigorously arguing that the metabolic syndrome is of great value, and refute most allegations [3,6].