Epidemiology of the metabolic syndrome and the RISC study

Abstract

The concept of the metabolic syndrome, comprising central obesity, hypertension, raised triglycerides and low HDL-cholesterol, and raised fasting plasma glucose concentrations, is now well established. However, it has only been possible to compare prevalence data between populations since the introduction of generally accepted definitions of the syndrome. Three definitions of the metabolic syndrome are currently in common use: the World Health Organization (WHO) definition; the European Group for the study of Insulin Resistance (EGIR) definition; and the National Cholesterol Education Programme Expert Panel Adult Treatment Panel III (ATP III) definition.1–3 It is problematic to compare the prevalence data in published studies when different definitions are used. Furthermore, studies often differ not only with respect to the study design and population selection but also with respect to the precise definition of the metabolic syndrome used. Importantly, the WHO definition requires a hyperinsulinaemic clamp to measure insulin resistance when surrogate measures such as fasting insulin or the homeostasis model index are usually used.4 Ideally, a single definition for the metabolic syndrome would allow direct comparisons between prevalence data in different populations. The International Diabetes Federation (IDF) consensus definition, which is due to be published in 2005, will therefore be a positive development. ### WHO and EGIR definitions The EGIR carried out a detailed analysis of eight European studies to investigate the prevalence of the metabolic syndrome in Europe.5 The frequencies of the metabolic syndrome, according to the WHO definition, were compared between these studies. Further, for non-diabetic subjects, the frequencies for the WHO and EGIR definitions were compared. In total, data for 8200 men and 9363 women were analyzed ( Table 1 ). View this table: Table 1 Frequency of the WHO defined metabolic syndrome in eight European countries for non-diabetic men aged 40–55.6 The frequency of the metabolic syndrome, using either the WHO or the EGIR …