Metabolic syndrome (MetS) in Europe

Previously, several different definitions for the metabolic syndrome (MetS) had been proposed and used by researchers. This resulted in confusion about the frequency of the MetS and its relationship with mortality.

Recently, the Consensus Panel International Diabetes Federation (IDF) proposed a new definition for the MetS in order to overcome the problems of comparability. The new IDF definition issued in April 2005, see also: (http://www.idf.org/webdata/docs/Metabolic_syndrome_definition.pdf). This IDF definition emphasizes the importance of central obesity (defined as waist circumference - d 94cm for Europid men and - d 80 cm for Europid women, with ethnic specific values for other groups).

A person can be defined as having the MetS if he/she has central obesity plus any two of the following four factors:

1. serum triglycerides - d 1.7 mmol/L, or specific treatment for this lipid abnormality;
2. serum HDL-cholesterol < 1.03 mmol/L in males and < 1.29 mmol/L in females, or specific treatment for this lipid abnormality
3. blood pressure - d130 mmHg systolic or „d85 mmHg diastolic, or treatment of previously diagnosed hypertension;
4. fasting plasma glucose - d 5.6 mmol/L, or previously diagnosed type 2 diabetes.

Using the data from 4600 men and 5500 women aged 30-89 years from seven European population-based studies were included in a collaborative analysis to study the epidemiology of the MetS. In subjects with the MetS, 91% of men and 90% of women had hypertension; the proportions for hyperglycemia were 73% and 64%; for elevated triglyceride and/or low-HDL 77% and 77%, respectively. The overall prevalence of the MetS was 38% in men and 36% in women. The age-specific prevalence increased up to the age of 60 years and leveled off thereafter in men, while in women it increased up to the oldest age group.

Table. The prevalence of the metabolic syndrome (%) in European men and women.

In the prospective follow-up with a median of 8.9 years cardiovascular (CVD) mortality was increased by 45% in men with MetS and by 73% in women with MetS compared with men and women without MetS. The analyses were adjusted for age, cholesterol and smoking. The corresponding relative risks (RRs) of MetS for all-cause mortality were 27% in men and 25% in women. In general, the 2005 IDF definition of MetS will produce a somewhat higher prevalence in Europe than previous definitions of the MetS did. Compared with men without the MetS, men with the MetS had increased CVD mortality regardless of the presence of diabetes. In women, however, the MetS was only predictive of CVD when diabetic women were included in the analysis. This confirms the finding from several previous studies that women with diabetes have a particularly risk of CVD.