Ethnic Disparities of the Metabolic Syndrome in Population-Based Samples of German and Iranian Adolescents

Background: Globalization of the western lifestyle may contribute to worldwide increases of adiposity and type 2 diabetes. In combination with genetic influences, this results in different prevalence rates among different ethnicities, particularly at younger ages. Since 2007, the unified pediatric definition of the metabolic syndrome by the International Diabetes Federation (IDF) has allowed a global comparison of the prevalence. Therefore, we compared the prevalence of the metabolic syndrome and its components in two large representative samples of adolescents in Germany and Iran. Methods: We used data from 3,647 German adolescents aged 10-15 years old participating in the German PEP Family Heart Study and 2,728 Iranians in the same age range participating in the CASPIAN Study. Results: The metabolic syndrome was four times more prevalent in Iranian (2.1%) than in German (0.5%) adolescents. The prevalence of three components of the metabolic syndrome was significantly (P < 0.0001) higher in Iranian than in German adolescents-the prerequisite abdominal obesity (11.1% vs. 11.4% vs 1.9%), low-serum high-density lipoprotein cholesterol (HDL-C) (41.9% vs. 7.2%) and hypertriglyceridemia (7.2% vs. 11.4%). Conclusions: The prevalence of the metabolic syndrome according to pediatric IDF criteria and its three main components differed considerably in two large ethnicities. The clinical impacts of these findings should be confirmed in future longitudinal studies.