Type 2 diabetes, the predominant type of diabetes in adults, was previously thought to seldom develop in children and adolescents. It is, however, rapidly emerging not only in children and adolescents of particular high-risk ethnic groups but also in Caucasians in parallel with a change of lifestyle in recent decades. Furthermore, type 2 diabetes is now the major type of diabetes in children and adolescents in some high-risk ethnic groups. 1-9 In Asian countries, lifestyles of children and adolescents, as well as those of adults, have changed rapidly, resulting in less physical activity and more fat intake. Consequently, obesity, which is a major risk factor for type 2 diabetes, has steeply increased in children and adolescents. 10,11 The threshold of body mass index (BMI) for the risks of cardiovascular diseases and type 2 diabetes (which are based on insulin resistance) is lower in Asian populations than Caucasian populations, suggesting a genetic predisposition to insulin resistance in Asian populations. 12,13 Loading of these environmental and genetic risk factors for type 2 diabetes in Asian populations is reflected both by the high frequency of childhood and adolescent type 2 diabetes and by its rapid increase in Asian populations, shown by some population-based and hospital-based studies.
Chronic complications develop in children and adolescents with type 2 diabetes as or more quickly than in those with type 1 diabetes. Therefore, an intensive intervention program to promote healthy