Type 1 diabetes is the predominant form of the disease in children and adolescents in most developed countries, where there is still a significant number of diabetes-related deaths among children. Further, mortality in undiagnosed diabetes is probably a large but hidden problem in the global perspective. At the same time, type 2 diabetes in the young is an emerging problem with potentially serious outcomes.
Diabetes is rapidly increasing in children and adolescents in many countries and a shift to younger age at onset is indicated. The increase in incidence in type 1 diabetes has been shown in countries having both high and low prevalence. There is, however, an indication of a steeper increase in some of the low prevalence countries and an association between the risk increase and gross national product (GNP) estimates. Thus part of the increasing trend may be due to potentially preventable lifestyle factors.
Although type 1 diabetes usually accounts for only a minority of the total burden of diabetes in a population, it is the predominant form of the disease in younger age groups in most developed countries. Apart from the rise in the incidence, factors contributing to a continued upward trend in the global prevalence include better diagnosis of type 1 diabetes, improving availability of insulin and access to treatment, and increases in overall population growth. Further, there are also indications of a decrease in deaths from both unrecognized diabetic ketoacidosis in children and from late complications in young adults in some developed countries which could lead to an additional increase in the prevalence of type 1 diabetes.
At the same time, there is a growing awareness that type 2 diabetes in the young is an emerging problem with potentially serious outcomes, at least in some ethnic groups. Yet our understanding of the worldwide burden of this disease among the young is somewhat fractured, with few studies mainly not population based but rather reporting on specific communities or ethnic groups.
This section looks at the global trends in childhood type 1 diabetes and reviews the available epidemiological data on type 2 diabetes in the young from around the world. By focusing on such data it is hoped that deficiencies in our knowledge of the disease will be highlighted, and that strategies to deal with it will be developed.