Background

Diabetes mellitus, a leading cause of nephropathy, retinopathy, neuropathy, and coronary and peripheral vascular disease, is the third most prevalent severe chronic disease of childhood in the United States. People with diabetes diagnosed before age 20 have a life expectancy that is 15-27 years shorter than non-diabetic people.

Until recently, diabetes diagnosed in children and adolescents was almost entirely considered to be type 1, which is usually due to the destruction of the beta cells of the pancreas leading to an absolute deficiency of insulin. Diabetes in children and adolescents is now acknowledged to be a complex disorder with heterogeneity in its pathogenesis, clinical presentation, and clinical outcome. However, because recognition of the broader spectrum of diabetes in children and adolescents is recent, there are no gold standard definitions for differentiating the types of diabetes in this age group.

Also recent are reports of children who present with diabetes that has the clinical characteristics of type 2 diabetes, which was heretofore considered a disease of adults. The incidence of type 2 diabetes in adolescents, especially minority adolescents, appears to be increasing at alarming rates, but the magnitude of this increase is not known.

Finally, information about the clinical course and evolution of diabetes in children and youth, particularly type 2 diabetes, is limited.

Objectives

The study "SEARCH for Diabetes in Youth" will identify prevalent and incident cases of diabetes among individuals under age 20 years in order to:

1. Estimate the population prevalence and incidence of type 1, type 2, and other types (or hybrids) of diabetes rates overall and by age and ethnicity.
2. Develop efficient and practical approaches to classification of diabetes type for prevalent and incident cases.
3. Describe and compare clinical presentation and course of type 1, type 2, and other types (or hybrids) of diabetes.

Secondarily, the study will:

1. Describe the distribution of risk factors for selected micro- and macrovascular disease complications and how they differ by diabetes type separately for prevalent and incidence cases.
2. Describe the distribution of selected acute and chronic complications and how they differ by diabetes types separately for prevalent and incidence cases.
3. Describe the health care utilization, processes of care, and quality of life separately for prevalent and incidence cases.

Finally, SEARCH will develop system(s) to maintain contact with study participants in order to facilitate ancillary studies and long term follow-up, and it will establish a repository for long-term storage of biologic specimens obtained as a part of SEARCH and establish processes for access to these specimens.