Identifying Metabolic and Psychosocial Antecedents and Characteristics of youth-onset Type 2 diabetes (IMPACT DM) - (<30 lines) Youth-onset type 2 diabetes (YO-T2D) is increasingly prevalent in parallel with the obesity epidemic, yet effective treatment and prevention strategies are limited. The physiologic increase in insulin resistance occurring during puberty, in combination with obesity-related insulin resistance, enhances the risk of T2D. Yet, it remains unclear why some youth progress through puberty with intact β-cell function, while others do not, despite similar phenotypic and metabolic characteristics. More information is needed regarding the unique events during puberty to better understand 1) the basic pathophysiology of glucose control, insulin sensitivity, β-cell function, and T2D risk in youth, 2) differences among girls and boys, populations at highest risk, and urban and rural geographies, and 3) the potential contribution of other risk factors including psychological, behavioral, and social and external contexts. Importantly, this research needs to address the timeline of pathophysiology and progression from normoglycemia or prediabetes to YO-T2D. The DISCOVERY of Risk Factors for Type 2 Diabetes in Youth (DISCOVERY) study provides a unique opportunity to characterize the risk progression profile and mechanisms underlying the development of YO-T2D, and evaluate the effects of modifiable and non-modifiable risk factors. Ultimately, the results of this study will establish a basic pathophysiology to inform future studies aimed at achieving target glycemia, improving insulin sensitivity, preserving β-cell function, and/or preventing YO-T2D. To address this goal, DISCOVERY will recruit, enroll, and follow a nationally-representative cohort of 3,600 at-risk obese youth in early puberty; extensively phenotype them as they transition through puberty; and characterize the course of decline and dysfunction in pathophysiological indicators that lead to YO-T2D. The expected duration of the DISCOVERY is 5 years, including planning, recruitment, follow-up, analysis, and reporting. In addition, DISCOVERY will store longitudinal biospecimens and genetic material with the intention of acquiring additional ancillary funding to pursue analysis of emerging indicators. The University of Oklahoma Health Sciences Center has experience in multicenter and diabetes-related investigations and will contribute to DISCOVERY through the recruitment of approximately 240 at-risk youth, implementation of the IRB-approved consensus protocol, participation on DISCOVERY committees, and collaboration on the analyses and dissemination of the findings from DISCOVERY.