Objective: The Diabetes Control and Complications Trial (DCCT) demonstrated the powerful impact of glycemic control on the early manifestations of microvascular complications. Contemporary prospective data on the evolution of macrovascular and late microvascular complications of type 1 diabetes are limited. The Epidemiology of Diabetes Interventions and Complications (EDIC) study is a multi-center, longitudinal, observational study designed to utilize the well-characterized DCCT cohort of ~1,400 participants to determine the long-term effects of prior separation of glycemic levels on micro- and macrovascular outcomes. The current phase of EDIC also focuses on the interaction between and the effects of aging and long-duration diabetes on cognitive and physical function as well as the long-term effects of diabetes-related complications on quality-of-life and health care costs. EDIC is in its 27th year of follow-up.
Methods: Data collection focuses on micro- and macrovascular complications. Annual or biennial measurements (using DCCT methods, standardized protocols and central laboratories) of vascular events, albumin excretion, GFR, ECG, ankle-brachial BP index, serum lipids and HbA1c allows the following analyses: 1) continuation of intention-to-treat analyses to determine long-term effects of prior separation of glycemic levels; 2) risk factors for macrovascular outcomes; 3) correlation of progression of micro- and macrovascular outcomes.