Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study at 30 Years: Advances and Contributions

TLDR: An overview of the major scientific advances provided by the DCCT/EDIC Research Group, the resulting changes in therapy that have improved long-term outcomes in patients with T1D worldwide, and the challenges that remain are presented.

Abstract: The Diabetes Control and Complications Trial (DCCT) (1) and its observational follow-up, the Epidemiology of Diabetes Interventions and Complications (EDIC) Study (2), are celebrating the 30th anniversary since the start of the DCCT and 20th since the reporting of the DCCT primary results (3). During the past three decades, our understanding of the relationship between metabolic control and complications and the treatment of type 1 diabetes (T1D) has been transformed by the results of DCCT/EDIC. Most importantly, the long-term prospects for patients have dramatically improved with the adoption of intensive therapy designed to achieve near-normal glycemia as the standard of care of T1D. In this Perspective, we present an overview of the major scientific advances provided by the DCCT/EDIC Research Group, the resulting changes in therapy that have improved long-term outcomes in patients with T1D worldwide, and the challenges that remain. ### Background and rationale. After the introduction of insulin therapy in 1922, type 1 diabetes (T1D) was transformed from a uniformly fatal disease to a chronic degenerative one (4). During the 1930–1960s, the development of chronic complications affecting the eyes, kidneys, peripheral and autonomic nervous system, and a substantially increased risk of cardiovascular disease (CVD) were observed in patients who had survived >20 years with the disease (5). The origin of these newly discovered complications was debated vigorously, and theories to explain them abounded (4,6). The debate led to two opposing philosophies of diabetes treatment: one in which treatment to achieve glucose concentrations as low as possible was endorsed and another in which glycemic levels were thought to be inconsequential, at least with regard to the pathogenesis of long-term complications (7,8). Although the debate regarding the so-called glucose hypothesis was vigorous, it was largely academic, since objective means of measuring long-term glycemia and of achieving near-normal glycemia did not …