Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) (Protocol NIH N01-DK-6-2203)
The epidemiology of Diabetes interventions and Complications (eDiC) trial is a longitudinal non-interventional study of the long-term complications of diabetes. This study of the 1429 surviving patients in the DCCT (99% of the original cohort) was conducted between 1994 and 2005, and extended another 10 years. Twenty-eight participating clinics conduct annual anniversary physical examinations which include assessments of the eyes, nerves, kidneys, heart and blood vessels, and thinking ability. Questionnaires to assess urologic function, nerve function, eye function, and psychological status have also been administered.
Between 1997 and 2005, the study group collaborated wtih the Medical university of South Carolina to assess blood and urine measures of cardiovascular risk factors. in 2002, the DCCT/eDiC initiated a study of DCCT/eDiC relatives designed to learn the genetic relationships regarding the development of diabetes and diabetic complications. This project has been completed. in 2009, the DCCT/eDiC began a case-control study of the epigenetic characteristics of approximately 114 individuals with type 1 diabetes who have participated in the DCCT/eDiC between 1983 and 2008. other than data analysis, this project is completed. in 2009-2010, the study group began measurement of skin advanced glycation end-products using the SCouT device manufactured by Vera Light, inc (albuquerque, nM). This project will be completed at the end of 2011. in 2010, the DCCT/eDiC study group repeated questionnaires to assess urologic and sexual function in all participating subjects, as well as testosterone and PSa levels in participating males. an abbreviated version of this questionnaire is being administered through eDiC year 23 (Calendar year 2016). Such questionnaires had been administered in 2003, as well. in 2011-2012, assessments of thickening of the skin and hands and limited joint mobility (cheiroarthropathy), as well as musculoskeletal disorders such as carpal tunnel syndrome, frozen shoulder, Dupuytren's contracture, and trigger finger will be done. These assessments will involve asking questions about these conditions, visual observations of the hands, and measurements of the fingers and shoulders using a goniometer. Subjects will also be asked to complete a questionnaire about the impact of symptoms of these conditions on daily life and the ability to perform usual activities. in 2011-2012, a pilot study will determine if residual C-Peptide levels are detectable in a subset of subjects. in 2015 and 2016, C-Peptide levels will be measured in all diabetic eDiC participants. Between 2014 and 2016, eDiC subjects will have hearing testing and will be asked questionnaires about hearing problems, factors that can affect hearing, any treatment of hearing problems, and the impact of any hearing problems. During this same period, 15 randomly selected spouses of eDiC participants will be asked to participate in the hearing study as control subjects. They will complete the same questionnaires and hearing testing as for the eDiC participants. in addition, the control subjects for the Hearing Study will have a brief physical exam including height, weight, waist measurements, palpation of peripheral pulses, blood pressure, and heart rate. The control subjects will also have 7 ml of blood drawn for Hbalc level. The control subjects will only have one visit.
The procedures that compose the core protocol, and procedures that have been added and completed throughout eDiC will be further defined below.
Only subjects who participated in the DCCT between 1983 and 1993 are eligible to participate in EDIC. 16 randomly selected spouses of DCCT/EDIC subjects will be asked to participate in the Hearing Ancillary Study as normal controls. This would be a one-time visit for the control subjects.