Diabetes Control and Complications Trial (DCCT)

The DCCT is a clinical study conducted from 1983 to 1993 by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The study showed that keeping blood glucose levels as close to normal as possible slows the onset and progression of eye, kidney, and nerve diseases caused by diabetes. In fact, it demonstrated that any sustained lowering of blood glucose helps, even if the person has a history of poor control.

The largest, most comprehensive diabetes study ever conducted, the DCCT involved 1,441 volunteers with type 1 diabetes and 29 medical centers in the United States and Canada. Volunteers had diabetes for at least 1 year but no longer than 15 years. They also were required to have no, or only early signs of, diabetic eye disease.

The study compared the effects of two treatment regimens—standard therapy and intensive control—on the complications of diabetes. Volunteers were randomly assigned to each treatment group.