Because intensive control of blood glucose levels in type 1 diabetes can have negative side effects such as repeated bouts of low-blood sugar (hypoglycemia) it is important to evaluate whether such tight control is worth the risk.
The Diabetes Control and Complications Trial (DCCT) was a major clinical study conducted over a period of ten years (1983 to 1993). Researchers found that keeping blood glucose levels as close to normal as possible slows the onset and progression of the eye, kidney, and nerve damage caused by diabetes. In fact, the trial demonstrated that any sustained lowering of blood glucose helps, even if the person has a history of poor control.
When the DCCT ended in 1993, researchers continued to study more than 90 percent of participants. The follow-up study, called Epidemiology of Diabetes Interventions and Complications (EDIC), which has been running for 30 years, is assessing the incidence and predictors of cardiovascular disease events such as heart attack, stroke, or needed heart surgery, as well as diabetic complications related to the eye, kidney, and nerves.
The first results of the EDIC study have now been presented at a conference of the American Diabetes Association, and reviewed in MedPage Today. Over 18 years, the researchers found, patients who successfully met target glucose levels had a 46 percent lower risk of eye damage, and a 61 percent lower risk of urinary loss of protein (an indicator of kidney damage).
Study co-chair Dr. David Nathan of the Massachusetts General Hospital was quoted As we follow this population longer, we ve been able to show that early benefits with regard to early complications has extended. He added We ve demonstrated that loss of kidney function is reduced, people develop less severe eye complications that we didn t see during the initial trial because the patients were too young and had diabetes for a relatively short period of time.