Objective: To analyze the long-term effects of early implementation of intensive glycemic treatment in patients with type 1 diabetes.
Methods: Data from the Diabetes Control and Complications Trial (DCCT) and the Epidemiology of Diabetes Interventions and Complications (EDIC) followup study are reviewed, particularly in terms of reduction of diabetes-related complications.
Results: In the DCCT, intensive intervention resulted in a 63% reduction in retinopathy progression, a 47% decrease in development of severe nonproliferative diabetic retinopathy, a 39% and 54% reduction in microalbuminuria and macroalbuminuria, respectively, and a 60% reduction in clinical neuropathy at 5 years. Aggressive early intervention before the manifestation of complications yielded the best results. In both intensive and conventional treatment groups in the DCCT, there was approximately a 40% reduction in risk of progression of retinopathy for each 10% proportional reduction in hemoglobin A1c (HbA1c). At the conclusion of the DCCT, participants learned about the results, and all were encouraged and helped to adopt intensive treatment. Thereafter, the HbA1c levels of the two groups rapidly approached each other and have not been significantly different for the past 5 years of the EDIC study.
Conclusion: The findings in the DCCT and the EDIC follow-up study support early intensive treatment in patients with type 1 diabetes, with the goal of maintaining HbA1c levels as close to normal as is safely possible, to achieve long-term beneficial effects on the risk of complications.