1. The DCCT Research Group: The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med 329:977–986, 1993
2. Okwa H, Khishkawa Y, Araki E, Takao M, Isami S, Motoryoshi S, Kojima Y, Furuyoshi N, Shichiri M:Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with NIDDM: a randomized prospective six year study. Diabetes Res Clin Pract 28: 103–117,1995
3. U.K. Prospective Diabetes Study Group:Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes. Lancet 352:837–853, 1998
4. U.K. Prospective Diabetes Study Group:Effect of intensive blood glucose control with metformin on complications in over-weight patients with type 2 diabetes. Lancet 352: 854–865,1998
5. The DCCT/EDIC Research Group: Intensive diabetes therapy and cardiovascular disease in patients with type I diabetes. N Engl J Med 353:2643–2653, 2005