Complications of Diabetes Mellitus

Reducing the Complications of Type 1 Diabetes: A Job Well Done

University of South Alabama | November 2, 2009

Dr Rutecki is professor of medicine at the University of South Alabama College of Medicine in Mobile. He is also a member of the editorial board of CONSULTANT.
Dr Rutecki reports that he has no relevant financial relationships to disclose.

Chronic diseases and multiple comorbid conditions can be a frustrating part of any primary care day. Health care professionals work hard and are long overdue to see the “fruits” of their many labors. One area in which progress and personal satisfaction have been particularly slow in coming is the day-to-day management of diabetes. Often, the tragic litany of amputations, blindness from retinopathy, sudden death from coronary disease, and dialysis for failed kidneys was the only consistent refrain. But that has changed, and now is the time to say, “A job well done!”1

In 1993, the results of the Diabetes Control and Complications Trial (DCCT) were published; this study compared intensive insulin therapy with what had been done for patients with type 1 diabetes mellitus for many years—so-called conventional therapy—and showed the impact of “tight” control on potential diabetic complications. 2 These and other results from the DCCT group have informed the past 20 years of diabetes care. Has the rate of complications consequent to type 1 diabetes responded to the new treatment paradigm? The answer is a resounding yes.

The regimen for intensive therapy for type 1 diabetes was 3 or more daily injections of insulin or an insulin pump, aiming for a near-normal level of glucose. One cohort was followed for a mean of 18.5 years.2 The patients in that group were compared with those who received conventional therapy (1 or 2 injections of insulin a day, not aiming for tight control).

Only 5 of 1441 DCCT participants had vision loss worse than 20/100 in either eye, and only 1 of these patients with retinopathy was in the intensive treatment group. Renal insufficiency developed in 10 patients in the intensive group, and only 4 required renal replacement therapy. A mere 7 intensively treated patients underwent an amputation. Patients who followed the intensive regimen had appropriately lower hemoglobin A1c values that corroborated the intended target for glucose with tight control.

The DCCT authors predicted an approximately 50% reduction in the rates of diabetic complications over time. Statistical data demonstrated that the total DCCT complication rate was 50% for retinopathy, 25% for nephropathy, and 14% for cardiovascular disease. Compared with historical controls, that is, conventional treatment before intensive insulin therapy was empirically tested by DCCT, the frequency of complications in type 1 diabetes has been and will continue to be lower. The success has been a true partnership. Congratulations to the DCCT group. They implemented a prescient idea through a great design. Patients were followed for decades, and the study generated considerable data that continue to emerge.

Patients had to sacrifice. More injections, more finger sticks, and more hypoglycemic reactions accompanied the tight control model. Type 1 diabetes used to be called “juvenile” diabetes, and many parents, grandparents, and other family members pitched in to help with what is truly a 24-hour-a-day disease.

Many primary care practitioners read the data, probably after a long day at work, and responded to the science by integrating the results into their practice. You have contributed to successful outcomes for a new generation of patients with type 1 diabetes. I salute all of you.


1. Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Research Group. Modern-day clinical course of type 1 diabetes mellitus after 30 years’ duration: The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications and Pittsburgh Epidemiology of Diabetes Complications Experience (1983-2005). Arch Intern Med. 2009;169:1307-1316.
2. The Diabetes Control and Complications Trial 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. 1993;329:977-986.