Type 1 diabetes is usually diagnosed in children and young adults. People with Type 1 diabetes do not produce insulin, a hormone that is needed to convert sugar (glucose), starches, and other food into energy needed for daily life. The University of Iowa has assisted in a diabetes control and complications trial with these young diabetic patients that may lead to a new treatment plan. Dr. William Sivitz, director of endocrinology and metabolism, tells us more about this study and possible new treatment.

Tell us a little about the initial study, the Diabetes Control and Complications Trial (DCCT). What did the DCCT set out to do?

To really understand what it set out to do, we need to go back in history nearly 100 years to 1922 when insulin was first discovered. Prior to that time, persons with Type 1 diabetes, unfortunately, just didn't survive. Insulin became available and then this new life-saving, miracle drug was found to lower the blood sugar; and in fact, keep people from dying of this horrible disease. As time went on into the 30s and 40s, it did become apparent that persons who were taking insulin with diabetes—although they could survive and function—they gradually developed long-term complications: damage to the eyes and the kidneys and the nervous system and the heart. And the thought was that, OK, we were keeping the blood sugar lower, but we weren't completely normalizing the blood sugar. What would happen if we actually normalized the blood sugar? It took until about 1980 or the late 70s to really develop the methodology to do this—glucose monitoring and better ways to take insulin, insulin pumps, etc. So in 1983, a trial was begun to determine if persons randomly assigned a more intensive control (near normalization of the blood sugar), compared to a more conventional treatment (what we were typically doing at the time); which group would do better in terms of the development and progression of the long-term complications of diabetes.

Who was enrolled?

These were all persons with Type 1 diabetes who volunteered to participate. They were ages 13 to 39 at onset, both men and women in equal proportions.

What were participants asked to do?

They were randomly assigned either to receive intensive treatment designed to achieve as normal blood sugar as safely possible, or to continue on the standard, conventional treatment at the time.

How long did the study run?

The study ran until 1993, from 1983 the patients were recruited over the first five or six years, so the average duration of participation was about seven years.

What were the findings of the DCCT?

In 1993, the findings were reported for the development of eye disease, kidney disease, and nervous system dysfunction. All three of these complications were lessened, they had a lower frequency of onset, and they progressed at a slower rate in the volunteers who were treated with intensive therapy compared to conventional. There was more hypoglycemia in the intensively treated patients, but it did not make a difference in terms of their function other than the episodes they had.

Though the trail has ended—are the participants followed long-term?

Yes, they are. We have a study called Epidemiology of Diabetes Intervention and Complications—the long name. This is designed to continue to follow the subjects; however, it is very important that in 1993, when we had the initial data, all of the subjects were recommended to intensive therapy. So those participants in the standard group were told no, we now know that intensive therapy is better. We recommend everybody go on to intensive therapy. So since 1993, we've been working to control everyone in the DCCT at an intensive level of blood sugar, as low as safely possible.

Do the results of this initial trial give researchers an insight on keeping health care costs down in the long-term care of diabetic patients?

Yes, they do. It's a little hard to be sure and I'm not one of the experts in the economics of this, but the thought is if we can prevent the complications, then down the road we'll have much less in the way of heart disease, blindness, kidney disease—which are immensely expensive to manage. So basically we've learned that this is a great preventive measure—control the diabetes, prevent these costly, long-term complications.

What effect do you believe this study may have long-term on not only people with Type 1 diabetes, but Type 2 diabetes as well?

It's already had a tremendous effect. We're now, in 2009, we're 26 years into this and we have already learned of the benefits. The difficulty remains to achieve the near normalization. We still have to carefully and compulsively manage patients. People need to measure their blood sugar frequently, they need to take insulin injections multiple times a day or use an insulin pump, keep up with appointments, and be very careful about matching insulin to food intake and activity. So we know we have to do this.

What's happened though is this has spurred tremendous efforts to do this more efficiently. Since 1993, industry researchers have worked to develop better ways to do this. We already have more efficient ways to measure the glucose; we're developing new techniques for administering insulin; people are working at transplanting islets or changing stem cells or even normal body cells—treating them genetically to alter their genes so that we can actually recreate islets—make an artificial islet (those are the cells that make insulin). So lots of research has been spurred. This, we think, will have future benefits. The impact has been tremendous; it's affected people with Type 1 diabetes world-wide. Does it affect Type 2 diabetes as well? We do know that the complications of Type 2 diabetes are very similar. A study was done in the United Kingdom and since then other studies that have supported the benefit of intensive glucose management in Type 2 diabetic patients, as well. And there's evidence that in those patients, which really make up a much more common group of people with diabetes, that in those patients we also get strong benefit to prevent the complications.

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