The DCCT proved that good Diabetes control works
Strict control reduces risk of eye, nerve and kidney complications. The DCCT proved it. Patients who maintain strict control of their Diabetes are more likely to avoid the development of complications, in comparison to those who control it in the standard or traditional way. However, this study doesn’t include people exercising “poor control” of their Diabetes, in which case the rates of complications would obviously be much higher. Before the American Diabetes Association annual meeting of June 13th 1993, DCCT researchers had already announced the results of this important research.
DCCT investigators chose retinopathy as the complication they’d analyze in more depth, because “step by step” progression is well known and there are specific ways to document this progression. “They sought an answer to two (2) questions”:
- Can the onset of retinopathy be prevented or delayed?
- Can the progression of retinopathy be slowed?
To answer these 2 questions, 2 groups of patients were needed. Of a total of 1,441 volunteers, about half didn’t have signs of retinopathy, this group was called the “Primary prevention group”. Researchers needed to test if the “strict control” could prevent or delay the onset of retinopathy. Half of this group of primary prevention were assigned to the “strict control” group and the other to the “standard control” group.
There were several similarities between both groups, all participants had had Diabetes for nearly the same amount of years, their ages ranged between 13 and 39 years, and there was an almost equal amount of men and women in each group. The only main difference between the groups was the “standard control” versus “strict control” they were to maintain. Patients in the “strict control” group got a much better control of their Diabetes, as shown by their Glycated Hemoglobin (Hb A1c) levels, of only 7% (6% is considered normal) while patients in the “standard control” control had about 9%. Researchers measured the onset and progression of retinopathy, taking photographs of the patients’ eyes every 6 months. They sought a certain degree of retinopathy development and throughout the first 3 years of the study, about the same amount of patients in both groups (standard vs. strict control) developed moderate signs of retinopathy, but on the fourth year a great difference appeared between both groups and it became increasingly different throughout the rest of the investigation.
After nine years of research, the “strict control” group had reduced progression of retinopathy by 60% and if retinopathy is left untreated, it tends to worsen. Therefore, researchers also measured the degree of retinopathy progression, which is a progression degree observed in 2 (consecutive) sets of eye pictures, taken every 6 months. The “strict control” group reduced their retinopathy risk with an “established progression” by 76%.
Can we delay it?
Now, in the case of patients who already have signs of retinopathy, can they benefit from strict control?
The other half of the 1,441 volunteers had low to moderate retinopathy when they entered the investigation. In this group called “secondary intervention group” the researchers needed to test if strict Diabetes control could slow down or stop retinopathy progression. The researchers repeated the methodology they used with the previous group, they divided them into two groups, one with standard treatment and the other with strict treatment, and there was perhaps a greater expectation than with the “primary prevention” study group, because some research conducted before the DCCT, did suggest that “strict control” worsened an existing retinopathy. By the end of the investigation, “strict control” had reduced the risk of a vision-threatening retinopathy (proliferative diabetic retinopathy) by 45%.
Lawrence Rand, an ophthalmologist form the Boston area (Massachusetts), who was working with the DCCT since the beginning, presented the retinopathy results at the ADA annual meeting and said: “Strict control of Diabetes, has a potent effect, by not only slowing down the onset and progression of retinopathy, but also decreasing the risk of progressing into more severe stages that threaten vision in patients where retinopathy is already present. Therefore, there’s no doubt that strict control is a fundamental basis for any strategy for the treatment of Diabetes. ”
Can strict control stop or slow down the onset and progression of kidney disease? Yes, according to the DCCT. If your kidneys are healthy, you won’t have protein in your urine. Secretion of certain low levels of protein in the urine (microalbuminuria), are a sign that the kidneys aren’t working perfectly and this may culminate in kidney disease. Fewer people in the “strict control” group had microalbuminuria, in comparison to the “standard control” group, where strict control reduced the occurrence of microalbuminuria by 35%. Nephropathy occurs when larger amounts of protein are being secreted through urine (proteinuria). “Strict control” reduced this risk by 56% in comparison to the standard group.
Neuropathy causes pain, it can affect the heart and can end in amputation, but now we know that it isn’t inevitable. The DCCT showed that the “strict control” reduced the risk of neuropathy by 60% in comparison to the standard group.
Seeking the Perfect Level in Diabetes control
For those who aren’t yet ready to make the commitment of a “strict control” on their Diabetes or can’t do it safely, the good news is that by better controlling their Diabetes in any degree, the risk of complications is reduced. The less stringent the treatment is, the less complications will be decreased, and therefore, a stricter control will lead to a higher number of reduction in the risk of complications. The high incidence of complications is due to the high percentage of patients who don’t have proper Diabetes education and therefore exert “poor control” on their Diabetes without knowing the risks this poses to their health. As Dr. Oscar Crofford said in the year 1993, at a conference after announcing the results of the DCCT:
“Until a cure for Diabetes is found, strict control is the best way to prevent complications.”