THE DIABETES CONTROL AND COMPLICATIONS TRIAL: WHAT DOES IT TELL
US
The Diabetes
Control and Complications Trial (DCCT) is a landmark multicenter
trial designed to test the proposition that the complications of
diabetes mellitus are related to elevation of the plasma glucose
concentration. The study design was simple. Two groups of
patients were followed long term, one treated conventionally
(goal: clinical well-being; called standard treatment group) and
another treated intensively (goal: normalization of blood
glucose; called intensive treatment group). The intensive
treatment group was clearly distinguished from the standard
treatment group in terms of glycated hemoglobin levels and
capillary blood glucose values throughout the duration of the
study. Over the study period, which averaged 7 years, there was
a >60% reduction in risk between the intensive treatment group
and the standard treatment group in diabetic retinopathy,
nephropathy, and neuropathy. The benefit of intensive therapy
resulted in a delay in the onset and a major slowing of the
progression of these three complications. Finally, the benefits
of intensive therapy were seen in all categories of subjects
regardless of age, sex, or duration of diabetes.
Are the results
of the DCCT achievable for most people with diabetes? In
theory, the answer is yes. However, in the real world, great
effort will be required to reproduce the results of the DCCT. It
must be recognized that the study group was young, generally
healthy, and highly motivated. The professional personnel
conducting the study were highly trained endocrinologists and
diabetes educators in academic centers who were highly motivated
and meticulous in their management of the study subjects. The
intensively treated group received far more attention and
medical services than are routinely available in clinical
practice. In many cases, participants and professionals became
"family." Broad implementation of intensive therapy will require
expanded health care teams. Importantly, even if the DCCT
results are not absolutely achieved, any improvement in blood
glucose control has been shown to slow the development and
progression of microvascular complications.
What form of
intensive treatment is recommended? Improved glucose control in
type1 diabetes had beneficial effects whether delivered by
multiple daily injections or programmable insulin-infusion
pumps. The choice of treatment depends on the wishes of the
individual patient and the comfort/competence of the health care
team with a given technique.
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