The Diabetes Control and Complications Trial (DCCT) was a 10-year study
of people with
type 1 diabetes. The study looked at whether people
with type 1 diabetes treated in the standard way had more or fewer
complications from diabetes than people using tightly controlled
therapy.1
Standard therapy
The people using standard therapy:
- Injected
insulin once or twice daily.
- Checked their
blood sugar levels daily.
- Visited a doctor, a diabetes nurse
educator, and/or dietitian at least 4 times per year.
Tightly controlled therapy
The people using
tightly controlled therapy:
- Injected
short-acting insulin 3 or more times daily or used an
insulin pump.
- Checked their blood sugar
levels 4 times a day.
- Had monthly visits with a doctor, diabetes
nurse educator, and a dietitian.
By the end of
the study, the group using tightly controlled therapy had 76% fewer incidences
of eye disease, 54% fewer incidences of kidney disease, and 60% fewer
incidences of nerve damage than the group using standard therapy. However, the
people who tightly controlled blood sugar had more episodes of low blood sugar
and gained more weight than those in the other group.2
The follow-up 12-year study (Epidemiology of
Diabetes Interventions and Complications, or EDIC) looked at whether tight
control can decrease the heart and blood vessel diseases (macrovascular
disease) related to diabetes. People who took part in the DCCT were invited to
participate in this study. The researchers compared tightly controlled blood
sugar with conventional blood sugar control. They found that tightly controlled
blood sugar:
- Lowered the risk of heart disease
events, like heart attacks, by 40%.1
- Lowered the risk of death from heart disease by about 60%.1
- Slowed the progress of eye disease (diabetic
retinopathy) and kidney disease (diabetic
nephropathy) by 35% to 90%.3