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