Research Articles in Diabetes and Diabetic
Retinopathy
Intensive blood-glucose control with sulfonylureas or insulin
compared with conventional treatment and risk of complications in patients with type 2
diabetes (UKPDS 33)
(From Lancet 1998; 352: 837-853, UK Prospective Diabetes Study (UKPDS) Group)
Tight blood pressure control and risk of macrovascular and microvascular complications
in type 2 diabetes: UKPDS 38
(From the British Medical Journal 1998;317:703-713, UK Prospective Diabetes
Study Group)
OVERVIEW:
Due to similarities in the two studies above, the content on this page will refer to
both studies together rather than separately.
The United Kingdom Prospective Diabetes Study (UKPDS) involved over 4000 patients (mean
age 54 years) from 1977 to 1997 with newly diagnosed Type 2 diabetes mellitus. Previously,
no large studies had found evidence that improved glucose control in Type 2 diabetics
would reduce microvascular complications (such as diabetic retinopathy).
Two questions asked by this study were:
In this study, Intensive control of diabetes aimed for a fasting blood glucose (FBG) of
less than 6 mmol/L, and a pre-meal blood glucose ranging from 4 - 7 mmol/L. A dietician
was used for counseling of patients. Oral diabetic medications (sulfonylureas) and/or
insulin could be used.
Conventional control of diabetes aimed to control blood sugar using diet alone as well
as possible. If symptoms of hyperglycemia developed, or if the FBG exceeded 15 mmol/L,
then medications were added.
RESULTS:
The group intensively treated maintained an average HbA1c 11% lower than the
conventionally treated group (intensively treated ranged from 6.2% - 8.2% with an average
of 7.0%, conventionally treated ranged from 6.9% - 8.8% with an average of 7.9%). The
intensively treated group had a higher risk of hypoglycemia and increased weight gain.
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The intensively treated group was found to have a 26% reduction in microvascular
complications (such as retinopathy and kidney damage). There was found to be no advantage
between the use of insulin or sulfonylureas.
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Tight blood glucose alone did not improve cardiovascular risk or stroke risk.
The importance of blood pressure control was evaluated in the Intensively controlled
diabetic group. Tight hypertensive control aimed for a blood pressure of less than 150/85.
Less tight control aimed for a blood pressure of less than 180/105.
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The average blood pressure in the more tightly controlled group was 144/82, and the
other group was 154/87.
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The group with the more tightly controlled blood pressure was found to have a 37%
reduction in eye and kidney damage. (Remember that this group also was in the intensively
controlled blood sugar group.)
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There was a significant reduction in the need for laser treatment for diabetic
retinopathy (photocoagulation) in the more tightly controlled blood pressure group.
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There was a 34% reduction in the risk of deterioration of retinopathy with tightly
controlled blood pressure and diabetes, and a 47% reduction in the risk of losing 3 lines
of vision related to retinopathy.
For information about diabetic eye disease in general, and
for an explanation of terminology used below, go to
Diabetic Eye Disease.
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