Diabetes Care, Vol 19, Issue 12 1375-1381, Copyright © 1996 by American Diabetes Association
Evaluations of retinopathy in the VA Cooperative Study on Glycemic Control and Complications in Type II Diabetes (VA CSDM). A feasibility study
N Emanuele, R Klein, C Abraira, J Colwell, J Comstock, WG Henderson, S Levin, F Nuttall, C Sawin, C Silbert, HS Lee and N Johnson-Nagel
Hines VA Hospital, Endocrinology/Diabetes Section (11IA), IL 60141-5000, USA.
OBJECTIVE: The main goal of the study of 153 male veterans was to determine
whether a statistically and clinically significant difference in HbA1c
could be achieved between a standard therapy and an intensively treated
group of patients with type II diabetes. A second major goal was to assess
the feasibility of collecting reliable high-quality endpoint data,
including microvascular and macrovascular events. Retinopathy was defined
as a key microvascular endpoint. RESEARCH DESIGN AND METHODS: This was a
randomized prospective trial of 153 men between the ages of 40 and 69
years, with type II diabetes for 15 years or less. Of the patients, 78 were
assigned to the standard therapy arm and 75 to the intensive therapy arm.
The goal of standard therapy was good general medical care and well-being
and avoiding excessive hyperglycemia, glycosuria, ketonuria, or
hypoglycemia. This was generally accomplished with one shot of insulin per
day. The goal of intensive therapy was to obtain an HbA1c within two
standard deviations of the mean of nondiabetic subjects (4.0-6.1%). This
was obtained by a four-step management technique, with patients moving to
the next step only if operational goals were not met. The steps were as
follows: step 1: evening intermediate or long-acting insulin only; step 2:
evening insulin with daytime glipizide; step 3: insulin, twice a day, no
glipizide; and step 4: more than two injections of insulin, no glipizide.
Retinopathy was assessed at baseline, 12, and 24 months by seven-field
stereo fundus photography done at each of the five participating VA medical
centers and read at the Central Reading Center at the Department of
Ophthalmology, University of Wisconsin Medical School, Madison. Visual
acuity was determined by ophthalmologists at each of the participating
hospitals. RESULTS: After the 6th month of the 24-month study, an average
HbA1c of approximately 7.1% in the intensively treated group was sustained
for the full study and was significantly lower than that seen in the
standard group (9.2%, P < 0.001). Compliance in obtaining fundus
photographs was excellent. Near normalization of glycemia did not cause
transient worsening of retinal morphology nor did it prevent the onset or
delay the progression of retinopathy. There was no effect on visual acuity.
CONCLUSIONS: 1) A glycemic control intervention study in people with type
II diabetes is feasible and safe; 2) intensive control did not cause
transient deterioration of retinopathy; and 3) although no improvement was
seen in retinopathy, the follow-up was 24 months, an interval shorter than
the 3 years or more of intensive therapy before improvement is seen in type
1 diabetic studies. This does not rule out the possibility that longer
periods of intensive therapy would have improved retinopathy. A full-scale
intervention trial in type II diabetes is needed to resolve this issue.