Research Articles in Diabetes and Diabetic
Retinopathy
Diabetic Retinopathy in African Americans with Type I Diabetes: The
New Jersey 725, Part II. Risk Factors
(From Archives of Ophthalmology 2000;118:105-115, Roy, Monique S MD. Diabetic
Retinopathy in African Americans with Type I Diabetes: The New Jersey 725, Part II. Risk
Factors)
OVERVIEW:
This study looks at the association between diabetic retinopathy in Type I African
American diabetic and 6 risk factors: duration of diabetes, glycemic control, systemic
hypertension, renal disease, socioeconomic status, and male sex. The New Jersey Department
of Health database was used as a source of patients with diabetes. African Americans with
type I diabetes, treated and diagnosed with insulin before the age of 30 were considered
eligible.
RESULTS:
After being identified as an eligible patient for this study, a clinical evaluation was
performed including ocular examination, fundus photography, blood pressure measurements,
and assays of blood and urine samples. Severity of diabetic retinopathy was determined
based on grading of the worse eye. A detailed medical and socioeconomic history was taken.
Glycemic control, as evaluated by the total glycosylated hemoglobin values taken
at the time of the examination, was poor. Only 10.2% of patients had values within the
"normal" range of 4% to 8%. 35.8% had values of at least 15%. Glycosylated
hemoglobin levels were significantly worse with advancing age and duration or diabetes.
60.9% followed a specific diabetic diet no more than half of the time, and 35% had
received no dietary advice in the preceding year. Most patients (54.2%) rarely adjusted
their insulin dosage.
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Patients in the highest quartile were, on average, 3 times as likely to have any
retinopathy, compared to those in the best (lowest) quartile.
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Glycosylated hemoglobin levels were found to not be significantly associated with the
development of proliferative diabetic retinopathy.
Systemic hypertension (systolic at least 160 and/or diastolic at least 95) was
found in 34.3% of patients, and in 69.3% of those with proliferative retinopathy. After
adjusting for duration of diabetes, hypertensive patients were found to be 4 times as
likely to have proliferative retinopathy compared to those without hypertension.
Renal disease was found in 49.8% of patients, and 9.2% were undergoing dialysis.
Among patients with micro- or macroproteinuria, 84.1% had some retinopathy, and 35%
proliferative retinopathy. After adjusting for duration of diabetes, those with renal
disease were 3 times more likely to have any retinopathy compared with those patients
without renal disease. They were also, on average, 14% more likely to have proliferative
retinopathy.
There was found to be no significant association between socioeconomic status and the
frequency of diabetic retinopathy, nor was there any association between retinopathy and
gender.
For discussion on the effect of duration of diabetes and age on retinopathy, see the
companion article to this. Diabetic Retinopathy in African Americans
with Type I Diabetes: The New Jersey 725, Part I. Methodology, population, frequency of
retinopathy, and visual impairment.
COMMENTS:
This study indicates high rates of poor glycemic control, systemic hypertension, and renal
disease. These all are associated with a higher rate of diabetic retinopathy and the more
severe proliferative retinopathy in African Americans with Type I diabetes. This is
significant even after controlling for duration of diabetes.
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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