Diabetes Care, Vol 21, Issue 5 792-795, Copyright © 1998 by American Diabetes Association
Development of proliferative diabetic retinopathy in African-Americans and whites with type 1 diabetes
CL Arfken, PL Reno, JV Santiago and R Klein
Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. carfken@med.wayne.edu
OBJECTIVE: To investigate the comparable risk of developing proliferative
diabetic retinopathy (PDR) in African-Americans and whites with type 1
diabetes. RESEARCH DESIGN AND METHODS: Using a cohort design with the
sample drawn from medical records, the sample consisted of 312 people with
type 1 diabetes (97 African-Americans, 215 whites) having at least two
visits to a Model Demonstration Unit with gradeable fundus photographs
(stereo, color, 7 standard fields). Excluded were subjects with preexisting
or treated PDR or hemoglobinopathy. Masked grading of the fundus
photographs was conducted at the Wisconsin Reading Center. RESULTS: At
baseline, African-Americans had poorer glycemic control (mean HbA1 of 11.3
vs. 10.0%, P < 0.0001), higher systolic blood pressure (mean of 117 vs.
110 mmHg, P < 0.001), and were older (mean of 26.8 vs. 19.3 years, P
< 0.0001) than the white subjects. African-Americans also tended to have
slightly longer duration of diabetes and length of follow-up. In the
African-Americans, 17.5% developed PDR, compared with 10.2% in the 215
whites, for an odds ratio (OR) of 1.86 (95% CI 0.93-3.70). When adjusted
for baseline glycemic control, retinopathy grade, and length of follow-up,
race was not a significant risk factor (OR = 0.73, 95% CI 0.30-1.78).
CONCLUSIONS: African-Americans with type 1 diabetes may have a higher rate
of developing PDR. The observed racial difference, however, is attributable
to the presence of a worse risk factor profile, especially to poorer
glycemic control. Efforts should be expanded to improve the care for all
individuals with poor glycemic control.