Diabetes Care, Vol 21, Issue 1 53-61, Copyright © 1998 by American Diabetes Association
Incidence and progression of diabetic retinopathy in Hispanics and non-Hispanic whites with type 2 diabetes. San Luis Valley Diabetes Study, Colorado
SM Tudor, RF Hamman, A Baron, DW Johnson and SM Shetterly
Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver 80262, USA.
OBJECTIVE: To learn if Hispanic people with type 2 diabetes have excess
incidence and/or progression of diabetic retinopathy and to explore the
association of risk factors with diabetic retinopathy. RESEARCH DESIGN AND
METHODS: There were 244 subjects with type 2 diabetes (65.3% Hispanic) with
at least one follow-up visit between 1984 and 1992 examined for the
development of retinopathy over a median of 4.8 years (range 2.0-6.6
years). Stereo fundus photos were graded by the University of Wisconsin
Reading Center. RESULTS: Of the 169 subjects without retinopathy at
baseline, 47 developed some retinopathy, an incidence rate of 63.7 per
1,000 person-years (PY), or a 4-year cumulative incidence of 22.5%. The
Hispanic incidence rate was 58.3/1,000 PY (95% CI: 39.4-83.3), which was
lower than among non-Hispanic whites, 76.1/1,000 PY (44.3-121.9).
Progression occurred in 24 of the 75 subjects with retinopathy at baseline,
a 4-year cumulative rate of 24.1%. Logistic regression showed that insulin
treatment was associated with higher risk of any retinopathy (odds ratio
[OR] = 8.45, 2.65-26.97), and both systolic blood pressure (odds ratio [OR]
= 1.58, 0.99-2.52) and total GHb (OR = 1.46, 0.99-2.17) nearly attained
statistical significance. After adjustment for multiple potential risk
factors, the Hispanic/non-Hispanic white OR was 0.66 (0.28-1.57).
CONCLUSIONS: No excess risk for incident retinopathy was found among
Hispanic compared with non-Hispanic white subjects in this population.
These results are consistent with our previously reported prevalence data
from the same population but differ from reports of excess prevalence among
Texas Hispanics. No other Hispanic incidence data are available to assist
in reconciling this difference.