Biologic Risk Factors Associated with Diabetic Retinopathy: The Los Angeles Latino Eye Study
Received 30 June 2006; accepted 6 October 2006. published online 15 February 2007.
Objective
To identify biologic risk factors associated with having diabetic retinopathy (DR) in Latinos with type 2 diabetes mellitus (T2DM).
Design
Population-based cross-sectional study.
Participants
Six thousand three hundred fifty-seven Latinos ages ≥40 years from 6 census tracts in Los Angeles, California.
Methods
An in-home interview was administered to all participants in the Los Angeles Latino Eye Study (LALES). All participants diagnosed with T2DM underwent a complete ophthalmologic examination including stereoscopic fundus photography (7 standard Early Treatment Diabetic Retinopathy Study fields). Photographs were graded in a masked manner using a modified Airlie House grading system to assess presence and severity of DR. Univariate and stepwise logistic regression analyses were used to identify independent risk factors.
Main Outcome Measures
Biologic risk factors associated with any DR and proliferative DR (PDR).
Results
Of the 7789 eligible individuals in LALES, 6357 (82%) had a clinical examination. One thousand two hundred sixty-three participants had definite diabetes and 1187 Latinos had T2DM. Of those with T2DM, 46% (544) had DR. Stepwise logistic regression analyses revealed that compared with females, males had a 50% higher risk of having any DR (OR = 1.50; P = 0.006). Factors independently associated with a greater risk of having any DR were longer duration of known diabetes (per year, OR = 1.08, P<0.0001), higher glycosylated hemoglobin levels (per 1%, OR = 1.22, P<0.0001); higher systolic blood pressure (per 20 mmHg, OR = 1.26, P = 0.002); and insulin treatment (OR = 1.60, P = 0.01). Factors independently associated with PDR included longer duration of known diabetes (per year, OR = 1.06, P<0.0001); being on insulin treatment (OR = 3.2, P<0.0001); and a higher systolic blood pressure (per 20 mmHg, OR = 1.44, P = 0.01). The relationship of these variables to the risk of having DR or PDR is not a constant linear function in all cases and varies depending on the variable.
Conclusions
Our study showed that the high risk of DR in adult Latinos is independently associated with both nonmodifiable and modifiable risk factors. These findings suggest that controlling hyperglycemia and hypertension in this ethnic group may reduce the high risk of having DR associated with T2DM.
1Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California.
2Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.
3Department of Ophthalmology, University of Wisconsin–Madison, Madison, Wisconsin.
Correspondence to Rohit Varma, MD, MPH, Doheny Eye Institute, Suite 4900, 1450 San Pablo Street, Los Angeles, CA 90033.
Manuscript no. 2006-721.
Supported by the National Eye Institute and National Center on Minority Health and Health Disparities (grant nos. EY 11753, EY 03040), Bethesda, Maryland, and an unrestricted grant from Research to Prevent Blindness, New York, New York.
The authors have no proprietary or commercial interest in any materials discussed in the article.
ABSTRACT