Prevalence and risk factors for diabetic retinopathy: The Korea National Health and Nutrition Examination Survey 2008-2011

Purpose. We evaluated the prevalence and risk factors for diabetic retinopathy (DR) in a representative Korean population. MethodS. This cross-sectional study involved 16,109 subjects aged >40 years who had participated in the Korean National Health and Nutrition Survey from 2008 to 2011. Seven standard retinal fundus photographs were obtained after pupil dilatation from both eyes. The DR was graded using the modified Airlie House classification system. Risk factors for DR and vision-threatening diabetic retinopathy (VTDR) were evaluated, including age, sex, diabetes duration, glycated hemoglobin (HbA1c), hypertension, lipid profiles, and refractive error. Results. Of the 16,109 eligible individuals participating in the study, 14,595 (90.6%) had fasting blood glucose results available. Of these, 2023 (13.8%) were diagnosed with diabetes mellitus. Among these, gradable photographs were available for 1678 subjects (82.9%), including 1323 subjects with known diabetes mellitus (KDM) and 355 with newly diagnosed diabetes mellitus (NDM). The prevalences of any DR and VTDR were 15.8% (95% confidence interval [CI], 14.1-17.5), and 4.6% (95% CI, 3.6-5.6), respectively. Any DR was associated with a longer duration of diabetes (odds ratio [OR], 1.08; 95% CI, 1.06-1.10), higher HbA1C level (OR, 1.52; 95% CI, 1.28-1.80), higher systolic blood pressure (OR, 1.02; 95% CI, 1.01- 1.03), and lower body mass index (OR, 0.91; 95% CI, 0.87-0.96) in a multivariate analysis. Conclusions. We provide data on the prevalence and risk factors for DR in a representative Korean population. The prevalence of any DR and VTDR in the Korean population was lower than that reported previously. The condition of DR was associated with a longer duration of diabetes, poor glycemic control, and higher systemic blood pressure.