Background: To evaluate the prevalence and associated factors of diabetic retinopathy in adult Chinese with diabetes mellitus.
Methods: The Beijing Eye Study 2006 is a population-based cross-sectional study that included 3,251 (73.2%) subjects (aged 45+ years) out of 4,439 subjects originally participating in the Beijing Eye Study 2001. Diabetes defined as fasting glucose concentrations > or = 7.0 mmol/L or self-reported diagnosis of diabetes was detected in 381/3,251 (12.9%) subjects. Diabetic retinopathy was defined by the presence of at least one microaneurysm in the diabetic subjects according to the Early Treatment of Diabetic Retinopathy Study (ETDRS).
Results: Gradable fundus photographs were available for 362 (95.0%) subjects. Diabetic retinopathy was detected in 101 subjects (27.9%). Most of the diabetic retinopathy was of the mild type (74/101; 73%). Severe non-proliferative or proliferative diabetic retinopathy was present in 16 (16%) subjects, and clinically significant macular edema in four (4%) subjects. Presence of diabetic retinopathy was significantly associated with rural region (Odds ratio (OR): 3.52), duration of diabetes mellitus (OR: 1.08), fasting plasma glucose concentration (OR: 1.14), type of diabetes treatment (OR: 2.09), and marginally significantly, with hyperopic refractive error (OR: 1.13; P = 0.08). The stage of diabetic retinopathy was associated with rural region (P < 0.001), known duration of diabetes (P = 0.001), type of diabetes treatment (P = 0.001), concentrations of high-density lipoproteins (P = 0.004), and fasting glucose concentrations (P = 0.002).
Conclusions: Prevalence of diabetic retinopathy among adult diabetic Chinese was about 27.9%. The stage of retinopathy was mild in 75% of the subjects with diabetic retinopathy. Associated factors were diabetes duration, diabetic treatment type, low metabolic control, rural region, and marginally hyperopia.