Prevalence and risk factors for diabetic retinopathy: the Beijing Communities Diabetes Study 6.

Background: To examine prevalence and associated factors of diabetic retinopathy in patients with Type 2 diabetes mellitus in urban communities of Beijing.

Methods: The community health care center-based study included subjects with diabetes mellitus and an age of 20 years to 80 years, who were recruited from 15 community health centers in urban Beijing. Diabetes mellitus was defined using the World Health Organization criteria. Fundus photographs were graded using the modified Airlie House classification system.

Results: Of 2,642 eligible patients, 2,007 (76.0%) subjects (1,199 women) with a mean age of 64.1 ± 9.0 years participated. The overall prevalence of diabetic retinopathy was 24.7 ± 1.0% (95% confidence interval [CI], 22.8-26.6). In binary logistic analysis, presence of diabetic retinopathy was associated with younger age (odds ratio [OR], 0.97; 95% CI, 0.95-0.98), longer duration of diabetes (OR, 1.10; 95% CI, 1.08-1.12), higher concentration of glycosylated hemoglobin HbA1c (OR, 1.23; 95% CI, 1.14-1.33), higher systolic blood pressure (OR, 1.01; 95% CI, 1.01-1.02), lower body mass index (OR, 0.95; 95% CI, 0.92-0.98), and elevated blood urea concentration (OR, 1.01; 95% CI, 1.00-1.01). Microalbuminuria was an additional associated factor (OR, 1.55; 95% CI, 1.16-2.08). Patients with microalbuminuria were 4.7 times more likely to have a severe or proliferating diabetic retinopathy than those without microalbuminuria.

Conclusion: In the urban population of Beijing, prevalence of diabetic retinopathy in diabetic patients was 25%. As in whites, increased blood pressure besides elevated plasma glucose concentrations was highly significantly associated with diabetic retinopathy in Chinese. It suggests that in Chinese as also in whites, blood pressure control beside control of plasma glucose levels is important to prevent development or progression of diabetic retinopathy.