Abstract:

Objective We aimed to provide updated data for the relation between Glycosylated hemoglobin(HbA1c) and diabetic retinopathy(DR), and to estimate cut-off of HbA1c for DR. Design Community-based cross-sectional investigation. Participants The community health care center-based study included 2642 subjects with diabetes mellitus and an age of 20 years to 80 years, who were recruited from 15 community health centers in urban Beijing. Of 2642 eligible patients, 2007 (76.0%) subjects (1199 women) with a mean age of 64.1±9.0 years participated. Methods A cluster sampling technique was used to identify and include patients with type 2 diabetes mellitus from urban Beijing communities. HbA1c was measured by the liquid chromatography technique. Fundus photographs were graded using the modified Airlie House classification system. The area under the receiver operating characteristic (ROC) curve was used to determine the diagnostic value of HbA1c between the study groups. Main Outcome Measures Sensitivity, specificity, area under the curve(AUC). Results The overall prevalence of DR was (24.7±1.0)% (95% confidence interval [CI], 22.8~26.6). In binary logistic regression analysis, presence of DR was associated with higher concentration of HbA1c (OR=1.23; 95%CI, 1.14~1.33). With the increase of HbA1c, the prevalence of DR showed an increasing trend. The Receiver Operating Characteristic analysis showed that the cut-off value of 6.5% had 75.1% sensitivity and 43.4% specificity with 59.2% maximum. In binary logistic regression analysis, presence of DR was also associated with younger age (OR=0.97; 95%CI, 0.95~0.98), longer duration of diabetes (OR=1.10; 95%CI, 1.08~1.12), 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). Conclusions HbA1c value ≥6.5% is significantly related with DR and PDR. In a screening program, the cut-off value of HbA1c≥6.5% may provide a maximum yield of DR. (Ophthalmol CHN, 2016, 25: 321-325)

Key words: diabetic retinopathy, glycosylated hemoglobin, Beijing Community Diabetes Study