Cystatin C Predicts Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes

This study aims to identify the predictive value of cystatin C for diabetic retinopathy (DR) in Chinese patients with type 2 diabetes. Data from a cross-sectional hospitalbased survey of 450 type 2 diabetes patients were analyzed in the study. DR was assessed by fundus fluorescein angiography. Duration of diabetes and other related information were obtained by questionnaire. Body mass index, blood pressure, HbA1c, cystatin C, glomerular filtration rate, urinary albumin excretion, blood lipids, and uric acid were measured. Binary logistic regression was performed to evaluate potential risk factors for DR. The predictive value of cystatin C for DR was evaluated using ROC curve. Cystatin C (P=0.039) was a risk factor for DR after GFR, and other possibly related variables were adjusted. Cystatin C had a significant predictive value for any DR (AUC, 0.763, P<0.001; optimal cutoff value, 1.11 mg/L; sensitivity, 56.00 %; specificity, 83.90 %) or severe DR (AUC, 0.821, P<0.001; optimal cutoff value, 1.23 mg/L; sensitivity, 73.60 %; specificity, 88.70 %). Cystatin C is a novel risk factor for DR and should be used to screen and forecast the presence of DR (especially severe DR) in Chinese patients with type 2 diabetes. The association between cystiatin C and DR should not depend on the excellent ability of cystatin C for the estimation of GFR.