Changes and Significance of Serum Retinol Binding Protein 4 and Cystatin C Levels in Patients with Diabetic Retinopathy

Abstract

Objective: To detect the serum retinol binding protein 4 (RBP4) and cystatin C (Cys-C) levels in patients with diabetic retinopathy (DR), and examine their correlations with the development of DR.

Methods: A total of 150 outpatients and inpatients with type 2 diabetes mellitus (T2DM) that were admitted to the Department of Endocrinology and Department of Ophthalmology, the People’s Hospital of Haian County Affiliated to Nantong University between January 2015 and June 2016 were enrolled and grouped. Fifty diabetic patients without DR were assigned to the non-DM (NDM) group, 50 diabetic patients with nonproliferative DR (NPDR) were assigned to the NPDR group, 50 diabetic patients with proliferative DR (PDR) were assigned to the PDR group, and 50 normal healthy individuals served as controls. The serum levels of fasting blood glucose (FPG), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), 2-hour postprandial blood glucose (2 hPG), glycosylated hemoglobin (HbA1c), RBP4, and Cys-C were measured.

Results: There were significant differences in serum FPG, TG, TC, LDL-C, HDL-C, 2 hPG, HbA1c, RBP4, and Cys-C levels among the four groups (P<0.05). Higher levels of FPG, TG, TC, 2 hPG, HbA1c, RBP4, and Cys-C, and a lower HDL-C concentrationwere detectedin the NPDR group than in the NDM group; in addition, the serum levels of FPG, TC, 2 hPG, HbA1c, RBP4 and Cys-C were higher in the PDR group than in the NPDR group (P<0.05). Multivariate Logistic regression analyses revealed that the course of the disease 〔OR=3.128, 95%CI (1.458, 7.641)〕, HbA1c 〔OR=6.933, 95%CI (1.604, 29.962)〕, RBP4 〔OR=2.746, 95%CI (1.043, 7.230)〕, and Cys-C 〔OR=3.062, 95%CI (1.098, 9.389)〕 were risk factors for developing DR (P<0.05).

Conclusion: Elevated serum RBP4 and Cys-C levels are strongly associated with the development of DR.