Elevated serum levels of AGEs, sRAGE, and pentosidine in Tunisian patients with severity of diabetic retinopathy.

OBJECTIVES: The advanced glycation end products (AGEs)-receptor for AGE (RAGE) axis activity are implicated in diabetic vascular complications. We measured serum AGE, sRAGE and pentosidine levels in Tunisian patients with diabetic retinopathy (DR) and examined whether these biomarkers are related to the severity of DR.

DESIGN AND METHODS: We included 30 healthy control subjects and 100 diabetic patients were divided into 2 subgroups: 40 patients with nonproliferative diabetic retinopathy (NPDR), and 60 patients with proliferative diabetic retinopathy (PRD). AGEs, sRAGE and pentosidine were measured in serum by ELISA.

RESULTS: Serum levels of AGEs, sRAGE and pentosidine were significantly increased in patients with diabetes mellitus compared to nondiabetic controls (P<.01, P<.001, P<.001 respectively). In diabetic patients, serum AGEs, sRAGE and pentosidine levels were significantly higher in patients who had PDR than in those with NPDR (P=.001, P=.01, P=.005 respectively). Furthermore, in stepwise multivariate regression analysis, the levels of pentosidine and duration of diabetes were independently associated with severity of DR.

CONCLUSION: Serum AGEs, sRAGE, and pentosidine levels are related with the presence of DR. Duration of diabetes and pentosidine were independently correlated with the severity of DR.