<h4>Background</h4>This article analysed the relationship between serum advanced glycation end-products (AGEs), carnosinase-1 (CN-1) and diabetic nephropathy (DN) and diabetic retinopathy (DR).<h4>Methods</h4>150 patients with type 2 diabetes mellitus (DM2) were grouped: DN and non-DN, DR and non-DR groups. Here, CNDP1 is linked to diabetes mellitus.