A VARIANT OF PARAOXONASE (PON1) GENE IS ASSOCIATED WITH DIABETIC-RETINOPATHY IN IDDM

Serum paraoxonase is a glycoprotein which binds to high-density lipopr oteins (HDL) and may prevent oxidation of LDL by hydrolyzing lipid per oxides. Two polymorphisms identified in the paraoxonase gene (Met-Leu 54 and Gln-Arg 192) have been associated with cardiovascular disease. Oxidative low-density lipoprotein (LDL) is also toxic to retinal capil lary endothelial cells and pericytes, so that mildly modified LDL may contribute to the development of diabetic retinopathy. To investigate the potential significance of these polymorphisms in the pathogenesis of diabetic retinopathy in IDDM, 80 patients with diabetic retinopathy and 119 controls without diabetic retinopathy were investigated in th e current project. The allelic frequency of leucine 54 (L) was signifi cantly higher in the group with retinopathy than without retinopathy ( 73% vs. 57%, p<0.001). The genotype Ln was strongly associated with th e development of diabetic retinopathy (p<0.001), but a similar associa tion was not found with Gln-Arg 192. Leucine 54 is a risk factor for d iabetic retinopathy.