Correlation Research Between Len Advanced Glycation End Products And Diabetic Retinopathy

Objective: Advanced glycation end products(AGEs) are a series of stable covalent compounds which are produced by the complicated chemical reactions between the aldehyde or ketone groups of reducing sugar and protein. The purpose of this study is to investigate the levels of advanced glycation end products(AGEs) in human cataractous lenes of diabetic and non-diabetic patients, and further explore the corrrelation between content in cataractous lenes and diabetic retinopathy progression.Methods: The lenes of 30 cases of diabetic cataract patients and 10 cases of non-diabetic cataract patients were extracted as the experimental group and control group respectively. The diabetic group was divided into 3 subgroups: 10 patients without diabetic retinopathy(NDR), 10 patients with non-proliferative diabetic retinopathy(NPDR), and 10 patients with proliferative diabetic retinopathy(PDR). The content of advanced glycation end products(AGEs) including Pentosidine, Imidazolone, and carboxymethyl lysine(CML) were determined using enzyme-linked immunosorbent assay(Elisa) technique.Results: Lenes levels of pentosidine was significantly increased in patients with diabetes compared to non-diabetic controls(35.56±5.47pg/ml, 27.69±1.53pg/ml, respectively, p=0.004); In diabetic patients, pentosidine was significantly higher in patients who had PDR than in those who had NDR(38.59±5.11pg/ml, 31.90±5.00pg/ml, respectively, p=0.008), no significant difference was found between the NPDR and PDR subgroups. Lenes levels of CML was also significantly increased in patients with diabetes compared to non-diabetic controls(20.75±4.21ug/L, 11.36±1.47ug/L, respectively, p=0.000); In diabetic patients, CML was significantly higher in patients who had PDR than in those who had NDR(23.77±4.73ug/L, 18.82±3.84ug/L, respectively, p=0.019), and also in PDR and NPDR(23.77±4.73ug/L, 19.65±2.12ug/L, respectively, p=0.022).No significant difference was found between the other two subgroups. Lenes levels of imidazolone was significantly increased in patients with diabetes compared to non-diabetic controls(14.32±2.60pg/ml, 10.21±0.54pg/ml, respectively, p=0.000). However, no significant difference was found between any two subgroups. The pentosidine, CML, imidazolone levels in the lenes correlated significantly with each other(CML-pentosidine, r=0.623, p=0.000; CML-imidazolone,r=0.717, p=0.000; pentosidine-imidazolone, r=0.669, p=0.000).Conclusion:The AGEs distribution corroborates the hypothesis that the advanced glycation process occurs vigorously in diabetic patients compared with non-diabetic controls. As for the corrrelation between content in cataractous lenes and diabetic retinopathy progression, it needs more sample size to verify.