Relationship Between Serum Monosaccharide Level And Diabetes Retinopathy

Objective:The purpose of this study is to find biomarkers by detecting the changes of monosaccharide(free monosaccharide and bound monosaccharide)concentration in peripheral blood of DR patients,and to explore the occurrence and development mechanism of DR at the level of monosaccharide.Methods:Blood samples from 92 patients with Diabetes Retinopathy(DR)and 80 healthy people were collected as experimental group and control group.According to whether there were neovascularization and other proliferative changes in the fundus retina,92 patients with DR were further divided into non-proliferative diabetic retinopathy(NPDR)group and proliferative diabetic retinopathy(PDR)group.The monosaccharide was released from blood samples by ampoule sealed acid hydrolysis,and then the monosaccharide composition of serum samples was analyzed by traditional HPLC(high performance liquid chromatograph).The differences of monosaccharide composition between the experimental group and the control group were compared.Statistical methods used independent-sample t-Test,one-way ANOVA and logistic binary regression analysis.Result:1.Compared with the control group,the levels of D-Glc(degrading glucose),D-Gal(degrading galactose)and D-Fuc(degrading fucose)in the experimental group increased(P < 0.001),and the level of D-Man(degrading mannose)decreased(P < 0.001).ROC curves showed that the areas under D-Man,D-Glc,D-Gal and D-Fuc curves were 0.9990(P < 0.001),0.6792(P < 0.001),0.7575(P < 0.001)and 0.7474(P < 0.001),respectively.2.Compared with the control group,the level of plasma F-Man(free mannose)(P < 0.001)in the experimental group increased and the level of D-Man decreased(P < 0.001).3.In the experimental group,compared with NPDR group,the levels of D-Man(P = 0.009)and D-Gal(P = 0.007)in PDR group increased.4.After univariate analysis,D-Man(OR value,4.414,95% CI,1.393-13.983,P = 0.012)and D-Gal(OR value,7.381,95% CI,1.531-35.577,P = 0.013)were selected as independent related factors of PDR.It was found that D-Gal was significantly correlated with angiogenesis of PDR(OR value,30.921,95% CI,1.371-697.398,P = 0.031).Conclusion:1.D-Man is a good biomarker for diabetes retinopathy.The level of F-Man in peripheral blood of DR patients increased and the level of D-Man decreased,which reflected the change of mannose level in peripheral blood of DR patients.2.There is a specific receptor for recognizing mannose in RPE cell membrane,which realizes phagocytosis by recognizing mannose conjugate.During DR,the increased F-Man and decreased D-Man damage the phagocytosis mechanism of RPE cells.There are more d-man in peripheral blood in PDR phase than in NPDR phase,reflecting the aggravation of retinal barrier disintegration and phagocytosis of RPE cells.3.The level of plasma D-Gal in PDR phase is significantly higher than that in NPDR phase.D-Gal is significantly related to the formation of neovascularization and proliferation in PDR phase,which is similar to angiogenesis in tumor.Galactose and galectin may activate angiogenesis signal through non VEGF dependent pathway and prevent VEGFR2 endocytosis to mediate neovascularization.4.The change of monosaccharide level in peripheral blood can reveal the mechanism of DR development and bring new hope for the prevention,diagnosis and treatment of diabetes retinopathy in the future.