An Analysis Of Correlation And It’s Impacting Factors Between The Serum Glucagon-like Peptide 1 Level And Diabetic Retinopathy In Patients With T2DM

ObjectiveTo investigate the correlation between serum GLP-1(Glucagon-like peptide 1)level and DR(Diabetic retinopathy)in patients with T2DM(type 2diabetes mellitus),and to analyze its influencing factors.MethodA retrospective study of 416 subjects was conducted.All subjects were selected from Endocrinology Department of The Second Affiliated Hospital of Fujian Medical University between July 2019 and January 2020.The clinical data(gender,age,height,weight)was collected.Venous blood was retained to detect the related indexes,including fasting C-peptide,FPG(Fasting plasma glucose),Hb A1c(Hemoglobin A1c),WBC(White blood cell),HGB(Hemoglobin),PLT(Platelets),ALT(Alanine aminotransferase),AST(Aspartate aminotransferase),ALB(Albumin),HDL-C(High-density lipoprotein cholesterol),LDL-C(Low-density lipoprotein cholesterol),TG(Triglyceride),CHO(Cholesterol),CREA(Creatinine),BUN(Blood urea nitrogen),FT3(Free triiodothyronine),FT4(Free thyroxine),TSH(Thyroid stimulating hormone),and the fasting serum GLP-1 level was detected by ELISA(Enzyme Linked Immunosorbent Assay).Morning urine was collected to detect microalbumin content.Professional technicians completed the examination of carotid artery ultrasound,digestive system ultrasound,nerve conduction velocity measurement and fundus photography.The subjects were divided into two groups according to the measured fasting GLP-1 level: A group(high GLP-1 level group): GLP-1 concentration ≥7.4pmol/l,a total of 158 cases;B group(low GLP-1 level group): GLP-1 concentration <7.4,a total of 258 cases.In addition,the subjects were divided into another two groups according to whether they were complicated with DR,namely case group(DR group): a total of 124 patients were diagnosed as DR after the completion of fundus examination during the hospitalization,or were diagnosed as DR after relevant examination in the past medical history;Control group(non DR group): a total of 292 patients were not diagnosed as DR or had no previous history of DR.SPSS 26.0 were utilized to evaluate the correlation between GLP-1 level and DR risk in 416 subjects.All test methods were bilateral test,and P<0.05 was considered statistically significant.Resultes1,Compared with the low GLP-1 level group,the high GLP-1 level group had lower PLT level [229.5(181,268.25)vs 237.5(203,290.75),P=0.010],and lower proportion of DR(24.7% vs 34.1%,P=0.043).There were no significant differences in age,diabetes mellitus course,gender,C-peptide,FPG,fasting insulin,Hb A1 c,ALT,AST,CHO,TG,HDL-C,LDL-C,history of hypertension,history of coronary heart disease,fatty liver,DPN(Diabetic peripheral neuropathy),atherosclerosis,and urinary microalbumin grade between the two groups(P>0.05).2,Spearman correlation analysis was performed between fasting GLP-1 level and clinical data.GLP-1 was negatively correlated with PLT(r=-0.152,P=0.002)and positively correlated with ALT(r=0.114,P=0.021)and AST(r=0.162,P=0.001).It showed no correlation with age,diabetes mellitus course,C-peptide,FPG,fasting insulin,Hb A1 c,ALT,AST,CHO,TG,HDL-C,LDL-C,etc.3,Chi-square test and Mann-Whitney U test were used to investigate the basic clinical characteristics of DR group and non-DR group.The results showed that there was no statistically significant difference in the gender distribution between the DR group and the non-DR group in each age group(P>0.05),while the difference in the course of diabetes between the two groups was statistically significant(P =0.008).Compared with the non-DR group,the course of diabetes in the combined DR group was longer [ 9(3,10)vs 6(1,10)].4,Compared with the non-DR group,the HGB level [136(121.25,144.75)vs139(126,152),P= 0.011],ALB level [42.6(39.08,45.85)vs 44(40.7,47.0),P=0.027],FT3 level [4.04(3.48,4.50)vs 4.27(3.70,4.72),P= 0.036],and the proportion of high GLP-1 level(24.7% vs75.3%,P=0.043)in the DR group were lower.The proportion of DPN(54.3% vs 35.6%,P<0.000),poor blood glucose control(89.5% vs76.2%,P=0.002)and urinary microalbumin grade were higher,while there was no significant difference in C-peptide,FPG,fasting insulin,CHO,TG,HDL-C,LDL-C,history of coronary heart disease,fatty liver,atherosclerosis and other aspects between the two groups.5,We took the combination of DR as the dependent variable,and PLT,GLP-1,HGB,ALB,blood glucose control,diabetic course,DPN,gender and age were taken as independent variables to perform binary logistic regression analysis.The results indicated that after adjusting for age and sex,GLP-1 level,glycemic control,duration of diabetes and DPN had significant impact on DR.Among them,GLP-1[OR=0.537(95%CI:0.329～0.877),P=0.013] was a protective factor,while glucose control[OR=2.599(95%CI:1.325-5.099),P=0.005],duration of diabetes [OR =1.048(95%CI:1.005-1.093),P=0.029],DPN [OR =2.114(95%CI:1.327～3.370),P=0.002]were risk factors.ConclusionsGLP-1 is closely related to DR,and is an independent risk factor for DR.Fasting serum GLP-1 level may be used as a predictor of DR lesions in T2 DM patients.