Correlation Analysis Of Serum Complement C3,C4 And Glycolipid Metabolism Indexes With Type 2 Diabetes Retinopathy

Objective: By detecting the changes of complement factor C3,C4 and glycolipid metabolism in blood,we explored the correlation between type 2diabetes retinopathy and the above factors,and provided a theoretical basis for exploring the pathogenesis of Diabetic Retinopathy(DR),and looking for new directions for the diagnosis and treatment of diabetes.Methods: According to diagnostic criteria,111 patients with type 2diabetes mellitus diagnosed in ophthalmology and endocrinology outpatient department and Department of internal medicine from Qing Hai University Affiliated Hospital from October 2020 to February 2022 were selected.They were divided into 40 groups without retinopathy group(group NDR)and 71 patients with retinopathy group(group DR)according to the fundus photography condition,including 40 cases of non proliferative lesion group(group NPDR),31 cases of proliferative lesion group(group PDR).Collect the basic information of patients,measure the blood complement C3,C4,glycosylated hemoglobin(Hb A1c),fasting blood glucose(FPG),postprandial blood glucose(PPG),fasting C-peptide(FCP),fasting insulin(FINS),homeostasis model assessment-insulin resistance(HOMA-IR),triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),lipoprotein(a)[Lp(a)],and analyze the influencing factors of DR and the changes and correlation between various indexes.Results:(1)The course of disease,systolic blood pressure,Hb A1c,PPG,fins,HOMA-IR,TG,TC,LDL-C,LP(a)and C3 in Dr group were significantly higher than those in NDR group,while FCP and HDL-C were significantly lower;Multivariate logistic regression analysis showed that Hb A1c and C3 were independent risk factors for Dr,and FCP was independent protective factor for DR;The AUCs of C3,FCP and Hb A1c to Dr were 0.811,0.231 and 0.731 respectively.(2)BMI,Hb A1c,fins,HOMAIR,LDL-C and LP(a)in PDR group were significantly higher than those in NPDR group.Multivariate logistic regression analysis showed that Hb A1c,HOMA-IR and LP(a)were independent risk factors for PDR;The AUCs of HOMA-IR,Hb A1c and LP(a)on PDR were 0.650,0.873 and 0.872respectively.(3)The levels of C3 and C4 in NPDR group were significantly higher than those in NDR group and PDR group.(4)The regression equation of C3 and C4 is:C3=1015.51+126.86×TG,C4=389.89+7.21×TG-5.18×Hb A1c。(the above results are P<0.05)Conclusion:(1)Hb A1 c and complement factor C3 were independent risk factors for Dr;FCP is the independent protective factor of DR;Hb A1 c,HOMA-IR and LP(a)were independent risk factors for PDR;(2)Complement factors C3,FCP,Hb A1 c have great diagnostic value for DR,Complement factors C3,Hb A1 c and LP(a)have great diagnostic value for PDR;(3)Complement factors C3 and C4 increased in the early stage of DR and decreased in the end stage of DR;(4)Complement system and glucose and lipid metabolism are involved in the pathological process of DR.