Research On Relationship Between Insulin Resistance And Diabetic Retinopathy

Objective:Based on a prospective cohort study and cross-sectional research, the study is to explore the correlation between insulin resistance and diabetic retinopathy.Methods: According to the REACTION research initiated by CMA(Chinese Medical Association), altogether we selected 10207 samples from all of Dalian residents who is greater than or equal to 40 years old and have participated in our survey from Date 16-Aug-2011 to Date 10-Dec-2011. Based on entering and eliminating criteria, altogether we collected 2186 complete samples with type 2 diabetics. They were tested in fasting plasma glucose(FPG), 2 hours postprandial blood glucose(2h FPG), glycosylated hemoglobin(Hb AIc), high density lipoprotein(HDL-C), low density lipoprotein(LDL-C), Total cholesterol(TC), triglyceride level(TG); Besides, their weight, height, waistline, hipline, systolic and diastolic blood pressure as well as pulse rate were measured and their average blood pressure, average pulse rate, BMI, waist-to-hip ratio as well as the HOMA-IR were calculated. We adopted non-mydriatic fundus camera to diagnose whether they were suffering with diabetic retinopathy or not. All of the selected diabetics will be divided into 4 quartile groups R1, R2, R3 and R4 by different HOMA-IR Values. Then we compared the biochemical indicator of each quartile group with the current diabetic retinopathy prevalence to see where there is any difference in between and we analyzed the correlativity between insulin resistance and diabetic retinopathy.Type 2 diabetics without diabetic retinopathy have been giving a follow-up examination during 01-Jul-2014 to 25-Dec-2014, the follow-up time, test records and measurement result, all the items are same with the previous examination we done 3 years ago. These diabetics will also be divided into 4 quartile groups R1, R2, R3 and R4 by different HOMA-IR Values, and we apply non-mydriatic fundus camera to diagnose whether there is diabetic retinopathy occurred. The causing factors of diabetic retinopathy were carefully analyzed and the possibility of DR were compared in each group.Results:1.The differences among the age, weight, BMI, waistline, hipline, waist-to-hip ratio, systolic and diabetic pressure, heart rate, course of disease, FPG, 2h PG, Hb A1 c, FINS, TG, HDL-C of the patients from Group R1,R2,R3 and R4 were significant(P<0.05) while the differences among height, TC, LDL-C of the four groups were not significant(P>0.05). After comparison between each group, it is found that the weight, BMI, waistline, hipline, FPG differ(P<0.05).The indexes mentioned above increase with increasing insulin resistance.2.There were 2186 patients analysed on the baseline study, among whom there were 225 DR sufferers, with a morbidity of 10.3%. The prevalence of DR is 8.2%, 9.1%, 10.4%, 13.4%respectively. The differences among the four groups is significant(χ2=8.883,p=0.031). After another comparision between each groups, it found that the morbidity rate of DR differs between Group R1 and Group R4(χ2=7.449,p=0.008), which is significant. So does Group R2 and Group R4(χ2=4.894,p=0.028). However, the morbidity rate of DR of Group R3 and Group R4 is not significant(χ2=2.268,p=0.136).3.The analysis of baseline using Logistic regression finally shows that the OR rates(95%CI)of course of disease, systolic blood pressure, Hb A1 c, HOMA-IR, BMI are 1.045(1.021-1.070), 1.010(1.206-1.418), 1.308(1.003-1.016), 1.344(1.073-1.682), 0.928(0.887-0.972)respectively. The regression coefficient of course of disease, systolic blood pressure, Hb A1 c, HOMA-IR is the postive value(P<0.05). The regression coefficient of BMI is negative value(P<0.05).4.By applying Cox regression analysis on data collected by Follow-up Examination, the result reveals that 2th, 3th and 4th of HOMA-IR quartiles and the age, course of disease, waistline, systolic blood pressure, diastolic blood pressure, Hb A1 c were significant(P<0.05). The HR rates(95%CI)of age, course of disease, waistline, systolic blood pressure, diastolic blood pressure, Hb A1 c are 0.973(0.959-0.987), 1.029(1.009-1.049), 1.020(1.006-1.033), 1.014(1.007-1.020), 0.981(0.969-0.993), 1.191(1.113-1.274);Q2, Q3 and Q4 are 1.609(HR95%CI:1.135-2.280) times, 1.414 times(HR95%CI:1.022-1.957)and, 1.544 times(HR95%CI:1.128-2.115)respectively more than Q1 in the possibility of DR.Conclusions:This cross-sectional study reveals that the morbidity grows with the growth of HOMA-IR among the diabetic patients. HOMA-IR is related to diabetic retinopathy.The study of follow-up examination confirmed that the insulin resistance is the independent risk factor causing diabetic retinopathy.