Investigation On Relationship Between Serum Level Of Adiponectin And Type 2 Diabetic Retinopathy

BACKGROUNDAdiponectin is an adipocyte-specific secreted protein that usually exists as polymers in blood.By different molecular weight,it can be divided into three isforms, including the low-molecular-weight trimer,the middle-molecular-weight hexamer and the high-molecular-weight form composed of 12-18 molecules.Most researches focus on the relationship between adiponectin and obesity/diabetes/diabetic macrovascular diseases/cancer and indicate that adiponectin possesses many biological activities, such as enhanced insulin sensitivity,anti-inflammatory,anti-atherosclerosis, anti-cancer,etc.So far,a few researches are done about the relationship between adiponectin and diabetic retinopathy.And three types of controversial opinions are held.The first opinion is that with the severity of diabetic retinopathy,the serum adiponectin concentration was lower and lower.And it was significantly lower than type 2 diabetic patients without retinopathy.The second view is that as diabetic retinopathy develops, serum adiponectin level does not change.This may indicate that microvascular lesions do not affect serum adiponectin level in type 2 diabetes.The third view is that as the diabetic retinopathy grows more severe,the serum adiponectin concentration increases gradually.By further analysis,we found some defects in these previous studies.For example,they neither control other variables impacting adiponectin nor observe the dynamic trend of adiponectin from healthy people to type 2 diabetic retinopathy patients.Therefore,from the point of view of disease prevention and control,it has great theoretical and practical significance on revealing the pathogenesis of diabetic retinopathy by making clear that the variation of serum adiponectin in type 2 diabetic retinopathy controlled by diabetes and health group,exploring the cutting point of adiponectin preventing the diabetic retinopathy,and analyzing the influencing factors to type 2 diabetic retinopathy.It is also crucial to do researches through rational division,correct use of statistic methods and controlling factors influencing adiponectin.OBJECTIVES1.After controlling the factors influencing adiponectin,to analyze the serum level of the high-molecular-weigh adiponectin(HMW-adiponectin),total-adiponectin and their ratio in simple diabetic,non-proliferative diabetic retinopathy and proliferative diabetic retinopathy.2.To observe the dynamic variation of adiponectin from healthy people to diabetic retinopathy patients.3.To explore the waming value of serum level of HMW-adiponectin and total-adiponectin to simple diabetes,non-proliferatibe diabetic retinopathy and prolifeative diabetic retinopathy.4.To investigate the impacting factors of type 2 diabetic retinopathy.METHODSIn accordance with the proposed scheme,we calculated the size.In Shandong Shierming Eye Hospital,we chose 88 proliferative diabetic retinopathy patients,124 non-proliferative diabetic retinopathy patients,78 simple diabetes patients and 84 health control objects from October 2007 to December 2008.We investigated their gender,age,diabetes duration,disease history,family history,drug history and measured their height,weight,blood pressure,fasting plasma glucose(FPG),fasting insulin(FINS),triglyceride(TG),total cholesterol(T-C),high-density-lipoprotein cholesterol(HDL-C),low-density-lipoprotein cholesterol(LDL-C),tumor necrosis factor-α(TNF-α),creatinine,total-adiponectin and HMW-adiponectin.We use SPSS 16.0 to set up the database for statistical analysis.By covariance analysis,after controlling the factors influncing the adiponectin,we observed the serum level of total-adiponectin and HMW-adiponectin within the four groups.By ROC curve analysis,we analyzed the warning value of the serum level total of totaladiponectin and HMW-adiponectin to simple diabetes and diabetic retinopathy.By Cumulative logit model,we analyzed the influencing factors of type 2 diabetic retinopathy.RESULTS1.The analysis of serum adiponectin level in patients with type 2 diabetic retinopathy.Single factor analysis shows that hypertension history,drug history,age,duration, FPG,FINS,T-C,TG,HDL-C,TNF-α,creatinine,HMW-adiponectin and totaladiponectin have significant differences within four groups(P＜0.05).After controlling the factors influencing the adiponectin,covariance analysis shows that total-adiponectin has significant differences within four groups(F=18.792,P＜0.01). The total-adiponectin level of health control group is higher than the groups of simple diabetes,non-proliferative diabetic retinopathy and proliferative diabetic retinopathy (P＜0.01).The total-adiponectin level of proliferative diabetic retinopathy is higher than the group of non-proliferative diabetic retinopathy(P＜0.05).The serum level of HMW-adionectin has significant differences within four groups(F=14.025,P＜0.01). The HMW-adiponectin level of health control group is higher than the groups of simple diabetes,non-proliferative diabetic retinopathy and proliferative diabetic retinopathy(P＜0.01).The ratio of HMW-adiponectin/total-adiponectin has no differences(P＞0.05).From health control,simple diabetes to each phrases of diabetic retinopathy,also with the severity of retinopathy,the dynamic variations of HMW and totaladiponectin grow down at the beginning and then grow up.2.The warning value of adiponectin to type 2 diabetic retinopathy.Total-adiponectin is better to forecast the occurance of simple diabetes.The optimal cut-point is 4.796μg/ml,sensitivity is 89.7%,specificity is 81.0%.To prevent the occurrence of non-proliferative diabetic retinopathy,the optimal cut-point of total-adiponectin is 3.406μg/ml,sensitivity is 66.9%,specificity is 72.2%.We do not find the optimal cut-point of adiponectin to proliferative diabetic retinopathy.To avoid the false-positive mistake,further study is needed.3.The analysis of influencing factors of type 2 diabetic retinopathy.Atα=0.05 level,there is finally seven variables retained in the cumulative logit model,including age,duration of disease,drug history,HDL-C,TNF-α,HMWadiponectin and total-adiponectin. CONCLUSIONS1.With the severity of diabetic retinopathy,the trends of HMW-adiponectin and total-adiponectin are all first down and then up.In the phase of non-proliferative diabetic retinopathy,both are the lowest.This indicates that lower level of serum adiponectin may participate the happening of non-proliferative diabetic retinopathy.2.Serum total-adiponectin has greater value to forecast the simple diabetes and non-proliferative diabetic retinopathy.3.Drug history,the high level of HDL-C,HMW-adiponectin and totaladiponectin have protective effects to the non-proliferative diabetic retinopathy.Older age,long duration of diabetes,high levels of TNF-αare risk factors of nonproliferative diabetic retinopathy.