Abstract:

Objective To investigate the change of urinary microalbumin（mAlb）to creatinine（Cr）ratio in patients with diabetic retinopathy（DR） and its significance. Methods A total of 173 type 2 diabetes mellitus（T2DM）patients were enrolled,and 40 healthy subjects were enrolled as healthy controls. T2DM patients were classified into 3 groups,non-DR（NDR） group（76 cases）,non-proliferative DR（NPDR） group（58 cases） and proliferative DR（PDR） group（39 cases）. Fasting plasma glucose（FPG）,total cholesterol（TC）,2 h postprandial plasma glucose（2 hPG）,triglyceride（TG）,high-density lipoprotein cholesterol（HDL-C）,low-density lipoprotein cholesterol（LDL-C）,C-reactive protein （CRP）,glycated hemoglobin A_1c（HbA_1c）,urinary mAlb and Cr were determined,and urinary mAlb/Cr ratio was calculated. Simultaneously,related clinical data were collected,including height,weight,waist circumference,hip circumference,the duration of diabetes mellitus and so on. The relationship between urinary mAlb/Cr ratio and other parameters was analyzed by Spearman's rank correlation analysis and multiple linear regression analysis. Logistic regression analysis was used to identify the risk factors of DR.Results Urinary mAlb/Cr ratio increased progressively from NDR,NPDR to PDR groups,and there was statistical significance among the groups（P<0.05）. Urinary mAlb/Cr ratio in T2DM patients was positively correlated with the duration of diabetes mellitus,FPG,2 hPG,LDL-C,HbA_1c and CRP（r=0.372,0.227,0.276,0.231,0.294 and 0.308,P<0.05）. Urinary mAlb/Cr ratio was correlated independently with the duration of diabetes mellitus,CRP and HbA_1c in multiple linear regression analysis（β=0.194,0.169 and 0.183,P=0.007,0.018 and 0.013）. Logistic regression analysis showed that urinary mAlb/Cr ratio,the duration of diabetes mellitus,HbA_1c and CRP were independent risk factors for DR {odds ratio（OR）[95% confidence interval（CI）] 1.212（1.083-1.417）,1.036（1.012-1.063）,1.469（1.140-1.892） and 1.330（1.011-1.273）}. Conclusions Urinary mAlb/Cr ratio is a risk factor for DR,and it is closely related with the development of DR. CRP and HbA_1c may be involved in the development and pathogenesis of DR through damaging renal function.

Key words: Urinary microalbumin to creatinine ratio, C-reactive protein, Glycated hemoglobin A1c, Diabetic retinopathy