| Objective:To investigate the correlation between hematological tests such as serum cystatin C(CysC),homocysteine(Hcy)and diabetic retinopathy(DR)in patients with type 2 diabetes mellitus(T2DM)to find simple,reliable and widely used hematological indicators for DR screening.Methods:A retrospective study was conducted in 168 patients with T2DM admitted to Shandong Provincial Hospital from June 2021 to January 2022,including 92 male patients and 76 female patients.The average age of the patients was 59.76±8.86 years old.The duration of T2DM was 0-33 years.The patients were divided into 3 groups according to dilated fundus examination:non-diabetic retinopathy group(N group,54 patients),non-proliferative diabetic retinopathy group(NPDR group,61 patients),proliferative diabetic retinopathy group(PDR group,53 patients).General clinical data such as gender,age,body mass index(BMI),duration of diabetes,smoking history,high blood pressure(HBP)history and coronary atherosclerotic heart disease(CHD)history were collected from all patients.Detailed ophthalmologic examinations were also conducted.Laboratory hematological tests include serum CysC,Hcy,triacylglycerol(TG),total cholesterol(TC),estimated glomerular filtration rate(eGFR),glycosylated hemoglobin A1c(HbA1c).Correlations between DR stages and the above-mentioned tests were evaluated.The relevant indicators were incorporated in Logistic regression.The effects and odds ratios of the risk factors were analyzed so that hematological indicators related to DR progression were found out.Receiver operation curve(ROC curve)was used to analyze the value of correlated hematological indicators in predicting DR.Their predictive value for the diagnosis of DR were evaluated.The statistical software used in this study is SPSS22.0 statistical software.Results:(1)Comparison of general information among three groupsThere were significantly statistical differences in age and duration of diabetes among the three groups(P<0.05).There were no significantly statistical differences in gender,BMI,HBP history and CHD history among the three groups(P>0.05).The comparisons among three groups showed that in terms of age,the N group was smaller than the NPDR group(P<0.05).In terms of duration of diabetes,the N group was smaller than the NPDR group and the PDR group(P<0.05).There was no significant difference in duration of diabetes between the NPDR group and the PDR group(P>0.05).(2)Comparison of hematological tests among three groupsThere were significantly statistical differences in CysC,Hcy,and the proportion of eGFR≤90 patients among the three groups(P<0.05).There was no significantly statistically difference in TG,TC,and HbAlc among the three groups(P>0.05).The comparisons between groups showed that in terms of serum CysC level,N group<NPDR group<PDR group,the differences were statistically significant(P<0.05).In terms of serum Hcy level,N group<NPDR group<PDR group,the differences were statistically significant(P<0.05).In terms of the proportion of eGFR≤90 patients,N group<NPDR group<PDR group,the differences were statistically significant(P<0.05).(3)Ordinal Logistic regression analysis of the risk factors of DR in T2DMSerum CysC and serum Hcy were converted into level variables according to their respective quartiles.Serum CysC level,serum Hcy level,whether eGFR≤90 were incorporated as the independent variables in Ordinal Logistic regression.Univariate Ordinal Logistic regression analysis showed that serum CysC level,serum Hcy level,and whether eGFR<90 were positively correlated with DR staging(P<0.05).Their odds ratios were 2.21,1.95 and 5.14,respectively.Then these three variables were incorporated in multivariate Ordinal Logistic regression as independent variables.The results showed that serum CysC level and whether eGFR≤90 were positively correlated with DR staging(P<0.05).Their odds ratios were 1.71 and 2.50,respectively.There was no significantly statistical difference in serum Hcy level(P>0.05).It suggests that serum CysC level,serum Hcy level,and whether eGFR≤90 are risk factors for DR progression in patients with type 2 diabetes mellitus,and serum CysC level and whether eGFR≤90 is an independent risk factor for DR progression in type 2 diabetes mellitus patients.(4)ROC curve to evaluate the predictive value of serum CysC for DRAccording to whether having DR,the patients were divided into a lesion group and a nonlesion group.ROC curve was used to analyze the value of serum CysC in diagnosis of DR.The results showed that the areas under ROC curve(AUC)of serum CysC was 0.724(P<0.05).The optimal cut-off value was 0.83 mg/L,and the sensitivity and the specificity of the diagnostic model were 0.816 and 0.500,respectively.Serum CysC has a good value in screening DR in T2DM patients.Conclusions:(1)The duration of diabetes,serum CysC,serum Hcy,and renal function are related to DR.(2)Serum CysC level,Serum Hcy level and whether eGFR≤90 are risk factors for DR progression.Serum CysC level and whether eGFR≤90 are independent risk factors for DR progression.(3)Serum CysC can be used as an effective indicator for DR screening with high diagnostic efficiency,which is helpful for screening DR in T2DM patients. |
