摘要
Abstract
Objective To study the diagnostic validity and find out the optimum diagnostic cut-off point of glycosylated hemoglobin ( HbA1 c) for the purpose of large population screening for diabetes by comparing the correlations between the blood levels of HbA1c and fasting plasma glucose(FPG),plasma glucose 2 hours after meal(2hPG) in the diagnosis of diabetes mellitus .Methods The blood levels of HbA 1 c of 1294 patients with type 2 diabetes mellitus were determined by high pressure liquid chromatography (HPLC).Then the patients were divided into two groups of HbA1 c>or=6.5%and HbA1 c>or=6.2%,and the correlation between HbA 1 c and blood glucose was studied .The validities of HbA 1 c of different levels as the tool for the diagnosis of diabetes were analyzed by receiver-operating characteristic (ROC) curve.Results FPG>or=7.0 mmol/L was found in 748(57.89%) diabetic patients,and 2hPG>or=11.1 mmol/L in 828(64.18%) diabetic patients.For HbA1 c at a diagnostic cut-off point of>or=6.5%which was recommended by ADA,699 (54.01%) diabetes patients were detected ,and the sensitivity and specificity were 54.0%and 100.0%,respectively . There was significant difference among HbA 1c>or=6.5%,FPG and 2hPG in the diagnosis of correlation (P<0.01). For HbA1 c at a diagnostic cut-off point of>or=6.2%,953(73.65%) diabetic patients were detected,which was significantly different from FPG(P<0.01),but wasn′t significantly different from 2hPG(P>0.05),in the detection rate .For HbA1 c at a diagnostic cut-off point of>or=6.2%,the maximal area under ROC curve was 0.992 while the maximal diagnostic index was 1.73,and the sensitivity and specificity were 73.64%and 99.0%,respectively.Conclusion For HbA1 c at a diagnostic cut-off point of>or=6.2%,its validity for the diagnosis of diabetes is superior to that of HbA 1 c at a diagnostic cut-off point of>or=6.5%or FPG at a cut-off point of>or=7.0 mmol/L,and is similar to that of 2hPG at a cut-off point of>or=11.1 mmol/L.HbA1 c>or=6.2%used as the diagnostic cut-off point is more accurate in the diagnosis of diabetes and is suitable for a large population screening for diabetes .关键词
糖尿病/糖化血红蛋白/血糖/诊断阈值/ROC曲线Key words
Diabetes mellitus/Glycosylated hemoglobin/Blood glucose/Cut-off point/Receiver operating characteristic curve分类
医药卫生
