酶法测定糖化白蛋白的方法学评价及其与糖尿病诊断的相关性研究

目的对酶法测定糖化白蛋白(GA)进行方法学评价,验证其作为临床常规方法的各项性能指标。研究糖尿病患者糖化血红蛋白(HbA1c)和GA的相关性,为糖尿病早期诊断和治疗效果监测提供更好的方法。方法按美国临床实验室标准化协会(CLSI)EP10-A3文件对酶法测定GA的精密度、线性、偏差、互染率、漂移性进行评价。测定336例糖尿病患者GA和HbA1c浓度,研究其变化并进行相关性分析。根据美国糖尿病学会(ADA)标准(HbA1c7%为血糖控制良好、7%~8%为血糖控制一般、8%为血糖控制不佳),采用受试者工作特征(ROC)曲线确定GA/HbA1c比值评估血糖控制程度的临界值。结果酶法测定GA的总平均不精密度为1.62%,平均偏差为7.58%,截距、斜率、非线性、互染率、漂移性均可接受;非线性参数检测高值存在正向偏移,需要进行进一步观察以确认方法的线性性能,但对临床诊断不会带来影响。GA与HbA1c诊断糖尿病的一致性较好,为88.1%;两者相关系数(r)为0.879(P0.01)。ROC曲线显示GA/HbA1c比值评估血糖控制程度的最佳临界值为2.60,敏感性为86.8%、特异性为70.1%;如GA/HbA1c比值2.60,可认为血糖控制不佳。结论酶法测定GA的方法学性能符合常规检测质量标准。GA可用于糖尿病的诊断和疗效评估。GA/HbA1c比值可作为监测血糖控制的补充指标。

Assessment of enzymatic method for glycated albumin and its correlation research with the diagnosis of diabetes mellitus

Objective To evaluate the methodology and performance of serum glycated albumin （GA ） determination by enzymatic method as routine method and the correlation of glycosylated hemoglobin A1c （HbA1c ）with GA,in order to provide a better method for the early diagnosis and effect monitoring of diabetes mellitus.Methods The enzymatic method for GA was evaluated for precision,linearity,bias,carryover rate and drift according to the Clinical and Laboratory Standards Institute （CLSI）EP10-A3.The GA and HbA1c were determined in 336 patients with diabetes mellitus.The correlation between GA and HbA1c was analyzed.According to American Diabetes Association （ADA）standard （HbA1c 8% as blood glucose controlling poor）,the cut-off value of GA/HbA1c ratio was evaluated by receiver operating characteristic （ROC）curve.Results The total mean imprecision was 1.62%,and the mean bias was 7.58%.The intercept,slope,nonlinearity,carryover rate and drift of enzymatic method were acceptable.The nonlinearity parameter had forward bias when determining high-value,which should be observed further,however,there was no influence on its clinical diagnosis.The correlation analysis indicated that GA was well correlated with HbA1c [correlation coefficient （r）=0.879,P2.60 was considered as blood glucose controlling poor.Conclusions The routine determination of GA by enzymatic method is available.GA can be used into the diagnosis and effect evaluation of GA.GA/HbA1c ratio is valuable to monitor blood glucose controlling.