A New Assay Method-The Application Of Plasma 1,5-Anhydroglucitol In Diabetes Mellitus

Objective:To evaluate a new marker of 1,5-anhydroglucitol(1, 5-AG) for short-term glycemic monitoring with liquid chromatography-tandem mass spectrometry(LC-MS/MS) method.Method:1,5-AG concentrations from 243 diabetic patients (NIDDM),267 healthy subjects and 69 aged non-diabetic patients were determined by LC-MS/MS method.The correlation of 1,5-AG to other glycemic markers including hemoglobin Alc(HbAlc,n=327), fructosamine(FA,n=63),fasting blood glucose(FBG,n=174),and postprandial glucose(PPG,n=138) was evaluated.Results:Significant reduction of 1,5-AG level was observed in diabetic patients versus in control group(p＜0.001).Significant between-sex difference was observed in the control group(p＜0.001). The normal reference intervals were set as 14.13-43.81μg/ml for male and 7.77-30.15μg/ml for female subjects.There was significantly negative correlation of 1,5-AG to HbAlc,FA,FBG,and PPG with correlation coefficient(r) values of-0.578(n=327,p＜0.001),-0.539 (n = 63,p＜0.001),-0.409(n = 174,p＜0.001),and -0.503(n = 138,p＜0.001),respectively.Good correlation was observed among plasma, serum,and finger-prick blood samples(r＞0.980,p＜0.001).The LC-MS/MS method showed good linearity with r＞0.999 at 1-50μg/ml of 1,5-AG in plasma.The intra-,inter-assay precision(%) were less than 6.37%,8.75%,respectively,and accuracy ranged 96.2-103.1%.Conclusion:1,5-AG can be applied as a maker of short-term glycemic control,combined with existing ones,for full glycemic monitoring in diabetic patients.The LC-MS/MS method is simple, specific and cost-effective for 1,5-AG determination in clinical application.