Assessment of glycated hemoglobin as a screening and diagnosing tests in Gestational Disbetes Mellitus

Abstract

Objective To assess the screening and diagnosing values of glycesylated hemoglobin (HbA1c) for gestational diabetes mellitus(GDM)with determining HbA lc levels of pregnant women.Methods On the basis of 50 g Glucose Challenge Test(GCT) and 75g oral glucose tolerance test(OGTT), 305 pregnant women were distrbuted into four groups 87 normal pregnancy group, 76 normal glucose tolerance pregnancy group, 88 GDM, 54 IGT. Estimating HbAIc levels of the second trimester and late pregnancy in four preg-nancy Group. With HbA1c≥6.1% for the cut-off point, GDM will be divided into GDM 1 group (HbA1c ≥6.1% ) and GDM 2 group ( HbA1c <6.1% ).Results Pregnant women with C, DM in the second trimester and the late pregnancy, their HbA1c levels were higher than other groups, the difference was significant, p <0.01. Along with pregnancy weeks development, HbA1c level gradually increased, during the late pregnancy,HbA1c level is 5.87% ± 0.43%.HbA1c levels of other pregnancy group is gradually increased with the development of pregnancy. The area under recerver operating characteristic curve of HbA1c in the second trimester pregnancy was 0.760 (95% CI 0.663-0.858), the cut-off value was 5.25%, the sensitivity and specificity were 82.9% and 67.3% respectively, the diagnostic accuracy was 76.0%. The area under ROC in late pregnancy was 0.785 (95% CI 0.709-0.861), the cut-off value was 5.65%, the sensitivity and specificity were 78.8% and 71.6% respectively, diagnostic accuracy is 75.6%. When the boundary value of HbA1c was 6.1% in the late pregnancy, sensitivity for GDM was 31.0% and specificity was 97.5%.In GDM group 1, GCT, fasting blood glucose, 1 hour glucose were higher than GDM group 2, the difference was statistically significant.Conclusion The HbA1c is the middle accuracy test for the screening diagnosis of GDM and have a certain value. But the elevated HbA1c indicates the higher glucose levels, so HbA1c may contribute to the choosing and monitoring of clinical treatment in GDM. Key words: Gestational diabetes mellitus; Glycosylated hemoglobin