Journal of Diabetes and Metabolic Disorders11THE VALUE OF GLYCOSYLATED HEMOGLOBIN IN SCREENING FOR IMPAIRED GLUCOSE TOLERANCE AND DIABETES MELLITUS.6776MehrdadHosseinpourGashtasbSattariSassanHaghighiMassoudAmini20151005Background: Oral glucose tolerance testing (OGTT) is the gold standard for the diagnosis of diabetes mellitus and impaired glucose tolerance (IGT), but is time-consuming and difficult to perform. We investigated the value of glycosylated hemoglobin (HbA1C) in screening for diabetes mellitus and IGT. Methods: In a cross-sectional study, we measured the HBA1C levels of 497 people referred for OGTT. We calculated the sensitivity and specificity of HbA1C at 1, 2, 3 and 4 SD above the normal mean. We plotted receiver operating characteristic (ROC) curves after assigning our subjects to the diabetic, IGT, ‘diabetic+IGT', or normal group, based on WHO criteria for OGTT. Results: HbA1C levels (mean ± SD) in the four groups were 9.2±1.5, 8.4±1.3, 7.9±0.8 and 6.8±0.7 percent in the diabetic, diabetic+IGT, IGT and normal groups, respectively. All differences were statistically significant (p<0.0001). ROC curve analysis showed that HbA1C levels above 7.5% (mean + 1SD) gave the best combination of sensitivity and specificity for the detection of diabetes (97.53% and 73.8%), IGT (66.37 and 69.44%), and diabetes+IGT (80.22% and 86.66%). Conclusions: An HbA1C level of >7.5% is an optimal cutoff point for diabetes screening programs.https://jdmd.tums.ac.ir/index.php/jdmd/article/view/18