title: Assessment of HbA1c as a diagnostic tool in diabetes and prediabetes.
abstract: To evaluate HbA1c as a diagnostic tool in prediabetes-impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and newly detected diabetes (NDD), defined by plasma glucose and OGTT. 2,231 subjects, of mean age 50.3 ± 13.9 years and mean BMI 29.5 ± 6.2 kg/m(2), underwent an OGTT. HbA1c performance was assessed using the area under the receiver operating characteristics curve (AUC-ROC). HbA1c was significantly higher in all groups with altered glucose tolerance-5.72 ± 0.61% in IFG, 5.84 ± 0.63% in IGT, and 7.5 ± 1.69% in NDD when compared to normal glucose tolerance-5.23 ± 0.65% (P < 0.0001). HbA1c of both prediabetic groups was significantly lower in comparison with NDD (P < 0.0001); in IGT being significantly higher than in IFG (P = 0.02). ROC analysis demonstrated good performance of HbA1c for diagnosing diabetes-AUC-ROC 0.958 (95% CI: 0.946-0.970), as well as prediabetes-AUC-ROC 0.729 (95% CI: 0.702-0.755). The optimal cut-off level of HbA1c for diagnosing diabetes was 6.1% (sensitivity 86%, specificity 92%) and for undiagnosed prediabetes-5.5% (sensitivity 71%, specificity 64%). HbA(1c) appears to be a useful, convenient, and reliable tool for identifying subjects with prediabetes and diabetes and should be considered in the development of diagnostic strategies.
authors.affiliation: Department of Diabetology, Clinical Centre of Endocrinology, University Hospital of Endocrinology, Medical University, Sofia, Bulgaria. tankova@iname.com
authors.forename: Tsvetalina
authors.initials: T
authors.lastname: Tankova
authors.forename: Nevena
authors.initials: N
authors.lastname: Chakarova
authors.forename: Lilia
authors.initials: L
authors.lastname: Dakovska
authors.forename: Iliana
authors.initials: I
authors.lastname: Atanassova
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin