Combined utility of hemoglobin A1c and glycated albumin in diabetic screening

Abstract

To assess the validity of combined detection of hemoglobin A1c (HbA1c) and glycated albumin (GA) in diabetic screening. A total of 1480 subjects at our out-patient department from March 2007 to December 2009. Those suspected of diabetes or at a high risk of diabetes were enrolled. The study population included 677 males and 803 females with a mean age of 52.7 years. All subjects received an oral glucose tolerance test (OGTT) after a 10-hour fasting. Glycated albumin (GA) and hemoglobin A1c (HbA1c) were measured with liquid enzyme method and high pressure liquid chromatography respectively. (1) According to World Health Organization diabetes diagnosis criteria, there were 562 subjects with normal glucose tolerance (NGT), 411 subjects with impaired glucose regulation (IGR) and 507 subjects with newly diagnosed diabetes mellitus (DM). The level of HbA1c and GA had a rising tendency among NGT, IGR and DM groups (P < 0.01). (2) Pearson correlation analysis demonstrated that HbA1c had a positive association with GA (r = 0.75, P < 0.01). (3) Using OGTT as golden standard of diabetic diagnosis, receiver operator characteristic (ROC) curve indicated that HbA1c and GA were strong predictors of diabetes. The area under curve (AUC) was 0.882 and 0.881 respectively with no significant difference (P > 0.05). (4) The sensitivity of combined use of HbA1c and GA at optimal cut-off points of 6.1% and 17.1% was significantly higher than that of single use of HbA1c or GA in diabetic screening (94.7% vs 81.1%, 88.4%, P < 0.01). A combined detection of HbA1c and GA may improve the efficacy of diabetic screening. The subject with HbA1c ≥ 6.1% or GA ≥ 17.1% is recommended to undergo OGTT for confirming a diagnosis of diabetes.