Correlation of fasting plasma glucose, hemoglobin A1c and estimated average glucose levels in Diabetic patients with abnormal hemoglobin in Sirindhorn Hospital

Abstract

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are laboratory tests for diabetic diagnosis and monitoring diabetic control. HbA1c value is also used for estimating average glucose levels (eAG) in Diabetic patients. However, HbA1c assay may be unreliable due to interference by abnormal hemoglobin or thalassemia. In this study, FPG and HbA1c, which was assayed using both ion exchange HPLC and turbidimetric inhibition immunoassay of diabetic patients showed significantly high correlation. However, eAG levels calculated from HbA1c values were significant higher than FPG levels .Moreover, HbA1c assay by ion exchange HPLC was interfere by HbE. Therefore, this interference should be concerned for HbA1c assay in diabetic patients with HbE.