Haemoglobin variants may cause significant differences in haemoglobin A1c as measured by high-performance liquid chromatography and enzymatic methods in diabetic patients: a cross-sectional study

• Published in: Annals of clinical biochemistry 2017-07, Vol.54 (4), p.432-437
• Main Authors: Otabe, Shuichi, Nakayama, Hitomi, Ohki, Tsuyoshi, Soejima, Eri, Tajiri, Yuji, Yamada, Kentaro
• Format: Article
• Language: English
• Subjects: Adult; Aged; Chromatography, High Pressure Liquid - statistics & numerical data; Diabetes Mellitus - blood; Diabetes Mellitus - diagnosis; Enzyme Assays - statistics & numerical data; Female; gamma-Globins - analysis; gamma-Globins - genetics; Gene Expression; Glycated Hemoglobin A - analysis; Glycated Hemoglobin A - genetics; Hemoglobins, Abnormal - analysis; Hemoglobins, Abnormal - genetics; Humans; Male; Middle Aged; Mutation; Outpatients; Quality Control; Sensitivity and Specificity
• ISSN: 0004-5632; 1758-1001
• DOI: 10.1177/0004563216664366

Background We aimed to determine whether the discrepancy between haemoglobin A1c values determined by high-performance liquid chromatography and enzymatic haemoglobin A1c measurements in diabetic patients was clinically relevant. Methods We randomly recruited 1421 outpatients undergoing diabetic treatment and follow-up who underwent at least three haemoglobin A1c measurements between April 2014 and March 2015 at our clinic. In 6369 samples, haemoglobin A1c was simultaneously measured by HA-8160 and MetaboLead (enzymatic assay), and the values were compared. Results haemoglobin A1c measurements by high-performance liquid chromatography and enzymatic assay were strongly correlated (correlation coefficient: 0.9828, linear approximation curve y = 0.9986x − 0.2507). Mean haemoglobin A1c (6.8 ± 1.0%) measured by high-performance liquid chromatography was significantly higher than that measured by enzymatic assay (6.5 ± 1.0%, P  C) mutation in the δ-globin gene. These unrelated asymptomatic subjects had normal erythrocyte profiles, without anaemia. Conclusions We showed that haemoglobin A1c values measured by high-performance liquid chromatography were significantly higher than those measured by enzymatic assay in diabetic subjects. However, when an oversized deviation (>0.7%) between glycaemic control status and haemoglobin A1c is apparent, clinicians should check the methods used to measure haemoglobin A1c and consider the possible presence of a haemoglobin variant.