Limitations of glycated albumin standardization when applied to the assessment of diabetes patients

• Published in: Clinical Chemistry and Laboratory Medicine (CCLM) Vol. 62; no. 12; pp. 2526 - 2533
• Main Authors: Lenters-Westra, Erna, Atkin, Stephen L., Kilpatrick, Eric S., Slingerland, Robbert J., Sato, Asako, English, Emma
• Format: Journal Article
• Language: English
• Published: Germany Walter de Gruyter GmbH 26.11.2024; De Gruyter; Walter De Gruyter & Company
• Subjects: Accuracy; Albumin; Albumins; analytical performance; certified reference material; Diabetes; Diabetes mellitus; Disease management; glycated albumin; Standardization; standardization; diabetes mellitus; glycated albumin; analytical performance; certified reference material
• ISSN: 1434-6621; 1437-4331; 1437-4331
• DOI: 10.1515/cclm-2024-0591

Glycated albumin (GA) has potential value in the management of people with diabetes; however, to draw meaningful conclusions between clinical studies it is important that the GA values are comparable. This study investigates the standardization of the Norudia Glycated Albumin and Lucica Glycated Albumin-L methods. The manufacturer reported imprecision was verified by performing CLSI-EP15-A3 protocol using manufacturer produced controls. The Japanese Clinical Chemistry Reference Material (JCCRM)611-1 was measured 20 times to evaluate the accuracy of both methods. GA was also measured in 1,167 patient samples and results were compared between the methods in mmol/mol and %. Maximum CV for Lucica was ≤0.6 % and for Norudia ≤1.8 % for control material. Results in mmol/mol and % of the JCCRM611-1 were within the uncertainty of the assigned values for both methods. In patient samples the relative difference in mmol/mol between the two methods ranged from -10.4 % at a GA value of 183 mmol/mol to +8.7 % at a GA value of 538 mmol/mol. However, the relative difference expressed in percentage units ranged from of 0 % at a GA value of 9.9 % to +1.7 % at a GA value of 30 %. The results in mmol/mol between the two methods for the patient samples were significantly different compared to the results in %. It is not clear why patient samples behave differently compared to JCCRM611-1 material. Valuable lessons can be learnt from comparing the standardization process of GA with that of HbA .