Evaluation of Bio-Rad D-100 HbA1c analyzer against Tosoh G8 and Menarini HA-8180V

A Comparative Evaluation of HbA1c Measurement Methods and Their Implications for Diabetes Management

In this study, we assessed the correlations between hemoglobin A1c (HbA1c) measurements obtained using three different diagnostic methods, namely reversed-phase cation-exchange chromatography, high-performance liquid chromatography, and lateral flow immunoassay (LIFA) with an AnyLab F instrument. HbA1c levels measured with the AnyLab F instrument and those measured with the HA8190V, HA8180, and D100 instruments were strongly correlated. High R-square values and low p-values indicated significant and reliable correlations, supporting the clinical interchangeability of these methods. Notably, demographic and clinical analyses revealed uniform HbA1c levels across age groups, suggesting minimal age-related variations in HbA1c levels in the cohort. This finding has implications for diabetes management strategies across different age groups, emphasizing the versatility of the AnyLab F instrument. Overall an average HbA1c level of 7.857% among diabetes mellitus-diagnosed participants suggests moderately elevated HbA1c levels, underscoring the need for improved diabetes management. Younger individuals exhibited lower HbA1c levels, potentially owing to heightened awareness and treatment plan adherence. Conversely, older adults had higher HbA1c levels, likely influenced by age-related changes and comorbidities. Larger sample sizes and a comprehensive evaluation of various measurement principles are needed to strengthen the findings herein. Additionally, exploring additional biomarkers and assessing LIFA performance in larger sample sets will advance the clinical utility of HbA1c measurements.

Labile glycated hemoglobin: an underestimated laboratory marker of short term glycemia

OBJECTIVES

Diabetes mellitus is a major public health problem. Hemoglobin A_1c (HbA_1c) is a key laboratory parameter in the management of diabetes patients. However, in diabetes monitoring, interpretation of HbA_1c results is hampered by the important interindividual variation in red blood cell (RBC) life span. Furthermore, HbA_1c only slowly responds to changes in glucose metabolism. Besides HbA_1c, there exists a labile HbA_1c fraction (l-HbA_1c), exhibiting much faster kinetics. As both HbA_1c and l-HbA_1c are measured by modern standard chromatography, we explored the possibilities of using the l-HbA_1c fraction for monitoring glycemia.

METHODS

l-HbA_1c and HbA_1c fractions were simultaneously assayed on a Tosoh G8 analyzer and expressed as %. l-HbA_1c results were compared with serum glucose and HbA_1c. Concomitantly, RBC distribution width (RDW) was determined on a Sysmex SN analyzer as a marker for erythrocyte life span.

RESULTS

l-HbA_1c could be measured with between-run coefficient of variations (CVs) between 2.2 and 2.3%. l-HbA_1c correlated with both glycemia (r=0.80) and HbA_1c results (r=0.73). In a multiple regression model (r²=0.752), glycemia and HbA_1c were the most determining factors. To a lesser extent, RDW correlated with l-HbA_1c (r=0.158). Furthermore, the l-HbA_1c/HbA_1c ratio weakly positively correlated with RDW (r=0.247).

CONCLUSIONS

L-HBA_1c represents an additional marker for monitoring the rapid occurrence of glycemic disorders that escape detection when using only HbA_1c and blood glucose. RDW can be used as an indicator of atypical RBCs life span, in which the l-HbA_1c fraction may be helpful.

Evaluation of an Ion-Exchange HPLC Device for HbA1c Measurement

BACKGROUND

The ADAMS™ HA-8180V is the 8th generation of a fully automated ion-exchange HPLC system from ARKRAY, and the first to be released onto the US market. We evaluated the HA-8180V, for routine hemoglobin A1c measurement in comparison with the Roche Cobas c501, the Tosoh G8 analyzer for normal hemoglobin, and with the Trinity analyzer for hemoglobin variants.

METHODS

The analytical performance (linearity, precision, carryover, and sample stability) was assessed based on the Clinical and Laboratory Standards Institute (CLSI) and manufacturer guidelines. A comparison of the HA-8180V against two major analytical methods was performed for 100 whole blood samples. HA-8180V variant mode was also compared against the Trinity ultra2 A1c analyzer for 50 samples containing hemoglobin variants (HbC 14, HbS 14, HbD 12, and HbE 10).

RESULTS

The within-run and total CVs were <0.01 and 0.75% at low HbA1c concentration and 0.46 and 0.63% at high HbA1c concentration, respectively. Linearity was shown in the concentration range 3.4-18.1% HbA1c, carryover was 0.00%, and stability values were excellent. Method comparison demonstrated a high concordance between methods.

CONCLUSION

The eighth generation ADAMS HA-8180V A1c analyzer demonstrated high analytical performance adequate for routine clinical use.

Analytical performance evaluation of the Norudia HbA1c assay

BACKGROUND

Hemoglobin A1c (HbA1c) is arguably the most important biomarker used in the diagnosis and treatment monitoring of diabetes mellitus. We evaluated the analytical performance of the Norudia HbA1c assay (Sekisui Medical Co., LTD), which uses an enzymatic method incorporated into a fully automated, high-throughput system.

METHODS

The precision, linearity, and carryover of the Norudia HbA1c assay were evaluated. Using 60 patient samples, comparative analysis of HbA1c measurements with two commonly used HbA1c assays, the D100 (Bio-Rad Laboratories, Inc) and HLC-723 G11 (Tosoh), was undergone. Thirteen commutable samples with known HbA1c concentrations measured using an IFCC reference measurement procedure were used to compare accuracy between methods. Interference of HbA1c measurement by Hb variants was evaluated using 16 known Hb variant samples.

RESULTS

Repeatability (% CV) for low and high concentrations ranged from 1.12%-1.50% and 0.66%-0.75%, respectively, and within-laboratory precision for low and high concentrations ranged from 1.73%-2.89% and 0.98%-1.64%, respectively. For linearity, the coefficient of determination was 0.9987. No significant carryover was observed. When compared to the D100 and HLC-723 G11 assays, the Norudia HbA1c assay showed the best accuracy with the lowest mean bias (-1.72%). Furthermore, the Norudia was least affected by Hb variants and gave the most reliable HbA1c measurements.

CONCLUSION

The Norudia HbA1c showed excellent analytical performance with good precision and linearity, and minimal carryover. When compared to other routine HbA1c methods, the Norudia HbA1c assay showed the highest accuracy and was least affected by Hb variants.

Screening for Gestational Diabetes Mellitus by Measuring Glycated Hemoglobin Can Reduce the Use of the Glucose Challenge Test

Background

Physiological changes during pregnancy, such as dilutional anemia and a reduced half-life of red blood cells, have prevented the use of glycated Hb (HbA_1c) as a biomarker for gestational diabetes mellitus (GDM). Nevertheless, increasing evidence supports the use of HbA_1c in GDM diagnostic strategies.We studied HbA_1c as a biomarker of GDM and its possible use as a screening test to avoid the use of the glucose challenge test (GCT).

Methods

This case-control study involved 607 pregnant women between the 24th and 28th week of gestation. HbA_1c level was determined, and GDM was diagnosed according to the National Diabetes Data Group criteria. The area under the ROC curve (AUC) was determined; two low and two high cut-off points were established to rule out GDM and classify high-risk pregnant women, respectively. For each cut-off, sensitivity (S), specificity (SP), and total number and percentage of GCTs avoided were determined.

Results

The AUC for HbA_1c diagnostic performance was 0.68 (95% confidence interval 0.57–0.79). Using 4.6% HbA_1c (27 mmol/mol) as the lower cut-off (S=100%), 14% of participants could avoid the GCT. Using 5.5% HbA_1c (36 mmol/mol) as the upper cut-off (SP =94.5%), 6% of participants would be considered at high risk.

Conclusions

HbA_1c can be used as a screening test prior to the GCT, thereby reducing the need for the GCT among pregnant women at a low risk of GDM.

Glycated albumin as a glycaemic marker in patients with advanced chronic kidney disease and anaemia: a preliminary report

Background: The association between glycated albumin (GA) and glycaemic status has not been fully described in patients with advanced chronic kidney disease (CKD) in relation to anaemia. The aim of this study was to evaluate the relationship between GA and fasting plasma glucose (FPG) and HbA1c in patients with advanced CKD and to evaluate the influence of anaemia in such relationship. Materials and methods: Patients with CKD stage 4 or 5 were included in the study. eGFR was calculated by the CKD-EPI creatinine equation. Plasma GA was measured by an enzymatic method. Results: Eighty-one patients were included in the study, 46 (57%) were males; the mean age was 67 ± 14 years. HbA1c was correlated with Hb (r = 0.39; p = .0003), and no significant correlation was detected between plasma GA and serum albumin (p = .82). A significant association between FPG and GA (r² = 0.41; p < .0001), and between FPG and HbA1c (r² = 0.42; p < .0001) was detected in the whole study population. Patients with moderate/severe anaemia had lower HbA1c than patients with no anaemia, while both FPG and GA were comparable between the two groups. Multivariate regression analysis showed that GA was a significant predictor of FPG in patients with moderate/severe anaemia while HbA1c did not (r² = 0.55; p < .0001 for the model). Conclusions: GA, alone or in combination with other biomarkers, can be considered for the evaluation of glycaemic status in patients with advanced CKD and severe anaemia.

Trends in HbA1c levels and implications for diabetes screening in tuberculosis cases undergoing treatment in India

SETTING

The optimal timing of screening for diabetes mellitus (DM) among tuberculosis (TB) cases is unclear due to the possibility of stress hyperglycemia.

DESIGN

We evaluated adult (18 years) pulmonary TB cases at treatment initiation as well as at 3 months, 6 months and 12 months. DM was identified by self-report (known DM) or glycated hemoglobin (HbA1c)  6.5% (new DM). Trends in HbA1c levels during treatment were assessed using non-parametric tests.

RESULTS

Of the 392 participants enrolled, 75 (19%) had DM, 30 (40%) of whom had new DM. Of the 45 participants with known DM, respectively 37 (82%) and 40 (89%) received medication to lower glucose levels at treatment initiation and completion; one participant with new DM initiated glucose-lowering medication during follow-up. The median HbA1c level in participants with known, new and no DM was respectively 10.1% (interquartile range [IQR] 8.3-11.6), 8.5% (IQR 6.7-11.5) and 5.6% (IQR 5.3-5.9) at treatment initiation, and 8.7% (IQR 6.8-11.3), 7.1% (IQR 5.8-9.5) and 5.3% (IQR 5.1-5.6) at treatment completion (P < 0.001). Overall, 5 (12%) with known and 13 (43%) with new DM at treatment initiation had reverted to HbA1c < 6.5% by treatment completion (P = 0.003); the majority of reversions occurred during the first 3 months, with no significant reversions beyond 6 months.

CONCLUSION

HbA1c levels declined with anti-tuberculosis treatment. Repeat HbA1c testing at treatment completion could reduce the risk of misdiagnosis of DM.

Clinical usefulness of Glycated Albumin in the diagnosis of diabetes: Results from an Italian study

OBJECTIVES

Glycated Albumin (GA) has been proposed as a screening marker for diabetes in Asian countries in the last years. Nevertheless, few studies have been conducted in Caucasian population. The aim of this study is to evaluate the clinical usefulness of GA in diabetes diagnosis in Caucasian asymptomatic subjects considered at risk of diabetes based on medical history and Fasting Plasma Glucose (FPG).

DESIGN AND METHODS

Three hundred and thirty-four Caucasian subjects having one or more risk factor for diabetes, and/or FPG ranging from 5.6 mmol/L to 6.9 mmol/L with no symptoms for diabetes were enrolled in this study. Plasma GA was measured by an enzymatic method (quantILab Glycated Albumin) on ILab Taurus instrument (Instrumentation Laboratory - A Werfen Company).

RESULTS

GA median levels were 13.2% (IQR:12.2-14.4). Eighteen subjects (5.4%) were classified as diabetics based on their HbA1c. According to the ROC curve analysis, GA identified subjects with diabetes with a sensitivity of 72.2% (95% CI: 46.5-90.3) and a specificity of 71.8% (95% CI: 66.5-76.7) (AUC: 0.80; 95% CI: 0.75-0.84; P < 0.0001) at the cut-off of 14%. The cut-off of 13.5% was associated to a higher sensitivity 88.9% (95%CI: 65.3-98.6) and a specificity of 60.4% (95%CI, 54.8-65.9).

CONCLUSIONS

This study confirms the clinical usefulness of GA for the diagnosis of diabetes in Caucasian subjects at risk for diabetes. More studies are required to clarify the role of GA in relation to the other diagnostic criteria for diabetes.