Glycated hemoglobin a1c as a modern biochemical marker of glucose regulation

Glycated Hemoglobin Structure and Synthesis of Molecule. Glycated hemoglobin A1c, the major fraction of glycated hemoglobin, is formed by irreversible nonenzymatic glycation. Its concentration depends only on the life span of red blood cells and blood glucose levels. Clinical Significance of Glycated Hemoglobin A1c. It is the key parameter for monitoring the regulation of diabetes and for assessing the risk of microvascular complications. It is a diagnostic criterion for diabetes as well. Its concentration reflects the average value of blood glucose over the last two to three months. The estimated average glucose, a new parameter which facilitates the patient?s self-monitoring of diabetes, can be calculated from its value. Methods for Determining Glycated Hemoglobin A1c and their Standardization. Immunoassay and ion-exchange chromatography are commonly used methods for the glycated hemoglobin determination in routine laboratory practice. The advantage of immunoassay is that there is no need for the sample pretreatment in order to eliminate unstable glycated hemoglobin A1c intermediary forms, and the possibility of false positive results is lower. The current program of standardization requires traceability to the International Federation of Clinical Chemistry and Laboratory Medicine reference method. Reporting and Interpretation of Results of Glycated Hemoglobin A1c Determination. Glycated Hemoglobin A1c can be reported as % or as mmol/mol. In our country, it is recommended to use the International Federation of Clinical Chemistry and Laboratory Medicine units (mmol/mol). When interpreting the results, the potential causes of falsely high or low values must always be taken into consideration. Recommendations for Clinical Practice. Periodic determinations of glycated hemoglobin A1c are recommended for monitoring of diabetes regulation. Additionally, the determination is recommended for the diagnosis of diabetes. The target value for the prevention of microvascular complications is < 7% and the diagnostic criterion for diabetes is ? 6.5%.

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Abstract TP208: 1,5-anhydro-d-glucitol as a Predictor of Cerebral Infarction in Patients With Glycated Hemoglobin A1c-based Good Diabetes Control

Stroke ◽

10.1161/str.47.suppl_1.tp208 ◽

2016 ◽

Vol 47 (suppl_1) ◽

Author(s):

Yuji Shiga ◽

Yuhei Kanaya ◽

Shinichi Takeshima ◽

Yasunori Fujikawa ◽

Kazuhiro Takamatsu ◽

...

Keyword(s):

Blood Glucose ◽

Cerebral Infarction ◽

Hba1c Level ◽

Hemoglobin A1c ◽

Glycated Hemoglobin ◽

Glycemic Variability ◽

Diabetes Control ◽

Short Term ◽

High Group ◽

Glycated Hemoglobin A1c

Introduction: Current guidelines set the goal of diabetes control to a glycated hemoglobin A1c (HbA1c) level of <7% in order to prevent macrovascular events. However, we often experience diabetes patients with cerebral infarction (CI), even though their HbA1c level is well-controlled. A reason for this disparity between the diabetes control status and CI onset may be the limitation of HbA1c as a diabetes control indicator. HbA1c reflects the mean blood glucose level over the past 2-3 months. Therefore, with HbA1c, we cannot evaluate short-term blood glucose control and glycemic variability, which are reported as risk factors for CI. Measurement of 1,5-anhydro-D-glucitol (1,5AG) allows the evaluation of these factors. Hypothesis: 1,5AG can be used to evaluate the risk of CI in patients with well-controlled diabetes. Methods: We retrospectively reviewed the medical records of 1169 patients with diabetes who received treatment for CI at our hospital between 2009 and 2014. These patients were divided into the following two groups according to their HbA1c-based diabetes control status: a CI-low group (HbA1c <7%, n=549) and a CI-high group (HbA1c ≧7%, n=620). We also included a non-CI group of 394 diabetes patients without CI (control group), and these patients were further divided into the following two groups in the same manner: a nonCI-low group (n=199) and a nonCI-high group (n=195). The 1,5AG levels were compared between the CI-low and nonCI-low groups, and the CI-high and nonCI-high groups. Results: There was no difference in the 1,5AG level between the CI-high and nonCI-high groups (8.8±7.3% vs. 8.9±7.1%, p=0.83). However, the 1,5AG level was significantly lower in the CI-low group than in the nonCI-low group (12.5±8.1% vs. 15.2±8.8%, p<0.001). This difference remained significant after adjusting for age and sex. Conclusion: The results of this study show that short-term glycemic control and glycemic variability have a significant relationship with existing CI especially in patients with good diabetes control. The 1,5AG level may be a surrogate measure of the risk of CI in patients with HbA1c levels that indicate good diabetes control.

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Introducing the new laboratory standard of HbA1c determination in Hungary

Orvosi Hetilap ◽

10.1556/oh.2011.29084 ◽

2011 ◽

Vol 152 (14) ◽

pp. 555-558

Author(s):

Gabriella Bekő

Keyword(s):

Master Equation ◽

Clinical Chemistry ◽

Reference Method ◽

Laboratory Medicine ◽

International Federation ◽

New Method ◽

Interlaboratory Comparisons

A new laboratory standard, specific for HbA1c was prepared by the International Federation of Clinical Chemistry and Laboratory Medicine. Consequently, manufacturers will supply their calibrators with the International Federation of Clinical Chemistry and Laboratory Medicine standard. Laboratories in Hungary switch to this new method in April 1, 2011. After this date, results of HbA1c measurements will be reported in International Federation of Clinical Chemistry and Laboratory Medicine units (mmol/mol) and in the derived National Glycohemoglobin Standardization Program units (%) calculated by master equation from the International Federation of Clinical Chemistry and Laboratory Medicine/National Glycohemoglobin Standardization Program methods. Using the new standardization the HbA1c measurements will be traceable to the International Federation of Clinical Chemistry and Laboratory Medicine reference method and interlaboratory comparisons will be possible. Orv. Hetil., 2011, 152, 555–558.

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Gingival Crevicular Blood Glucose Evaluation in Patients with Periodontitis: Evolution of A New Screening Technique

Journal of The Pakistan Dental Association ◽

10.25301/jpda.294.193 ◽

2020 ◽

Vol 29 (04) ◽

pp. 193-198

Author(s):

Quratulain Saeed ◽

◽

Sarwat Memon ◽

Mervyn Hosein

Keyword(s):

Blood Glucose ◽

Hemoglobin A1c ◽

Glycated Hemoglobin ◽

Characteristic Curve ◽

Screening Method ◽

Capillary Blood ◽

Screening Technique ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Glycated Hemoglobin A1c

OBJECTIVE: The aim and objective of this study was to assess if gingival crevicular blood could be utilized for blood glucose evaluation in patients with periodontitis and to check the reliability of this screening method. METHODOLOGY: The study was conducted at the department of Oral Medicine, Ziauddin Dental Hospital, Karachi. The sample size involved 348 participants with chronic periodontitis. The gingival crevicular blood produced during periodontal probing was collected on a glucometer strip to assess random glucose levels. Glycemic levels were also checked by finger capillary blood via a glucometer. Intravenous blood glycated hemoglobin A1c test was performed in patients found with blood glucose levels in pre-diabetic or diabetic range. RESULTS: The results of this study demonstrate a strong correlation (0.987, p< 0.001) between gingival crevicular blood and finger capillary blood glucose values and good correlation (0.709, p<0.001) between gingival crevicular bloodglucose and glycated Hemoglobin A1c levels. Receiver operating characteristic curve showed 94.1% sensitivity and 100% specificity of GCB glucose screening at the cut-off value of 168mg/dl. Gingival crevicular blood glucose showed significant regression with Finger capillary bloodglucose (R=0.987, R2=0.974, p<0.001) andglycated hemoglobin A1clevels (R=0.709, R2=0.502, p<0.001). CONCLUSIONS: From this study we conclude that gingival crevicular blood can be relied upon for screening of blood glucose levels in periodontitis patients presenting with bleeding on probing. KEYWORDS: Blood glucose, Diabetes Mellitus, Gingival Crevicular blood,Inflammation, Periodontitis. HOW TO CITE: Saeed Q, Memon S, Hosein M. Gingival crevicular blood glucose evoluation in patients with periodontitis: Evolution of a new screening technique. J Pak Dent Assoc 2020;29(4):193-198.

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Coefficient of Variation for Hemoglobin A1c Results That Are Traceable to National Glycohemoglobin Standardization Program Must Be Distinguished from Coefficient of Variation for Results Traceable to International Federation of Clinical Chemistry and Laboratory Medicine

Diabetes Technology & Therapeutics ◽

10.1089/dia.2011.0106 ◽

2011 ◽

Vol 13 (12) ◽

pp. 1271-1272 ◽

Cited By ~ 4

Author(s):

Gunnar Nordin

Keyword(s):

Coefficient Of Variation ◽

Hemoglobin A1c ◽

Clinical Chemistry ◽

Laboratory Medicine ◽

International Federation

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Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: I. Analyte definition and proposal of a candidate reference method

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2007.107 ◽

2007 ◽

Vol 45 (4) ◽

Cited By ~ 84

Author(s):

International Federation of Clinica Jeppsson ◽

Torsten Arndt ◽

François Schellenberg ◽

Jos P.M. Wielders ◽

Raymond F. Anton ◽

...

Keyword(s):

Clinical Chemistry ◽

Reference Method ◽

Laboratory Medicine ◽

International Federation ◽

Serum Transferrin ◽

Clinical Use ◽

Primary Target ◽

Heavy Alcohol Consumption ◽

Carbohydrate Deficient Transferrin ◽

A Current

AbstractAn alcohol-associated change in the serum transferrin glycoform pattern, carbohydrate-deficient transferrin (CDT), is used as a biomarker of chronic moderate to heavy alcohol consumption. A current limitation in CDT analysis is the lack of standardization, which hampers clinical and analytical comparison between studies. This situation prompted initiation of a Working Group (WG) on CDT Standardization under the auspices of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). The standardization work aims to define and validate the analyte, select a reference method, work out procedures for the production of reference materials, and make suggestions for the clinical usage of CDT. The first recommendation of the WG is that disialotransferrin should be the primary target molecule for CDT measurement and the single analyte on which CDT standardization is based. It is further recommended that HPLC should be the analytical principle considered as the basis of an interim reference method until a suitable mass spectrometric reference method is established. In clinical use, CDT should be expressed in a relative amount (% CDT), to compensate for variations in the total transferrin concentration.Clin Chem Lab Med 2007;45:558–62.

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