Version 2.70

17855-8Hemoglobin A1c/Hemoglobin.total in Blood by calculationActive

Term Description

Changing from the property from Mass fraction to substance fraction has not effect on the meaning when the molecular weight of the numerator and the denominator are the same (for practical purposes). These terms had had a property of MFR in the past and we changed to SFR because we thought the LOINC community preferred SFR for HbA1c. But we mis understood the preference is to use the MFR variant- so we have changed back.
Source: Regenstrief LOINC

Part Description

LP16413-4   Hemoglobin A1c
Currently (2010), four standardization protocols exist for measuring Hgb A1c:

1. IFCC - designated as a Reference Method or RM (http://www.ifcchba1c.net/)
2. NGSP - the long standing protocol used in the US and most other countries since the DCCT study (http://www.ngsp.org/factors.asp)
3.JDS/JSCC - a protocol used in Japan, Spain and possibly other countries
4. Swedish - used in Sweden at least

Protocols 2-4 are known as Designated Comparison Methods (DCM) and have been connected to the Reference Method and each other through various regression equations.

Because of the high degrees of standardization within protocol it should no longer be necessary to specify a LOINC code with a method such as "HPLC", "electrophoresis" or anything else. Analytical instruments will be designed so that an Hgb A1c result can be traced back to a specific standardization protocol, so the important distinction will be the standardization protocol as described above and which will be carried in the method field.

A meeting of instrument manufacturers (presumably including Japanese) in Milan, Italy, December 12, 2007, agreed (among other items) that:

-All manufacturers should implement worldwide the traceability to the IFCC reference system for Hgb -A1c.
-All new instruments sold after January 1st, 2011 will report (as a result of an Hgb A1c test) both SI (mmol/mol – no decimals) and NGSP derived units (percentage – one decimal), in agreement with the Consensus Statement.
-Note they only committed to supporting protocol (1) and (2)

Different countries are adopting the international harmonization recommendations in different ways. We have information from the NGSP that the US will continue to report only Hgb A1c/NGSP, with the unit percent – i.e., no change. In Great Britain, labs have already started to report all results both as Hgb A1c (NGSP) in % and Hgb A1c (IFCC) in mmol/mol. In Canada, they are awaiting a recommendation from an expert panel. Any of these measures could be reported in the same units, but the convention for the reporting Hgb A1c under the new IFCC protocol will be to use units of mmol/mol to avoid confusion between the DCCT/NGSP and the IFFCC protocol.

LOINC has defined 59261-8 (Hemoglobin A1c/Hemoglobin.total in Blood) by IFCC protocol.

These protocols produce different results when expressed in the same units. For example, the equivalent of Hgb A1c (NGSP) of 6.5% is Hgb A1c (IFCC) is 4.8%.

The NGSP web site (http://www.ngsp.org/factors.asp) suggests the use of alternate measures, such as glycated albumen, for patients with severe iron deficiency, dialysis patients, and those with SS SC CC because of over or under reading that can occur with these interferences. It also describes the effect of abnormal hemoglobins on results of HbA1c by instrument.

Studies have demonstrated racial and ethnic differences in the relationship between glucose levels and hemoglobin A1C [22238408], and it has been suggested that some descendants of sub-Saharan Africa may have higher levels of measured hemoglobin A1C compared to glucose levels due to hemoglobin variants [PMID: 31675503] . Source: Regenstrief Help

Fully-Specified Name

Hemoglobin A1c/Hemoglobin.total

Additional Names

Short Name
HbA1c MFr Bld Calc
Display Name
HbA1c Calc (Bld) [Mass fraction]
Consumer Name Alpha
HbA1c/Total Hgb, Blood

Basic Attributes

First Released
Version 1.0l
Last Updated
Version 2.70
Change Reason
Release 2.70: CLASS: Hgb A1C was originally placed in the HEM class, but is more correctly classified in CHEM.;
Order vs. Observation

Formula (Readable)

(average glucose level [mg/dL]+46.7)/28.7

Reference Information

Type Source Reference
Webcontent Lab Tests Online®Copyright Copyright © 2001-2019 American Association for Clinical Chemistry Hemoglobin A1c

Language Variants Get Info

zh-CNChinese (China)
血红蛋白 A1c/血红蛋白.总计:质量分数:时间点:全血:定量型:计算法
nl-NLDutch (Netherlands)
hemoglobine A1c/hemoglobine.totaal:massafractie:moment:bloed:kwantitatief:berekend
et-EEEstonian (Estonia)
Hemoglobiin A1c/hemoglobiin.üld:MFr:Pt:B:Qn:Arvutuslik
fr-BEFrench (Belgium)
Hémoglobine A1c/Hémoglobine.totale:Fraction de masse:Temps ponctuel:Sang:Quantitatif:Calculé
fr-CAFrench (Canada)
Hémoglobine A1c/Hémoglobine.totale:Fraction de masse:Temps ponctuel:Sang:Quantitatif:Calculé
fr-FRFrench (France)
Hémoglobine A1c/hémoglobine totale:Fraction massique:Ponctuel:Sang:Numérique:Résultat calculé
de-DEGerman (Germany)
Hämoglobin A1c/Hämoglobin.total:SFr:Pkt:Blut:Qn:Errechnet
it-ITItalian (Italy)
Emoglobina A1c/Emoglobina.totale:MFr:Pt:Sangue:Qn:Calcolato
ko-KRKorean (Korea, Republic of)
혈색소 A1C/총혈색소:질량분획:검사시점:전혈:정량:계산된
pt-BRPortuguese (Brazil)
Hemoglobina A1c/Hemoglobina.total:SFr:Pt:SgTotal:Qn:Calculado
ru-RURussian (Russian Federation)
Гемоглобин А1с/Гемоглобин.общий:МассДол:ТчкВрм:Кр:Колич:Вычисленный
es-ARSpanish (Argentina)
hemoglobina A1c/hemoglobina.total:fracción de masa:punto en el tiempo:sangre:cuantitativo:calculado
es-ESSpanish (Spain)
Hemoglobina A1c (Hemoglobina glicosilada)/Hemoglobina.total:Fracción de masa:Punto temporal:Sangre:Qn:Calculado
tr-TRTurkish (Turkey)
Hemoglobin A1c/Hemoglobin.total:KütlFr:Zmlı:Kan:Kant:Hesaplanmış

Example Units

Unit Source
% Example UCUM Units

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