title: HbA1c: how do we measure it and what does it mean?
abstract: OBJECTIVE
  Description of recent developments in the standardization of HbA1c measurement and interpretation of HbA1c results.
  
  
  RESULTS
  HbA1c is extensively used in the management of patients with diabetes. The two major schemes to standardize HbA1c produce values that differ substantially. A prospective, multinational study revealed a linear correlation between HbA1c and average blood glucose. Some, but not all, assay methods are able to accurately measure HbA1c in individuals with common hemoglobin variants.
  
  
  CONCLUSIONS
  Progress in standardization of methods for HbA1c measurement has significantly reduced variation among different methods. The improved accuracy could allow HbA1c to be used for screening and diagnosis of diabetes. A consensus document recommends that HbA1c be reported in both NGSP (%) and IFCC (mmol/mol) units. HbA1c results can be translated into estimated average glucose (eAG), which could be reported in addition to HbA1c.
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Randie R
authors.initials: RR
authors.lastname: Little
authors.forename: David B
authors.initials: DB
authors.lastname: Sacks
mesh_terms: D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis; D005947:Glucose / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D012016:Reference Values
chemical_list: D005947:Glucose; D006442:Glycated Hemoglobin; D006454:Hemoglobins