Clin Chem Lab Med. 2013 Sep;51(9):1719-26. doi: 10.1515/cclm-2013-0060.
Glycated hemoglobin (HbA1c) plays a key role in diagnosing diabetes and monitoring the glycemic state. To guarantee the reliability of its measurement at the global level, the IFCC has defined a reference measurement system, based on the definition of the measurand as hemoglobin molecules having a special hexapeptide in common, which is the stable adduct of glucose to the N-terminal valine of the hemoglobin β-chain. In addition to the traceability of HbA1c results to the reference system, the establishment of analytical goals to make HbA1c measurements clinically reliable becomes crucial. However, allowable goals will depend on the assay specificity (i.e., selectivity) and, consequently, on units in which HbA1c results are expressed [mmol/mol for IFCC-aligned systems or % for National Glycohemoglobin Standardization Program (NGSP) converted numbers]. In this regard, analytical goals derived from biological variability studies in which the determination of HbA1c has been carried out by an assay providing the same selectivity for the measurand as defined by the IFCC are recommended. Only these targets should be used for evaluating the performance of commercial assays traceable to the IFCC system and of clinical laboratories using them through appropriately structured quality assessment schemes. Analytical systems following different calibration hierarchies (e.g., the NGSP-aligned assays) will require different analytical goals, possibly derived from clinical outcome data.
糖化血红蛋白（HbA1c）在诊断糖尿病和监测血糖状态方面发挥着关键作用。为了保证全球范围内该测量的可靠性，国际临床化学联合会（IFCC）基于将血红蛋白分子定义为具有共同特殊六肽的测量物，建立了参考测量系统，该六肽是葡萄糖与血红蛋白β链 N 端缬氨酸的稳定加合物。除了将 HbA1c 结果溯源至参考系统之外，建立使 HbA1c 测量具有临床可靠性的分析目标也变得至关重要。然而，可允许的目标将取决于测定方法的特异性（即选择性），因此，取决于 HbA1c 结果所表示的单位[IFCC 校准系统的 mmol/mol 或经美国国家糖化血红蛋白标准化计划（NGSP）转换的%]。在这方面，建议使用源自生物变异研究的分析目标，其中通过提供与 IFCC 定义的测量物相同选择性的测定方法来测定 HbA1c。只有这些目标可用于评估可溯源至 IFCC 系统的商业测定方法和使用这些方法的临床实验室的性能，方法是通过适当结构的质量评估计划。遵循不同校准层次结构的分析系统（例如，与 NGSP 一致的测定方法）将需要不同的分析目标，这些目标可能源自临床结果数据。
