Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Health System, Ann Arbor, MI 48106, USA.
Metabolism. 2011 Jan;60(1):86-91. doi: 10.1016/j.metabol.2010.06.017. Epub 2010 Aug 17.
An International Expert Committee made recommendations for using the hemoglobin A(₁C) (A1C) assay as the preferred method for the diagnosis of diabetes in nonpregnant individuals. A concentration of at least 6.5% was considered as diagnostic. It is the aim of this study to compare the sensitivity of A1C with that of plasma glucose concentrations in subjects with early diabetes or impaired glucose tolerance (IGT). We chose 2 groups of subjects who had A1C not exceeding 6.4%. The first group of 89 subjects had family histories of diabetes (MODY or type 2 diabetes mellitus) and had oral glucose tolerance test (OGTT) and A1C determinations. They included 36 subjects with diabetes or IGT and 53 with normal OGTT. The second group of 58 subjects was screened for diabetes in our Diabetes Clinic by fasting plasma glucose, 2-hour plasma glucose, or OGTT and A1C; and similar comparisons were made. Subjects with diabetes or IGT, including those with fasting hyperglycemia, had A1C ranging from 5.0% to 6.4% (mean, 5.8%). The subjects with normal OGTT had A1C of 4.2% to 6.3% (mean, 5.4%), or 5.5% for the 2 groups. The A1C may be in the normal range in subjects with diabetes or IGT, including those with fasting hyperglycemia. Approximately one third of subjects with early diabetes and IGT have A1C less than 5.7%, the cut point that the American Diabetes Association recommends as indicating the onset of risk of developing diabetes in the future. The results of our study are similar to those obtained by a large Dutch epidemiologic study. If our aim is to recognize early diabetic states to apply effective prophylactic procedures to prevent or delay progression to more severe diabetes, A1C is not sufficiently sensitive or reliable for diagnosis of diabetes or IGT. A combination of A1C and plasma glucose determinations, where necessary, is recommended for diagnosis or screening of diabetes or IGT.
一个国际专家委员会建议将血红蛋白 A₁C（A1C）检测作为诊断非妊娠个体糖尿病的首选方法。浓度至少为 6.5%被认为是诊断标准。本研究旨在比较 A1C 与早期糖尿病或糖耐量受损（IGT）患者血浆葡萄糖浓度的敏感性。我们选择了两组 A1C 不超过 6.4%的受试者。第一组 89 名受试者有糖尿病家族史（MODY 或 2 型糖尿病），进行了口服葡萄糖耐量试验（OGTT）和 A1C 测定。其中 36 名受试者患有糖尿病或 IGT，53 名受试者 OGTT 正常。第二组 58 名受试者在我们的糖尿病诊所通过空腹血糖、2 小时血糖或 OGTT 和 A1C 进行糖尿病筛查，并进行了类似的比较。包括空腹高血糖在内的糖尿病或 IGT 患者的 A1C 范围为 5.0%至 6.4%（平均 5.8%）。OGTT 正常的受试者的 A1C 为 4.2%至 6.3%（平均 5.4%），两组的平均值为 5.5%。糖尿病或 IGT 患者，包括空腹高血糖患者，A1C 可能在正常范围内。大约三分之一的早期糖尿病和 IGT 患者的 A1C 低于 5.7%，这是美国糖尿病协会建议的表明未来发生糖尿病风险的切点。我们的研究结果与一项大型荷兰流行病学研究相似。如果我们的目的是识别早期糖尿病状态，采取有效的预防措施来预防或延缓向更严重的糖尿病进展，那么 A1C 对于诊断糖尿病或 IGT 不够敏感或可靠。建议在必要时结合 A1C 和血浆葡萄糖测定进行糖尿病或 IGT 的诊断或筛查。
