Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Domino's Farms, 24 Frank Lloyd Wright Drive, Ann Arbor, MI 48109, USA.
Diabetes Technol Ther. 2011 Dec;13(12):1249-54. doi: 10.1089/dia.2011.0074. Epub 2011 Aug 21.
Hemoglobin A1c (A1C) has recently been recommended for diagnosing diabetes mellitus and diabetes risk (prediabetes). Its performance compared with fasting plasma glucose (FPG) and 2-h post-glucose load (2HPG) is not well delineated. We compared the performance of A1C with that of FPG and 2HPG in preoperative cardiac surgery patients.
Data from 92 patients without a history of diabetes were analyzed. Patients were classified with diabetes or prediabetes using established cutoffs for FPG, 2HPG, and A1C. Sensitivity and specificity of the new A1C criteria were evaluated.
All patients diagnosed with diabetes by A1C also had impaired fasting glucose, impaired glucose tolerance, or diabetes by other criteria. Using FPG as the reference, sensitivity and specificity of A1C for diagnosing diabetes were 50% and 96%, and using 2HPG as the reference they were 25% and 95%. Sensitivity and specificity for identifying prediabetes with FPG as the reference were 51% and 51%, respectively, and with 2HPG were 53% and 51%, respectively. One-third each of patients with prediabetes was identified using FPG, A1C, or both. When testing A1C and FPG concurrently, the sensitivity of diagnosing dysglycemia increased to 93% stipulating one or both tests are abnormal; specificity increased to 100% if both tests were required to be abnormal.
In patients before cardiac surgery, A1C criteria identified the largest number of patients with diabetes and prediabetes. For diagnosing prediabetes, A1C and FPG were discordant and characterized different groups of patients, therefore altering the distribution of diabetes risk. Simultaneous measurement of FGP and A1C may be a more sensitive and specific tool for identifying high-risk individuals with diabetes and prediabetes.
血红蛋白 A1c（A1C）最近被推荐用于诊断糖尿病和糖尿病风险（糖尿病前期）。它与空腹血糖（FPG）和 2 小时葡萄糖负荷后（2HPG）的性能尚未得到很好的描述。我们比较了 A1C 与 FPG 和 2HPG 在术前心脏手术患者中的表现。
分析了 92 例无糖尿病病史患者的数据。根据 FPG、2HPG 和 A1C 的既定标准，将患者分为糖尿病或糖尿病前期。评估了新 A1C 标准的敏感性和特异性。
所有被 A1C 诊断为糖尿病的患者也存在空腹血糖受损、葡萄糖耐量受损或其他标准的糖尿病。以 FPG 为参考，A1C 诊断糖尿病的敏感性和特异性分别为 50%和 96%，以 2HPG 为参考分别为 25%和 95%。以 FPG 为参考，识别糖尿病前期的敏感性和特异性分别为 51%和 51%，以 2HPG 为参考分别为 53%和 51%。用 FPG、A1C 或两者同时识别出三分之一的糖尿病前期患者。当同时检测 A1C 和 FPG 时，诊断糖基化异常的敏感性增加到 93%，规定一项或两项检测异常；如果要求两项检测均异常，则特异性增加到 100%。
在心脏手术前的患者中，A1C 标准识别出了最多的糖尿病和糖尿病前期患者。对于诊断糖尿病前期，A1C 和 FPG 不一致，描述了不同的患者群体，因此改变了糖尿病风险的分布。同时测量 FGP 和 A1C 可能是一种更敏感和特异的工具，用于识别糖尿病和糖尿病前期高危个体。
