Background

Hemoglobin A1c (HbA1c) is an accurate index of fluctuation in glycemia over the 2-3 months prior to quantitative assessment. During this time, hemoglobin (Hb) slowly glycates until it shows the properties of advanced glycation end-products. Glycation kinetics is intensified by prolonged glucose exposure. In subjects undergoing oral glucose tolerance testing (OGTT), immediately after ingestion, glucose is ostensibly transported by the glucose transporter 1 (GLUT1) to erythrocyte corpuscular hemoglobin. The earliest significant measurable level of hemoglobin glycation associated with this transportation is still not clear.

Subjects and methods

We attempted to explore the early impact of short-term glucose load on HbA1c levels, because it is now known that transmembrane GLUT1-mediated glucose transport occurs immediately. A total of 88 participants (46 patients and 42 clinically healthy controls) underwent fasting plasma glucose quantitation during an OGTT. HbA1c, revealed by a monoclonal anti-glycation epitope antibody and adiponectin, was quantitated before (T0) and 2 hours (T120) after 80 g glucose ingestion.

Results

Wilcoxon test revealed that the HbA1c values did not significantly vary (P = 0.15) during the OGTT, whereas glucose concentration varied strongly between T0 and T120.

Discussion

It is well known that quantitative estimation of HbA1c is informative for clinical care, independently of glucose level. The molecular mechanisms and dynamics by which glucose enters/exits red blood cells are incompletely known and may differ between individuals. We here show, for the first time, that HbA1c levels do not significantly increase during OGTT, supporting the view that non-enzymatic glycation of hemoglobin occurs slowly and that glycation during the 2 hours of an OGTT is insignificant.

中文翻译：

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口服葡萄糖耐量试验不影响常规测定法测量的血红蛋白糖化程度

背景

血红蛋白 A1c (HbA1c) 是定量评估前 2-3 个月血糖波动的准确指数。在此期间，血红蛋白 (Hb) 缓慢糖化，直至显示出晚期糖化终产物的特性。糖化动力学因长期接触葡萄糖而增强。在接受口服葡萄糖耐量试验 (OGTT) 的受试者中，葡萄糖在摄入后立即被葡萄糖转运蛋白 1 (GLUT1) 转运至红细胞红细胞血红蛋白。与这种运输相关的最早可测量的血红蛋白糖化水平尚不清楚。

主题和方法

我们试图探索短期葡萄糖负荷对 HbA1c 水平的早期影响，因为现在已知跨膜 GLUT1 介导的葡萄糖转运会立即发生。共有 88 名参与者（46 名患者和 42 名临床健康对照者）在 OGTT 期间进行了空腹血糖定量。HbA1c 由单克隆抗糖化表位抗体和脂联素显示，在摄入 80 g 葡萄糖之前 (T0) 和 2 小时 (T1​​20) 后进行定量。

结果

Wilcoxon 检验显示 HbA1c 值 在 OGTT 期间没有显着变化（P = 0.15），而葡萄糖浓度在 T0 和 T120 之间变化很大。

讨论

众所周知，HbA1c 的定量估计可为临床护理提供信息，而与血糖水平无关。葡萄糖进入/退出红细胞的分子机制和动力学尚不完全清楚，可能因人而异。我们在此首次表明 HbA1c 水平在 OGTT 期间没有显着增加，这支持了血红蛋白的非酶糖化发生缓慢且 OGTT 2 小时内的糖化不显着的观点。