糖化白蛋白於糖尿病患者之臨床應用

The Clinical Usefulness of Glycated Albumin in Patients with Diabetes Mellitus

楊逸亭(Yi-Ting Yang) ； 沈峰志(Feng-Chih Shen) ； 陳榮福(Jung-Fu Chen)

《內科學誌》 31卷3期 (2020/06) Pp. 170-179

https://doi.org/10.6314/JIMT.202006_31(3).05

摘要

台灣健保於2017年開始給付糖化白蛋白（glycated albumin, GA）於特定族群做為血糖監測的工具，但對於大部分的臨床醫師而言仍是一個相對陌生的檢驗。在糖尿病診斷及追蹤中，糖化血色素（glycated hemoglobin, HbA1c）為主要的指標，可推算近期二到三個月的平均血糖，並可反應糖尿病慢性併發症的風險。然而，在一些紅血球壽命受影響的情況下（慢性腎病變、懷孕、貧血、出血等），糖化血色素將無法正確的反應平均血糖，此時糖化白蛋白因不受紅血球壽命的影響，是更合適的血糖監測工具。除此之外，因白蛋白糖化速度較血紅素快且半衰期較短，所以可以反應較短時間內（二到四週）的血糖狀況，當短期內血糖有明顯改變時，糖化白蛋白較能及時反應血糖的變化。但糖化白蛋白在使用上仍有其限制，當白蛋白的生成代謝有問題而影響白蛋白壽命時（肝硬化、腎病症候群、甲狀腺功能異常等），其值就無法準確反應平均血糖值。此外，雖然陸續研究指出糖化白蛋白的高低可以用來評估糖尿病大小血管病變的風險，但仍缺乏大型前瞻性研究。因此臨床使用上，糖化白蛋白為一個在特定情況和病患上可供比對和參考用的另一種血糖監測指標，還不能取代糖化血色素常規使用在大部分糖尿病患的診斷和追蹤。

關鍵字

糖尿病（Diabetes mellitus） ； 糖化白蛋白（Glycated albumin） ； 糖化血色素（Glycated hemoglobin ； glycohemoglobin）

並列摘要

Taiwan Health Insurance had proved glycated albumin (GA) as a biomarker for glucose control in specific conditions since year 2017, but for most clinicians, it is a relativeunfamiliar biomarker. Glycated hemoglobin (HbA1c) is one of the criteria for the diagnosis of diabetes mellitus (DM) and is used as the gold standard for long-term glucose monitoring. HbA1c reflects the mean plasma glucose during the past 2 to 3 months and is also correlated to the long-term complications of DM. However, HbA1c does not reflect plasma glucose accurately under situations which may interfere with the life span of hemoglobin, such as chronic kidney disease, pregnancy, hemorrhage, anemia. In such situation, the GA is a better biomarker for glucose monitoring. In addition, because the glycation rate of albumin is faster than hemoglobin and the half-life of albumin also shorter, GA change precedes HbA1c when plasma glucose change rapidly during short period. Nevertheless, GA would showed false values in some situations that interfere with albumin metabolism, such as liver cirrhosis, nephrotic syndrome and thyroid dysfunction. Moreover, although there were many studies found out the association between GA and complication of DM, but unlike HbA1c, there was no large prospective study to provide stronger evidence. As a result, in clinical practice, GA is anextra biomarker for glucose monitor in specific patients, but cannot substitute HbA1c as a standard biomarker for diagnosis of DM and glucose level monitoring.