HbA1c不可靠时可改测果糖胺

新奥尔良(EGMN)——杜克大学的Thomas L. O' Connell博士在美国医师协会(ACP)年会上指出，如果遇到糖化血红蛋白A1c(HbA1c)与血糖监测数据不一致的情况，应当提高警惕。

Connell博士强调，由于任何可影响血红蛋白的因素都会干扰HbA1c检查，因此HbA1c与血糖监测结果不一致的情况实际上相当常见。例如，正在接受血液透析、近期接受了输血、患有贫血或血红蛋白病的患者，HbA1c检测值都可能严重失真。

 “对于刚刚输过血的患者，甚至都不用检测HbA1c。医院里常会出现这种情况：1例刚输过血的患者的指血糖高达300 mg/dl，而HbA1c仅为5.5%。”

血红蛋白病可导致HbA1c测得值虚假地偏高或偏低。人们已经发现了700多种血红蛋白病或异常血红蛋白变体，其中很多是无症状的。美国最常见的血红蛋白病是镰状细胞特质，影响着大约200万人。

O' Connell博士称，果糖胺检测是HbA1c检测的良好替代品。果糖胺检测的对象是血液中的糖化蛋白质而非糖化血红蛋白，因此不会受到血红蛋白病的干扰。如果将指血糖比作患者血糖控制情况的快照，将HbA1c比作反映3个月来代谢控制情况的电影，那么果糖胺就像是一部短片，描绘了既往2~3周内的平均血糖浓度。

O' Connell博士报告称担任赛诺菲-安万特和Amylin公司的顾问。

爱思唯尔  版权所有

BY BRUCE JANCIN
Elsevier Global Medical News
Breaking News

NEW ORLEANS (EGMN) – Suspect a problem with the hemoglobin A1c whenever it’s discordant with blood sugar–monitoring data.

This happens surprisingly often. The HbA1c level is a measure of glycolated hemoglobin, so any condition that affects hemoglobin, either qualitatively or quantitatively, can seriously distort the HbA1c value, Dr. Thomas L. O’Connell explained at the annual meeting of the American College of Physicians.

Examples include patients on hemodialysis, or who have recently been transfused, are anemic, or who have a hemoglobinopathy, noted Dr. O’Connell, an endocrinologist at Duke University, Durham, North Carolina.

“Don’t even bother measuring [HbA1c] in a patient who has recently been transfused. This happens all the time in the hospital: a transfused patient’s blood sugar level on finger-stick testing is 300 mg/dL, but the [HbA1c] is 5.5%,” he observed.

Hemoglobinopathies can result in either a false-high or false-low HbA1c value. More than 700 hemoglobinopathies or abnormal hemoglobin variants have been described and many of these are asymptomatic. The most common hemoglobinopathy in the United States is sickle cell trait, affecting 2 million people.

“There are a lot of people out there with hemoglobinopathies,” the endocrinologist stressed.

When the HbA1c results seem sketchy, an excellent alternative is the fructosamine test. Not nearly as well known as the HbA1c, the fructosamine test measures glycolated protein in the blood rather than glycolated hemoglobin, so it is unaffected by hemoglobinopathies.

If blood glucose measurement by fingerstick provides a snapshot of a patient’s diabetic control and the HbA1c is more like a feature-length movie reflecting metabolic control over the past 3 months, then the fructosamine test is akin to a short film providing a view of a patient’s average blood glucose concentration during the previous 2-3 weeks.

Dr. O’Connell reported that he serves as a consultant to Sanofi-Aventis and Amylin.