Which glucose measurement method is susceptible to falsely low results due to ascorbate interference?

The glucose measurement method that is susceptible to falsely low results due to ascorbate interference is the glucose oxidase method, commonly referred to in the context of the Trinder reaction. This method relies on the enzymatic oxidation of glucose to gluconic acid and hydrogen peroxide, with the latter being involved in a colorimetric reaction.

Ascorbic acid (vitamin C) can interfere with this assay because it can reduce the hydrogen peroxide, affecting the color development that is proportional to the glucose concentration. This can lead to underestimation of the true glucose level in a sample containing ascorbate.

In contrast, other methods listed, such as hexokinase and glucose dehydrogenase, are not significantly affected by ascorbate. Hexokinase uses ATP in a reaction with glucose that is less prone to such interferences, and glucose dehydrogenase employs a different mechanism that also shows robustness against ascorbic acid. Polarography, while it can be affected by a variety of substances, typically does not experience the same type of interference from ascorbate as the glucose oxidase method does.

Understanding this potential interference is crucial for ensuring accurate glucose measurement in clinical settings, especially when patients are taking supplements or medications containing ascor