Koschinsky Theodor, Jungheim Karsten, Heinemann Lutz
German Diabetes Research Institute, Düsseldorf, Germany.
Diabetes Technol Ther. 2003;5(5):829-42. doi: 10.1089/152091503322527030.
In the last few years blood glucose meters have been developed allowing glucose measurements in capillary blood samples collected at sites other than the fingertips. The main reason for establishing this so-called alternate site testing (AST) was to sample blood from locations with reduced pain perception. It is well known that capillary blood glucose is closely correlated to systemic (i.e., arterial) glucose levels and that under steady-state conditions, glucose values measured in blood samples collected from alternate sites are virtually identical to those collected from the fingertip. However, during rapid changes in blood glucose levels, glucose concentrations in capillary blood samples from the fingertips can differ considerably in both domains (time and concentration) from those determined in capillary blood from alternate sites (i.e., the so-called AST phenomenon). Such differences can have serious clinical consequences (e.g., risky delays in hypoglycemia detection). There is evidence that all skin sites exhibiting a reduced blood flow (in comparison with the fingertip) within the superficial skin layers are prone to this AST phenomenon. Nearly all glucose sensors having been developed so far or being currently under development measure glucose levels at alternate sites and also in another compartment [e.g., interstitial fluid (ISF)] than blood. So, in principle they might be prone to an AST-like phenomenon (i.e., rapid changes in systemic blood glucose levels may also result in delayed ISF glucose readings). Our knowledge about the impact of an AST-like phenomenon on the performance of glucose monitoring systems is presently very limited. Glucose kinetics in the different compartments during dynamic systemic blood glucose changes have not been fully elucidated yet. If an AST-like phenomenon plays a role with glucose sensors should therefore be studied. Depending on the measurement technology used for the individual type of glucose monitoring system probably this phenomenon has a variable impact on the results obtained.
在过去几年中，已经开发出血糖仪，可对在指尖以外部位采集的毛细血管血样进行葡萄糖测量。建立这种所谓的替代部位检测（AST）的主要原因是从疼痛感受较低的部位采集血液。众所周知，毛细血管血糖与全身（即动脉）血糖水平密切相关，并且在稳态条件下，从替代部位采集的血样中测得的葡萄糖值与从指尖采集的血样中的葡萄糖值几乎相同。然而，在血糖水平快速变化期间，来自指尖的毛细血管血样中的葡萄糖浓度在时间和浓度这两个方面可能与从替代部位（即所谓的AST现象）采集的毛细血管血中测定的葡萄糖浓度有很大差异。这种差异可能会产生严重的临床后果（例如，低血糖检测的危险延迟）。有证据表明，浅表皮肤层内血流减少（与指尖相比）的所有皮肤部位都容易出现这种AST现象。到目前为止已经开发或正在开发的几乎所有葡萄糖传感器都在替代部位以及除血液之外的另一个隔室[例如组织间液（ISF）]中测量葡萄糖水平。因此，原则上它们可能容易出现类似AST的现象（即全身血糖水平的快速变化也可能导致ISF葡萄糖读数延迟）。我们目前对类似AST现象对葡萄糖监测系统性能的影响的了解非常有限。动态全身血糖变化期间不同隔室中的葡萄糖动力学尚未完全阐明。因此，应该研究类似AST的现象是否在葡萄糖传感器中起作用。根据用于个别类型葡萄糖监测系统的测量技术，这种现象可能对获得的结果有不同的影响。
