Rossetti P, Porcellati F, Fanelli C G, Bolli G B
Department of Internal Medicine, Endocrinology and Metabolism, University of Perugia, Perugia, Italy.
Diabetes Technol Ther. 2006 Jun;8(3):326-37. doi: 10.1089/dia.2006.8.326.
These studies were designed to evaluate the accuracy of a microdialysis-based subcutaneous glucose sensor (GlucoDay, A. Menarini Diagnostics, Firenze, Italy) compared with a standard reference method of plasma glucose measurement during insulin-induced hypoglycemia.
Nine subjects without diabetes were studied in eu-, hypo-, and hyperglycemia (clamp technique). The GlucoDay was calibrated against one arterialized plasma glucose measurement (Glucose Analyzer, Beckman, Brea, CA), and plasma glucose estimates every 3 min were compared with paired plasma glucose values.
Accuracy of glucose estimates was not homogeneously distributed among subjects and depended on stability of the sensor's current signal during spontaneous euglycemia (R +/- -0.68). Linear regression analysis showed a good correlation between the two methods of measurement (R = 0.9), Deming regression showed the inclusion of the unit in the confidence interval of the slope (slope 0.95, 95% confidence interval 0.87-1.02), and the accuracy of the GlucoDay reached 40 +/- 15% (American Diabetes Association criteria). The mean relative difference was 6 +/- 8% in euglycemia, 13 +/- 14% during plasma glucose fall, 5 +/- 22% in the hypoglycemic plateau, and -14 +/- 16% during recovery from hypoglycemia. The Bland-Altman analysis indicated a bias of -1.9 +/- 16.6 mg/dL, whereas the Error Grid Analysis showed 94% of the Gluco- Day measurements in the acceptable zones of the grid. The time to reach the glycemic nadir was longer when measured with the GlucoDay (90 +/- 5 vs. 72.5 +/- 9 min, P < 0.05). However, absolute values of glycemic nadir, time spent in hypoglycemia, and the rate of fall of glycemia and the rate of recovery from the hypoglycemia were not statistically different.
GlucoDay closely monitors changes in plasma glucose before, during, and after hypoglycemia. However, these results can be achieved only if calibration of the GlucoDay is performed under conditions of sensor signal stability. Similar studies have to be performed in subjects with diabetes to validate the GlucoDay system.
这些研究旨在评估基于微透析的皮下葡萄糖传感器（GlucoDay，A. Menarini Diagnostics，意大利佛罗伦萨）在胰岛素诱导的低血糖期间与血浆葡萄糖测量的标准参考方法相比的准确性。
对9名无糖尿病受试者进行了正常血糖、低血糖和高血糖状态下的研究（钳夹技术）。将GlucoDay与一次动脉化血浆葡萄糖测量值（葡萄糖分析仪，贝克曼，加利福尼亚州布雷亚）进行校准，并将每3分钟的血浆葡萄糖估计值与配对的血浆葡萄糖值进行比较。
葡萄糖估计的准确性在受试者之间分布不均匀，并且取决于自发正常血糖期间传感器当前信号的稳定性（R +/- -0.68）。线性回归分析显示两种测量方法之间具有良好的相关性（R = 0.9），戴明回归显示单位包含在斜率的置信区间内（斜率0.95，95%置信区间0.87 - 1.02），并且GlucoDay的准确性达到40 +/- 15%（美国糖尿病协会标准）。正常血糖时平均相对差异为6 +/- 8%，血浆葡萄糖下降期间为13 +/- 14%，低血糖平台期为5 +/- 22%，低血糖恢复期间为 -14 +/- 16%。布兰德 - 奥特曼分析表明偏差为 -1.9 +/- 16.6 mg/dL，而误差网格分析显示GlucoDay测量值的94%在网格的可接受区域内。使用GlucoDay测量时达到血糖最低点的时间更长（90 +/- 5对72.5 +/- 9分钟，P < 0.05）。然而，血糖最低点的绝对值、低血糖持续时间、血糖下降速率和低血糖恢复速率在统计学上没有差异。
GlucoDay可密切监测低血糖发生之前、期间和之后的血浆葡萄糖变化。然而，只有在传感器信号稳定的条件下对GlucoDay进行校准才能获得这些结果。必须在糖尿病患者中进行类似研究以验证GlucoDay系统。
