Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota.
Diabetes. 2013 Dec;62(12):4083-7. doi: 10.2337/db13-1132. Epub 2013 Sep 5.
The accuracy of continuous interstitial fluid (ISF) glucose sensing is an essential component of current and emerging open- and closed-loop systems for type 1 diabetes. An important determinant of sensor accuracy is the physiological time lag of glucose transport from the vascular to the interstitial space. We performed the first direct measurement of this phenomenon to our knowledge in eight healthy subjects under an overnight fasted condition. Microdialysis catheters were inserted into the abdominal subcutaneous space. After intravenous bolus administrations of glucose tracers, timed samples of plasma and ISF were collected sequentially and analyzed for tracer enrichments. After accounting for catheter dead space and assay noise, the mean time lag of tracer appearance in the interstitial space was 5.3-6.2 min. We conclude that in the overnight fasted state in healthy adults, the physiological delay of glucose transport from the vascular to the interstitial space is 5-6 min. Physiological delay between blood glucose and ISF glucose, therefore, should not be an obstacle to sensor accuracy in overnight or fasting-state closed-loop systems of insulin delivery or open-loop therapy assessment for type 1 diabetes.
连续间质液（ISF）葡萄糖感测的准确性是目前和新兴的 1 型糖尿病开环和闭环系统的重要组成部分。传感器准确性的一个重要决定因素是葡萄糖从血管到间质空间的生理时滞。我们在 8 名健康受试者进行了首次直接测量，这些受试者在夜间禁食条件下进行。微透析导管插入腹部皮下空间。在静脉推注葡萄糖示踪剂后，依次采集定时的血浆和 ISF 样本，并对示踪剂浓度进行分析。在考虑到导管死腔和分析噪音后，示踪剂出现在间质空间的平均时滞为 5.3-6.2 分钟。我们的结论是，在健康成年人的夜间禁食状态下，葡萄糖从血管到间质空间的生理延迟为 5-6 分钟。因此，在胰岛素输送的夜间或禁食状态闭环系统或 1 型糖尿病的开环治疗评估中，血糖和 ISF 血糖之间的生理延迟不应该成为传感器准确性的障碍。
