Is interstitial fluid (ISF) a reasonable alternative for blood? What about the lag?

ISF is a reasonable alternative for blood. Glucose can be measured in the ISF–the fluid around the body’s cells where glucose freely diffuses from capillaries to the interstitial space.1  The physiological delay in ISF glucose with respect to changes in blood glucose is about 5-10 minutes2  which is unlikely to impact routine day-to-day treatment decisions. The average lag time of the FreeStyle Libre system is approximately 2 minutes.3  

1. Rebrin K, Steil GM. Can interstitial glucose assessment replace blood glucose measurements? Diabetes Technol Ther. 2000;2(3):461-472. 

2. Rebrin K, Sheppard NF Jr, Steil GM. Use of subcutaneous interstitial fluid glucose to estimate blood glucose: revisiting delay and Sensor offset. J Diabetes Sci Technol. 2010;4(5):1087-1098. 

3. Data on File, Abbott Diabetes Care Inc, Clinical Report: Evaluation of the Accuracy of the Abbott Sensor-Based Interstitial Glucose Monitoring System 2014.

Cookie Policy

FreeStyle Libre uses cookies to give you the best possible service. By using our website, you consent to the use of cookies. 

Data protection