Continuous Glucose Monitoring in Conscious Unrestrained Mice

Measurement of blood glucose concentration is a common end point in studies using animal models of diabetes. Usually a blood glucose meter is used to measure non-fasted blood glucose concentrations, typically at frequencies of between 1 and 7 times per week. This process involves pricking the tip of the tail to collect a small blood sample (0.5-5 μL), which could potentially cause a stress response and affect blood glucose concentrations. Moreover, with blood glucose concentrations constantly fluctuating in response to feeding and activity, a single-point measurement can easily misrepresent the actual glycemic control of the animal. In this chapter, we discuss the use of continuous glucose monitoring in mice by radio-telemetry which allows second-by-second changes in blood glucose to be captured without restraining the mouse. Glucose excursions rather than single-point measurements may prove more useful in detecting effects of treatments, and lack of handling may avoid stress responses causing artefacts. We outline what is involved in implanting such devices into mice including some practical tips to maximize success.