Performance assessment of the Medtronic-MiniMed Continuous Glucose Monitoring System and its use for measurement of glycaemic control in Type 1 diabetic subjects

Aims To assess the accuracy, reliability and measurement of glycaemic control associated with the Medtronic-MiniMed Continuous Glucose Monitoring System (CGMS) in comparison with blood glucose self-monitoring (BGSM) in Type 1 diabetic patients. Methods Type 1 diabetic patients (n = 18) underwent glucose monitoring by the CGMS for up to 3 days, when control was also assessed by BGSM performed eight times daily. Results Ninety-five per cent of paired non calibration samples were in the clinically acceptable zones of the Clarke error grid, and 97% in a consensus grid. The median bias was 0.1 mmol/l and relative bias 15%. The failure rate of sensors was 28% of those initially inserted. The CGMS detected significantly more hypoglycaemia and post-prandial hyperglycaemia, but total duration of hyperglycaemia, blood glucose oscillations and day-to-day variability were similarly assessed by CGMS and BGSM. Conclusions The CGMS has acceptable clinical accuracy. Detection by the CGMS of more hypoglycaemia and post-prandial hyperglycaemia than BGSM promises a valuable tool for control assessment and optimization of treatment.