Accurate and precise blood glucose measurement in the hypoglycaemic range

The aim of the study was to evaluate the performance of an electrochemical blood glucose sensor, the satellite G, in the low-normal and hypoglycaemic range. Eighty-five venous blood samples with glucose concentrations below 4.0 mmol I-1 from six patients with Type 1 diabetes undergoing induced hypoglycaemia were measured in duplicate on the sensor and a reference method, the Yellow Springs whole blood glucose analyser. The sensor values correlated well with the reference method (r = 0.9, p < 0.001) with a mean absolute percentage bias of 10.7%. The 95% confidence limits of agreement between methods were +0.7 and -0.6 mmol I-1 with a mean difference of 0.004 mmol I-1. More than 80% of the sensor measurements were within 20%, and 60% were within 10% of the reference method. Measured over all samples, the sensor had a coefficient of variation of 7.2% for paired measurements. The coefficients of variation of 20 measurements on each of two samples with glucose concentrations of 1.3 and 2.6 mmol I-1 were 9.1% and 5.8%, respectively. We conclude that the satellite G measures blood glucose accurately and precisely in the low range.