No difference between venous and capillary blood sampling and the Minimed continuous glucose monitoring system for determining the blood glucose response to food

The aim of the study was to determine whether venous blood sampling and the Minimed continuous glucose monitoring system (CGMS) (Medtronic, Northridge, Calif) are possible alternative methods to capillary blood sampling for determining the blood glucose response to foods. Seven individuals without diabetes took part in the study. The glycemic glucose equivalent (GGE) expressed as GGE/bar of a muesli bar was determined on 3 occasions by capillary, venous, and CGMS blood sampling methods. The GGE was determined as the incremental area under the curve for 2 hours after consumption of a 50-g muesli bar compared with the incremental area under the curve for a 50-g glucose reference drink. The GGE of the bar was 21.4 ± 7.8 GGE/serve for the CGMS, 16.6 ± 6.0 GGE/serve for the venous, and 17.4 ± 5.5 GGE/serve for the capillary samples. The coefficients of variation were 36% for the CGMS and venous sampling methods and 30% for the capillary samples. The differences in GGE calculations produced by the 3 blood sampling methods were not statistically significant. Therefore, it appears that the CGMS and venous blood sampling produce similar results to capillary blood sampling for measuring blood glucose response to foods. The study also attempted to reduce the intraindividual variability in GGE measurements. Measuring the blood glucose value of an individual more frequently over the 2 hours or consuming the test food and reference drink on the same day did not significantly reduce the variability in the GGE measurements.