Evaluation of a glucose meter for determining the glycemic responses of foods

Abstract

Background Glucose meters are convenient for measuring postprandial glycemic responses. However, their performance for this purpose has not been evaluated. Methods Glucose responses of 7 potato meals were measured using the One Touch Ultra® (OTU) glucose meter and a reference method (Yellow Springs Instruments Glucose Analyzer, YSI) and the incremental areas under the curves (AUC) and glycemic index (GI) values compared. Results Mean AUC OTU was greater than AUC YSI (192 ± 8 vs. 175 ± 7 mmol×min/l, p = 0.001), but GI OTU tended to be less than GI YSI (69 ± 3 vs. 74 ± 3, p = 0.052). Bland–Altman difference plots showed wide 95% limits of agreement for AUC (−84 to 119 mmol×min/l) and GI (−21 to 26) values of individual subjects, and for the mean GI values of the 7 foods (−11 to 21). Total and error variance of AUC and GI values were greater for OTU than YSI, and food means differed significantly for YSI ( p < 0.01) but not OTU ( p = 0.11). Conclusion AUC and GI values determined by OTU are more variable and do not agree well with those obtained by YSI. Thus, the OTU is not recommended for determining AUC or GI in normal subjects. This conclusion does not necessarily apply to other glucose meters whose performance should be evaluated.