Determination Of The Glycemic Index Of Selected Chinese Traditional Foods Using Different Glucose Analyzers

Abstract

PURPOSE: To determine the glycemic index (GI) of 4 Chinese traditional foods and compare the agreement between portable glucose monitoring system (PoG) and the YSI glucose analyzer in determining the GI of the test foods. METHODS: Thirteen healthy adults (8 males and 5 females, age: 26.0 ± 1.3 y, BMI: 21.5 ± 0.6 kg·m-2) volunteered to participate the experiment. All subjects were required to refrain from alcohol consumption and vigorous physical activities 24h before test. After 10-14h overnight fast, the subjects consumed either reference (50g anhydrous glucose) or test foods containing 50g of available carbohydrate. The food included baked barbecued pork puff (BBPP), fried rice in Yangzhou-style (FRYS), fried fritter (FF), and "Mai-lai" cake (MLC). The finger-prick blood samples were collected immediately before, 15, 30, 45, 60, 90, and 120min after food consumption, and were analyzed with portable glucometer (Glucometer Elite, Bayer Diagnostics, Japan) and YSI glucose analyzer (YSI 1500, USA). The GI was calculated by expressing the incremental area under the blood glucose response curve (IAUC) for each test food as a percentage of each subject's average IAUC for the glucose. RESULTS: The mean glucose concentrations measured by PoG were higher than that measured by YSI (5.58 ± 0.05 vs. 5.39 ± 0.05 mmol·L-1, P<0.01). However, there were no differences in average IAUC (136.3 ± 8.3 vs. 135.8 ± 7.7 mmol·min·L-1) and GI (62.7 ± 4.6 vs. 68.8 ± 4.6) between PoG and YSI. There were no differences in the mean within-subject CV for the 13 subjects between IAUCYSI and IAUCPoG (47.3 ± 6.5 vs. 47.9 ± 3.2 %), GIYSI and GIPoG (47.9 ± 7.4 vs. 52.8 ± 3.1 %). Bland-Altman plots showed that the 95% limits of agreement for IAUC was -74.6 to 73.6 mmol·min·L-1, and for GI values was -45 to 57. No differences were observed in the mean GI values of the 4 food items determined by YSI and PoG (BBPP: 57 ± 7 vs. 54 ± 8; FRYS: 79 ± 7 vs. 73 ± 9; FF: 74 ± 9 vs. 69 ± 11; MLC: 66 ± 12 vs. 54 ± 9). CONCLUSIONS: The PoG and YSI glucose analyzer produced similar results in determining the GI of 4 Chinese traditional foods.