Blood samples were frozen the day of collection and analyzed
in a single batch. A YSI 2300 State Plus Glucose and Lactate
Analyzer with a sensitivity of 2.5 mg/dl was used to determine
glycemia (YSI International, Yellow Springs, OH). Insulin
concentrations were determined with an Immulite 1000 chemiluminescence
method (Siemens Medical Solutions Diagnostics;
Duluth, GA). This assay has a sensitivity of 2 mIU/mL, an intraassay
coefficient of 5.7%, and an inter-assay coefficient of 6.7%.
Graphs of glycemia or insulinemia vs. time were generated and
the area under the curve (AUC) was calculated for each by
measuring the area above the baseline. The average of the
AUCs for the three glucose standards was deemed a GI of 100;
the same was performed for insulin. The GI and II were reported
as the percent AUC as compared to the glucose standard. White
bread served as a method validation.