Fig. 2

PCE supplementation reduces preprandial glucose levels in the prediabetes group, but not in the group with blood glucose already within normal range. On the initial day of the study, we divided individuals into two groups based on their preprandial (before lunch) plasma glucose levels: a-b, Group I, ≤100 mg/dL; c-d, Group II, 101–125 mg/dL. Pre-prandial plasma glucose levels were measured and recorded on days 1 (initial), 12, 24, and 30 (a, c). We plotted individual study subject plasma glucose levels for the initial day and day 30 of the study (b, d). Data shown are mean ± SD for a and c. We calculated statistical significance (*, p ≤ 0.05; **, p ≤ 0.01) by comparing glucose levels measured at each time point to the initial value using a two-tailed t-test in GraphPad Prism 5.0 software