Fig. 3.

Meal tolerance test results for active glucagon-like peptide-1: changes in (a) plasma concentration and (b) area under the concentration–time curve (AUC). **p < 0.01 and ***p < 0.001 versus 0 min, and ^## p < 0.001 versus before sitagliptin (determined by Fisher’s least significant difference procedure method after two-way repeated ANOVA). Differences in AUCs were analyzed by Wilcoxon signed rank test. Panel a was plotted using means ± standard deviation, and panel b using medians and quartile values (minimum 25 %, and maximum 75 %)