In the subgroup with prediabetes, serum adiponectin was reduced in the anthocyanins group (− 0.51 μg/mL [− 0.86, − 0.16], p = 0.006) but not in the placebo group (− 0.17 μg/mL [− 0.53, 0.2], p = 0.365), and the net change between the two groups was nonsignificant (− 0.35 μg/mL [− 0.85, 0.16], p = 0.174) (Fig. 2b). Here, ADIPOQ is linked to prediabetes syndrome.