Anthocyanins increase serum adiponectin in newly diagnosed diabetes but not in prediabetes: a randomized controlled trial

Background: Epidemiological studies have suggested that adiponectin is associated with the development of insulin resistance and type 2 diabetes. This study first examined the effect of purified anthocyanins, a group of dietary flavonoids, on serum adiponectin in patients with prediabetes and newly diagnosed diabetes. Methods: A total of 160 patients with prediabetes (n = 90) or newly diagnosed diabetes (n = 70) were randomly assigned to either the anthocyanins group or the placebo group for 12 weeks of intervention.Serum adiponectin, a set of biomarkers related to glucolipid metabolism, anthropometric parameters, dietary intake and physical activity were measured before and after intervention. Results: Anthocyanins increased serum adiponectin compared with placebo (net change 0.46 mu g/mL, 95% CI [0.03, 0.90],p = 0.038) in the subjects with newly diagnosed diabetes. No significant difference in the change in adiponectin was observed between the two groups either in the overall subjects (0.02 mu g/mL [- 0.32, 0.36], p = 0.906) or in prediabetes (- 0.35 mu g/mL [- 0.85, 0.16], p = 0.174). Anthocyanins also decreased fasting glucose (- 0.5 mmol/L [- 1, - 0.04], p = 0.035) in the subjects with newly diagnosed diabetes, but no such change was observed in those with prediabetes. Conclusions: Anthocyanins supplementation for 12 weeks improved serum adiponectin and fasting glucose in patients with newly diagnosed diabetes, but not in patients with prediabetes.