Numerous clinical trials have examined the role of anthocyanins on cardiometabolic health, but their effects have not been quantitatively synthesized

Objective: In vitro and animal studies suggest that purified anthocyanins have favorable effects on metabolic profiles, but clinical trials have reported inconsistent findings. Furthermore, no study has been specifically conducted among individuals with prediabetes. The aim of this study was to investigate whether purified anthocyanins could improve cardiometabolic risk factors in Chinese adults with early untreated hyperglycemia. Research Design and Methods: This was a 12-week randomized, double-blind, placebo-controlled trial. A total of 160 participants aged 40–75 years with prediabetes or early untreated diabetes were randomly allocated to receive either purified anthocyanins (320 mg/day, n = 80) or placebo (n = 80) of identical appearance. A three-hour oral glucose tolerance test (OGTT) was performed, and cardiometabolic biomarkers (glycated hemoglobin A1c (HbA1c), fasting and postprandial glucose, insulin, C-peptide, and lipids) were measured at baseline and at the end of the trial. Results: A total of 138 subjects completed the protocol. Compared with placebo, purified anthocyanins moderately reduced HbA1c (−0.14%, 95% CI: −0.23~−0.04%; p = 0.005), low-density lipoprotein-c (LDL-c) (−0.2 mmol/L, 95% CI: −0.38~−0.01, p = 0.04), apolipoprotein A-1 (apo A1) (0.09 g/L, 95% CI: 0.02~0.17; p = 0.02), and apolipoprotein B (apo B) (−0.07 g/L, 95% CI: −0.13~−0.01; p = 0.01) according to intention-to-treat analysis. Subgroup analyses suggested that purified anthocyanins were more effective at improving glycemic control, insulin sensitivity, and lipids among patients with elevated metabolic markers. Conclusions: The 12-week randomized controlled trials (RCT) in Chinese adults with prediabetes or early untreated diabetes indicated that purified anthocyanins favorably affected glycemic control and lipid profile. Future studies of a longer duration that explore the dose-response relationship among patients with cardiometabolic disorders are needed to confirm our findings.

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 µg/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 µg/mL [− 0.32, 0.36], p = 0.906) or in prediabetes (− 0.35 µg/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. Trial registration: ClinicalTrials.gov, NCT02689765. Registered on 6 February 2016, https://clinicaltrials.gov/ct2/show/NCT02689765.

Background: Insulin-like growth factor binding protein-4 (IGFBP-4) fragments have been shown to be associated with cardiometabolic diseases. Anthocyanins as a subgroup of natural polyphenols could have benefits on treating cardiometabolic diseases. The aim of this study was to examine the effects of purified anthocyanins on serum IGFBP-4 fragments and glycemic control in patients with fasting hyperglycemia. Methods: A set of 121 participants with elevated fasting glucose (≥ 5.6 mmol/L), who were originally randomly assigned to anthocyanins (320 mg/day) or placebo groups, were included in this study. Serum IGFBP-4 fragments, fasting and postload glucose, insulin, and C-peptide after a three-hour oral glucose tolerance test (OGTT) were measured at baseline and at the end of 12 weeks. Results: Compared with placebo, anthocyanins increased serum IGFBP-4 fragments (net change 8.33 ng/mL, 95% CI [1.2, 15.47], p=0.023) and decreased fasting glucose (− 0.4 mmol/L [− 0.71, -0.1], p=0.01), 2-hour C-peptide (− 1.02 ng/mL [− 1.99, − 0.04], p=0.041) and the 3-hour area under the curve (AUC) of C-peptide (− 2.19 [− 4.11, − 0.27], p=0.026). No other significant difference in parameters for glycemic control and insulin resistance was observed. Conclusion: Anthocyanins supplementation for 12 weeks improved serum IGFBP-4 fragments and decreased fasting glucose and postload C-peptide in patients with fasting hyperglycemia. Further studies are needed to confirm our findings and clarify the potential mechanism. Trial Registration: ClinicalTrials.gov, NCT02689765. Registered on 6 February 2016, https://clinicaltrials.gov/ct2/show/NCT02689765.

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 µg/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 µg/mL [-0.32, 0.36], p=0.906) or in prediabetes (-0.35 µg/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.