Anthocyanin may reverse IGT by improving insulin sensitivity

Supplementation with anthocyanin improves insulin sensitivity, which could then significantly reverse impaired glucose tolerance (IGT), reports a study.

Sixty-eight participants with IGT were enrolled in a 12-week randomized, double-blind, placebo-controlled trial (anthocyanin 160 mg/day or placebo) conducted with routine lifestyle guidance. The authors performed intention-to-treat analyses.

The primary outcome was β-cell function: disposition index (DI). Secondary outcomes assessed were other oral glucose tolerance test (OGTT)-derived indices, insulin sensitivity, anthropometric measures, and levels of skin advanced glycation end products (AGEs) measured by skin autofluorescence.

DI did not significant differ between groups, with the adjusted mean differences of 61.3 (95 percent confidence interval [CI], ‒27.4 to 150.0; p=0.174).

The anthocyanin group showed a significantly higher IGT reversion rate (defined as 2-h OGTT glucose <7.8 mmol/L) than the placebo group (55.9 percent vs 29.4 percent; p=0.013), as well as greater improvement in Matsuda index (adjusted difference, 4.6, 95 percent CI, 2.5‒6.7; p=0.003).

Notably, only participants who received anthocyanin demonstrated a significant decrease in skin AGEs. This reduction was positively associated with the decrease in postprandial glucose AUC (r=0.302; p=0.001) and negatively with improved Matsuda index (r=‒0.344; p<0.001).

“The reduction of skin AGEs by anthocyanins might play a critical role in the dietary management of IGT,” the authors said.