(P04-019-25) Acute Supplementation With Green Coffee Extract and α-Lipoic Acid Enhances Postprandial Insulin Sensitivity in Healthy Females

Objectives: Chronic supplementation of green coffee extract (GCE) and α-lipoic acid (ALA) have been demonstrated to improve glycemic control and insulin sensitivity. However, the effect of a single dose of GCE and ALA on postprandial glucose metabolism remains underexplored. The objective of this study was to investigate the impact of acute supplementation of GCE combined with ALA on postprandial glycemia, insulinemia, and insulin sensitivity in healthy adults.

Methods: Twenty healthy adults (10M, 10F, 25 ± 4 yrs, BMI: 26.8 ± 7.5 kg/m²) completed a double-blind, randomized controlled trial with three metabolic trials separated by a minimum washout period of 4 days. Following an overnight fast and 30 minutes prior to a 75g oral glucose tolerance test (OGTT), participants consumed one of three supplements: 1) 200 mg GCE + 200 mg ALA (ALA-LOW); 2) 200 mg GCE + 400 mg ALA (ALA-HIGH); or 3) a placebo containing microcrystalline cellulose with 500 mg magnesium stearate + 5 mg silicon dioxide (PLA). Venous blood samples were obtained while fasted and every 15-20 min postprandial for 2 hours. Blood glucose and insulin concentrations were measured for determination of incremental area under the curve (iAUC) during the OGTT, and Matsuda Index was calculated as a marker of peripheral insulin sensitivity. Repeated measures ANOVA was used to assess differences between trials across all participants and within each sex subgroup.

Results: There was no effect of supplementation on glucose iAUC, insulin iAUC, or insulin sensitivity during the OGTT in the full sample (all p >0.05). However, exploratory sex-specific analysis revealed a main effect of supplement for insulin sensitivity among females (p=0.033), with higher values observed for ALA-HIGH compared to PLA (9.30 vs. 8.08, p=0.016). In contrast, no effect of supplementation on insulin sensitivity was found among males (p=0.423) and there was no significant difference between ALA-HIGH and PLA (12.05 vs. 13.07, p=0.885).

Conclusions: Consuming a supplement containing 200 mg GCE and 400 mg ALA 30 minutes before a 75g OGTT enhances postprandial insulin sensitivity in healthy females, highlighting potential sex-specific metabolic benefits of acute supplementation.

Funding Sources: Iovate Health Sciences International Inc.