Poster Topical Area: Nutritional Epidemiology
Location: Hall D
Poster Board Number: 839
Objective: Recent studies have shown that there is an increased circulation of branched-chain amino acids (BCAAs) in obese individuals, and this is associated with impaired glucose metabolism. However, it is not known if supplementation of additional BCAA will further impaired glucose metabolism. The purpose of this pilot study was to determine the effects of BCAA supplementation on body weight, body composition, and glucose metabolism in obese, prediabetic individuals.
Methods: This is a randomized, crossover study with 12 obese individuals with prediabetes. Participants (n=12) were randomly assigned to daily supplement with 20g BCAA or protein low in BCAA control (i.e. 4g BCAA) for 4 weeks, then switched to the other group for 4 weeks after a 2-week washout. Subjects were asked to maintain consistent consumption of calorie and protein for the duration of the study. During each visit, body weight, and body composition were recorded, and an oral glucose tolerance test (OGTT) was performed. Collected blood samples were used to measure glucose, insulin, biomarkers such as nerve growth factor (NGF), tumor necrosis factor-α (TNF-α), IL-6, IL-8, and monocyte chemoattractant protein (MCP-1).
Result: There were not significant changes in body weight, body fat and muscle mass after 4 weeks supplementation of BCAA compared to control. Serum glucose response to OGTT was evaluated by area under the curve (AUC: 0, 30, 60, 90 and 120 minutes). Compared to control, BCAAs supplementation showed a trend to normalize the serum glucose response during OGTT (p=0.055). Although not significant, the serum levels of NGF, which is associated with insulin resistance, tend to have a larger decrease by BCAA supplementation compared to control (BCAA: -29.85 ± 9.98% vs. control: -9.63 ± 8.84%, p=0.078). In addition, serum cytokines such as TNF-α, IL-6, IL-8, and MCP-1 were also not significantly different between BCAA supplementation and control.
Conclusion: Together, our data suggested that BCAA supplementation did not impair insulin resistance in obese, prediabetic subjects. Further larger studies are needed to confirm the results seen in the present study.
Shih Lung Woo
UCLA Center for Human Nutrition
Los Angeles, California