Effects of Branched-chain Amino Acids Supplementation on Glucose Homeostasis and Lipid Profile in Humans
Claudia R. da Luz Medicine & Science in Sports & Exercise. 2012 44(5S): p 444
Branched-chain amino acids (BCAA), particularly leucine, play an important role on glucose homeostasis through insulin secretagogue action. Some studies have also demonstrated that BCAA
may modulate the immune response on inflammatory conditions. However, it is unknown if BCAA may affect the glucose homeostasis kinetics at rest and if the inflammatory response can
modulate such response.
PURPOSE: To evaluate the effects of BCAA and leucine supplementation on glucose homeostasis, lipid profile, and the possible interaction with inflammatory response in healthy humans.
METHODS: In a double-blind, randomized, and crossover design 08 healthy male adults (24.4 ± 1.2 years; 79.1 ± 3.5 kg; 179.5 ± 2.5 cm; BMI 24.55 ± 1.0 kg·m-2) ingested either BCAA (2.4
g of leucine, 1.6 g of isoleucine, and 1.6 g of valine), leucine (LEU; 2.4 g of leucine + 3.2 g of alanine) or isonitrogenous supplement (PLA; 5.6 g of alanine). Experimental sessions were
conducted on different days (7 d apart). After an overnight fast, participants ingested a single dose of the supplement and blood samples were collected before, and after 15, 30, 60, 90, and 120
min to determine serum glucose and insulin concentrations, lipid profile, and interleukin (IL)-6 concentration. Data were analyzed using repeated measures ANOVA (p<0.05) one-way or twoway
as appropriated and are presented as mean ± SEM changes.
RESULTS: Serum glucose curve and AUC did not differ between treatments (p > 0.05). BCAA and LEU increased serum insulin 60’ after ingestion when compared to PLA (BCAA 75.1 ±
23.8 mU·L-1; LEU 76.2 ± 12.3 mU·L-1; PLA 25.3 ± 3.6 mU·L-1; p < 0.05). However, there was no difference on serum insulin AUC (p > 0.05). There was no difference on serum lipid profile
curve and AUC in all time points between treatments (p > 0.05). LEU decreased serum IL-6 concentration 60’ after ingestion when compared to BCAA and PLA (LEU -1.7 ± 0.3 pg.mL-1;
BCAA 1.1 ± 1.5 pg.mL-1; PLA 2.3 ± 0.4 pg.mL-1; p < 0.05).
CONCLUSION: BCAA and leucine supplementation had no effects on serum glucose and lipid profile kinetics but increased serum insulin concentration 60’ after ingestion. This effect may
be related to insulin secretagogue role of BCAA and/or to the possible role of leucine on IL-6 secretion.
