Effects of an amylopectin and chromium complex on the anabolic response to a suboptimal dose of whey protein

Background: previous research has demonstrated the permissive effect of insulin on muscle protein kinetics,and the enhanced insulin sensitizing effect of chromium. in the presence of adequate whole protein and/or essential amino acids (eaa),insulin has a stimulatory effect on muscle protein synthesis,whereas in conditions of lower blood eaa concentrations,insulin has an inhibitory effect on protein breakdown. in this study,we determined the effect of an amylopectin/chromium (acr) complex on changes in plasma concentrations of eaa,insulin,glucose,and the fractional rate of muscle protein synthesis (fsr). methods: using a double-blind,cross-over design,ten subjects (six men,four women) consumed 6 g whey protein + 2 g of the amylopectin-chromium complex (wpacr) or 6 g whey protein (wp) after an overnight fast. fsr was measured using a primed,continuous infusion of ring-d5-phenylalanine with serial muscle biopsies performed at 2,4,and 8 h. plasma eaa and insulin were assayed by ion-exchange chromatography and elisa,respectively. after the biopsy at 4 h,subjects ingested their respective supplement,completed eight sets of bilateral isotonic leg extensions at 80% of their estimated 1-rm,and a final biopsy was obtained 4 h later. results: both trials increased eaa similarly,with peak levels noted 30 min after ingestion. insulin tended (p = 0.09) to be higher in the wpacr trial. paired samples t-tests using baseline and 4-h post-ingestion fsr data separately for each group revealed significant increases in the wpacr group (+0.0197%/h,p = 0.0004) and no difference in the wp group (+0.01215%/hr,p = 0.23). independent t-tests confirmed significant (p = 0.045) differences in post-treatment fsr between trials. conclusions: these data indicate that the addition of acr to a 6 g dose of whey protein (wpacr) increases the fsr response beyond what is seen with a suboptimal dose of whey protein alone. © 2017 the author(s).