title: Effect of alpha-lipoic acid combined with creatine monohydrate on human skeletal muscle creatine and phosphagen concentration.
abstract: Alpha-lipoic acid has been found to enhance glucose uptake into skeletal muscle in animal models. Studies have also found that the co-ingestion of carbohydrate along with creatine increases muscle creatine uptake by a process related to insulin-stimulated glucose disposal. The purpose of this study was to determine the effect of alpha-lipoic acid on human skeletal muscle creatine uptake by directly measuring intramuscular concentrations of creatine, phosphocreatine, and adenosine triphosphate when creatine monohydrate was co-ingested with alpha-lipoic acid. Muscle biopsies were acquired from the vastus lateralis m. of 16 male subjects (18-32 y) before and after the experimental intervention. After the initial biopsy, subjects ingested 20 g x d(-1) of creatine monohydrate, 20 g x d(-1) of creatine monohydrate + 100 g x d(-1) of sucrose, or 20 g x d(-1) of creatine monohydrate + 100 g x d(-1) of sucrose + 1000 mg x d(-1) of alpha-lipoic acid for 5 days. Subjects refrained from exercise and consumed the same balanced diet for 7 days. Body weight increased by 2.1% following the nutritional intervention, with no differences between the groups. There was a significant increase in total creatine concentration following creatine supplementation, with the group ingesting alpha-lipoic acid showing a significantly greater increase (p < .05) in phosphocreatine (87.6 --> 106.2 mmol x kg(-1) dry mass [dm]) and total creatine (137.8 --> 156.8 mmol x kg(-1) dm). These findings indicate that co-ingestion of alpha-lipoic acid with creatine and a small amount of sucrose can enhance muscle total creatine content as compared to the ingestion of creatine and sucrose or creatine alone.
authors.affiliation: Department of Human Kinetics, St. Francis Xavier University, Antigonish, Nova Scotia, Canada B2G 2W5.
authors.forename: Darren G
authors.initials: DG
authors.lastname: Burke
authors.forename: Philip D
authors.initials: PD
authors.lastname: Chilibeck
authors.forename: Gianni
authors.initials: G
authors.lastname: Parise
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolsky
authors.forename: Darren G
authors.initials: DG
authors.lastname: Candow
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology*; D001707:Biopsy, Needle; D003401:Creatine / Q000378:metabolism* / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism*; D013395:Sucrose / Q000008:administration & dosage; D008063:Thioctic Acid / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D010725:Phosphocreatine; D013395:Sucrose; D008063:Thioctic Acid; D000255:Adenosine Triphosphate; D003401:Creatine