Human skeletal muscle has large capacity to increase carnosine content in response to beta-alanine supplementation: a systematic review with Bayesian individual and aggregate data E-Max model and meta-analysis.

Rezende, Nathalia Saffioti; Swinton, Paul; de Oliveira, Luana Farias; da Silva, Rafa Pires; da Silva, Vinicius Eira; Nemezio, Kleiner; Yamaguchi, Guilherme; Artioli, Guilherme G.; Gualano, Bruno; Saunders, Bryan; Dolan, Eimear

Abstract

Beta-alanine (BA) supplementation increases muscle carnosine content (MCarn) and is ergogenic in many situations. Currently, many questions on the nature of the Mcarn response to supplementation are open, and the responses to these have considerable potential to enhance the efficacy and applications of this supplementation strategy. The objective of this study was to conduct a Bayesian analysis of available data on the Mcarn response to BA supplementation. A systematic review (with meta-analysis) of individual and published aggregate data was conducted, using a dose response (Emax) model. The protocol was designed according to PRISMA guidelines. A three-step screening strategy was undertaken in order to identify studies that measured the Mcarn response to BA supplementation. In addition, the research analysed individual data from five separate studies, conducted in the authors' laboratory. Data were extracted from all controlled and uncontrolled supplementation studies conducted on healthy humans. Meta-regression was used to consider the influence of potential moderators on the primary outcome, including dose, sex, age, baseline Mcarn and analysis method used. The Emax model indicated that human skeletal muscle has a large capacity for non-linear Mcarn accumulation and that commonly-used BA supplementation protocols may not come close to saturating muscle carnosine content. Neither baseline values nor sex appear to influence subsequent response to supplementation. Analysis of individual data indicated that Mcarn is relatively stable in the absence of intervention, and effectually all participants respond to BA supplementation (99.3% response [95%CrI: 96.2 –100]).

Citation

SAFFIOTI REZENDE, N., SWINTON, P., FARIAS DE OLIVEIRA, L., PIRES DA SILVA, R., EIRA DA SILVA, V., NEMEZIO, K., YAMAGUCHI, G., ARTIOLI, G.G., GUALANO, B., SAUNDERS, B. and DOLAN, E. 2019. Human skeletal muscle has large capacity to increase carnosine content in response to beta-alanine supplementation: a systematic review with Bayesian individual and aggregate data E-Max model and meta-analysis. bioRxiv [online]. Available from: https://doi.org/10.1101/870584

• Deposit Date: Jan 14, 2020
• Publicly Available Date: Feb 3, 2020
• Keywords: Beta-alanine; Histidine containing dipeptides; Metabolism; Supplements; Muscle carnosine content
• Public URL: https://rgu-repository.worktribe.com/output/828655
• Publisher URL: https://doi.org/10.1101/870584