Creatine supplementation for optimisation of physical function in the patient at risk of functional disability: A systematic review and meta-analysis

BackgroundThe efficacy of creatine replacement through supplementation for the optimisation of physical function in the population at risk of functional disability is unclear. MethodsWe conducted a systematic literature search of MEDLINE, EMBASE, Cochrane Library and CINAHL until November 2022. Studies included were randomised controlled trials comparing the use of creatine supplementation with placebo in older adults and adults with chronic disease. The primary outcome was physical function measured by the sit-to-stand test after pooling data using random effects modelling. We also performed a Bayesian meta-analysis to describe the treatment effect in probability terms. Secondary outcomes included other measures of physical function, muscle function and body composition. The risk of bias was assessed using the Cochrane risk-of-bias tool. ResultsWe identified 33 RCTs, comprising 1076 participants. From 6 trials reporting the primary outcome, the pooled standardised mean difference was 0.51 (95% CI 0.01 to 1.00; I =62%; p=0.04); using weakly informative priors, the posterior probability that creatine supplementation improves physical function was 66.7%. Upper body muscle strength (SMD 0.25, 95% CI 0.06 to 0.44; I =0%; p=0.01), handgrip strength (SMD 0.23, 95% CI 0.01 to 0.45; I =0%; p=0.04) and lean tissue mass (MD 1.08kg; 95% CI 0.77 to 1.38; I =26%; p<0.01) improved with creatine supplementation. The quality of evidence for all outcomes was low or very low due to a high risk of bias. ConclusionCreatine supplementation improves sit-to-stand performance, muscle function and lean tissue mass. It is crucial to conduct high-quality prospective RCTs to confirm these hypotheses (Prospero number, CRD42023354929).