The Effects of Creatine Supplementation on Kidney Function in Healthy Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and/or Objectives: The objective of this study is to investigate the effects of creatine supplementation on kidney function parameters in healthy individuals.

Design: Systematic review and meta-analysis.

Setting : Athletic training centers, sports institutions.

Participants : 200 healthy participants.

Interventions: The intervention group received creatine supplementation in the form of creatine monohydrate or creatine nitrate. The control group received no supplementation or sham.

Main Outcome Measures: Serum creatinine, BUN, serum albumin, eGFR, microalbuminuria.

Results: 10 studies were included for statistical analysis of kidney function parameters. 3 studies were included for narrative report. 9 studies measuring serum creatinine demonstrated Cohen’s d 0.98 (95% CI 0.68, 1.27 p-value < 0.01) indicating a large effect size in serum creatinine. Subgroup analysis revealed a significant difference (p < 0.001) which was supported by an increase in the weighted mean serum creatinine in the interventional group (+0.067±0.16) and not the control group (-0.0075). 4 studies measuring serum albumin after creatine supplementation revealed Cohen’s d 0.29 (95% CI -0.64, 1.22 p-value=0.54) indicating no significant difference. Subgroup analysis was also not significant (p-value= 0.73). 4 studies measuring BUN exhibited no significant changes after creatine supplementation. eGFR was measured in 2 studies and no significant changes were observed. 4 studies measuring microalbuminuria/albuminuria reported no significant change in results. None of the 10 studies reported any instance of renal dysfunction or adverse events post-creatine supplementation.

Conclusions: Creatine supplementation does not damage renal function in healthy individuals. Supplementation with creatine increases serum creatinine; however, this effect does not indicate kidney damage. This is supported by the absence of significant changes in any other measure of kidney function including BUN, serum albumin, eGFR, and microalbumin. All included studies described no altered kidney function or adverse events from creatine supplementation; however, no direct measure of renal parenchymal damage was assessed, suggesting a direction for future research.