Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of clinical trials.
PubMed 31375416 · doi:10.1053/j.jrn.2019.05.004
What was done
A systematic review and meta-analysis evaluated the effects of creatine supplementation on renal function. From 290 non-duplicated records identified, 15 studies were included in the qualitative synthesis and 6 studies were included in the quantitative meta-analysis of serum creatinine and plasma urea levels.
What was found
Quantitative analysis of 6 studies showed a standardized mean difference (SMD) of 0.48 (95% CI 0.24 to 0.73, P = .001, I² = 22%) for serum creatinine levels and an SMD of 1.10 (95% CI 0.34 to 1.85, P = .004, I² = 28%) for plasma urea values. Despite statistically significant numerical shifts, the authors concluded creatine supplementation did not induce renal damage or meaningfully alter renal function markers in the evaluated regimens.
Why it matters
This review pools controlled data to address persistent clinical concerns regarding potential kidney toxicity from creatine supplementation.
Limits
The quantitative meta-analysis is based on only 6 studies. The abstract does not report total participant counts, underlying participant health, baseline kidney function, supplementation doses, or study durations, nor does it measure direct glomerular filtration rate (GFR). The abstract also contains an internal discrepancy by describing markers with statistically significant SMD elevations (P < 0.05) as not significantly altered.