From the Guidelines
Creatine supplementation does increase creatinine levels, but this elevation does not necessarily indicate kidney dysfunction. When considering the impact of creatine supplementation on kidney function, as assessed through creatinine levels, it's crucial to understand that the increase in creatinine is a result of the body's metabolism of creatine into creatinine, not due to kidney damage 1. This is supported by a study where a 20-year-old man with a solitary kidney underwent creatine monohydrate supplementation, showing an increase in serum creatinine level but no difference in measured GFR using 51 Cr-EDTA clearance measurement 1.
Key Points to Consider
- The increase in creatinine levels due to creatine supplementation is generally modest, and while the exact range can vary, it is essential to recognize this change to avoid misinterpreting it as a sign of kidney dysfunction.
- The mechanism behind this increase is the normal metabolic conversion of creatine to creatinine, which does not imply kidney damage.
- Healthcare providers should be informed about creatine supplementation before interpreting kidney function tests to accurately assess kidney health.
Clinical Implications
- Patients on creatine supplementation should be aware of the potential for elevated creatinine levels and inform their healthcare providers to ensure accurate interpretation of kidney function tests.
- The decision to use creatine supplements should consider the individual's overall health, including kidney function, and be made under the guidance of a healthcare provider, especially for those with pre-existing kidney issues.
- The increase in creatinine due to creatine supplementation highlights the importance of comprehensive assessment and monitoring of kidney function, beyond reliance on a single marker like creatinine.
From the Research
Creatine Supplementation and Creatinine Levels
- Creatine supplementation may increase creatinine levels, but this does not necessarily indicate renal dysfunction 2.
- A study found that short-term high-dose creatine supplementation slightly increased serum creatinine levels, but this was considered a false indicator of kidney function impairment 3.
- Another study reported that creatine supplementation may transitorily rise serum creatinine levels, mimicking a kidney disease, especially when combined with a high protein diet 4.
Effects of Creatine Supplementation on Renal Function
- A systematic review and meta-analysis found that creatine supplementation did not significantly alter serum creatinine levels or plasma urea values, suggesting that it does not induce renal damage 5.
- A review of clinical and experimental data found that short- and long-term creatine supplementation had no significant effects on kidney function in healthy athletes and bodybuilders without underlying kidney diseases 6.
- However, it is recommended that creatine supplementation not be used by individuals with pre-existing kidney disease or those at risk of kidney dysfunction 6, 4.
Safety of Creatine Supplementation
- Creatine supplementation appears to be safe for healthy adults when used at recommended doses, but its safety in children and adolescents has not been established 2.
- Individuals with a history of renal disease or those taking nephrotoxic medications may be at increased risk of renal dysfunction when using creatine supplementation 2.