From the Guidelines
Ingesting creatine supplements can increase creatinine levels in a metabolic panel, but this elevation does not necessarily indicate kidney dysfunction. According to a study published in the American Journal of Kidney Diseases 1, creatine supplementation can lead to increased creatinine production, which may result in elevated serum creatinine levels. This is because creatine is metabolized to creatinine in the body through a non-enzymatic conversion process.
When considering the potential impact of creatine supplements on kidney function, it is essential to distinguish between creatine-induced elevations in creatinine levels and actual kidney dysfunction. The study highlights that in a patient with a solitary kidney, creatine supplementation did not alter kidney function, but it did affect creatinine clearance measurements, leading to a misclassification of acute kidney injury 1.
Key points to consider:
- Creatine supplements can raise serum creatinine levels by approximately 0.3-0.4 mg/dL in some individuals
- This elevation is not indicative of kidney dysfunction, but rather reflects increased creatinine production from the supplemental creatine
- For accurate assessment of kidney function in patients taking creatine supplements, it's advisable to temporarily discontinue the supplement for 24-48 hours before blood testing if possible
- Healthcare providers should be informed about creatine supplementation when interpreting metabolic panel results to avoid misdiagnosis of kidney problems based solely on elevated creatinine levels.
In clinical practice, it is crucial to consider the potential effects of creatine supplements on creatinine levels to ensure accurate diagnosis and treatment of patients. By understanding the relationship between creatine supplementation and creatinine levels, healthcare providers can make informed decisions and avoid misinterpreting elevated creatinine levels as indicative of kidney dysfunction 1.
From the Research
Effects of Creatine Supplementation on Creatinine Levels
- Creatine supplementation may increase serum creatinine (Crn) concentration for some individuals, but it does not necessarily indicate kidney dysfunction, as creatine is spontaneously converted into Crn 2.
- Creatine supplementation appears to be safe when used by healthy adults at the recommended loading and maintenance doses, but it may be associated with an increased risk of renal dysfunction in people with a history of renal disease or those taking nephrotoxic medications 3.
- Short- and long-term creatine supplementations had no known significant effects on different studied indexes of kidney function, such as glomerular filtration rate, at least in healthy athletes and bodybuilders with no underlying kidney diseases 4.
Renal Function and Creatine Supplementation
- Although creatine supplementation appears to have no detrimental effects on kidney function of individuals without underlying kidney diseases, it seems more advisable to suggest that creatine supplementation not be used by sportsmen or women with pre-existing kidney disease or those with a potential risk for kidney dysfunction 4, 5.
- Creatine supplements may transitorily rise serum creatinine levels and mimic a kidney disease, especially if its use is associated with a high protein diet, which can lead to overdiagnosis of chronic renal failure 5.
Special Considerations
- Reports of kidney damage associated with creatine use are scanty, but creatine supplements should not be used in people with chronic renal disease or using potentially nephrotoxic medications 5, 6.
- Creatine supplementation resulted in greater cyst growth and worsened renal function in an animal model of renal cystic disease, indicating that creatine supplements may exacerbate disease progression in individuals with compromised renal function 6.