Creatine supplementation does not affect kidney function in an animal model with pre-existing renal failure

Area of Science:

• Sports Science
• Nephrology
• Nutritional Biochemistry

Background:

• Creatine is a popular ergogenic aid for athletes.
• Concerns exist regarding the long-term safety of creatine intake, particularly for kidney function.
• Previous research has yielded conflicting results, necessitating further investigation.

Purpose of the Study:

• To evaluate the impact of prolonged creatine supplementation on renal function.
• To assess creatine's effects in both healthy animals and those with pre-existing kidney damage.

Main Methods:

• Male Wistar rats were divided into four groups: sham-operated (control/creatine) and two-thirds nephrectomized (control/creatine).
• Creatine was administered at 2% w/w for 4 weeks.
• Renal function was assessed via glomerular filtration rate (inulin/creatinine clearance), albumin excretion, urea clearance, and serum cystatin C.

Main Results:

• Creatine supplementation did not negatively affect renal function in either sham-operated or nephrectomized rats.
• No significant differences were observed in inulin or creatinine clearance rates between groups.
• Serum cystatin C, urinary protein, albumin, and urea clearance remained comparable, while serum and muscle creatine levels increased in supplemented groups.

Conclusions:

• Four weeks of creatine supplementation (2% w/w) does not impair kidney function in animals with normal or pre-existing renal failure.
• These findings suggest creatine is safe for renal health, even in compromised kidney states.